WorldWideScience

Sample records for allylic silanolate salts

  1. Organocatalytic Enantioselective Allylic Etherification of Morita-Baylis-Hillman Carbonates and Silanols.

    Science.gov (United States)

    Liu, Hui-Li; Xie, Ming-Sheng; Qu, Gui-Rong; Guo, Hai-Ming

    2016-10-21

    The organocatalytic asymmetric allylic etherification reaction of Morita-Baylis-Hillman carbonates and silanols was reported for the first time. With modified cinchona alkaloid (DHQD) 2 PYR as the catalyst, a series of aromatic, heterocyclic, or aliphatic Morita-Baylis-Hillman carbonates (25 examples) worked well with triphenylsilanol, affording the corresponding products in moderate to good yields (up to 98%), high regioselectivities (>20:1), and good enantioselectivities (up to 92%). When dimethylphenylsilanol was used as the nucleophile, the product was obtained in 60% yield and 87% ee.

  2. Enantioselective Copper-Catalyzed Arylation-Driven Semipinacol Rearrangement of Tertiary Allylic Alcohols with Diaryliodonium Salts.

    Science.gov (United States)

    Lukamto, Daniel H; Gaunt, Matthew J

    2017-07-12

    A copper-catalyzed enantioselective arylative semipinacol rearrangement of allylic alcohols using diaryliodonium salts is reported. Chiral Cu(II)-bisoxazoline catalysts initiate an electrophilic alkene arylation, triggering a 1,2-alkyl migration to afford a range of nonracemic spirocyclic ketones with high yields, diastereo- and enantioselectivities.

  3. CATALYTIC ENANTIOSELECTIVE ALLYLIC OXIDATION

    NARCIS (Netherlands)

    Rispens, Minze T.; Zondervan, Charon; Feringa, Bernard

    Several chiral Cu(II)-complexes of cyclic amino acids catalyse the enantioselective allylic oxidation of cyclohexene to cyclohexenyl esters. Cyclohexenyl propionate was obtained in 86% yield with e.e.'s up to 61%.

  4. Tris(2-methyl-8-quinolinolato)iron(III) as a novel spectrophotometric probe for silanol detection.

    Science.gov (United States)

    Uehara, Nobuo; Kawata, Sumiko; Shimizu, Tokuo

    2006-03-01

    Tris(2-methyl-8-quinolinolato)iron(III) was proposed as a sensitive spectrophotometric silanol-detecting probe based on the coordination ability of silanol groups on the surface of octadecylsylanized silica gel (ODS silica gel) for reversed-phase high-performance liquid chromatography. A peak of the iron(III) complex on a chromatogram abruptly collapsed as the silanol content in an ODS column increased, indicating that the iron(III) complex could sense trace amounts of silanol groups. The change of the peak parameters, such as the peak height and the peak area was highly related to the output of some nitrogen-containing compounds used as silanol-detecting probes as a function of the silanol content in an ODS column. The response of the peak height of the iron(III) complex to the silanol content was much more sensitive than the response of the nitrogen-containing probes, and was comparable to that of tris(2-methyl-8-quinolinolato)gallium(III), which had been proposed as a fluorometric silanol-detecting probe based on the coordination ability of the silanol groups.

  5. Synthesis of silanol-functionalized latex nanoparticles through miniemulsion copolymerization of styrene and gamma-methacryloxypropyltrimethoxysilane.

    Science.gov (United States)

    Zhang, Sheng-Wen; Zhou, Shu-Xue; Weng, Yu-Ming; Wu, Li-Min

    2006-05-09

    The polystyrene latex nanoparticles bearing silanol groups on their surfaces were successfully synthesized via miniemulsion polymerization using gamma-methacryloxypropyltrimethoxysilane (MPS) as the functional comonomer and oil-soluble AIBN as the initiator at neutral conditions. FTIR and 29Si NMR spectra showed that the condensation of silanol groups was suppressed effectively. zeta potential and XPS analyses demonstrated that the silanol groups were enriched at the surfaces of the latex particles and could be tailored by MPS concentration. These silanol-functionalized latex particles could be easily coated with silica or other inorganic or organic compounds to prepare novel hybrid particles and hollow microspheres.

  6. Transition metal catalysed Grignard-like allylic activation across ...

    Indian Academy of Sciences (India)

    Unknown

    The reaction chosen for the present study is the Barbier variation of the Grignard reaction, wherein the organic halide and a carbonyl compound react to provide the corresponding homoallylic alcohol5. With specific reference to carbonyl allylation via tin(II) salts, it was previously shown that allyltrihalostannane is formed as a ...

  7. Tsuji-Trost N-allylation with allylic acetates using cellulose-Pd catalyst

    Science.gov (United States)

    Allylic amines are synthesized using heterogeneous cellulose-Pd catalyst via N-allylation of amines; aliphatic and benzyl amines undergo facile reaction with substituted and unsubstituted allyl acetates in high yields.

  8. Silanol suppressing potency of alkyl-imidazolium ionic liquids on C18 stationary phases.

    Science.gov (United States)

    Fernández-Navarro, J J; Torres-Lapasió, J R; Ruiz-Ángel, M J; García-Álvarez-Coque, M C

    2012-04-06

    Residual silanols on C18 columns yield undesirable slow-kinetics ion-exchange interactions with positively charged basic compounds that result in asymmetrical peaks, low efficiencies and long retention times. The purity of the silica employed as supporting material, and the technique used to form the bonded phase, which varies with the brand and manufacturer, give rise to different amounts of residual silanols in the packings, and consequently, different chromatographic performance. One of the most efficient and widespread strategies to reduce or even eliminate the different performance among columns is the addition of a reagent to the mobile phase to block the silanol sites. However, the intrinsic nature of both stationary phase and additive leads to particular results. In this work, a group of basic compounds were analysed using six C18 stationary phases (Zorbax SB-C18, X-Terra MS C18, Kromasil, Lichrospher, Nucleosil, and Spherisorb) and acetonitrile-water mixtures. Two ionic liquids (ILs), 1-butyl- and 1-hexyl-3-methyl-imidazolium tetrafluoroborates, were added to the mobile phases to evaluate their silanol suppressing potency, based on the decreased retention of the basic compounds when the silanols are blocked (described by the Horváth equation), and the improvement in peak profile (described by the plots of the peak half-widths at diverse retention times). The suppressing potency based on the retention can be misleading when the adsorption of the IL anion is not negligible, since the anion attracts the cationic basic compounds increasing the retention. However, the accessibility of basic compounds to the silanols is prevented by both IL cation and anion, improving the peak profiles for all stationary phases. This was especially remarkable for Spherisorb, which in the absence of additive yielded by far the worst performance. 1-Hexyl-3-methyl-imidazolium tetrafluoroborate was the best additive in terms of retention and peak profile (width and asymmetry

  9. Evaluation of the Oxygen pi-Donation in Permethyltitanocene Silanolates and Alcoholates

    Czech Academy of Sciences Publication Activity Database

    Varga, V.; Císařová, I.; Gyepes, R.; Horáček, Michal; Kubišta, Jiří; Mach, Karel

    2009-01-01

    Roč. 28, č. 6 (2009), s. 1748-1757 ISSN 0276-7333 R&D Projects: GA AV ČR KAN100400701; GA MŠk(CZ) LC06070 Institutional research plan: CEZ:AV0Z40400503 Keywords : oxygen * silanolates * alcoholates Subject RIV: CF - Physical ; Theoretical Chem istry Impact factor: 4.204, year: 2009

  10. One-pot synthesis of silanol-free nanosized MFI zeolite

    Science.gov (United States)

    Grand, Julien; Talapaneni, Siddulu Naidu; Vicente, Aurélie; Fernandez, Christian; Dib, Eddy; Aleksandrov, Hristiyan A.; Vayssilov, Georgi N.; Retoux, Richard; Boullay, Philippe; Gilson, Jean-Pierre; Valtchev, Valentin; Mintova, Svetlana

    2017-10-01

    The synthesis of nanostructured zeolites enables modification of catalytically relevant properties such as effective surface area and diffusion path length. Nanostructured zeolites may be synthesized either in alkaline media, and so contain significant numbers of hydrophilic silanol groups, or in expensive and harmful fluoride-containing media. Here, we report and characterize, using a combination of experimental and theoretical techniques, the one-pot synthesis of silanol-free nanosized MFI-type zeolites by introducing atomically dispersed tungsten; this prevents silanol group occurrence by forming flexible W-O-Si bridges. These W-O-Si bonds are more stable than Si-O-Si in the all-silica MFI zeolite. Tungsten incorporation in nanosized MFI crystals also modifies other properties such as structural features, hydrophobicity and Lewis acidity. The effect of these is illustrated on the catalytic epoxidation of styrene and separation of CO2 and NO2. Silanol-free nanosized W-MFI zeolites open new perspectives for catalytic and separation applications.

  11. The allylic chalcogen effect in olefin metathesis

    Directory of Open Access Journals (Sweden)

    Yuya A. Lin

    2010-12-01

    Full Text Available Olefin metathesis has emerged as a powerful tool in organic synthesis. The activating effect of an allylic hydroxy group in metathesis has been known for more than 10 years, and many organic chemists have taken advantage of this positive influence for efficient synthesis of natural products. Recently, the discovery of the rate enhancement by allyl sulfides in aqueous cross-metathesis has allowed the first examples of such a reaction on proteins. This led to a new benchmark in substrate complexity for cross-metathesis and expanded the potential of olefin metathesis for other applications in chemical biology. The enhanced reactivity of allyl sulfide, along with earlier reports of a similar effect by allylic hydroxy groups, suggests that allyl chalcogens generally play an important role in modulating the rate of olefin metathesis. In this review, we discuss the effect of allylic chalcogens in olefin metathesis and highlight its most recent applications in synthetic chemistry and protein modifications.

  12. The allylic chalcogen effect in olefin metathesis.

    Science.gov (United States)

    Lin, Yuya A; Davis, Benjamin G

    2010-12-23

    Olefin metathesis has emerged as a powerful tool in organic synthesis. The activating effect of an allylic hydroxy group in metathesis has been known for more than 10 years, and many organic chemists have taken advantage of this positive influence for efficient synthesis of natural products. Recently, the discovery of the rate enhancement by allyl sulfides in aqueous cross-metathesis has allowed the first examples of such a reaction on proteins. This led to a new benchmark in substrate complexity for cross-metathesis and expanded the potential of olefin metathesis for other applications in chemical biology. The enhanced reactivity of allyl sulfide, along with earlier reports of a similar effect by allylic hydroxy groups, suggests that allyl chalcogens generally play an important role in modulating the rate of olefin metathesis. In this review, we discuss the effect of allylic chalcogens in olefin metathesis and highlight its most recent applications in synthetic chemistry and protein modifications.

  13. The silanol content and in vitro cytolytic activity of flame-made silica.

    Science.gov (United States)

    Spyrogianni, Anastasia; Herrmann, Inge K; Keevend, Kerda; Pratsinis, Sotiris E; Wegner, Karsten

    2017-12-01

    The surface chemistry of synthetic amorphous silicas is essential for their applicational performance and for understanding their interactions with biological matter. Synthesis of silica by flame spray pyrolysis (FSP) allows to control the content and type of hydroxyl groups which also affects the cytolytic activity. By controlling the FSP process variables, silica nanoparticles with the same specific surface area but different surface chemistry and content of internal silanols are prepared by combustion of hexamethyldisiloxane sprays, as characterized by Raman and infrared spectroscopy, thermogravimetric analysis, and titration with lithium alanate. Cytolytic activity is assessed in terms of membrane damage in human blood monocytes in vitro. Unlike commercial fumed silica, FSP-made silicas contain a significant amount of internal silanol groups and a high surface hydroxyl density, up to ∼8OH/nm 2 , similar to silicas made by wet-chemistry. Increasing the residence time of particles at high temperature during their synthesis reduces the internal and surface hydroxyl content and increases the relative amount of isolated silanols. This suggests incomplete oxidation of the silica matrix especially in short and "cold" flames and indicates that the silica particle formation pathway involves Si(OH) 4 . The surface chemistry differences translate into lower cytolytic activity for "cold-" than "hot-flame" silicas. Copyright © 2017 Elsevier Inc. All rights reserved.

  14. A Green Approach for Allylations of Aldehydes and Ketones: Combining Allylborate, Mechanochemistry and Lanthanide Catalyst

    Directory of Open Access Journals (Sweden)

    Viviane P. de Souza

    2016-11-01

    Full Text Available Secondary and tertiary alcohols synthesized via allylation of aldehydes and ketones are important compounds in bioactive natural products and industry, including pharmaceuticals. Development of a mechanochemical method using potassium allyltrifluoroborate salt and water, to successfully perform the allylation of aromatic and aliphatic carbonyl compounds is reported for the first time. By controlling the grinding parameters, the methodology can be selective, namely, very efficient for aldehydes and ineffective for ketones, but by employing lanthanide catalysts, the reactions with ketones can become practically quantitative. The catalyzed reactions can also be performed under mild aqueous stirring conditions. Considering the allylation agent and its by-products, aqueous media, energy efficiency and use of catalyst, the methodology meets most of the green chemistry principles.

  15. Dual Palladium(II)/Tertiary Amine Catalysis for Asymmetric Regioselective Rearrangements of Allylic Carbamates.

    Science.gov (United States)

    Bauer, Johannes Moritz; Frey, Wolfgang; Peters, René

    2016-04-11

    The streamlined catalytic access to enantiopure allylic amines as valuable precursors towards chiral β- and γ-aminoalcohols as well as α- and β-aminoacids is desirable for industrial purposes. In this article an enantioselective method is described that transforms achiral allylic alcohols and N-tosylisocyanate in a single step into highly enantioenriched N-tosyl protected allylic amines via an allylic carbamate intermediate. The latter is likely to undergo a cyclisation-induced [3,3]-rearrangement catalysed by a planar chiral pentaphenylferrocene palladacycle in cooperation with a tertiary amine base. The otherwise often indispensable activation of palladacycle catalysts by a silver salt is not required in the present case and there is also no need for an inert gas atmosphere. To further improve the synthetic value, the rearrangement was used to form dimethylaminosulfonyl-protected allylic amines, which can be deprotected under non-reductive conditions. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Highly enantio- and diastereoselective allylic alkylation of Morita-Baylis-Hillman carbonates with allyl ketones

    KAUST Repository

    Tong, Guanghu

    2013-05-17

    The asymmetric allylic alkylation of Morita-Baylis-Hillman (MBH) carbonates with allyl ketones has been developed. The α-regioselective alkylation adducts, containing a hexa-1,5-diene framework with important synthetic value, were achieved in up to 83% yield, >99% ee, and 50:1 dr by using a commercially available Cinchona alkaloid as the catalyst. From the allylic alkylation adduct, a cyclohexene bearing two adjacent chiral centers was readily prepared. © 2013 American Chemical Society.

  17. Allyl functionalized phosphinite and phosphonite ligands: Synthesis ...

    Indian Academy of Sciences (India)

    Allyl functionalized phosphinite and phosphonite ligands: Synthesis, transition metal chemistry and orthopalladation reactions. SINGAPPAGUDEM GOVINDARAJUa, GUDDEKOPPA S ANANTHNAGa, SUSMITA NAIKa,. SHAIKH M MOBINb and MARAVANJI S BALAKRISHNAa,∗. aPhosphorus Laboratory, Department of ...

  18. A defiltration control method of pressurized liquid in zeolite ZSM-5 by silanol introduction

    Science.gov (United States)

    Sun, Yueting; Lu, Weiyi; Li, Yibing

    2014-09-01

    The defiltration performance of the zeolite ZSM-5/liquid system can be effectively modified by sodium hydroxide (NaOH) additive with various concentrations. The infiltration of NaOH aqueous solutions increases the density of silanol (Si-OH) groups on inner surface of the porous ZSM-5, converting the originally hydrophobic surface to hydrophilic and ceasing the liquid outflow. More importantly, the defiltration performance of the system can be adjusted independently without affecting the working pressure of the system. This unique infiltration associated hydrophobic-hydrophilic transition of nanopore surface leads the ZSM-5 based liquid system to an efficient energy absorption system instead of a super-elastic molecular spring.

  19. Novel 3-hydroxypropyl-bonded phase by direct hydrosilylation of allyl alcohol on amorphous hydride silica.

    Science.gov (United States)

    Gómez, Jorge E; Navarro, Fabián H; Sandoval, Junior E

    2014-09-01

    A novel 3-hydroxypropyl (propanol)-bonded silica phase has been prepared by hydrosilylation of allyl alcohol on a hydride silica intermediate, in the presence of platinum (0)-divinyltetramethyldisiloxane (Karstedt's catalyst). The regio-selectivity of this synthetic approach had been correctly predicted by previous reports involving octakis(dimethylsiloxy)octasilsesquioxane (Q8 M8 (H) ) and hydrogen silsesquioxane (T8 H8 ), as molecular analogs of hydride amorphous silica. Thus, C-silylation predominated (∼94%) over O-silylation, and high surface coverages of propanol groups (5 ± 1 μmol/m(2) ) were typically obtained in this work. The propanol-bonded phase was characterized by spectroscopic (infrared (IR) and solid-state NMR on silica microparticles), contact angle (on fused-silica wafers) and CE (on fused-silica tubes) techniques. CE studies of the migration behavior of pyridine, caffeine, Tris(2,2'-bipyridine)Ru(II) chloride and lysozyme on propanol-modified capillaries were carried out. The adsorption properties of these select silanol-sensitive solutes were compared to those on the unmodified and hydride-modified tubes. It was found that hydrolysis of the SiH species underlying the immobilized propanol moieties leads mainly to strong ion-exchange-based interactions with the basic solutes at pH 4, particularly with lysozyme. Interestingly, and in agreement with water contact angle and electroosmotic mobility figures, the silanol-probe interactions on the buffer-exposed (hydrolyzed) hydride surface are quite different from those of the original unmodified tube. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. Compound list: allyl alcohol [Open TG-GATEs

    Lifescience Database Archive (English)

    Full Text Available allyl alcohol AA 00010 ftp://ftp.biosciencedbc.jp/archive/open-tggates/LATEST/Human/in_vitro/allyl_alcohol....Human.in_vitro.Liver.zip ftp://ftp.biosciencedbc.jp/archive/open-tggates/LATEST/Rat/in_vitro/allyl_alcohol...dbc.jp/archive/open-tggates/LATEST/Rat/in_vivo/Liver/Repeat/allyl_alcohol.Rat.in_vivo.Liver.Repeat.zip ftp:/.../ftp.biosciencedbc.jp/archive/open-tggates/LATEST/Rat/in_vivo/Kidney/Single/allyl_alcohol.Rat.in_vivo.Kidney....Single.zip ftp://ftp.biosciencedbc.jp/archive/open-tggates/LATEST/Rat/in_vivo/Kidney/Repeat/allyl_alcohol.Rat.in_vivo.Kidney.Repeat.zip ...

  1. Quantification of water and silanol species on various silicas by coupling IR spectroscopy and in-situ thermogravimetry.

    Science.gov (United States)

    Gallas, Jean-Paul; Goupil, Jean-Michel; Vimont, Alexandre; Lavalley, Jean-Claude; Gil, Barbara; Gilson, Jean-Pierre; Miserque, Olivier

    2009-05-19

    Five silica samples (four precipitated silicas provided by commercial suppliers and one with the MCM-41 structure) have been studied by infrared spectroscopy and by a homemade thermogravimetry-infrared spectrum (TG-IR) setup. The silanol amount, accessibility to water, and different alcohols, and the affinity to water of these various silicas were compared and quantified. TG-IR measurements allowed the precise determination of the integrated molar absorption coefficient of the (nu+delta)OH band, epsilon(nu+delta)OH=(0.16+/-0.01) cm micromol(-1). It is independent of the sample origin and the concentration of silanol groups on silicas. For the precipitated dried samples evacuated at room temperature, the silanol concentration COH varies between 3.6 and 7.0 mmol g(-1). It is 5.3 mmol g(-1) in the case of the MCM-41 sample. Exchange experiments with D2O, followed by back-exchanges with different alcohols (methanol, propan-2-ol, 2-methyl-propan-2-ol, and 3-ethyl-pentan-3-ol) have been followed by infrared spectroscopy. All of the silanols of the MCM-41 sample are accessible to water and alcohol molecules. By contrast, about 20% of the silanols in precipitated samples are not exchanged by D2O (internal silanols). Accessibility decreases with alcohol size; the main effect is relative to methanol. Taking into account the sample specific surface areas and the silanol accessibility to D2O, the surface silanol density of precipitated silicas is close to 8 OH per nm2, at maximum coverage. At variance, the silanol surface density of the MCM silica is much lower, 4 OH per nm2. The TG-IR setup has also been used to determine the amount of water adsorbed on silicas through the intensity of the deltaH2O band. It varies linearly with the concentration of adsorbed water, whatever the silica sample. The integrated molar absorption coefficient of two bands, epsilondeltaH2O=(1.53+/-0.03) cm micromol(-1) and epsilon(nu+delta)H2O=(0.22+/-0.01) cm micromol(-1), have been determined. The

  2. Two-dimensional NMR studies of allyl palladium complexes of ...

    Indian Academy of Sciences (India)

    Administrator

    h3-Allyl complexes are intermediates in organic synthetic reactions such as allylic alkylation and amination. There is growing interest in understanding the structures of chiral h3-allyl intermediates as this would help to unravel the mechanism of enantioselective C–C bond forming reactions. Two-dimensional NMR study is a.

  3. Palladium-Catalyzed Asymmetric Allylic Allylation of Racemic Morita-Baylis-Hillman Adducts.

    Science.gov (United States)

    Wang, Xubin; Wang, Xiaoming; Han, Zhaobin; Wang, Zheng; Ding, Kuiling

    2017-01-19

    A palladium-catalyzed asymmetric allyl-allyl cross-coupling of acetates of racemic Morita-Baylis-Hillman adducts and allylB(pin) has been developed using a spiroketal-based bis(phosphine) as the chiral ligand, thus affording a series of chiral 1,5-dienes bearing a vinylic ester functionality in good yields, high branched regioselectivities, and uniformly excellent enantioselectivities (95-99 % ee). Further synthetic manipulations of the allylation products provided novel ways for rapid access to a range of chiral polycyclic lactones and polycyclic lactams, as well as the antidepressant drug (-)-Paroxetine, in high optical purities. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. Palladium Catalyzed Allylic C-H Alkylation

    DEFF Research Database (Denmark)

    Engelin, Casper Junker; Fristrup, Peter

    2011-01-01

    an acetate ion coordinated to Pd. Several of the reported systems rely on benzoquinone for re-oxidation of the active catalyst. The scope for nucleophilic addition in allylic C-H alkylation is currently limited, due to demands on pKa of the nucleophile. This limitation could be due to the pH dependence...

  5. A silanol-based nanocomposite coating for protection of AA-2024 aluminium alloy

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez, E.; Pavez, J.; Azocar, I.; Zagal, J.H. [Departamento de Quimica de los Materiales, Facultad de Quimica y Biologia, Universidad de Santiago de Chile, Avenida Bernardo O' Higgins 3363, Casilla 40, Correo 33, Santiago (Chile); Zhou, X. [Corrosion and Protection Centre, School of Materials, University of Manchester, Manchester M13 9PL (United Kingdom); Melo, F. [Departamento de Fisica, Facultad de Ciencias, Universidad de Santiago de Santiago de Chile, Avenida Bernardo O' Higgins 3363, Santiago (Chile); Thompson, G.E. [Corrosion and Protection Centre, School of Materials, University of Manchester, Manchester M13 9PL (United Kingdom); Paez, M.A., E-mail: maritza.paez@usach.cl [Departamento de Quimica de los Materiales, Facultad de Quimica y Biologia, Universidad de Santiago de Chile, Avenida Bernardo O' Higgins 3363, Casilla 40, Correo 33, Santiago (Chile)

    2011-09-01

    Highlights: {center_dot} A new silanol-based hybrid coating has been synthesized. {center_dot} The incorporation of CeO{sub 2} and ZrO{sub 2} nanoparticles into the coating greatly improves the corrosion resistance of the coated aluminium alloy. {center_dot} The effectiveness of the coating is increasingly evident for long term exposure to the sodium chloride solution. {center_dot} The silanol-based nanocomposite coatings have self-healing ability. - Abstract: A new hybrid sol-gel type film, composed of tetraethylorthosilicate (TEOS) and tetraocthylorthosilicate (TEOCS), and modified with different nanoparticle systems, has been investigated as a coating for protection of AA-2024-T3 aluminium alloy. The nanoparticle systems considered were either ZrO{sub 2} or CeO{sub 2} or their combination{sub .} The zirconia nanoparticles were prepared from a Zr (IV) propoxide sol (TPOZ), using an organic stabilizer, and the CeO{sub 2} nanoparticles were developed spontaneously after adding cerium nitrate solution to the hybrid sol. The chemical composition and the structure of the hybrid sol-gel films were examined by X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) and atomic force microscopy (AFM). The corrosion resistance of the coated AA-2024 alloy was examined by potentiodynamic polarization. The results revealed that, for short exposure times in the electrolyte, incorporation of ZrO{sub 2} or CeO{sub 2} nanoparticles in the hybrid film does not provide an increase in the corrosion resistance of the coated AA-2024 alloy. Further, the resistance was significantly reduced by increasing the nanoparticle content. Conversely, by incorporating both nanoparticles (ZrO{sub 2} and CeO{sub 2}), the corrosion resistance of the resulting hybrid films increased slightly. The behavior changed significantly when the coated alloy was exposed to the electrolyte for 5 days. The corrosion resistance of the coatings, unmodified and modified with CeO{sub 2} or Zr

  6. Pressure Dependent Product Formation in the Photochemically Initiated Allyl + Allyl Reaction

    Directory of Open Access Journals (Sweden)

    Thomas Zeuch

    2013-11-01

    Full Text Available Photochemically driven reactions involving unsaturated radicals produce a thick global layer of organic haze on Titan, Saturn’s largest moon. The allyl radical self-reaction is an example for this type of chemistry and was examined at room temperature from an experimental and kinetic modelling perspective. The experiments were performed in a static reactor with a volume of 5 L under wall free conditions. The allyl radicals were produced from laser flash photolysis of three different precursors allyl bromide (C3H5Br, allyl chloride (C3H5Cl, and 1,5-hexadiene (CH2CH(CH22CHCH2 at 193 nm. Stable products were identified by their characteristic vibrational modes and quantified using FTIR spectroscopy. In addition to the (re- combination pathway C3H5+C3H5 → C6H10 we found at low pressures around 1 mbar the highest final product yields for allene and propene for the precursor C3H5Br. A kinetic analysis indicates that the end product formation is influenced by specific reaction kinetics of photochemically activated allyl radicals. Above 10 mbar the (re- combination pathway becomes dominant. These findings exemplify the specificities of reaction kinetics involving chemically activated species, which for certain conditions cannot be simply deduced from combustion kinetics or atmospheric chemistry on Earth.

  7. SYNTHESIS OF ALLYL PHENYL ETHER AND CLAISEN REARRANGEMENT

    Directory of Open Access Journals (Sweden)

    Gagik Torosyan

    2011-12-01

    Full Text Available It has been established the possibility for phenol allylation on natural zeolites and them analogs. Here is demonstrated the synthesis of allyl phenol, which has wide industrial applications. The offered method in comparison with the traditional methods has more advantages – higher selectivity, smaller material and power resources consumption. It has been obtained the mixture of allylating phenols (30% in general with allyl phenyl ether (1 with 80% yields. At 600 K is obtained allylphenyl ether, at 700 K beginning the formation of allyl phenols, which is the result of direct C-allylation of the aromatic ring. It has been investigated the possibility of Claisen rearrangement in the same conditions. All of that are established by gas-liquid chromatography and liquid chromatography data.

  8. Toward Efficient Palladium-Catalyzed Allylic C-H Alkylation

    DEFF Research Database (Denmark)

    Jensen, Thomas; Fristrup, Peter

    2009-01-01

    Recent breakthroughs have proved that direct palladium (II)-catalyzed allylic C-H alkylation can be achieved. This new procedure shows that the inherent requirement for a leaving group in the Tsuji-Trost palladium-catalyzed allylic alkylation can be lifted. These initial reports hold great promise...... for the development of allylic C-H alkylation into a widely applicable methodology, thus providing a means to enhance synthetic efficiency in these reactions....

  9. Effect of Al content on the strength of terminal silanol species in ZSM-5 zeolite catalysts: a quantitative DRIFTS study without the use of molar extinction coefficients.

    Science.gov (United States)

    Bräuer, Pierre; Situmorang, Olivia; Ng, Pey Ling; D'Agostino, Carmine

    2018-02-07

    The strength of terminal hydroxyl Si-OH groups (silanols) in zeolites is important for many non-size-selective catalytic reactions occurring onto the external surface of the zeolite crystals and may often be responsible for catalyst deactivation, e.g., coke formation. A quantitative analysis of Si-OH strength and its link with the Al content, hence varying silica-to-alumina ratio (SAR = SiO 2 /Al 2 O 3 ), has not been established yet. Various hypotheses have been proposed in the literature; nonetheless, the role of Al content in determining silanol strength remains still unclear and the object of speculation. In this work, we have systematically investigated the effect of the Al content on the strength of terminal silanol sites in ZSM-5 zeolite catalysts with varying SAR using Diffuse Reflectance Infrared Fourier Transform Spectroscopy (DRIFTS) at variable temperatures without molar extinction coefficients. Two base probe molecules with different proton affinity values, pyridine and collidine, were used. To quantify the strength of terminal silanol sites the change of the terminal silanol peak in the OH stretching region, together with data on elemental analysis, was used. With this experimental protocol, unlike most IR studies, the use of molar extinction coefficients, often difficult to obtain, is not needed for quantification. The results reported here show for the first time that for ZSM-5 zeolite catalysts the fraction of occupied terminal silanol acid sites for both pyridine and collidine increases with increasing concentration of external Brønsted acid sites, hence establishing a clear link between the two types of acid sites. In summary, this work shows that the use of DRIFTS without molar extinction coefficients is able to quantitatively probe the strength of terminal silanol acid sites and establishes a link between the external Brønsted Al content and the strength of terminal silanol species in ZSM-5 zeolites with varying SAR at elevated temperatures.

  10. Polymerizations of beta-substituted allylic arsonium ylides with catalytic amounts of organoboron compounds

    International Nuclear Information System (INIS)

    Mondiere, R.

    2004-01-01

    My Ph.D. work consisted in the generalization and optimization of a new polymerization reaction involving allylic arsonium ylides and catalytic amounts of various boron compounds. Thus, various β-substituted allylic arsonium salts were produced according to synthetic strategies that depended on the nature of the functional group born by the salt. These salts were converted in situ to the corresponding arsonium ylides which were then treated with boron compounds to yield polymers. Our new method of polymerization afforded either non conjugated polyenes that are functionalized every three atoms of carbon, or statistic copolymers, depending on the nature of the group R born on the β position of the ylide. These new polymers cannot be synthesized by usual methods of polymerization. Initial molar ratios of reactants were found to give molar mass control of the synthesized polymers. This controlled polymerization allowed us to produce several bloc copolymers. All the polymers were characterized by NMR techniques, by size exclusion chromatography and, for some of them, by mass spectrometry. Investigation of their physicochemical properties will need additional experiments. (author)

  11. Radiation and thermal polymerization of allyl(p-allylcarbonate) benzoate

    International Nuclear Information System (INIS)

    Lopez-V, D.; Herrera-G, A.M.; Castillo-Rojas, S.

    2011-01-01

    Bulk polymerization of novel allyl(p-allylcarbonate) benzoate was investigated using different sources of energy, such as gamma rays, ultraviolet rays as well as thermal polymerization. The poly(allyl(p-allylcarbonate) benzoate) obtained is a cross-linking, transparent, thermoset polycarbonate. Compositions of the monomer and the polycarbonate were analyzed by infrared spectroscopy, elemental analysis, and 1 H NMR spectroscopy.

  12. Allyl borates: a novel class of polyhomologation initiators

    KAUST Repository

    Wang, De

    2016-12-24

    Allyl borates, a new class of monofunctional polyhomologation initiators, are reported. These monofunctional initiators are less sensitive and more effective towards polymethylene-based architectures. As an example, the synthesis of α-vinyl-ω-hydroxypolymethylenes is given. By designing/synthesizing different allylic borate initiators, and using 1H and 11B NMR spectroscopy, the initiation mechanism was elucidated.

  13. Reactivity of (η3-allyl)dicarbonylnitrosyl iron complexes with ...

    African Journals Online (AJOL)

    The introduction of variable substituents exhibited diverse reactivities. Generally, it was observed that the reactivity decreased by increasing the size of substituentin (η3-allyl)dicarbonylnitrosyl iron complexes (1–9). Strong impact on the reactivity was observed due to substitution pattern of the allyl moiety. A considerable ...

  14. Ti-catalyzed Barbier-type allylations and related reactions.

    Science.gov (United States)

    Estévez, Rosa E; Justicia, José; Bazdi, Btissam; Fuentes, Noelia; Paradas, Miguel; Choquesillo-Lazarte, Duane; García-Ruiz, Juan M; Robles, Rafael; Gansäuer, Andreas; Cuerva, Juan M; Oltra, J Enrique

    2009-01-01

    Titanocene(III) complexes, easily generated in situ from commercial Ti(IV) precursors, catalyze Barbier-type allylations, intramolecular crotylations (cyclizations), and prenylations of a wide range of aldehydes and ketones. The reaction displays surprising and unprecedented mechanistic subtleties. In cyclizations a fast and irreversible addition of an allyl radical to a Ti(III)-coordinated carbonyl group seems to occur. Intermolecular additions to conjugated aldehydes proceed through a coupling of a Ti(IV)-bound ketyl radical with an allyl radical. Reactions of ketones with allylic halides take place by the classical addition of an allylic organometallic reagent. The radical coupling processes enable transformations such as the highly regioselective alpha-prenylation that are otherwise difficult to achieve. The mild reaction conditions and the possibility to employ titanocene complexes in only catalytic quantities are highly attractive features of our protocol. These unusual properties have been taken advantage of for the straightforward synthesis of the natural products rosiridol, shikalkin, and 12-hydroxysqualene.

  15. Catalytic Oxidation of Allylic Alcohols to Methyl Esters

    DEFF Research Database (Denmark)

    Gallas-Hulin, Agata; Kotni, Rama Krishna; Nielsen, Martin

    2017-01-01

    Aerobic oxidation of allylic alcohols to methyl esters using gold nanoparticles supported on different metal oxide carriers has been performed successfully under mild conditions (room temperature, 0.1 MPa O2) without significant loss of catalytic activity. The effects of different reaction...... parameters are studied to find the suitable reaction conditions. All catalysts are characterised by XRD, XRF and TEM. Among these catalysts, Au/TiO2 showed the most efficient catalytic activity towards the selective oxidation of allylic alcohols to the corresponding esters. Moreover, the same Au/TiO2...... to synthesize methyl esters from allylic alcohols....

  16. Direct, Intermolecular, Enantioselective, Iridium-Catalyzed Allylation of Carbamates to Form Carbamate-Protected, Branched Allylic Amines

    Science.gov (United States)

    Weix, Daniel J.; Marković, Dean; Ueda, Mitsuhiro; Hartwig, John F.

    2009-01-01

    The direct reaction between carbamates and achiral allylic carbonates to form branched, conveniently protected primary allylic amines with high regioselectivity and enantioselectivity is reported. This process occurs without base or with 0.5 equiv K3PO4 in the presence of a metalacyclic iridium catalyst containing a labile ethylene ligand. The reactions of aryl, heteroaryl and alkyl-substituted allylic carbonates with BocNH2, FmocNH2, CbzNH2, TrocNH2, TeocNH2, and 2-oxazolidinone occur in good yields, with high selectivity for the branched isomer, and high enantioselectivities (98% average ee). PMID:19552468

  17. The zeolite mediated isomerization of allyl phenyl ether

    Science.gov (United States)

    Pebriana, R.; Mujahidin, D.; Syah, Y. M.

    2017-04-01

    Allyl phenyl ether is an important starting material in organic synthesis that has several applications in agrochemical industry. The green transformation of allyl phenyl ether assisted by heterogeneous catalyst is an attractive topic for an industrial process. In this report, we investigated the isomerization of allyl phenyl ether by heating it in zeolite H-ZSM-5 and Na-ZSM-5. The conversion of allyl phenyl ether (neat) in H-ZSM-5 was 67% which produced 40% of 2-allylphenol, 17% of 2-methyldihydrobenzofuran, and other product (4:1.7:1), while in Na-ZSM-5 produced exclusively 2-allylphenol with 52% conversion. These results showed that zeolite properties can be tuned to give a selective transformation by substitution of metal ion into the zeolite interior.

  18. Asymmetric allylation, crotylation, and cinnamylation of N-heteroaryl hydrazones.

    Science.gov (United States)

    Feske, Miriam Inbar; Santanilla, Alexander Buitrago; Leighton, James L

    2010-02-19

    A new class of N-heteroaryl hydrazones has been developed as an alternative to N-acylhydrazones and 2-aminophenol-derived imines in asymmetric allylation, crotylation, and cinnamylation reactions with chiral allylchlorosilanes. The hydrazones are readily and inexpensively prepared, perform well in the allylation chemistry, and more importantly, the product hydrazides may be smoothly reduced by Pd(OH)(2)-catalyzed hydrogenation to reveal the corresponding amine products.

  19. Zinc Mediated Tandem Fragmentation-Allylation of Methyl 5-Iodopentofuranosides

    DEFF Research Database (Denmark)

    Hyldtoft, Lene; Madsen, Robert

    1999-01-01

    In the presence of zinc and allyl bromide methyl 5-iodopentofuranosides undergo a tandem fragmentation alkylation to give functionalized dienes. These can undergo ring-closing olefin metathesis to produce cyclohexenes which on dihydroxylation give quercitols.......In the presence of zinc and allyl bromide methyl 5-iodopentofuranosides undergo a tandem fragmentation alkylation to give functionalized dienes. These can undergo ring-closing olefin metathesis to produce cyclohexenes which on dihydroxylation give quercitols....

  20. General Allylic C–H Alkylation with Tertiary Nucleophiles

    Science.gov (United States)

    2015-01-01

    A general method for intermolecular allylic C–H alkylation of terminal olefins with tertiary nucleophiles has been accomplished employing palladium(II)/bis(sulfoxide) catalysis. Allylic C–H alkylation furnishes products in good yields (avg. 64%) with excellent regio- and stereoselectivity (>20:1 linear:branched, >20:1 E:Z). For the first time, the olefin scope encompasses unactivated aliphatic olefins as well as activated aromatic/heteroaromatic olefins and 1,4-dienes. The ease of appending allyl moieties onto complex scaffolds is leveraged to enable this mild and selective allylic C–H alkylation to rapidly diversify phenolic natural products. The tertiary nucleophile scope is broad and includes latent functionality for further elaboration (e.g., aliphatic alcohols, α,β-unsaturated esters). The opportunities to effect synthetic streamlining with such general C–H reactivity are illustrated in an allylic C–H alkylation/Diels–Alder reaction cascade: a reactive diene is generated via intermolecular allylic C–H alkylation and approximated to a dienophile contained within the tertiary nucleophile to furnish a common tricyclic core found in the class I galbulimima alkaloids. PMID:24641574

  1. General allylic C-H alkylation with tertiary nucleophiles.

    Science.gov (United States)

    Howell, Jennifer M; Liu, Wei; Young, Andrew J; White, M Christina

    2014-04-16

    A general method for intermolecular allylic C-H alkylation of terminal olefins with tertiary nucleophiles has been accomplished employing palladium(II)/bis(sulfoxide) catalysis. Allylic C-H alkylation furnishes products in good yields (avg. 64%) with excellent regio- and stereoselectivity (>20:1 linear:branched, >20:1 E:Z). For the first time, the olefin scope encompasses unactivated aliphatic olefins as well as activated aromatic/heteroaromatic olefins and 1,4-dienes. The ease of appending allyl moieties onto complex scaffolds is leveraged to enable this mild and selective allylic C-H alkylation to rapidly diversify phenolic natural products. The tertiary nucleophile scope is broad and includes latent functionality for further elaboration (e.g., aliphatic alcohols, α,β-unsaturated esters). The opportunities to effect synthetic streamlining with such general C-H reactivity are illustrated in an allylic C-H alkylation/Diels-Alder reaction cascade: a reactive diene is generated via intermolecular allylic C-H alkylation and approximated to a dienophile contained within the tertiary nucleophile to furnish a common tricyclic core found in the class I galbulimima alkaloids.

  2. Molecular Mechanics and Quantum Chemistry Based Study of Nickel-N-Allyl Urea and N-Allyl Thiourea Complexes

    Directory of Open Access Journals (Sweden)

    P. D. Sharma

    2009-01-01

    Full Text Available Eigenvalue, eigenvector and overlap matrix of nickel halide complex of N-allyl urea and N-allyl thiourea have been evaluated. Our results indicate that ligand field parameters (Dq, B’ and β evaluated earlier by electronic spectra are very close to values evaluated with the help of eigenvalues and eigenvectors. Eigenvector analysis and population analysis shows that in bonding 4s, 4p, and 3dx2-y2, 3dyz orbitals of nickel are involved but the coefficient values differ in different complexes. Out of 4px, 4py, 4pz the involvement of either 4pz or 4py, is noticeable. The theoretically evaluated positions of infrared bands indicate that N-allyl urea is coordinated to nickel through its oxygen and N-allyl thiourea is coordinated to nickel through its sulphur which is in conformity with the experimental results.

  3. Water promoted allylic nucleophilic substitution reactions of (E)-1,3 diphenylallyl acetate

    KAUST Repository

    Ghorpade, Seema Arun

    2017-11-30

    Transition metal free, water based, greener protocol for allylic alkylation, allylic amination, O-allylation of (E)-1,3-diphenylallyl acetate is described. The developed methodology is applicable for a wide range of nucleophiles furnishing excellent yields of corresponding products up to 87% under mild reaction conditions. A Distinct effect of water and base is explored for allylic nucleophilic substitution reactions of (E)-1,3-diphenylallyl acetate.

  4. Urinary excretion of N-acetyl-S-allyl-L-cystein upon garlic consumption by human volunteers.

    NARCIS (Netherlands)

    de Rooij, B.M.; Boogaard, P.J.; Rijksen, D.A.; Commandeur, J.N.M.; Vermeulen, N.P.E.

    1996-01-01

    N-Acetyl-S-allyl-L-cysteine (allylmercapturic acid, ALMA) was previously detected in urine from humans consuming garlic. Exposure of rats to allyl halides is also known to lead to excretion of ALMA in urine. ALMA is a potential biomarker for exposure assessment of workers exposed to allyl halides.

  5. Rapid synthesis of polyprenylated acylphloroglucinol analogs via dearomative conjunctive allylic annulation.

    Science.gov (United States)

    Grenning, Alexander J; Boyce, Jonathan H; Porco, John A

    2014-08-20

    Polyprenylated acylphloroglucinols (PPAPs) are structurally complex natural products with promising biological activities. Herein, we present a biosynthesis-inspired, diversity-oriented synthesis approach for rapid construction of PPAP analogs via double decarboxylative allylation (DcA) of acylphloroglucinol scaffolds to access allyl-desoxyhumulones followed by dearomative conjunctive allylic alkylation (DCAA).

  6. Redox-Neutral Rh(III)-Catalyzed Olefination of Carboxamides with Trifluoromethyl Allylic Carbonate.

    Science.gov (United States)

    Park, Jihye; Han, Sangil; Jeon, Mijin; Mishra, Neeraj Kumar; Lee, Seok-Yong; Lee, Jong Suk; Kwak, Jong Hwan; Um, Sung Hee; Kim, In Su

    2016-11-18

    The rhodium(III)-catalyzed olefination of various carboxamides with α-CF 3 -substituted allylic carbonate is described. This reaction provides direct access to linear CF 3 -allyl frameworks with complete trans-selectivity. In particular, a rhodium catalyst provided Heck-type γ-CF 3 -allylation products via the β-O-elimination of rhodacycle intermediate and subsequent olefin migration process.

  7. A convenient procedure for the synthesis of allyl and benzyl ethers ...

    Indian Academy of Sciences (India)

    Unknown

    Allyl and benzyl groups are commonly employed for the protection of alcohol and phenol moieties for ease of synthesis and convenient deprotection. Allyl and benzyl ethers are also intermediates in sigmatropic rearrangement reactions such as the Claisen and the. Cope rearrangements. Allyl ethers can be prepared from ...

  8. Iridium-Catalyzed Selective Isomerization of Primary Allylic Alcohols.

    Science.gov (United States)

    Li, Houhua; Mazet, Clément

    2016-06-21

    This Account presents the development of the iridium-catalyzed isomerization of primary allylic alcohols in our laboratory over the past 8 years. Our initial interest was driven by the long-standing challenge associated with the development of a general catalyst even for the nonasymmetric version of this seemingly simple chemical transformation. The added value of the aldehyde products and the possibility to rapidly generate molecular complexity from readily accessible allylic alcohols upon a redox-economical isomerization reaction were additional sources of motivation. Certainly influenced by the success story of the related isomerization of allylic amines, most catalysts developed for the selective isomerization of allylic alcohols were focused on rhodium as a transition metal of choice. Our approach has been based on the commonly accepted precept that hydrogenation and isomerization are often competing processes, with the latter being usually suppressed in favor of the former. The cationic iridium complexes [(Cy3P)(pyridine)Ir(cod)]X developed by Crabtree (X = PF6) and Pfaltz (X = BArF) are usually considered as the most versatile catalysts for the hydrogenation of allylic alcohols. Using molecular hydrogen to generate controlled amounts of the active form of these complexes but performing the reaction in the absence of molecular hydrogen enabled deviation from the typical hydrogenation manifold and favored exclusively the isomerization of allylic alcohols into aldehydes. Isotopic labeling and crossover experiments revealed the intermolecular nature of the process. Systematic variation of the ligand on the iridium center allowed us to identify the structural features beneficial for catalytic activity. Subsequently, three generations of chiral catalysts have been investigated and enabled us to reach excellent levels of enantioselectivity for a wide range of 3,3-disubstituted aryl/alkyl and alkyl/alkyl primary allylic alcohols leading to β-chiral aldehydes. The

  9. Oxy-Allyl Cation Catalysis: An Enantioselective Electrophilic Activation Mode

    Science.gov (United States)

    Liu, Chun; Oblak, E. Zachary; Vander Wal, Mark N.; Dilger, Andrew K.; Almstead, Danielle K.; MacMillan, David W. C.

    2016-01-01

    A generic activation mode for asymmetric LUMO-lowering catalysis has been developed using the long-established principles of oxy-allyl cation chemistry. Here, the enantioselective conversion of racemic α-tosyloxy ketones to optically enriched α-indolic carbonyls has been accomplished using a new amino alcohol catalyst in the presence of electron-rich indole nucleophiles. Kinetic studies reveal that the rate-determining step in this SN1 pathway is the catalyst-mediated α-tosyloxy ketone deprotonation step to form an enantiodiscriminant oxy-allyl cation prior to the stereodefining nucleophilic addition event. PMID:26797012

  10. Poly(4-vinylpyridine) as a reagent with silanol-masking effect for silica and its specific selectivity for PAHs and dinitropyrenes in a reversed phase

    International Nuclear Information System (INIS)

    Ihara, Hirotaka; Fukui, Megumi; Mimaki, Takamasa; Shundo, Atsuomi; Dong, Wei; Derakhshan, Mahnaz; Sakurai, Toshihiko; Takafuji, Makoto; Nagaoka, Shoji

    2005-01-01

    This paper demonstrates that poly(4-vinylpyridine) is applicable as an effective masking reagent for silica to reduce undesirable side effects due to silanol groups. It also shows that this chemical modification brings about unique retention behaviors absolutely different from conventional ODS, which appear in molecular-shape selectivity for polycyclic aromatic hydrocarbons and in selectivity for position isomerism, especially for electron-withdrawing substitution compounds. Separation of 1,6- and 1,8-dinirtopyrenes as carcinogens is also described

  11. Surficial Siloxane-to-Silanol Interconversion during Room-Temperature Hydration/Dehydration of Amorphous Silica Films Observed by ATR-IR and TIR-Raman Spectroscopy.

    Science.gov (United States)

    Warring, Suzanne L; Beattie, David A; McQuillan, A James

    2016-02-16

    Silica has been frequently studied using infrared and Raman spectroscopy due to its importance in many practical contexts where its surface chemistry plays a vital role. The majority of these studies have utilized chemical-vapor-deposited films in vacuo after high-temperature calcination. However, room-temperature hydration and dehydration of thin silica particle films has not been well characterized in spite of the importance of such films as substrates for polymer and surfactant adsorption. The present study has utilized ATR-IR spectroscopy and thin silica particle films exposed to varying humidity to clearly show reversible conversion between surface siloxanes and hydrogen-bonded silanols without the need for semiempirical peak deconvolution. The IR spectra from corresponding hydration experiments on deuterated silica films has confirmed the vibrational mode assignments. The variation of humidity over silica films formed from silica suspensions of differing pH gave IR spectra consistent with the change in the relative populations of siloxide to silanol surface groups. In addition, total internal reflection Raman spectroscopy has been used to provide further evidence of room-temperature dehydroxylation, with spectral evidence for the presence of three-membered siloxane rings when films are dehydrated under argon. The confirmation of room-temperature siloxane-to-silanol interconversion is expected to benefit understanding in many silica surface chemical contexts.

  12. REACTIVITY OF (η3-ALLYL)DICARBONYLNITROSYL IRON ...

    African Journals Online (AJOL)

    iron complexes to develop a green chemistry approach [7]. Catalysis based on such metal complexes have been recognized as powerful synthetic tool in organic synthesis. Roustan et al. reported the first Fe–catalyzed allylic substitution and observed good regioselectivity, where substitution preferentially occurred at the ...

  13. Investigation Of Total Phenolic, Total Flavonoid, Antioxidantand Allyl ...

    African Journals Online (AJOL)

    Background: This study was carried out to investigate the total polyphenol (TP), total flavonoid (TF), antioxidative effect and allyl isothyocyanate (ITC) content in different organs of wasabi plant grown in an organic system. Materials and Methods: Invitro study of methanol and boiled water extracts of wasabi were conducted ...

  14. Stereoselective Barbier-type allylation reaction of trifluoromethyl aldimines.

    Science.gov (United States)

    Legros, Julien; Meyer, Franck; Coliboeuf, Matthieu; Crousse, Benoît; Bonnet-Delpon, Danièle; Bégué, Jean-Pierre

    2003-08-08

    Trifluoromethyl aldimines could react, under Barbier conditions in the presence of activated zinc, in DMF at room temperature or in THF at reflux, with various allyl bromides to provide the corresponding homoallylamines. Secondary homoallyl trifluoromethylamines were stereoselectively obtained from the optically active aldimine 12 with an excellent diastereoisomeric excess (98%).

  15. 1-Allyl-5-chloroindoline-2,3-dione

    Directory of Open Access Journals (Sweden)

    Zineb Tribak

    2016-06-01

    Full Text Available In the title compound, C11H8ClNO2, the allyl side chain is almost perpendicular to the 5-chloroindoline-2,3-dione ring system, with a dihedral angle of 88.0 (3°. In the crystal, C—H...O interactions link the molecules into layers lying parallel to the bc plane.

  16. Low-cost route for synthesis of mesoporous silica materials with high silanol groups and their application for Cu(II) removal

    International Nuclear Information System (INIS)

    Wang Yangang; Huang Sujun; Kang Shifei; Zhang Chengli; Li Xi

    2012-01-01

    Graphical abstract: A simple and low-cost route to synthesize mesoporous silica materials with high silanol groups has been demonstrated by means of a sol–gel process using citric acid as the template and acid catalyst, further studies on the adsorption of Cu(II) onto the representative amine-functionalized mesoporous silica showed that it had a high Cu(II) removal efficiency. Highlights: ► A low-cost route to synthesize mesoporous silica with high silanol groups was demonstrated. ► Citric acid as the template and acid catalyst for the reaction of tetraethylorthosilicate. ► Water extraction method was an effective technique to remove template which can be recycled. ► The mesoporous silica with high silanol groups was easily modified by functional groups. ► A high Cu(II) removal efficiency on the amine-functionalized mesoporous silica. - Abstract: We report a simple and low-cost route for the synthesis of mesoporous silica materials with high silanol groups by means of a sol–gel process using citric acid as the template, tetraethylorthosilicate (TEOS) as the silica source under aqueous solution system. The citric acid can directly work as an acid catalyst for the hydrolysis of TEOS besides the function as a pore-forming agent in the synthesis. It was found that by using a water extraction method the citric acid template in as-prepared mesoporous silica composite can be easily removed and a high degree of silanol groups were retained in the mesopores, moreover, the citric acid template in the filtrate can be recycled after being dried. The structural properties of the obtained mesoporous silica materials were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FT-IR), and nitrogen adsorption–desorption analysis. Furthermore, an adsorption of Cu(II) from aqueous solution on the representative amine-functionalized mesoporous silica was investigated

  17. ION EXCHANGE SUBSTANCES BY SAPONIFICATION OF ALLYL PHOSPHATE POLYMERS

    Science.gov (United States)

    Kennedy, J.

    1959-04-14

    An ion exchange resin having a relatively high adsorption capacity tor uranyl ion as compared with many common cations is reported. The resin comprises an alphyl-allyl hydrogen phosphate polymer, the alphyl group being either allyl or a lower alkyl group having up to 5 carbon atoins. The resin is prepared by polymerizing compounds such as alkyl-diallyl phosphate and triallyl phosphate in the presence of a free radical generating substance and then partially hydrolyzing the resulting polymer to cause partial replacement of organic radicals by cations. A preferred free radical gencrating agent is dibenzoyl peroxide. The partial hydrolysis is brought about by refluxing the polymer with concentrated aqueous NaOH for three or four hours.

  18. Radiation initiated copolymerization of allyl alcohol with acrylonitrile

    International Nuclear Information System (INIS)

    Solpan, Dilek; Guven, Olgun

    1996-01-01

    Copolymerization of allyl alcohol (AA) with acrylonitrile (AN) initiated by γ-rays has been investigated to determine the respective reactivity ratios. Three different experimental techniques, namely Fourier Transform Infrared (FTIR), Ultraviolet (UV/vis) and elemental analysis (EA) have been used for the determination of copolymer compositions. Fineman-Ross (FR), Kelen-Tudos (KT), Non-Linear Least Square (NLLS) Analysis and Q-e methods have been applied to the three sets of experimental data. It has been concluded that data obtained from elemental analysis as applied to the Non-Linear Least Square approach gave the most reliable reactivity ratios as 2.09 and 0.40 for acrylonitrile and allyl alcohol, respectively. (Author)

  19. Aqueous Barbier Allylation of Aldehydes Mediated by Tin

    OpenAIRE

    Ivani Malvestiti; Lothar W. Bieber; Marcelo Navarro; Fernando Hallwass; Lívia N. Cavalcanti; Maria Ester S. B. Barros; Dimas J. P. Lima; Ricardo L. Guimarães

    2007-01-01

    The aqueous tin-mediated Barbier reaction affords good to excellent yields and moderate syn diastereoselectivity under basic and acidic conditions. The high yields and stereoselectivity observed in the case of o-substituted aldehydes suggest a cyclic organotin intermediate or transition state in K2HPO4 solution. A practical and efficient aqueous tin allylation of methoxy- and hydroxybenzaldehydes can be carried out in HCl solution in 15 minutes to afford the corresponding homoallylic alcohols...

  20. Reduction of Acute Inflammatory Effects of Fumed Silica Nanoparticles in the Lung by Adjusting Silanol Display through Calcination and Metal Doping.

    Science.gov (United States)

    Sun, Bingbing; Pokhrel, Suman; Dunphy, Darren R; Zhang, Haiyuan; Ji, Zhaoxia; Wang, Xiang; Wang, Meiying; Liao, Yu-Pei; Chang, Chong Hyun; Dong, Juyao; Li, Ruibin; Mädler, Lutz; Brinker, C Jeffrey; Nel, André E; Xia, Tian

    2015-09-22

    The production of pyrogenic (fumed) silica is increasing worldwide at a 7% annual growth rate, including expanded use in food, pharmaceuticals, and other industrial products. Synthetic amorphous silica, including fumed silica, has been generally recognized as safe for use in food products by the Food and Drug Administration. However, emerging evidence from experimental studies now suggests that fumed silica could be hazardous due to its siloxane ring structure, high silanol density, and "string-of-pearl-like" aggregate structure, which could combine to cause membrane disruption, generation of reactive oxygen species, pro-inflammatory effects, and liver fibrosis. Based on this structure-activity analysis (SAA), we investigated whether calcination and rehydration of fumed silica changes its hazard potential in the lung due to an effect on silanol density display. This analysis demonstrated that the accompanying change in surface reactivity could indeed impact cytokine production in macrophages and acute inflammation in the lung, in a manner that is dependent on siloxane ring reconstruction. Confirmation of this SAA in vivo, prompted us to consider safer design of fumed silica properties by titanium and aluminum doping (0-7%), using flame spray pyrolysis. Detailed characterization revealed that increased Ti and Al doping could reduce surface silanol density and expression of three-membered siloxane rings, leading to dose-dependent reduction in hydroxyl radical generation, membrane perturbation, potassium efflux, NLRP3 inflammasome activation, and cytotoxicity in THP-1 cells. The reduction of NLRP3 inflammasome activation was also confirmed in bone-marrow-derived macrophages. Ti doping, and to a lesser extent Al doping, also ameliorated acute pulmonary inflammation, demonstrating the possibility of a safer design approach for fumed silica, should that be required for specific use circumstances.

  1. Conversion of alkyl radicals to allyl radicals in irradiated single crystal mats of polyethylene

    International Nuclear Information System (INIS)

    Fujimura, T.; Hayakawa, N.; Kuriyama, I.

    1978-01-01

    The decay of alkyl radicals, the conversion of alkyl radicals to allyl radicals and the trapping of allyl radicals in irradiated single crystal mats of polyethylene have been studied by electron spin resonance (e.s.r.). It has been suggested that in the crystal core alkyl radicals react with trans-vinylene double bonds and are converted into trans-vinylene allyl radicals; at the crystal surface, alkyl radicals react with vinyl end groups and are converted into allyl radicals with vinyl end groups. The decay of radical pairs and the formation of trans-vinylene double bonds are discussed. (author)

  2. Direct and enantioselective α-allylation of ketones via singly occupied molecular orbital (SOMO) catalysis

    Science.gov (United States)

    Mastracchio, Anthony; Warkentin, Alexander A.; Walji, Abbas M.; MacMillan, David W. C.

    2010-01-01

    The first enantioselective organocatalytic α-allylation of cyclic ketones has been accomplished via singly occupied molecular orbital catalysis. Geometrically constrained radical cations, forged from the one-electron oxidation of transiently generated enamines, readily undergo allylic alkylation with a variety of commercially available allyl silanes. A reasonable latitude in both the ketone and allyl silane components is readily accommodated in this new transformation. Moreover, three new oxidatively stable imidazolidinone catalysts have been developed that allow cyclic ketones to successfully participate in this transformation. The new catalyst platform has also been exploited in the first catalytic enantioselective α-enolation and α-carbooxidation of ketones. PMID:20921367

  3. Allylic C-S Bond Construction through Metal-Free Direct Nitroalkene Sulfonation.

    Science.gov (United States)

    Lei, Xue; Zheng, Lei; Zhang, Chuanxin; Shi, Xiaodong; Chen, Yunfeng

    2018-02-16

    A metal-free, open-flask protocol was developed for the preparation of allylic sulfones through direct condensation of sodium arylsulfinates and β,β-disubstituted nitroalkenes. The key step of this process was the Lewis base-promoted equilibrium between nitroalkenes and allylic nitro compounds. Through this process, the readily available conjugated nitroalkenes can be easily converted into allylic nitro compounds, which contain more reactive C═C bonds toward the sulfonyl radical addition. As a result, allylic sulfones were prepared in excellent yields with a broad substrate scope under mild conditions.

  4. Regioselective and stereoselective copper(I)-promoted allylation and conjugate addition of N-Boc-2-lithiopyrrolidine and N-Boc-2-lithiopiperidine.

    Science.gov (United States)

    Coldham, Iain; Leonori, Daniele

    2010-06-18

    Copper salts have been screened for transmetalation and electrophilic quench of N-tert-butoxycarbonyl-2-lithiopyrrolidine (N-Boc-2-lithiopyrrolidine) and N-Boc-2-lithiopiperidine, formed by deprotonation of N-Boc-pyrrolidine and N-Boc-piperidine, respectively. Transmetalation with zinc chloride then (lithium chloride solubilized) copper cyanide followed by allylation typically gives mixtures of regioisomers (S(N)2 and S(N)2' products), whereas transmetalation with copper iodide.TMEDA then allylation occurs regioselectively (S(N)2 mechanism). Addition to an enone or alpha,beta-unsaturated ester occurs by 1,4-addition. Asymmetric deprotonation of N-Boc-pyrrolidine or dynamic resolution in the presence of a chiral ligand of N-Boc-2-lithiopiperidine followed by the zinc/copper chemistry was successful and gave the allylated pyrrolidine and piperidine products with good enantioselectivity, although use of the copper iodide chemistry resulted in some loss of enantiopurity. The chemistry provides formal syntheses of (+)-allosedridine, (+)-lasubine II, and (+)-pseudohygroline and has been used for the synthesis of (+)-coniine, (-)-pelletierine, (+)-coniceine, (-)-norhygrine, and the ant extract alkaloids cis- and trans-2-butyl-5-propylpyrrolidine.

  5. Z-Selective Copper-Catalyzed Asymmetric Allylic Alkylation with Grignard Reagents

    NARCIS (Netherlands)

    Giannerini, Massimo; Fananas-Mastral, Martin; Feringa, Ben L.; Fañanás-Mastral, Martín

    2012-01-01

    Allylic gem-dichlorides undergo regio- and enanantioselective (er up to 99:1) copper-catalyzed allylic alkylation with Grignard reagents affording chiral Z-vinyl chlorides. This highly versatile class of synthons can be subjected to Suzuki cross coupling affording optically active Z-alkenes and

  6. Catalytic membrane-installed microchannel reactors for one-second allylic arylation.

    Science.gov (United States)

    Yamada, Yoichi M A; Watanabe, Toshihiro; Torii, Kaoru; Uozumi, Yasuhiro

    2009-10-07

    A variety of catalytic membranes of palladium-complexes with linear polymer ligands were prepared inside a microchannel reactor via coordinative and ionic molecular convolution to provide catalytic membrane-installed microdevices, which were applied to the instantaneous allylic arylation reaction of allylic esters and aryl boron reagents under microflow conditions to afford the corresponding coupling products within 1 second of residence time.

  7. Highly diastereoselective preparation of aldol products using new functionalized allylic aluminum reagents.

    Science.gov (United States)

    Shen, Zhi-Liang; Peng, Zhihua; Yang, Chun-Ming; Helberg, Julian; Mayer, Peter; Marek, Ilan; Knochel, Paul

    2014-02-07

    Chloro-substituted triethylsilyl enol ethers derived from cyclohexanone and related ketones are converted with aluminum powder in the presence of indium trichloride to functionalized allylic aluminum reagents which represent a new type of synthetic equivalent of metal enolates. These allylic organometallics undergo highly diastereoselective additions to aldehydes and methyl aryl ketones, giving aldol products with a β-quaternary center.

  8. Allyl sulphides in olefin metathesis: catalyst considerations and traceless promotion of ring-closing metathesis.

    Science.gov (United States)

    Edwards, Grant A; Culp, Phillip A; Chalker, Justin M

    2015-01-11

    Allyl sulphides are reactive substrates in ruthenium-catalysed olefin metathesis reactions, provided each substrate is matched with a suitable catalyst. A profile of catalyst activity is described, along with the first demonstration of allyl sulphides as traceless promoters in relayed ring-closing metathesis reactions.

  9. Isomerization Reactions of Allylic Alcohols into Ketones with the Grubbs Reagent

    Directory of Open Access Journals (Sweden)

    Motoo Tori

    2004-06-01

    Full Text Available Allylic alcohols were isomerized into ketones by the action of the Grubbs reagent. Some model alcohols were prepared and tested under similar conditions to reveal that less substituted alkenes rearrange more easily. More hindered alcohols are stable under these conditions, however, the simple allylic alcohols tend to isomerize producing ethyl ketone and the corresponding degraded methyl ketone.

  10. A convenient method for lactonization of α-allyl esters using iodine ...

    African Journals Online (AJOL)

    A simple method for the synthesis of α-γ-disubstituted-γ-butyrolactones by cyclization of α-allyl esters using iodine in dimethylsulphoxide is reported. This method is efficient and operationally simple in comparison to methods using transition metal complexes. KEY WORDS: γ-Butyrolactones, α-Allyl esters, Iodine, Dimethyl ...

  11. Noticeable facilitation of the bismuth-mediated Barbier-type allylation of aromatic carbonyl compounds under solvent-free conditions.

    Science.gov (United States)

    Wada, Shinobu; Hayashi, Nobuyuki; Suzuki, Hitomi

    2003-06-21

    When milled together with bismuth shot in the presence of allyl halide, aromatic aldehydes readily underwent a Barbier-type allylation to afford the corresponding homoallyl alcohols in good yield. In contrast to the failure in solution reaction, aromatic ketones also underwent allylic carbonyl addition under solvent-free conditions to give the expected tertiary homoallyl alcohols in moderate to good yield.

  12. Effect of allyl isothiocyanate against Anisakis larvae during the anchovy marinating process.

    Science.gov (United States)

    Giarratana, Filippo; Panebianco, Felice; Muscolino, Daniele; Beninati, Chiara; Ziino, Graziella; Giuffrida, Alessandro

    2015-04-01

    Allyl isothiocyanate (AITC), is a natural compound found in plants belonging to the family Cruciferae and has strong antimicrobial activity and a biocidal activity against plants parasites. Anisakidosis is a zoonotic disease caused by the ingestion of larval nematodes in raw, almost raw, and marinated and/or salted seafood dishes. The aim of this work was to evaluate the effect of AITC against Anisakis larvae and to study its potential use during the marinating process. The effects of AITC against Anisakis larvae were tested in three experiment: in vitro with three liquid media, in semisolid media with a homogenate of anchovy muscle, and in a simulation of two kinds of anchovy fillets marinating processes. For all tests, the concentrations of AITC were 0, 0.01, 0.05, and 0.1%. Significant activity of AITC against Anisakis larvae was observed in liquid media, whereas in the semisolid media, AITC was effective only at higher concentrations. In anchovy fillets, prior treatment in phosphate buffer solution (1.5% NaCl, pH 6.8) with 0.1% AITC and then marination under standard conditions resulted in a high level of larval inactivation. AITC is a good candidate for further investigation as a biocidal agent against Anisakis larvae during the industrial marinating process.

  13. Organocatalyzed Asymmetric Vinylogous Allylic-Allylic Alkylation of Morita-Baylis-Hillman Carbonates with Olefinic Azlactones: Facile Access to Chiral Multifunctional α-Amino Acid Derivatives.

    Science.gov (United States)

    Zhao, Shuai; Zhao, Yuan-Yuan; Lin, Jun-Bing; Xie, Ting; Liang, Yong-Min; Xu, Peng-Fei

    2015-07-02

    Vinylogous reactivity of olefinic azlactones was realized through the development of a chiral amine-catalyzed highly stereoselective allylic-allylic alkylation with Morita-Baylis-Hillman carbonates. The Lewis base activation of electrophile and Brønsted base activation of nucleophile were efficiently combined, giving access to multifunctional acyclic α-amino acid derivatives in a highly stereocontrolled manner. The synthetic utility of these versatile synthons was further demonstrated by the facile synthesis of protected cyclic quaternary α-amino acids.

  14. Decarbonylation and hydrogenation reactions of allyl alcohol and acrolein on Pd(110)

    Science.gov (United States)

    Shekhar, Ratna; Barteau, Mark A.

    1994-11-01

    Allyl alcohol and acrolein reactions on the Pd(110) surface were investigated using temperature programmed desorption. For both unsaturated oxygenates, three coverage-dependent reaction pathways were observed. At low coverages, allyl alcohol decomposed completely to CO, hydrogen and carbonaceous species on the surface. For θ > 0.15 monolayer, ethylene (and small amounts of ethane) desorbed at ca. 295 K. Near saturation coverages, desorption of propanal was detected at ca. 235 K. The parent molecule, allyl alcohol, desorbed only after exposures sufficient to saturate these channels. Acrolein decomposition spectra were similar to those observed for allyl alcohol decomposition on the clean surface. Additional experiments with allyl alcohol on hydrogen- and deuterium-precoveredPd(110) surfaces demonstrated increased hydrogenation of the C 2-hydrocarbon products along with hydrogenation of allyl alcohol to 1-propanol. However, in contrast to previous results for allyl alcohol on the Pd(111) surface, there was no evidence for C-O scission reactions of any C 3 oxygenate on Pd(110).

  15. A Facile and Mild Synthesis of Trisubstituted Allylic Sulfones from Morita-Baylis-Hillman Carbonates

    Directory of Open Access Journals (Sweden)

    Lin Jiang

    2015-05-01

    Full Text Available An efficient and catalyst-free synthesis of trisubstituted allylic sulfones through an allylic sulfonylation reaction of Morita-Baylis-Hillman (MBH carbonates with sodium sulfinates has been developed. Under the optimized reaction conditions, a series of trisubstituted allylic sulfones were rapidly prepared in good to excellent yields (71%–99% with good to high selectivity (Z/E from 79:21 to >99:1. Compared with known synthetic methods, the current protocol features mild reaction temperature, high efficiency and easily available reagents.

  16. A facile and mild synthesis of trisubstituted allylic sulfones from Morita-Baylis-Hillman carbonates.

    Science.gov (United States)

    Jiang, Lin; Li, Yong-Gen; Zhou, Jiang-Feng; Chuan, Yong-Ming; Li, Hong-Li; Yuan, Ming-Long

    2015-05-07

    An efficient and catalyst-free synthesis of trisubstituted allylic sulfones through an allylic sulfonylation reaction of Morita-Baylis-Hillman (MBH) carbonates with sodium sulfinates has been developed. Under the optimized reaction conditions, a series of trisubstituted allylic sulfones were rapidly prepared in good to excellent yields (71%-99%) with good to high selectivity (Z/E from 79:21 to >99:1). Compared with known synthetic methods, the current protocol features mild reaction temperature, high efficiency and easily available reagents.

  17. Aqueous reactions of triplet excited states with allylic compounds

    Science.gov (United States)

    Kaur, R.; Anastasio, C.; Hudson, B. M.; Tantillo, D. J.

    2016-12-01

    Triplet excited states of dissolved organic matter react with several classes of aromatic organics such as phenols, anilines, sulfonamide antibiotics and phenylurea herbicides. Aqueous triplets appear to be among the most important oxidants for atmospheric phenols in regions with biomass burning, with phenol lifetimes on the order of a few hours to a day. However, little is known of the reactions of triplets with other classes of organic compounds. Recent work from our group shows that triplets react rapidly with several biogenic volatile organic compounds (BVOCs), such as methyl jasmonate, cis-3-hexenyl acetate, and cis-3-hexen-1-ol. However, there are only a few rate constants for aqueous reactions between alkenes such as these and triplet excited states. For our work, we refer to these and similar alkenes which have hydrogen(s) attached to a carbon adjacent to the double bond, as allylic compounds. To better assess the importance of triplets as aqueous oxidants, we measured second-order rate constants (kAC+3BP*) for a number of allylic compounds (ACs) with the triplet state of benzophenone; then established a quantitative structure-activity relationship (QSAR) between kAC+3BP* and computed oxidation potential of the ACs (R2 =0.65). Using the QSAR, we estimated the rate constants for triplets with some allylic isoprene and limonene oxidation products that have high Henry's law constants (KH>103 M atm-1). Hydroxylated limonene products and the delta-isomers of isoprene hydroxyhydroperoxides (δ4ISOPOOH) and hydroxynitrates (δ4ISONO2) were faster with predicted kAC+3BP* values ranging between (0.5-3.5) x 109 M-1-s-1 whereas the beta-isomers of ISOPOOH and ISONO2 were slower (kAC+3BP* gas and aqueous hydroxyl radical and ozone, triplets in fog could account for up to 20 % of the measured loss of these compounds in the atmosphere. We are currently evaluating the importance of triplets in particulate matter (PM) which can have much higher concentrations of triplet

  18. Direct synthesis of B-allyl and B-allenyldiisopinocampheylborane reagents using allyl or propargyl halides and indium metal under Barbier-type conditions.

    Science.gov (United States)

    Hirayama, Lacie C; Haddad, Terra D; Oliver, Allen G; Singaram, Bakthan

    2012-05-04

    We report the first one-pot process for the asymmetric addition of allyl, methallyl, and propargyl groups to aldehydes and ketones using B-chlorodiisopinocampheylborane ((d)DIP-Cl) and indium metal. Under Barbier-type conditions, indium metal was used to generate allyl- and allenylindium intermediates, and subsequent reaction with (d)DIP-Cl successfully promoted the transfer of these groups to boron forming the corresponding chiral borane reagents. The newly formed borane reagents were reacted with aldehydes and ketones to produce the corresponding alcohol products in high yields and up to excellent enantioselectivity (98% ee). This method produced excellent enantioenriched secondary homoallylic alcohols from the allylation and methallylation of benzaldehyde. Using this method, the methallylation and cinnamylation of ketones afforded the highest enantioselectivities, while the propargylation of both aldehydes and ketones provided low enantiomeric excesses. In addition, this procedure provided the first synthesis of B-allenyldiisopinocampheylborane, which was characterized by (1)H and (11)B NMR spectroscopy. This is the first example of the direct synthesis of allylboranes that contained substitutions from the corresponding allyl bromide and indium, thereby expanding the utility of the DIP-Cl reagent. Hence, a general and straightforward route to these chiral organoborane reagents in one-pot has been developed along with the asymmetric Barbier-type allylation and propargylation of aldehyde and ketone substrates using these chiral organoborane reagents in subsequent coupling reactions.

  19. Polymerization of allyl alcohol by radiation to obtain microencapsulated structure

    International Nuclear Information System (INIS)

    Usanmaz, A.; Saricilar, S.

    1989-01-01

    Allyl alcohol was polymerized by radiation under various conditions. The limiting conversions were about 30 % in bulk, 35 % when containing 0.03 mole fraction AlCl 3 and 50 % when water was contained at 27 % (v/v). Irradiation was done with Co-60 gamma rays at room temperature and under vacuum. The presence of oxygen did not cause any change in the reaction rate. Molecular weights were determined by viscosity and cryoscopic methods. K and α values were found to be 3.57 x 10 -4 and 0.62 for solutions in methanol at 25degC. The polymers up to about 10 % conversion were viscous liquids having microcapsular structures: at high conversions, they became hard and glassy. The microencapsulated structures were also retained in solutions in methanol, acetone, and isopropyl alcohol. The samples were insoluble in water, benzene, and toluence. (author)

  20. Synthesis of acrylic and allylic bifunctional cross-linking monomers derived from PET waste

    International Nuclear Information System (INIS)

    Cruz-Aguilar, A; Herrera-González, A M; Vázquez-García, R A; Coreño, J; Navarro-Rodríguez, D

    2013-01-01

    An acrylic and two novel allylic monomers synthesized from bis (hydroxyethyl) terephthalate, BHET, are reported. This was obtained by glycolysis of post-consumer PET with boiling ethylene glycol. The bifunctional monomer bis(2-(acryloyloxy)ethyl) terephthalate was obtained from acryloyl chloride, while the allylic monomers 2-(((allyloxi)carbonyl)oxy) ethyl (2-hydroxyethyl) terephthalate and bis(2-(((allyloxi)carbonyl)oxy)ethyl) terephthalate, from allyl chloroformate. Cross-linking was studied in bulk polymerization using two different thermal initiators. Monomers were analyzed by means of 1 H NMR and the cross-linked polymers by infrared spectroscopy. Gel content higher than 90% was obtained for the acrylic monomer. In the case of the mixture of the allylic monomers, the cross-linked polymer was 80 % using BPO initiator, being this mixture 24 times less reactive than the acrylic monomer.

  1. α,β-Unsaturated imines via Ru-catalyzed coupling of allylic alcohols and amines.

    Science.gov (United States)

    Rigoli, Jared W; Moyer, Sara A; Pearce, Simon D; Schomaker, Jennifer M

    2012-03-07

    A convenient synthesis of α,β-unsaturated imines requiring only an allylic alcohol, an amine and a Ru catalyst has been developed. The use of large excesses of oxidant and the purification of sensitive intermediates can be avoided.

  2. Electronic differentiation competes with transition state sensitivity in palladium-catalyzed allylic substitutions

    Directory of Open Access Journals (Sweden)

    Goldfuss Bernd

    2007-10-01

    Full Text Available Abstract Electronic differentiations in Pd-catalyzed allylic substitutions are assessed computationally from transition structure models with electronically modified phospha-benzene-pyridine ligands. Although donor/acceptor substitutions at P and N ligand sites were expected to increase the site selectivity, i.e. the preference for "trans to P" attack at the allylic intermediate, acceptor/acceptor substitution yields the highest selectivity. Energetic and geometrical analyses of transition structures show that the sensitivity for electronic differentiation is crucial for this site selectivity. Early transition structures with acceptor substituted ligands give rise to more intensive Pd-allyl interactions, which transfer electronic P,N differentiation of the ligand more efficiently to the allyl termini and hence yield higher site selectivities.

  3. Development of chiral terminal-alkene-phosphine hybrid ligands for palladium-catalyzed asymmetric allylic substitutions.

    Science.gov (United States)

    Liu, Zhaoqun; Du, Haifeng

    2010-07-02

    A variety of novel chiral terminal-alkene-phosphine hybrid ligands were successfully developed from diethyl L-tartrate for palladium-catalyzed asymmetric allylic alkylations, etherifications, and amination to give the desired products in excellent yields and ee's.

  4. Total synthesis of broussonetine F: the orthoamide Overman rearrangement of an allylic diol.

    Science.gov (United States)

    Hama, Naoto; Aoki, Toshihiro; Miwa, Shohei; Yamazaki, Miki; Sato, Takaaki; Chida, Noritaka

    2011-02-18

    A first total synthesis of broussonetine F from diethyl L-tartrate was achieved. The cornerstone of our synthesis was an orthoamide Overman rearrangement, which provided an allylic amino alcohol with complete diastereoselectivity.

  5. Enantioselective synthesis of almorexant via iridium-catalysed intramolecular allylic amidation

    NARCIS (Netherlands)

    Fananas Mastral, Martin; Teichert, Johannes F.; Fernandez-Salas, Jose Antonio; Heijnen, Dorus; Feringa, Ben L.

    2013-01-01

    An enantioselective synthesis of almorexant, a potent antagonist of human orexin receptors, is presented. The chiral tetrahydroisoquinoline core structure was prepared via iridium-catalysed asymmetric intramolecular allylic amidation. Further key catalytic steps of the synthesis include an oxidative

  6. Solid radiation curable polyene compositions containing liquid polythiols and solid styrene-allyl copolymer based polyenes

    International Nuclear Information System (INIS)

    Morgan, C.R.

    1977-01-01

    Novel styrene-allyl alcohol copolymer based solid polyene compositions which when mixed with liquid polythiols can form solid curable polyene-polythiol systems are claimed. These solid polyenes, containing at least two reactive carbon-to-carbon unsaturated bonds, are urethane or ester derivatives of styrene-allyl alcohol copolymers. The solid polyenes are prepared by treating the hydroxyl groups of a styrene-allyl alcohol copolymer with a reactive unsaturated isocyanate, e.g., allyl isocyanate or a reactive unsaturated carboxylic acid, e.g., acrylic acid. Upon exposure to a free radical generator, e.g., actinic radiation, the solid polyene-polythiol compositions cure to solid, insoluble, chemically resistant, cross-linked polythioether products. Since the solid polyene-liquid polythiol composition can be cured in a solid state, such a curable system finds particular use in preparation of coatings, imaged surfaces such as photoresists, particularly solder-resistant photoresists, printing plates, etc

  7. Biomarkers derived from heterolytic and homolytic cleavage of allylic hydroperoxides resulting from alkenone autoxidation

    Digital Repository Service at National Institute of Oceanography (India)

    Rontania, J.F; Harji, R.; Volkmanc, J.K.

    Laboratory incubation of alkenone mixtures with tert-butyl hydroperoxide and di-tert-butyl nitroxide (radical initiator) in hexane, as a means to simulate alkenone autoxidation processes, rapidly led to the formation of allylic hydroperoxides, whose...

  8. A Concomitant Allylic Azide Rearrangement/Intramolecular Azide–Alkyne Cycloaddition Sequence

    Science.gov (United States)

    2015-01-01

    An intramolecular Huisgen cycloaddition of an interconverting set of isomeric allylic azides with alkynes affords substituted triazoles in high yield. The stereoisomeric vinyl-substituted triazoloxazines formed depend on the rate of cycloaddition of the different allylic azide precursors when the reaction is carried out under thermal conditions. In contrast, dimerized macrocyclic products were obtained when the reaction was done using copper(I)-catalyzed conditions, demonstrating the ability to control the reaction products through changing conditions. PMID:24635056

  9. Selective epoxidation of allylic alcohols with a titania-silica aerogel

    Energy Technology Data Exchange (ETDEWEB)

    Dusi, M.; Mallat, T.; Baiker, A. [Lab. of Technical Chemistry, Swiss Federal Inst. of Technology, ETH-Zentrum, Zuerich (Switzerland)

    1998-12-31

    An amorphous mesoporous titania-silica aerogel (20 wt%TiO{sub 2} - 80 wt% SiO{sub 2}) and tert.-butylhydroperoxide (TBHP) have been used for the epoxidation of various allylic alcohols. Allylic alcohols possessing an internal double bond were more reactive than those with a terminal C=C bond. Epoxide selectivities could be improved by addition of (basic) zeolite 4 A and NaHCO{sub 3} to the reaction mixture. (orig.)

  10. Diastereo- and Enantioselective Iridium Catalyzed Carbonyl (α-Cyclopropyl)allylation via Transfer Hydrogenation.

    Science.gov (United States)

    Tsutsumi, Ryosuke; Hong, Suckchang; Krische, Michael J

    2015-09-07

    The first examples of diastereo- and enantioselective carbonyl α-(cyclopropyl)allylation are reported. Under the conditions of iridium catalyzed transfer hydrogenation using the chiral precatalyst (R)-Ir-I modified by SEGPHOS, carbonyl α-(cyclopropyl)allylation may be achieved with equal facility from alcohol or aldehyde oxidation levels. This methodology provides a conduit to hitherto inaccessible inaccessible enantiomerically enriched cyclopropane-containing architectures. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. Highly diastereoselective epoxidation of allyl-substituted cycloalkenes catalyzed by metalloporphyrins.

    Science.gov (United States)

    Chan, Wing-Kei; Liu, Peng; Yu, Wing-Yiu; Wong, Man-Kin; Che, Chi-Ming

    2004-05-13

    Highly diastereoselective epoxidations of allyl-substituted cycloalkenes including allylic alcohols, esters, and amines using sterically bulky metalloporphyrins [Mn(TDCPP)Cl] (1) and [Ru(TDCPP)CO] (2) as catalysts have been achieved. The "1 + H(2)O(2)" and "2 + 2,6-Cl(2)pyNO" protocols afforded trans-epoxides selectively in good yields (up to 99%) with up to >99:1 trans-selectivity.

  12. Sea salt

    OpenAIRE

    Galvis-Sánchez, Andrea C.; Lopes, João Almeida; Delgadillo, Ivone; Rangel, António O. S. S.

    2013-01-01

    The geographical indication (GI) status links a product with the territory and with the biodiversity involved. Besides, the specific knowledge and cultural practices of a human group that permit transforming a resource into a useful good is protected under a GI designation. Traditional sea salt is a hand-harvested product originating exclusively from salt marshes from specific geographical regions. Once salt is harvested, no washing, artificial drying or addition of anti-caking agents are all...

  13. Atmospheric degradation of 2-chloroethyl vinyl ether, allyl ether and allyl ethyl ether: Kinetics with OH radicals and UV photochemistry.

    Science.gov (United States)

    Antiñolo, M; Ocaña, A J; Aranguren, J P; Lane, S I; Albaladejo, J; Jiménez, E

    2017-08-01

    Unsaturated ethers are oxygenated volatile organic compounds (OVOCs) emitted by anthropogenic sources. Potential removal processes in the troposphere are initiated by hydroxyl (OH) radicals and photochemistry. In this work, we report for the first time the rate coefficients of the gas-phase reaction with OH radicals (k OH ) of 2-chloroethyl vinyl ether (2ClEVE), allyl ether (AE), and allyl ethyl ether (AEE) as a function of temperature in the 263-358 K range, measured by the pulsed laser photolysis-laser induced fluorescence technique. No pressure dependence of k OH was observed in the 50-500 Torr range in He as bath gas, while a slightly negative T-dependence was observed. The temperature dependent expressions for the rate coefficients determined in this work are: The estimated atmospheric lifetimes (τ OH ) assuming k OH at 288 K were 3, 2, and 4 h for 2ClEVE, AE and AEE, respectively. The kinetic results are discussed in terms of the chemical structure of the unsaturated ethers by comparison with similar compounds. We also report ultraviolet (UV) and infrared (IR) absorption cross sections (σ λ and σ(ν˜), respectively). We estimate the photolysis rate coefficients in the solar UV actinic region to be less than 10 -7 s -1 , implying that these compounds are not removed from the atmosphere by this process. In addition, from σ(ν˜) and τ OH , the global warming potential of each unsaturated ether was calculated to be almost zero. A discussion on the atmospheric implications of the titled compounds is presented. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. Effect of allyl isothiocyanate on developmental toxicity in exposed Xenopus laevis embryos

    Directory of Open Access Journals (Sweden)

    John Russell Williams

    2015-01-01

    Full Text Available The pungent natural compound allyl isothiocyanate isolated from the seeds of Cruciferous (Brassica plants such as mustard is reported to exhibit numerous beneficial health-promoting antimicrobial, antifungal, anticarcinogenic, cardioprotective, and neuroprotective properties. Because it is also reported to damage DNA and is toxic to aquatic organisms, the objective of the present study was to determine whether it possesses teratogenic properties. The frog embryo teratogenesis assay-Xenopus (FETAX was used to determine the following measures of developmental toxicity of the allyl isothiocyanate: (a 96-h LC50, defined as the median concentration causing 50% embryo lethality; (b 96-h EC50, defined as the median concentration causing 50% malformations of the surviving embryos; and (c teratogenic malformation index (TI, equal to 96-h LC50/96-h EC50. The quantitative results and the photographs of embryos before and after exposure suggest that allyl isothiocyanate seems to exhibit moderate teratogenic properties. The results also indicate differences in the toxicity of allyl isothiocyanate toward exposed embryos observed in the present study compared to reported adverse effects of allyl isothiocyanate in fish, rodents, and humans. The significance of the results for food safety and possible approaches to protect against adverse effects of allyl isothiocyanate are discussed.

  15. Phosphate Salts

    Science.gov (United States)

    ... many different combinations of the chemical phosphate with salts and minerals. Foods high in phosphate include dairy products, whole grain cereals, nuts, and certain meats. Phosphates found in dairy products ... People use phosphate salts for medicine. Be careful not to confuse phosphate ...

  16. Radiation synthesis and characterization of new hydrogels based on acrylamide copolymers cross-linked with 1-allyl-2-thiourea

    Energy Technology Data Exchange (ETDEWEB)

    Sahiner, Nurettin [Department of Chemistry, Faculty of Science, Hacettepe University, Beytepe Campus, 0653 Ankara (Turkey); Malci, Savas [Department of Chemistry, Faculty of Science, Hacettepe University, Beytepe Campus, 0653 Ankara (Turkey); Celikbicak, Oemuer [Department of Chemistry, Faculty of Science, Hacettepe University, Beytepe Campus, 0653 Ankara (Turkey); Kantoglu, Oemer [Ankara Nuclear Research Center, Turkish Atomic Energy Authority, 06983 Ankara (Turkey); Salih, Bekir [Department of Chemistry, Faculty of Science, Hacettepe University, Beytepe Campus, 0653 Ankara (Turkey)]. E-mail: bekir@hacettepe.edu.tr

    2005-10-01

    Poly(acrylamide-1-allyl-2-thiourea) hydrogels, Poly(AA-AT), were synthesized by gamma irradiation using {sup 60}Co {gamma} source in different irradiation dose and at different 1-allyl-2-thiourea content in the monomer mixture. For the characterization of the hydrogels, Fourier transform infrared spectrometer (FT-IR), thermogravimetric analyzer (TGA), elemental analyzer and the swellability of the hydrogels were used. It was noted that 1-allyl-2-thiourea in the synthesized hydrogels was increased by the increasing the content of the 1-allyl-2-thiourea in the irradiation monomer mixture and increasing the radiation dose for the hydrogel synthesis. sis.

  17. Enhanced Retention of Chelating Reagents in Octadecylsilyl Silica Phase by Interaction with Residual Silanol Groups in Solid Phase Extraction of Divalent Metal Ions.

    Science.gov (United States)

    Ohmuro, Satoshi; Fujii, Kan; Yasui, Takashi; Takada, Kazutake; Yuchi, Akio; Kokusen, Hisao

    2016-01-01

    Solid-phase extraction (SPE) of divalent metal ions with a lipophilic and potentially divalent hexadentate chelating reagent (H2L), with which octadecylsilyl silica (ODS), was impregnated with was studied to gain more insight into and develop the potential of this methodology. This is the first time to demonstrate that this reagent as well as other common nitrogen-containing reagents were retained both by adsorption due to hydrogen bonding between nitrogen atoms of the reagent and residual silanol groups in the ODS phase and by simple distribution into the hydrophobic space. An appreciably large amount of this reagent could be retained by the adsorption mechanism even with a relatively thin loading solution. The divalent metal ions of Mn(2+), Co(2+) and Zn(2+) were extracted as 1:1 neutral complexes ([ML]), while Ni(2+) and Cu(2+) as ion-pairs of 1:1 cationic complex ([MHL](+)) with anion in SPE with H2L. The extractability and selectivity were substantially the same as that in liquid-liquid extraction.

  18. Competing effects of silanol surface concentration and solvent dielectric constant on electrostatic layer-by-layer assembly of silica nanoparticles on gold.

    Science.gov (United States)

    Yang, Ruidong; Wang, Feng; Blunk, Richard H; Angelopoulos, Anastasios P

    2010-09-01

    Two types of silica nanoparticles having differing concentrations of ionizable surface groups are used to investigate the interplay between nanoparticle surface charge and solvent dielectric constant in nanostructure development during layer-by-layer assembly with a cationic polyacrylamide. Zeta (zeta) potential measurements are used to determine the extent of silanol dissociation with pH. For 19-nm-diameter X-Tec 3408 silica nanoparticles from Nano-X GmbH (NanoX), complete dissociation yields a zeta-potential value of about -44mV and occurs between pH 5 and 6 in 50% ethanol-in-water mixture by volume. By contrast, 65-nm-diameter polishing silica from Electron Microscopy Supply (EMS) has a zeta potential that does not equilibrate even up to pH 7 with a value of -59mV under otherwise similar solution conditions. The more negative zeta potential at a given pH is found to substantially reduce nanoparticle adsorption. This behavior is opposite that observed when the dielectric constant of the suspension is decreased, independent of particle size. Nanoparticle surface chemical heterogeneity is discussed as a plausible explanation for such seriously discrepant behavior and the effects on multilayer electrical contact resistance for proton-exchange membrane (PEM) fuel-cell coating applications are presented. Copyright 2010 Elsevier Inc. All rights reserved.

  19. Production of allyl phenyl carbinol (APC by biotrans-formation using Rhizopus arrhizus

    Directory of Open Access Journals (Sweden)

    Vilas B. Shukla

    2000-01-01

    Full Text Available The objective of the present work was to study the stereoselective synthesis of homo-allylic alcohol using stereoselective hydrolysis by Rhizopus arrhizus and also to study the stereoselective synthesis of allyl phenyl carbinol (APC or 1-Phenyl-3-butene-1-o by combination of chemical synthesis and biotransformation from cheap raw materials such as benzaldehyde and allyl bromide. Stereospecific synthesis of allyl phenyl carbinol (APC was achieved by acetate hydrolysis by R. arrhizus giving R (+ enantiomer. Maximum enantiomeric excess of APC was obtained at 16 h where as maximum yield of it was obtained at 48 h of biotransformation.O objetivo deste trabalho foi estudar a síntese estereo-seletiva do álcool homo-allylico usando hidrólise estereo-seletiva pelo Rhizopus arrhizus e também estudar a síntese estereo-seletiva do allyl phenyl carbinol (APC ou 1-Phenyl-3-butene- 1-o pela combinação da síntese química e biotransformação dos materiais brutos e baratos, tais como; benzaldehyde and allyl bromide. A síntese Stereospecifica do allyl phenyl carbinol (APC foi conseguida pela hidrólise de acetato pelo R. arrhizus fornecendo enantiomero R (+. O excesso máximo do enantiomérico do APC foi obtido em 16 h sendo que seu rendimento máximo foi obtido após 48 h de biotransformação.

  20. Resonance effect in the allyl cation and anion: a revisit.

    Science.gov (United States)

    Mo, Yirong

    2004-08-20

    The interest over the magnitude of the conjugation effect in the allyl cation (1) and anion (2) has been revived recently by Barbour and Karty (J. Org. Chem. 2004, 69, 648-654), who derived the resonance energies of 20-22 and 17-18 kcal/mol for 1 and 2, respectively, using an empirical extrapolation approximation. This paper revisits the case by explicitly calculating the Pauling-Wheland resonance energy, which measures the stabilization from the most stable resonance structure to the delocalized energy-minimum state of a conjugated system, using our newly developed block-localized wave function (BLW) method. This BLW method has the geometrical optimization capability. The computations result in adiabatic resonance energies of 37 kcal/mol for 1 and 38 kcal/mol for 2. The significant disagreement between these values and Barbour and Karty's results originates from the neglect of structural and electronic variations in their derivation which are energy costing. Copyright 2004 American Chemical Society

  1. Release of allyl isothiocyanate from mustard seed meal powder.

    Science.gov (United States)

    Dai, Ruyan; Lim, Loong-Tak

    2014-01-01

    Allyl isothiocyanate (AITC) is a wide-spectrum antimicrobial compound found in mustard seeds, produced when their tissues are disrupted. The formation of AITC in mustard seed is mediated by the myrosinase enzyme which catalyzes the release of volatile AITC from a glucosinolate-sinigrin. Since water is a substrate in the reaction, humidity from the air can be used to activate the release of AITC from mustard seed. In this study, defatted and partially defatted mustard seed meals were ground into powders with particle size ranging from 5 to 300 μm. The mustard seed meal powder (MSMP) samples were enclosed within hermetically sealed glass jars wherein the headspace air was adjusted to 85% or 100% relative humidity at 5, 20, or 35 °C. Data from gas chromatography analysis showed that AITC release rate and amount increased with increasing relative humidity and temperature. Moreover, the release rate can be manipulated by particle size and lipid content of the MSMP samples. The amount of AITC released ranged from 2 to 17 mg/g MSMP within 24 h under the experimental conditions tested. In view of the antimicrobial properties of AITC, the mustard meal powder may be used as a natural antimicrobial material for extending the shelf life of food products. © 2013 Institute of Food Technologists®

  2. Aqueous Barbier allylation of aldehydes mediated by tin.

    Science.gov (United States)

    Guimarães, Ricardo L; Lima, Dimas J P; Barros, Maria Ester S B; Cavalcanti, Lívia N; Hallwass, Fernando; Navarro, Marcelo; Bieber, Lothar W; Malvestiti, Ivani

    2007-08-29

    The aqueous tin-mediated Barbier reaction affords good to excellent yields and moderate syn diastereoselectivity under basic and acidic conditions. The high yields and stereoselectivity observed in the case of o-substituted aldehydes suggest a cyclic organotin intermediate or transition state in K2HPO4 solution. A practical and efficient aqueous tin allylation of methoxy- and hydroxybenzaldehydes can be carried out in HCl solution in 15 minutes to afford the corresponding homoallylic alcohols in high yields. Aliphatic aldehydes give moderate to excellent yields with reaction times ranging from 30 to 60 minutes. Under these conditions, crotylation gives exclusively the gamma-product and the syn isomer is formed preferentially. For 2-methoxybenzaldehyde, an equilibration of the isomers to a syn/anti ratio of 1:1 can be observed after several hours. Control experiments with radical sources or scavengers give no support for radical intermediates. NMR studies suggest a mechanism involving an organotin intermediate. The major organotin species formed depends on the reaction medium and the reaction time. The use of acidic solution reduces the reaction times, due to the acceleration of the formation of the allyltin(IV) species.

  3. Aqueous Barbier Allylation of Aldehydes Mediated by Tin

    Directory of Open Access Journals (Sweden)

    Ivani Malvestiti

    2007-08-01

    Full Text Available The aqueous tin-mediated Barbier reaction affords good to excellent yields and moderate syn diastereoselectivity under basic and acidic conditions. The high yields and stereoselectivity observed in the case of o-substituted aldehydes suggest a cyclic organotin intermediate or transition state in K2HPO4 solution. A practical and efficient aqueous tin allylation of methoxy- and hydroxybenzaldehydes can be carried out in HCl solution in 15 minutes to afford the corresponding homoallylic alcohols in high yields. Aliphatic aldehydes give moderate to excellent yields with reaction times ranging from 30 to 60 minutes. Under these conditions, crotylation gives exclusively the γ-product and the syn isomer is formed preferentially. For 2-methoxybenzaldehyde, an equilibration of the isomers to a syn/anti ratio of 1:1 can be observed after several hours. Control experiments with radical sources or scavengers give no support for radical intermediates. NMR studies suggest a mechanism involving an organotin intermediate. The major organotin species formed depends on the reaction medium and the reaction time. The use of acidic solution reduces the reaction times, due to the acceleration of the formation of the allyltin(IV species.

  4. Allyl isothiocyanate induced stress response in Caenorhabditis elegans

    Directory of Open Access Journals (Sweden)

    Saini AkalRachna K

    2011-11-01

    Full Text Available Abstract Background Allyl isothiocyanate (AITC from mustard is cytotoxic; however the mechanism of its toxicity is unknown. We examined the effects of AITC on heat shock protein (HSP 70 expression in Caenorhabditis elegans. We also examined factors affecting the production of AITC from its precursor, sinigrin, a glucosinolate, in ground Brassica juncea cv. Vulcan seed as mustard has some potential as a biopesticide. Findings An assay to determine the concentration of AITC in ground mustard seed was improved to allow the measurement of AITC release in the first minutes after exposure of ground mustard seed to water. Using this assay, we determined that temperatures above 67°C decreased sinigrin conversion to AITC in hydrated ground B. juncea seed. A pH near 6.0 was found to be necessary for AITC release. RT-qPCR revealed no significant change in HSP70A mRNA expression at low concentrations of AITC ( 1.0 μM resulted in a four- to five-fold increase in expression. A HSP70 ELISA showed that AITC toxicity in C. elegans was ameliorated by the presence of ground seed from low sinigrin B. juncea cv. Arrid. Conclusions • AITC induced toxicity in C. elegans, as measured by HSP70 expression. • Conditions required for the conversion of sinigrin to AITC in ground B. juncea seed were determined. • The use of C. elegans as a bioassay to test AITC or mustard biopesticide efficacy is discussed.

  5. Salt cookbook

    CERN Document Server

    Saha, Anirban

    2015-01-01

    If you are a professional associated with system and infrastructure management, looking at automated infrastructure and deployments, then this book is for you. No prior experience of Salt is required.

  6. Metallocene-catalyzed alkene polymerization and the observation of Zr-allyls

    Science.gov (United States)

    Landis, Clark R.; Christianson, Matthew D.

    2006-01-01

    Single-site polymerization catalysts enable exquisite control over alkene polymerization reactions to produce new materials with unique properties. Knowledge of catalyst speciation and fundamental kinetics are essential for full mechanistic understanding of zirconocene-catalyzed alkene polymerization. Currently the effect of activators on fundamental polymerization steps is not understood. Progress in understanding activator effects requires determination of fundamental kinetics for zirconocene catalysts with noncoordinating anions such as [B(C6F5)4]−. Kinetic NMR studies at low temperature demonstrate a very fast propagation rate for 1-hexene polymerization catalyzed by [(SBI)Zr(CH2SiMe3)][B(C6F5)4] [where SBI is rac-Me2Si(indenyl)2] with complete consumption of 1-hexene before the first NMR spectrum. Surprisingly, the first NMR spectrum reveals, aside from uninitiated catalyst, Zr-allyls as the sole catalyst-containing species. These Zr-allyls, which exist in two diastereomeric forms, have been characterized by physical and chemical methods. The mechanism of Zr-allyl formation was probed with a trapping experiment, leading us to favor a mechanism in which Zr-polymeryl undergoes β-H transfer to metal without dissociation of coordinated alkene followed by σ-bond metathesis to form H2 and Zr-allyl. Zr-allyl species undergo slow reactions with alkene but react rapidly with H2 to form hydrogenation products. PMID:17032772

  7. SYNTHESIS OF 4-ALLYL-2-METHOXY-6-AMINOPHENOL FROM NATURAL EUGENOL

    Directory of Open Access Journals (Sweden)

    I Made Sudarma

    2010-06-01

    Full Text Available The aim of this preliminary research was to synthesize derivatives of eugenol such as 4-allyl-2-methoxy-6-nitrophenol (2 and 4-allyl-2-methoxy-6-aminophenol (3. The result could be used as a reference on the transformation of eugenol to its derivatives. Theoriticaly nitration of eugenol (1 by nitric acid could produced 4-allyl-2-methoxy-6-nitrophenol (2 and followed by reduction could achieved 4-allyl-2-mehtoxy-6-aminophenol (3. The formation of this product was analyzed by analytical thin layer chromatography (TLC and GC-MS. These analysis showed the formation of product (2 and (3 were visible. TLC showed product (1 less polar than eugenol and gave orange colour, and supported by GC-MS which showed molecular ion at m/z 209 due to the presence of -NO2 by replacing one H at 6 position of eugenol. Product (3 was afforded by reduction of (2 with Sn/HCl and tlc analysis showed compound (3 more polar than eugenol (1 and (2 and supported by GC-MS which showed molecular ion at m/z 179 due to the presence of -NH2.   Keywords: Synthesis, 4-allyl-2-methoxy-6-aminophenol, Eugenol

  8. Synthesis of optically active bifunctional building blocks through enantioselective copper-catalyzed allylic alkylation using Grignard reagents

    NARCIS (Netherlands)

    van Zijl, Anthoni W.; Lopez, Fernando; Minnaard, Adriaan J.; Feringa, Ben L.

    2007-01-01

    Enantioselective copper-catalyzed allylic alkylations were performed on allylic bromides with a protected hydroxyl or amine functional group using several Grignard reagents and Taniaphos L1 as a ligand. The terminal olefin moiety in the products was transformed into various functional groups without

  9. Dual platinum and pyrrolidine catalysis in the direct alkylation of allylic alcohols: selective synthesis of monoallylation products.

    Science.gov (United States)

    Shibuya, Ryozo; Lin, Lu; Nakahara, Yasuhito; Mashima, Kazushi; Ohshima, Takashi

    2014-04-22

    A dual platinum- and pyrrolidine-catalyzed direct allylic alkylation of allylic alcohols with various active methylene compounds to produce products with high monoallylation selectivity was developed. The use of pyrrolidine and acetic acid was essential, not only for preventing undesirable side reactions, but also for obtaining high monoallylation selectivity. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Indium- and zinc-mediated Barbier-type allylations of an N,N-(dimethylsulfamoyl)-protected aldimine and subsequent deprotection

    NARCIS (Netherlands)

    Kallstrom, Sara; Saloranta, Tiina; Minnaard, Adriaan J.; Leino, Reko; Källström, Sara

    2007-01-01

    Barbier-type Zn and In-mediated allylations of an N,N-(dimethylsulfamoyl)-protected aldimine with different allyl bromides were investigated for the preparation of N-homoallylic sulfamides. The desired N,N-(dimethylsulfamoyl)-protected products were obtained in moderate to high yields in THF as the

  11. On the Nature of the Intermediates and the Role of Chloride Ions in Pd-Catalyzed Allylic Alkylations: Added Insight from Density Functional Theory

    DEFF Research Database (Denmark)

    Fristrup, Peter; Ahlquist, Mårten Sten Gösta; Tanner, David Ackland

    2008-01-01

    The reactivity of intermediates in palladium-catalyzed allylic alkylation was investigated using DFT (B3LYP) calculations including a PB-SCRF solvation model. In the presence of both phosphine and chloride ligands, the allyl intermediate is in equilibrium between a cationic eta(3)-allylPd complex...

  12. How phenyl makes a difference: mechanistic insights into the ruthenium( ii )-catalysed isomerisation of allylic alcohols

    KAUST Repository

    Manzini, Simone

    2013-10-16

    [RuCl(η5-3-phenylindenyl)(PPh3)2] (1) has been shown to be a highly active catalyst for the isomerisation of allylic alcohols to the corresponding ketones. A variety of substrates undergo the transformation, typically with 0.25-0.5 mol% of catalyst at room temperature, outperforming commonly-used complexes such as [RuCl(Cp)(PPh3) 2] and [RuCl(η5-indenyl)(PPh3) 2]. Mechanistic experiments and density functional theory have been employed to investigate the mechanism and understand the effect of catalyst structure on reactivity. These investigations suggest a oxo-π-allyl mechanism is in operation, avoiding intermediate ruthenium hydride complexes and leading to a characteristic 1,3-deuterium shift. Important mechanistic insights from DFT and experiments also allowed for the design of a protocol that expands the scope of the transformation to include primary allylic alcohols. © 2013 The Royal Society of Chemistry.

  13. The effects of γ-irradiation on the garlic oil contents in garlic bulbs and the radiolysis of allyl trisulfide

    International Nuclear Information System (INIS)

    Wei Genshuan, Wang Guanghui; Yang Ruipu; Wu Jilan

    1995-01-01

    The study of the effects of γ-irradiation on the garlic oil contents in the garlic bulbs and the radiolysis of allyl trisulfide and disulfide were carried out. The content of garlic oil in fresh garlic bulbs treated by gamma ray keeps nearly constant as stored for 10 months long. The main components of the garlic oil are allyl trisulfide (about 60%) and allyl disulfide (about 30%). The G values of radiolysis products of allyl disulfide and trisulfide in ethanol system were determined. The results show that allyl trisulfide is a very effective solvated electron scavenger and can oxidize CH 3 C HOH radical into acetaldehyde, which causes that the formation of 2,3-butanediol is extensively inhibited. (author)

  14. The effects of γ-irradiation on garlic oil content in garlic bulbs and on the radiolysis of allyl trisulfide

    International Nuclear Information System (INIS)

    Wei Genshuan; Wang Guanghui; Yang Ruipu; Wu Jilan

    1996-01-01

    A study of the effects of γ-irradiation on garlic oil content in garlic bulbs and on the radiolysis of allyl trisufide and disulfide was carried out. The content of garlic oil in fresh garlic bulbs treated by gamma ray keeps nearly constant when stored for 10 months. The main components of garlic oil are allyl trisulfide (about 60%) and allyl disulfide (about 30%). The G values of radiolysis products of allyl disulfide and trisulfide in ethanol system were determined. The results show that allyl trisulfide is a very effective solvated electron scavenger and can oxidize CH 3 C . HOH radical into acetaldehyde, which means that the formation of 2,3-butanediol is extensively inhibited. (author)

  15. Allylic azides as potential building blocks for the synthesis of nitrogenated compounds

    Directory of Open Access Journals (Sweden)

    Sá Marcus M.

    2003-01-01

    Full Text Available The synthetic potential of multifunctional allylic azides and imines in attempted intramolecular cyclizations to nitrogen-containing heterocycles was investigated. Tandem Staudinger/aza-Wittig reaction of (E-3-aryl-2-(azidomethylpropenoates with triphenylphosphine and aldehydes yielded N-allylic imines in good yield. The (E-stereochemistry of C=C and C=N bonds was assigned based on NOESY experiments. AlCl3 mediated formation of 3-carbomethoxyquinoline from methyl (E-2-(azidomethyl-3-phenylpropenoate is also described.

  16. Surprisingly Mild Enolate-Counterion-Free Pd(0)-Catalyzed Intramolecular Allylic Alkylations

    DEFF Research Database (Denmark)

    Madec, David; Prestat, Guillaume; Martini, Elisabetta

    2005-01-01

    Palladium-catalyzed intramolecular allylic alkylations of unsaturated EWG-activated amides can take place under phase-transfer conditions or in the presence of a crown ether. These new reaction conditions are milder and higher yielding than those previously reported. A rationalization for such an......Palladium-catalyzed intramolecular allylic alkylations of unsaturated EWG-activated amides can take place under phase-transfer conditions or in the presence of a crown ether. These new reaction conditions are milder and higher yielding than those previously reported. A rationalization...

  17. Transient overexpression of adh8a increases allyl alcohol toxicity in zebrafish embryos.

    Directory of Open Access Journals (Sweden)

    Nils Klüver

    Full Text Available Fish embryos are widely used as an alternative model to study toxicity in vertebrates. Due to their complexity, embryos are believed to more resemble an adult organism than in vitro cellular models. However, concerns have been raised with respect to the embryo's metabolic capacity. We recently identified allyl alcohol, an industrial chemical, to be several orders of magnitude less toxic to zebrafish embryo than to adult zebrafish (embryo LC50 = 478 mg/L vs. fish LC50 = 0.28 mg/L. Reports on mammals have indicated that allyl alcohol requires activation by alcohol dehydrogenases (Adh to form the highly reactive and toxic metabolite acrolein, which shows similar toxicity in zebrafish embryos and adults. To identify if a limited metabolic capacity of embryos indeed can explain the low allyl alcohol sensitivity of zebrafish embryos, we compared the mRNA expression levels of Adh isoenzymes (adh5, adh8a, adh8b and adhfe1 during embryo development to that in adult fish. The greatest difference between embryo and adult fish was found for adh8a and adh8b expression. Therefore, we hypothesized that these genes might be required for allyl alcohol activation. Microinjection of adh8a, but not adh8b mRNA led to a significant increase of allyl alcohol toxicity in embryos similar to levels reported for adults (LC50 = 0.42 mg/L in adh8a mRNA-injected embryos. Furthermore, GC/MS analysis of adh8a-injected embryos indicated a significant decline of internal allyl alcohol concentrations from 0.23-58 ng/embryo to levels below the limit of detection (< 4.6 µg/L. Injection of neither adh8b nor gfp mRNA had an impact on internal allyl alcohol levels supporting that the increased allyl alcohol toxicity was mediated by an increase in its metabolization. These results underline the necessity to critically consider metabolic activation in the zebrafish embryo. As demonstrated here, mRNA injection is one useful approach to study the role of candidate enzymes

  18. Use of Cyclic Allylic Bromides in the Zinc–Mediated Aqueous Barbier–Grignard Reaction

    OpenAIRE

    Breton, Gary W.; Shugart, John H.; Hughey, Christine A.; Conrad, Brian P.; Perala, Suzanne M.

    2001-01-01

    The zinc–mediated aqueous Barbier–Grignard reaction of cyclic allylic bromide substrates with various aldehydes and ketones to afford homoallylic alcohols was investigated. Aromatic aldehydes and ketones afforded adducts in good yields (66–90%) and with good diastereoselectivities. Non–aromatic aldehydes also reacted well under these conditions, but only poor yields were obtained with non–aromatic ketones. Regioselectivity was high when some substituted cyclic allylic...

  19. Antimicrobial activity of allylic thiocyanates derived from the Morita-Baylis-Hillman reaction

    Directory of Open Access Journals (Sweden)

    Marcus Mandolesi Sá

    2014-09-01

    Full Text Available Bacterial resistance to commonly used antibiotics has been recognized as a significant global health issue. In this study, we carried out the screening of a family of allylic thiocyanates for their action against a diversity of bacteria and fungi with a view to developing new antimicrobial agents. Allylic thiocyanates bearing halogenated aryl groups, which were readily obtained in two steps from the Morita-Baylis-Hillman adducts, showed moderate-to-high activity against selective pathogens, including a methicillin-resistant S. aureus (MRSA strain. In particular cases, methyl (Z-3-(2,4-dichlorophenyl-2-(thiocyanomethyl-2-propenoate exhibited antimicrobial activity comparable to the reference antibiotic Imipenem.

  20. Antimicrobial activity of allylic thiocyanates derived from the Morita-Baylis-Hillman reaction.

    Science.gov (United States)

    Sá, Marcus Mandolesi; Ferreira, Misael; Lima, Emerson Silva; dos Santos, Ivanildes; Orlandi, Patrícia Puccinelli; Fernandes, Luciano

    2014-01-01

    Bacterial resistance to commonly used antibiotics has been recognized as a significant global health issue. In this study, we carried out the screening of a family of allylic thiocyanates for their action against a diversity of bacteria and fungi with a view to developing new antimicrobial agents. Allylic thiocyanates bearing halogenated aryl groups, which were readily obtained in two steps from the Morita-Baylis-Hillman adducts, showed moderate-to-high activity against selective pathogens, including a methicillin-resistant S. aureus (MRSA) strain. In particular cases, methyl (Z)-3-(2,4-dichlorophenyl)-2-(thiocyanomethyl)-2-propenoate exhibited antimicrobial activity comparable to the reference antibiotic Imipenem.

  1. Crystal structure of 4′-allyl-4,5,6,7,2′,7′-hexachlorofluorescein allyl ester unknown solvate

    Directory of Open Access Journals (Sweden)

    Lili Wang

    2018-01-01

    Full Text Available In the title compound, 4′-allyl-4,5,6,7,2′,7′-hexachlorofluorescein allyl ester {systematic name: prop-2-en-1-yl 2,3,4,5-tetrachloro-6-[2,7-dichloro-6-hydroxy-3-oxo-4-(prop-2-en-1-yl-3H-xanthen-9-yl]benzoate}, C26H14Cl6O5, accompanied by unknown solvate molecules, the dihedral angle between the xanthene ring system (r.m.s. deviation = 0.046 Å and the pentasubstituted benzene ring is 71.67 (9°. Both allyl groups are disordered over two sets of sites in statistical ratios. The scattering contributions of the disordered solvent molecules (both Ph2O and CHCl3, as identified by NMR were removed with the PLATON SQUEEZE algorithm [Spek (2015. Acta Cryst. C71, 9–18]. In the crystal, tetrameric supramolecular aggregates linked by O—H...O hydrogen bonds occur; these further interact with neighboring aggregates through C—Cl...π interactions arising from the benzene rings, forming infinite two-dimensional sheets. Each C6Cl4 ring shifts in the direction perpendicular to the two-dimensional sheet, exhibiting a helical chain in which every C6Cl4 ring is utilized as both a donor and an acceptor of Cl...π contacts. Thus, these two-dimensional sheets pack in a helical fashion, constructing a three-dimensional network.

  2. Bath Salts

    Science.gov (United States)

    ... to get the same high, and feel withdrawal symptoms when they stop. People who abuse bath salts may feel driven to do whatever they can to keep getting high, including taking risks. Users can also develop what is called "excited delirium." When this happens, people get dehydrated , their muscle ...

  3. 40 CFR 721.7000 - Polymer of disodium maleate, allyl ether, and ethylene oxide.

    Science.gov (United States)

    2010-07-01

    ... ether, and ethylene oxide. 721.7000 Section 721.7000 Protection of Environment ENVIRONMENTAL PROTECTION... ethylene oxide. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as a polymer of disodium maleate, allyl ether, and ethylene oxide (P-91...

  4. Functionality of whey proteins covalently modified by allyl isothiocyanate. Part 2

    NARCIS (Netherlands)

    Keppler, Julia K.; Steffen-Heins, Anja; Berton-Carabin, Claire C.; Ropers, Marie Hélène; Schwarz, Karin

    2018-01-01

    Allyl isothiocyanate (AITC) is a small electrophilic molecule which can be found in cabbage after degradation of glucosinolates. The covalent attachment of AITC to whey protein isolate (WPI) was previously reported to increase their hydrophobicity and structural flexibility at acidic pH values. It

  5. Synthesis of telechelic vinyl/allyl functional siloxane copolymers with structural control

    DEFF Research Database (Denmark)

    Madsen, Frederikke Bahrt; Javakhishvili, Irakli; Jensen, Rasmus Egekjær

    2014-01-01

    Multifunctional siloxane copolymers with terminal vinyl or allyl functional groups are synthesised through the borane-catalysed polycondensation of hydrosilanes and alkoxysilanes. Copolymers of varying mole- cular weights ( M ̄ w =13200 – 70 300 g mol − 1 ), spatially well-distributed functional ...

  6. FeCl3 catalysed regioselective allylation of phenolic substrates with ...

    Indian Academy of Sciences (India)

    Oxylipid from brown algae (IV). Chart 1. Selected products obtained using vinylphospho- nates. cyclic phosphonate is that in general, it leads to solid crystalline products. Removal of α-OH by a Lewis acid. (LA) can lead to allyl cation V which is in resonance with VI. Hence if arylation is accomplished, we can get either an ...

  7. Enantioselective Allylation of Thiophene-2-carbaldehyde: Formal Total Synthesis of Duloxetine

    Czech Academy of Sciences Publication Activity Database

    Motloch, P.; Valterová, Irena; Kotora, M.

    2014-01-01

    Roč. 356, č. 1 (2014), s. 199-204 ISSN 1615-4150 Grant - others:GA ČR(CZ) GAP207/11/0587 Institutional support: RVO:61388963 Keywords : aldehydes * allylation * Lewis bases * organocatalysis * synthetic methods Subject RIV: CC - Organic Chemistry Impact factor: 5.663, year: 2014

  8. Copper-catalyzed asymmetric allylic substitution reactions with organozinc and Grignard reagents

    NARCIS (Netherlands)

    Geurts, Koen; Fletcher, Stephen P.; van Zijl, Anthoni W.; Minnaard, Adriaan J.; Feringa, Ben L.; Bignall, H. E.; Jauncey, D. L.; Lovell, J. E. J.; Tzioumis, A. K.; Kedziora-Chudczer, L. L.; MacQuart, J. P.; Tingay, S. J.; Rayner, D. P.; Clay, R. W.

    Asymmetric allylic alkylations (AAAs) are among the most powerful C-C bond-forming reactions. We present a brief overview of copper-catalyzed AAAs with organometallic reagents and discuss our own contributions to this field. Work with zinc reagents and phosphoramidite ligands provided a framework

  9. A convenient procedure for the synthesis of allyl and benzyl ethers ...

    Indian Academy of Sciences (India)

    Unknown

    (scheme 1). Even though benzyl protection on a carbohydrate substrate was previously carried out with benzyl chloride in the presence of potassium hydroxide pellets 9, the scope of the reaction was not fully explored. While our work was in progress, Bogdal and coworkers recently reported 10 solvent-free allyl and benzyl ...

  10. Cu-Catalyzed Asymmetric Allylic Alkylation of Phosphonates and Phosphine Oxides with Grignard Reagents

    NARCIS (Netherlands)

    Hornillos, Valentin; Perez, Manuel; Fananas-Mastral, Martin; Feringa, Ben L.

    An efficient and highly enantioselective copper-catalyzed allylic alkylation of phosphonates and phosphine oxides with Grignard reagents and Taniaphos or phosphoramidites as chiral ligands is reported. Transformation of these products leads to a variety of new phosphorus-containing chiral

  11. Nematicidal activity of allyl bromide and dibromo(nitro)methane under laboratory conditions.

    Science.gov (United States)

    Oka, Yuji; Shuker, Shimshon; Tkachi, Nadia

    2016-01-01

    Restrictions on soil fumigants are prompting the development of new compounds for controlling nematodes, other soilborne pathogens and weeds. We evaluated the nematicidal activity of five bromine compounds against Meloidogyne javanica in vitro, and tested the two most effective ones against Pratylenchus penetrans and Xiphinema index in vitro and in soil. Only allyl bromide and dibromo(nitro)methane showed nematicidal activity against M. javanica juveniles in vitro at activity than dibromo(nitro)methane against M. javanica and P. penetrans in soil. Allyl bromide at 40 and 20 mg L(-1) soil eliminated root galls and nematode eggs on tomato roots grown in M. javanica-inoculated loess and sandy soils respectively, showing higher nematicidal activity than 1,3-dichloropropene. No P. penetrans were recovered from soil treated with 80 mg allyl bromide L(-1) soil or 320 mg dibromo(nitro)methane L(-1) soil. Allyl bromide showed high nematicidal activity against all three nematode species, and nematicidal activity of dibromo(nitro)methane was discovered. These compounds could serve as new fumigation nematicides, pending further experiments. © 2015 Society of Chemical Industry.

  12. Enantioconvergent synthesis by sequential asymmetric Horner-Wadsworth-Emmons and palladium-catalyzed allylic substitution reactions

    DEFF Research Database (Denmark)

    Pedersen, Torben Møller; Hansen, E. Louise; Kane, John

    2001-01-01

    A new method for enantioconvergent synthesis has been developed. The strategy relies on the combination of an asymmetric Horner-Wadsworth-Emmons (HWE) reaction and a palladium-catalyzed allylic substitution. Different $alpha@-oxygen-substituted, racemic aldehydes were initially transformed by asy...

  13. α-Regioselective Barbier Reaction of Carbonyl Compounds and Allyl Halides Mediated by Praseodymium.

    Science.gov (United States)

    Wu, San; Li, Ying; Zhang, Songlin

    2016-09-02

    The first utility of praseodymium as a mediating metal in the Barbier reaction of carbonyl compounds with allyl halides was reported in this paper. In contrast to the traditional metal-mediated or catalyzed Barbier reactions, exclusive α-adducts were obtained in this one-pot reaction with a broad scope of substrates and feasible reaction conditions.

  14. Enantioselective copper catalyzed allylic alkylation using Grignard reagents; Applications in synthesis

    NARCIS (Netherlands)

    Zijl, Anthoni Wouter van

    2009-01-01

    Enantioselective copper catalyzed allylic alkylation is a powerful carbon-carbon bond forming reaction. In this thesis the development of a new catalyst for the use of Grignard reagents in this reaction is described. This catalyst is based on copper and the ligand Taniaphos. The high regio- and

  15. Bio-based acrylic acid from sugar via propylene glycol and allyl alcohol

    NARCIS (Netherlands)

    Pramod, C. V.; Fauziah, R.; Seshan, K.; Lange, J. P.

    2018-01-01

    A new route for producing bio-based acrylic acid is proposed. It starts with the conversion of carbohydrates to propylene glycol, being main or by-product, and proceeds via a subsequent dehydration to allyl alcohol under gas-phase conditions over K-modified ZrO2 and a final oxidation over MoWVOx

  16. Catalytic Enantioselective Synthesis of Naturally Occurring Butenolides via Hetero-Allylic Alkylation and Ring Closing Metathesis

    NARCIS (Netherlands)

    Mao, Bin; Geurts, Koen; Fañanás-Mastral, Martín; Zijl, Anthoni W. van; Fletcher, Stephen P.; Minnaard, Adriaan J.; Feringa, Bernard

    2011-01-01

    An efficient catalytic asymmetric synthesis of chiral γ-butenolides was developed based on the hetero-allylic asymmetric alkylation (h-AAA) in combination with ring closing metathesis (RCM). The synthetic potential of the h-AAA-RCM protocol was illustrated with the facile synthesis of (-)-whiskey

  17. Catalytic enantioselective synthesis of naturally occurring butenolides via hetero-allylic alkylation and ring closing metathesis.

    Science.gov (United States)

    Mao, Bin; Geurts, Koen; Fañanás-Mastral, Martín; van Zijl, Anthoni W; Fletcher, Stephen P; Minnaard, Adriaan J; Feringa, Ben L

    2011-03-04

    An efficient catalytic asymmetric synthesis of chiral γ-butenolides was developed based on the hetero-allylic asymmetric alkylation (h-AAA) in combination with ring closing metathesis (RCM). The synthetic potential of the h-AAA-RCM protocol was illustrated with the facile synthesis of (-)-whiskey lactone, (-)-cognac lactone, (-)-nephrosteranic acid, and (-)-roccellaric acid.

  18. Catalytic asymmetric allylation of aliphatic aldehydes by chiral bipyridine N,N'-dioxides

    Czech Academy of Sciences Publication Activity Database

    Hrdina, R.; Boyd, T.; Valterová, Irena; Hodačová, Jana; Kotora, Martin

    -, č. 20 (2008), s. 3141-3144 ISSN 0936-5214 Grant - others:GA MŠk(CZ) LC06070 Program:LC Institutional research plan: CEZ:AV0Z40550506 Keywords : allylations * aldehydes * Lewis base * asymmetric catalysis * solvent effect Subject RIV: CC - Organic Chemistry Impact factor: 2.659, year: 2008

  19. Preparation of pyrrolizinone derivatives via sequential transformations of cyclic allyl imides: synthesis of quinolactacide and marinamide.

    Science.gov (United States)

    Simic, Milena; Tasic, Gordana; Jovanovic, Predrag; Petkovic, Milos; Savic, Vladimir

    2018-03-28

    A facile synthetic route has been developed for the preparation of pyrrolizinone derivatives employing N-allyl imides as starting materials. The nucleophilic addition of a vinyl Grignard reagent/RCM/elimination sequence afforded pyrrolizinones in good yields and has been applied for the preparation of naturally occurring quinolactacide and marinamide.

  20. On the key role of water in the allylic activation catalysed by Pd (II ...

    Indian Academy of Sciences (India)

    Palladium and platinum complexes of bisphosphinites and bisphosphines derived from mandelic acid have been prepared and characterized. Their ability to catalyze allylation of imines with allyltributylstannane has been studied. Bisphophinite complexes of Pd (II) are shown to be ideal and they work best in the presence ...

  1. On the key role of water in the allylic activation catalysed by Pd (II ...

    Indian Academy of Sciences (India)

    On the key role of water in the allylic activation catalysed by Pd (II) bisphosphinite complexes. RAKESH KUMAR SHARMA and ASHOKA G SAMUELSON*. Department of Inorganic and Physical Chemistry, Indian Institute of Science, Bangalore 560 012 e-mail: ashoka@ipc.iisc.ernet.in. Abstract. Palladium and platinum ...

  2. Reactivity of olefin and allyl ligands in π-complexes of metals

    International Nuclear Information System (INIS)

    Kukushkin, Yu.N.

    1987-01-01

    The data on reactivity of olefin and allyl ligands in transition metal (Ru, W) π-complexes, published up to 1984 are presented. Metal ion coordination of olefins causes their appreciable reactivity change. Transformations of π-olefin ligands into σ-alkyl ones, interaction of π-complexes with oxygen nucleophilic reagents, amines, halogenides and pseudohalogenides are considered

  3. Organocatalytic asymmetric allylic amination of Morita–Baylis–Hillman carbonates of isatins

    Directory of Open Access Journals (Sweden)

    Hang Zhang

    2012-08-01

    Full Text Available The investigation of a Lewis base catalyzed asymmetric allylic amination of Morita–Baylis–Hillman carbonates derived from isatins afforded an electrophilic pathway to access multifunctional oxindoles bearing a C3-quaternary stereocenter, provided with good to excellent enantioselectivity (up to 94% ee and in high yields (up to 97%.

  4. Organocatalytic asymmetric allylic amination of Morita-Baylis-Hillman carbonates of isatins.

    Science.gov (United States)

    Zhang, Hang; Zhang, Shan-Jun; Zhou, Qing-Qing; Dong, Lin; Chen, Ying-Chun

    2012-01-01

    The investigation of a Lewis base catalyzed asymmetric allylic amination of Morita-Baylis-Hillman carbonates derived from isatins afforded an electrophilic pathway to access multifunctional oxindoles bearing a C3-quaternary stereocenter, provided with good to excellent enantioselectivity (up to 94% ee) and in high yields (up to 97%).

  5. Method of preparing water purification membranes. [polymerization of allyl amine as thin films in plasma discharge

    Science.gov (United States)

    Hollahan, J. R.; Wydeven, T. J., Jr. (Inventor)

    1974-01-01

    Allyl amine and chemically related compounds are polymerized as thin films in the presence of a plasma discharge. The monomer compound can be polymerized by itself or in the presence of an additive gas to promote polymerization and act as a carrier. The polymerized films thus produced show outstanding advantages when used as reverse osmosis membranes.

  6. Syntheses of a Flobufen Metabolite and Dapoxetine Based on Enantioselective Allylation of Aromatic Aldehydes

    Czech Academy of Sciences Publication Activity Database

    Hessler, F.; Korotvička, A.; Nečas, D.; Valterová, Irena; Kotora, M.

    2014-01-01

    Roč. 2014, č. 12 (2014), s. 2543-2548 ISSN 1434-193X Grant - others:GA ČR(CZ) GAP207/11/0587 Institutional support: RVO:61388963 Keywords : synthetic methods * asymmetric catalysis * organocatalysis * allylation * aldehydes * enantioselectivity Subject RIV: CC - Organic Chemistry Impact factor: 3.065, year: 2014

  7. A Regio- and Enantioselective CuH-Catalyzed Ketone Allylation with Terminal Allenes.

    Science.gov (United States)

    Tsai, Erica Y; Liu, Richard Y; Yang, Yang; Buchwald, Stephen L

    2018-02-14

    We report a method for the highly enantioselective CuH-catalyzed allylation of ketones that employs terminal allenes as allylmetal surrogates. Ketones and allenes bearing diverse and sensitive functional groups are efficiently coupled with high stereoselectivity and exclusive branched regioselectivity. In stoichiometric experiments, each elementary step of the proposed hydrocupration-addition-metathesis mechanism can be followed by NMR spectroscopy.

  8. Iterative asymmetric allylic substitutions: syn- and anti-1,2-diols through catalyst control.

    Science.gov (United States)

    Park, Jin Kyoon; McQuade, D Tyler

    2012-03-12

    A copper-catalyzed asymmetric allylic boronation (AAB) gives access to syn- and anti-1,2-diols. The method facilitates an iterative strategy for the preparation of polyols, such as the fully differentiated L-ribo-tetrol and protected D-arabino-tetrol. P=protecting group. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. Rationalizing Ring-Size Selectivity in Intramolecular Pd-Catalyzed Allylations of Resonance-Stabilized Carbanions

    DEFF Research Database (Denmark)

    Norrby, Per-Ola; Mader, Mary M.; Vitale, Maxime

    2003-01-01

    Computational methods were applied to the Pd-catalyzed intramolecular allylations of resonance-stabilized carbanions obtained from amide and ketone substrates, with the aim of rationalizing the endo- vs. exo-selectivity in the cyclizations. In addition, ester substrates were prepared and subjecte...

  10. Cascade synthesis of dihydrobenzofuran via Claisen rearrangement of allyl aryl ethers using FeCl3/MCM-41 catalyst

    Directory of Open Access Journals (Sweden)

    Sachin S. Sakate

    2018-05-01

    Full Text Available Dihydrobenzofuran as one of the active ingredients of the naturally occurring motif is synthesized by using in situ generation of ortho allyl phenols. Aryl allyl ethers on reacting with catalytic amounts of non noble metal iron (III chloride supported on MCM-41 under moderate reaction conditions yield dihydrobenzofuran. First step via Claisen rearrangement gives ortho allyl phenol followed by its in situ cyclization to yield dihydrobenzofuran in very good yields. Both Lewis as well as Brønsted acidity of the catalyst as evidenced by Py-FTIR studies was found to catalyze the cascade synthesis of dihydrobenzofuran. The scope of the present strategy was successfully demonstrated for several substrates with varying electronic effects for the synthesis of corresponding dihydrobenzofuran with high yields in a range of 71–86%. Keywords: Claisen rearrangement, Dihydrobenzofuran, Aryl allyl ether, MCM-41, Ferric chloride

  11. Pd Nanoparticle-Catalyzed Isomerization vs Hydrogenation of Allyl Alcohol: Solvent-Dependent Regioselectivity.

    Science.gov (United States)

    Sadeghmoghaddam, Elham; Gu, Hanmo; Shon, Young-Seok

    2012-09-07

    Our previous work has shown that alkanethiolate-capped Pd nanoparticles generated from sodium S -dodecylthiosulfate are excellent catalysts for selective isomerization of various allyl alcohols to the carbonyl analogues. The present work focuses on understanding the mechanism and the regioselectivity of Pd nanoparticles in different environments. First, the presence of H 2 gas has turned out to be essential for the efficient catalytic isomerization reaction. This suggests that the mechanism likely involves the Pd-alkyl intermediate rather than the η 3 π-allyl Pd hydride intermediate. Second, the Pd nanoparticles are found to convert allyl alcohol selectively to either propanal or 1-propanol depending on the type of solvent used for the catalytic reactions. The reaction pathway is most likely determined by steric hindrance, which is the result of the interaction between substrate and alkylthiolate ligands on Pd nanoparticles. Presumably, the conformation of alkylthiolate ligands changes upon the type of solvents, resulting in varying degree of available space close to the nanoparticle surface. In general, nonpolar or weakly polar solvents such as benzene and chloroform, respectively, promote the isomerization of allyl alcohol to propanal via the formation of the branched Pd-alkyl intermediate. On the other hand, polar protic solvents such as methanol and water foster the hydrogenation of allyl alcohol to 1-propanol involving the steric induced formation of a linear Pd-alkyl intermediate. Third, the use of sodium S -hexylthiosulfate instead of sodium S -dodecylthiosulfate for the synthesis of Pd nanoparticles results in nanoparticle catalysts with a lower regioselectivity toward isomerization over hydrogenation. This is due to the higher surface ligand density of hexanethiolate-capped Pd nanoparticles, which negatively impacts the formation of branched Pd-alkyl intermediate. The results clearly indicate that controlling the structure and surface density of

  12. Diastereo- and enantioselective iridium-catalyzed allylation of cyclic ketone enolates: synergetic effect of ligands and barium enolates.

    Science.gov (United States)

    Chen, Wenyong; Chen, Ming; Hartwig, John F

    2014-11-12

    We report asymmetric allylic alkylation of barium enolates of cyclic ketones catalyzed by a metallacyclic iridium complex containing a phosphoramidite ligand derived from (R)-1-(2-naphthyl)ethylamine. The reaction products contain adjacent quaternary and tertiary stereocenters. This process demonstrates that unstabilized cyclic ketone enolates can undergo diastereo- and enantioselective Ir-catalyzed allylic substitution reactions with the proper choice of enolate countercation. The products of these reactions can be conveniently transformed to various useful polycarbocyclic structures.

  13. Indium-mediated asymmetric Barbier-type allylation of aldimines in alcoholic solvents: synthesis of optically active homoallylic amines.

    Science.gov (United States)

    Vilaivan, Tirayut; Winotapan, Chutima; Banphavichit, Vorawit; Shinada, Tetsuro; Ohfune, Yasufumi

    2005-04-29

    [reaction: see text] Chiral aldimines derived from phenylglycinol were diastereoselectively allylated with indium powder/allyl bromide in alcoholic solvents. Both aliphatic and aromatic aldimines provided good yield of the desired products with high diastereoselectivity. A racemization-free protocol for removal of the phenylglycinol auxiliary was also developed. The stereochemical assignment of the homoallylic amine was made by NMR spectroscopy and a transition state model was proposed to explain the selectivity.

  14. Allylic chlorination of terpenic olefins using a combination of MoCl{sub 5} and NaOCl

    Energy Technology Data Exchange (ETDEWEB)

    Boualy, Brahim; Firdoussi, Larbi El; Ali, Mustapha Ait; Karim, Abdellah, E-mail: elfirdoussi@ucam.ac.m [Universite Cadi Ayyad, Marrakech (Morocco). Faculte des Sciences Semlalia. Lab. de Chimie de Coordination

    2011-07-01

    MoCl{sub 5} is applied as efficient agent in allylic chlorination of terpenic olefins in the presence of NaOCl as chlorine donor. Various terpenes are converted to the corresponding allylic chlorides in moderate to good yield under mild and optimized reaction conditions. Different molybdenum precursors are also studied. Among them, MoO{sub 3} gives good yield, but after a longer reaction time. (author)

  15. Crystal structure of (E-3-allyl-2-sulfanylidene-5-[(thiophen-2-ylmethylidene]thiazolidin-4-one

    Directory of Open Access Journals (Sweden)

    Rahhal El Ajlaoui

    2015-06-01

    Full Text Available Molecules of the title compound, C11H9NOS3, are built up by one thiophene and one 2-thioxathiazolidin-4-one ring which are connected by a methylene bridge. In addition, there is an allyl substituent attached to nitrogen. The two rings are almost coplanar, making a dihedral angle between them of 0.76 (11°. The allyl group is oriented perpendicular to the mean plane through both ring systems. The crystal structure exhibits inversion dimers in which molecules are linked by pairs of C—H...O hydrogen bonds. Additional π–π interactions between neighboring thiophene and 2-thioxathiazolidin-4-one rings [intercentroid distance = 3.694 (2 Å] lead to the formation of a three-dimensional network.

  16. A new polyester based on allyl α-hydroxy glutarate as shell for magnetite nanoparticles

    Science.gov (United States)

    Nan, Alexandrina; Feher, Ioana Coralia

    2017-12-01

    Allyl side-chain-functionalized lactide was synthesized from commercially available glutamic acid and polymerized by ring opening polymerization using 4-dimethylaminopyridine as an organocatalyst in the presence of magnetic nanoparticles. The resulting magnetic nanostructures coated with the allyl-containing polyester were then functionalized with cysteine by thiol-ene click reaction leading to highly functionalized magnetic nano-platforms of practical interest. The polyester precursors were characterized by nuclear magnetic resonance and mass spectrometry. The morphology of magnetic nanostructures based on the functionalized polyester was determined by transmission electron microscopy TEM, while the chemical structure was investigated by FT-IR. TGA investigations and the magnetic properties of the magnetic nanostructures are also described.

  17. Iron(III) chloride catalyzed glycosylation of peracylated sugars with allyl/alkynyl alcohols

    Energy Technology Data Exchange (ETDEWEB)

    Narayanaperumal, Senthil; Silva, Rodrigo Cesar da; Monteiro, Julia L.; Correa, Arlene G.; Paixao, Marcio W., E-mail: mwpaixao@ufscar.br [Universidade Federal de Sao Carlos (UFSCAR), SP (Brazil). Dept. de Quimica

    2012-11-15

    In this work, the use of ferric chloride as an efficient catalyst in glycosylation reactions of sugars in the presence of allyl and alkynyl alcohols is described. The corresponding glycosides were obtained with moderate to good yields. This new procedure presented greater selectivity when compared to classic methods found in the literature. Principal features of this simple method include non-hazardous reaction conditions, low-catalyst loading, good yields and high anomeric selectivity (author)

  18. Antenna elicitation and behavioral responses of oriental fruit moth, Grapholita molesta, to allyl cinnamate

    OpenAIRE

    Giner Gil, Marta; Balcells Fluvià, Mercè; Avilla Hernández, Jesús

    2014-01-01

    Female sex pheromones have been used in pest control since the 90s; attracting males to baited traps (mass-trapping and monitoring) or avoiding (or reducing) mating in fields under mating disruption. By contrast, little is done among the use of male sex pheromones in pest control. Allyl cinnamate was evaluated as potential oriental fruit moth (Grapholita molesta, Busck) (Lepidoptera: Tortricidae) behaviour modifier, after recording positive electroantenographical responses in both male and fe...

  19. Synthesis of alkenyl boronates from allyl-substituted aromatics using an olefin cross-metathesis protocol.

    Science.gov (United States)

    Hemelaere, Rémy; Carreaux, François; Carboni, Bertrand

    2013-07-05

    An efficient synthesis of 3-aryl-1-propenyl boronates from pinacol vinyl boronic ester and allyl-substituted aromatics by cross metathesis is reported. Although the allylbenzene derivatives are prone to isomerization reaction under metathesis conditions, we found that some ruthenium catalysts are effective for this methodology. This strategy thus provides an interesting alternative approach to alkyne hydroboration, leading to the preparation of unknown compounds. Moreover, the boron substituent can be replaced by various functional groups in good yields.

  20. FeCl3-catalysed Zn-mediated allylation of cyclic enol ethers in water

    Indian Academy of Sciences (India)

    FeCl3-catalysed Zn-mediated allylation of cyclic enol ethers in water. P CHAKRABORTY and ... To a stirred mixture of dihydropyran (84.2mg,. 1.0 mmol), water (5 ... 2b (syn/anti = 1:1) was prepared from dihydropyran and 1b following the procedure described for com- pound 2a. Viscous oil. Rf = 0.21 (30% ethyl acetate. 509 ...

  1. FeCl3 catalysed regioselective allylation of phenolic substrates with ...

    Indian Academy of Sciences (India)

    MAXIS mass spectrometer with ESI-QTOF-II method. Synthesis of the precursor 1 is described in the supple- mentary material. 2.1 General procedure for the allylation of arenes with phosphonoallylic alcohol 1. To phosphonoallylic alcohol 1 (0.282 g, 1 mmol) and. FeCl3 (0.016 g, 0.1 mmol) in nitromethane (3 mL) was.

  2. Tether-directed synthesis of highly substituted oxasilacycles via an intramolecular allylation employing allylsilanes

    Directory of Open Access Journals (Sweden)

    Cox Liam R

    2007-02-01

    Full Text Available Abstract Background Using a silyl tether to unite an aldehyde electrophile and allylsilane nucleophile into a single molecule allows a subsequent Lewis-acid-mediated allylation to proceed in an intramolecular sense and therefore receive all the benefits associated with such processes. However, with the ability to cleave the tether post allylation, a product that is the result of a net intermolecular reaction can be obtained. In the present study, four diastereoisomeric β-silyloxy-α-methyl aldehydes, which contain an allylsilane tethered through the β-carbinol centre, have been prepared, in order to probe how the relative configuration of the two stereogenic centres affects the efficiency and selectivity of the intramolecular allylation. Results Syn-aldehydes, syn-4a and syn-4b, both react poorly, affording all four possible diastereoisomeric oxasilacycle products. In contrast, the anti aldehydes anti-4a and anti-4b react analogously to substrates that lack substitution at the α-site, affording only two of the four possible allylation products. Conclusion The outcome of the reaction with anti-aldehydes is in accord with reaction proceeding through a chair-like transition state (T.S.. In these systems, the sense of 1,3-stereoinduction can be rationalised by the aldehyde electrophile adopting a pseudoaxial orientation, which will minimise dipole-dipole interactions in the T.S. The 1,4-stereoinduction in these substrates is modest and seems to be modulated by the R substituent in the starting material. In the case of the syn-substrates, cyclisation through a chair T.S. is unlikely as this would require the methyl substituent α to the reacting carbonyl group to adopt an unfavourable pseudoaxial position. It is therefore proposed that these substrates react through poorly-defined T.S.s and consequently exhibit essentially no stereoselectivity.

  3. Experimental and Kinetic Modeling Study of 2-Methyl-2-Butene: Allylic Hydrocarbon Kinetics.

    Science.gov (United States)

    Westbrook, Charles K; Pitz, William J; Mehl, Marco; Glaude, Pierre-Alexandre; Herbinet, Olivier; Bax, Sarah; Battin-Leclerc, Frederique; Mathieu, Olivier; Petersen, Eric L; Bugler, John; Curran, Henry J

    2015-07-16

    Two experimental studies have been carried out on the oxidation of 2-methyl-2-butene, one measuring ignition delay times behind reflected shock waves in a stainless steel shock tube, and the other measuring fuel, intermediate, and product species mole fractions in a jet-stirred reactor (JSR). The shock tube ignition experiments were carried out at three different pressures, approximately 1.7, 11.2, and 31 atm, and at each pressure, fuel-lean (ϕ = 0.5), stoichiometric (ϕ = 1.0), and fuel-rich (ϕ = 2.0) mixtures were examined, with each fuel/oxygen mixture diluted in 99% Ar, for initial postshock temperatures between 1330 and 1730 K. The JSR experiments were performed at nearly atmospheric pressure (800 Torr), with stoichiometric fuel/oxygen mixtures with 0.01 mole fraction of 2M2B fuel, a residence time in the reactor of 1.5 s, and mole fractions of 36 different chemical species were measured over a temperature range from 600 to 1150 K. These JSR experiments represent the first such study reporting detailed species measurements for an unsaturated, branched hydrocarbon fuel larger than iso-butene. A detailed chemical kinetic reaction mechanism was developed to study the important reaction pathways in these experiments, with particular attention on the role played by allylic C-H bonds and allylic pentenyl radicals. The results show that, at high temperatures, this olefinic fuel reacts rapidly, similar to related alkane fuels, but the pronounced thermal stability of the allylic pentenyl species inhibits low temperature reactivity, so 2M2B does not produce "cool flames" or negative temperature coefficient behavior. The connections between olefin hydrocarbon fuels, resulting allylic fuel radicals, the resulting lack of low-temperature reactivity, and the gasoline engine concept of octane sensitivity are discussed.

  4. Palladium-Catalyzed Allylation/Benzylation of H-Phosphinate Esters with Alcohols

    Directory of Open Access Journals (Sweden)

    Anthony Fers-Lidou

    2016-09-01

    Full Text Available The Pd-catalyzed direct alkylation of H-phosphinic acids and hypophosphorous acid with allylic/benzylic alcohols has been described previously. Here, the extension of this methodology to H-phosphinate esters is presented. The new reaction appears general, although its scope is narrower than with the acids, and its mechanism is likely different. Various alcohols are examined in their reaction with phosphinylidene compounds R1R2P(OH.

  5. Lewis base catalyzed enantioselective allylic hydroxylation of Morita-Baylis-Hillman carbonates with water

    KAUST Repository

    Zhu, Bo

    2011-08-19

    A Lewis base catalyzed allylic hydroxylation of Morita-Baylis-Hillman (MBH) carbonates has been developed. Various chiral MBH alcohols can be synthesized in high yields (up to 99%) and excellent enantioselectivities (up to 94% ee). This is the first report using water as a nucleophile in asymmetric organocatalysis. The nucleophilic role of water has been verified using 18O-labeling experiments. © 2011 American Chemical Society.

  6. Asymmetric allylic alkylation of Morita–Baylis–Hillman carbonates with α-fluoro-β-keto esters

    Directory of Open Access Journals (Sweden)

    Lin Yan

    2013-09-01

    Full Text Available In the presence of a commercially available Cinchona alkaloid as catalyst, the asymmetric allylic alkylation of Morita–Baylis–Hillman carbonates, with α-fluoro-β-keto esters as nucleophiles, have been successfully developed. A series of important fluorinated adducts, with chiral quaternary carbon centres containing a fluorine atom, was achieved in good yields (up to 93%, with good to excellent enantioselectivities (up to 96% ee and moderate diastereoselectivities (up to 4:1 dr.

  7. Asymmetric allylic alkylation of Morita-Baylis-Hillman carbonates with α-fluoro-β-keto esters.

    Science.gov (United States)

    Yan, Lin; Han, Zhiqiang; Zhu, Bo; Yang, Caiyun; Tan, Choon-Hong; Jiang, Zhiyong

    2013-01-01

    In the presence of a commercially available Cinchona alkaloid as catalyst, the asymmetric allylic alkylation of Morita-Baylis-Hillman carbonates, with α-fluoro-β-keto esters as nucleophiles, have been successfully developed. A series of important fluorinated adducts, with chiral quaternary carbon centres containing a fluorine atom, was achieved in good yields (up to 93%), with good to excellent enantioselectivities (up to 96% ee) and moderate diastereoselectivities (up to 4:1 dr).

  8. Effect of various process treatment conditions on the allyl isothiocyanate extraction rate from mustard meal.

    Science.gov (United States)

    Sharma, Harish K; Ingle, Sandeep; Singh, Charanjiv; Sarkar, Bhavesh C; Upadhyay, Ashutosh

    2012-06-01

    Allyl isothiocyanate (AITC), which has the potential to be used as flavoring, antibacterial, antifungal, antifermentative and antibrowning agent in food industry, was extracted from the pretreated MM by distillation technique. The mustard meal was analyzed for the proximate composition and the metals Fe, Mg and Zn. At the optimum pretreatment conditions of temperature 60 °C, time 120 min and pH 4.5, the effect of fractional distillation, mesh size and different additives was studied. Considerable effect of mesh size was observed, as the mesh size was decreased from 1,690 to 400 μm, the allyl isothiocyanate content was increased from 99.15 to 337.11 mg/100 ml. Addition of magnesium chloride (0.05 g/l to 0.2 g/l) and L-ascorbic acid (1 g/l to 5 g/l) increased allyl isothiocyanate from 257.79 to 317.28 mg/100 ml and 316.77 to 396.60 mg/100 ml respectively whereas the addition of the magnesium chloride and L-ascorbic acid in combination did not affect the AITC extraction rate as compare to their addition in single effect.

  9. Chemical Kinetics of Hydrogen Atom Abstraction from Allylic Sites by 3O2; Implications for Combustion Modeling and Simulation.

    Science.gov (United States)

    Zhou, Chong-Wen; Simmie, John M; Somers, Kieran P; Goldsmith, C Franklin; Curran, Henry J

    2017-03-09

    Hydrogen atom abstraction from allylic C-H bonds by molecular oxygen plays a very important role in determining the reactivity of fuel molecules having allylic hydrogen atoms. Rate constants for hydrogen atom abstraction by molecular oxygen from molecules with allylic sites have been calculated. A series of molecules with primary, secondary, tertiary, and super secondary allylic hydrogen atoms of alkene, furan, and alkylbenzene families are taken into consideration. Those molecules include propene, 2-butene, isobutene, 2-methylfuran, and toluene containing the primary allylic hydrogen atom; 1-butene, 1-pentene, 2-ethylfuran, ethylbenzene, and n-propylbenzene containing the secondary allylic hydrogen atom; 3-methyl-1-butene, 2-isopropylfuran, and isopropylbenzene containing tertiary allylic hydrogen atom; and 1-4-pentadiene containing super allylic secondary hydrogen atoms. The M06-2X/6-311++G(d,p) level of theory was used to optimize the geometries of all of the reactants, transition states, products and also the hinder rotation treatments for lower frequency modes. The G4 level of theory was used to calculate the electronic single point energies for those species to determine the 0 K barriers to reaction. Conventional transition state theory with Eckart tunnelling corrections was used to calculate the rate constants. The comparison between our calculated rate constants with the available experimental results from the literature shows good agreement for the reactions of propene and isobutene with molecular oxygen. The rate constant for toluene with O 2 is about an order magnitude slower than that experimentally derived from a comprehensive model proposed by Oehlschlaeger and coauthors. The results clearly indicate the need for a more detailed investigation of the combustion kinetics of toluene oxidation and its key pyrolysis and oxidation intermediates. Despite this, our computed barriers and rate constants retain an important internal consistency. Rate constants

  10. Effects of oral administration of brassica secondary metabolites, allyl cyanide, allyl isothiocyanate and dimethyl disulphide, on the voluntary food intake and metabolism of sheep.

    Science.gov (United States)

    Duncan, A J; Milne, J A

    1993-09-01

    Glucosinolates, such as sinigrin, and S-methyl cysteine sulphoxide (SMCO), which are found in forage brassica species have been implicated in the low intakes observed among lambs consuming such diets. To test both the individual and interactive effects of these compounds in sheep, all combinations of the sinigrin breakdown products, allyl cyanide (ACN) and allyl isothiocyanate (AITC; 10 mmol/d), and the SMCO metabolite dimethyl disulphide (DMDS; 25 mmol/d) were orally administered twice daily for 5 weeks to forty sheep offered dried grass pellets ad lib. As well as measuring voluntary food intake (VFI), a number of haematological and clinical function tests were conducted to assess the physiological effects of the compounds. VFI was significantly depressed by both ACN and AITC but not by DMDS. DMDS significantly ameliorated the effects of ACN on VFI (P < 0.001). Concentrations of reduced glutathione in the blood were depressed by ACN and AITC and elevated by DMDS but no significant interactions were evident. Elevated plasma gamma-glutamyl transpeptidase (EC 2.3.2.1) activity on ACN and AITC treatments indicated possible liver damage. DMDS elicited a rise in Heinz bodies to 11% by week 2 but this was not reflected in packed cell volume and blood haemoglobin levels which were unaffected by treatment. The increased Heinz body count caused by DMDS was not further influenced by ACN or AITC. In conclusion, the depressive effects of sinigrin breakdown products on VFI were not compounded by the additional presence of DMDS which, on the contrary, lessened the depression of VFI caused by ACN.

  11. [3+3] annulation of allylic phosphoryl-stabilized carbanions/phosphorus ylides and vinyl azides: a practice strategy for synthesis of polyfunctionalized anilines.

    Science.gov (United States)

    Liu, Shen; Chen, Wenteng; Luo, Jing; Yu, Yongping

    2014-08-11

    Tandem Michael addition and Witting or Horner-Wadsworth-Emmons olefination initiated [3+3] annulation between vinyl azides and allylic phosphorus ylides or allylic phosphoryl-stabilized carbanions has been developed. This one-pot protocol furnishes highly functionalized anilines in good to excellent yields under mild, room-temperature conditions. A rational mechanism is also proposed.

  12. Et3B-mediated and palladium-catalyzed direct allylation of β-dicarbonyl compounds with Morita–Baylis–Hillman alcohols

    Directory of Open Access Journals (Sweden)

    Ahlem Abidi

    2016-11-01

    Full Text Available A practical and efficient palladium-catalyzed direct allylation of β-dicarbonyl compounds with both cyclic and acyclic Morita–Baylis–Hillman (MBH alcohols, using Et3B as a Lewis acid promoter, is described herein. A wide range of the corresponding functionalized allylated derivatives have been obtained in good yields and with high selectivity.

  13. A highly efficient kinetic resolution of Morita-Baylis-Hillman adducts achieved by N-Ar axially chiral Pd-complexes catalyzed asymmetric allylation.

    Science.gov (United States)

    Wang, Feijun; Li, Shengke; Qu, Mingliang; Zhao, Mei-Xin; Liu, Lian-Jun; Shi, Min

    2011-12-28

    Palladium complexes with an axially chiral N-Ar framework have been developed. These complexes showed high stereoselectivities in asymmetric allylic arylation to achieve the kinetic resolution of Morita-Baylis-Hillman adducts, affording up to 99% ee of (E)-allylation products and 92% ee of recovered Morita-Baylis-Hillman adducts. This journal is © The Royal Society of Chemistry 2011

  14. Et3B-mediated and palladium-catalyzed direct allylation of β-dicarbonyl compounds with Morita-Baylis-Hillman alcohols.

    Science.gov (United States)

    Abidi, Ahlem; Oueslati, Yosra; Rezgui, Farhat

    2016-01-01

    A practical and efficient palladium-catalyzed direct allylation of β-dicarbonyl compounds with both cyclic and acyclic Morita-Baylis-Hillman (MBH) alcohols, using Et 3 B as a Lewis acid promoter, is described herein. A wide range of the corresponding functionalized allylated derivatives have been obtained in good yields and with high selectivity.

  15. 1,n-glycols as dialdehyde equivalents in iridium-catalyzed enantioselective carbonyl allylation and iterative two-directional assembly of 1,3-polyols.

    Science.gov (United States)

    Lu, Yu; Kim, In Su; Hassan, Abbas; Del Valle, David J; Krische, Michael J

    2009-01-01

    Unstable? We're able! 1,n-Glycols serve as synthetic equivalents to unstable dialdehydes in two-directional carbonyl allylation from the alcohol oxidation level under iridium-catalyzed transfer hydrogenation conditions. Iterative asymmetric allylation employing 1,3-propanediol enables the rapid assembly of protected 1,3-polyol substructures with exceptional levels of stereocontrol.

  16. The reaction of allyl and benzylarsonic acids with thiols: mechanistic aspects and implications for dioxygen activation by trivalent arsenic compounds.

    Science.gov (United States)

    Lala, Maria A; Ioannou, Panayiotis V

    2003-12-01

    The reaction of allyl and benzylarsonic acids with thiophenol gives not only the expected diphenyl alkyldithioarsonites and diphenyl disulfide but also various other compounds arising from the decomposition at the arsenic(V) oxidation level (the arsonic acids) by thiophenol and at the arsenic(III) oxidation level (mainly the alkyldithioarsonites) by thiophenol and by dissolved dioxygen. The reaction of these arsonic acids with 4-nitrothiophenol, which is not oxidized by dioxygen, revealed that the arsenic(III) of these alkyldithioarsonites is the active atom towards dioxygen. However, the reaction of allyl, benzyl, and 2-picolylarsonic acids with DL-penicillamine gives the expected products with no or very small oxidative decomposition. The decomposition pathways of allyl and benzylarsonic acids were elucidated. The results are briefly discussed in the contexts of the use of arsonic acids in chemotherapy and the ability of arsenic(III) compounds to generate reactive oxygen species.

  17. The reactivity of allyl and propargyl alcohols with solvated electrons: temperature and solvent effects

    International Nuclear Information System (INIS)

    Afanassiev, A.M.; Okazaki, K.; Freeman, G.R.

    1979-01-01

    The rate constants K 1 for the reaction of solvated electrons with allyl alcohol in a number of hydroxylic solvents differ by up to two orders of magnitude and decrease in the order tert-butyl alcohol > 2-propanol > l-propanol approximately ethanol > methanol approximately ethylene glycol > water. In methanol and ethylene glycol the rate constants (7 x 10 7 M -1 s -1 at 298 K) and activation energies (16 kJ/mol) are equal, in spite of a 32-fold difference in solvent viscosity (0.54 and 17.3 cP, respectively) and 3-fold difference in its activation energy (11 and 32 kJ/mol, respectively). The reaction in tert-butyl alcohol is nearly diffusion controlled and has a high activation energy that is characteristic of transport in that liquid (E 1 = 31 kJ/mol, E sub(eta) = 39 kJ/mol). The activation energies in the other alcohols are all 16 kJ/mol, and it is 14 kJ/mol in water. They do not correlate with transport properties. The solvent effect is connected primarily with the entropy of activation. The rate constants correlate with the solvated electron trap depth. When the electron affinity of the scavenger is small, a favorable configuration of solvent molecules about the electron/scavenger encounter pair is required for the electron jump to take place. The behavior of the rate parameters for propargyl alcohol is similar to that for allyl alcohol, but k 1 , A 1 , and E 1 are larger for the former. The ratio k(propargyl)/k(allyl) at 298 K equals 10.5 in water and decreases through the series, reaching 1.3 in tert-butyl alcohol. Rate parameters for several other scavengers are also reported. (author)

  18. Expression of liver functions following sub-lethal and non-lethal doses of allyl alcohol and acetaminophen in the rat

    DEFF Research Database (Denmark)

    Tygstrup, N; Jensen, S A; Krog, B

    1997-01-01

    BACKGROUND/AIMS: To relate severity of intoxication with allyl alcohol and acetaminophen to modulated hepatic gene expression of liver functions and regeneration. METHODS: Rats fasted for 12 h received acetaminophen 3.5 or 5.6 g per kg body weight, or allyl alcohol 100 or 125 microl by gastric tube...... synthesis, and for proteins related to liver regeneration. RESULTS: After allyl alcohol, mRNA of "positive" acute phase proteins was higher than after acetaminophen and increased with the dose, whereas after acetaminophen it decreased with the dose. The mRNA of the urea cycle enzymes and glutamine...... synthetase was uniformly reduced by allyl alcohol, whereas that of most urea cycle enzymes was above the controls after the non-lethal, but not after the sub-lethal, dose of acetaminophen. The mRNA of glutamine synthetase was significantly more reduced by acetaminophen than by allyl alcohol. The mRNA of cell...

  19. Direct asymmetric allylic alkenylation of N-itaconimides with Morita-Baylis-Hillman carbonates

    KAUST Repository

    Yang, Wenguo

    2012-08-03

    The asymmetric allylic alkenylation of Morita-Baylis-Hillman (MBH) carbonates with N-itaconimides as nucleophiles has been developed using a commercially available Cinchona alkaloid catalyst. A variety of multifunctional chiral α-methylene-β-maleimide esters were attained in moderate to excellent yields (up to 99%) and good to excellent enantioselectivities (up to 91% ee). The origin of the regio- and stereoselectivity was verified by DFT methods. Calculated geometries and relative energies of various transition states strongly support the observed regio- and enantioselectivity. © 2012 American Chemical Society.

  20. N-(2-Allyl-4-ethoxy-2H-indazol-5-yl-4-methylbenzenesulfonamide

    Directory of Open Access Journals (Sweden)

    Hakima Chicha

    2014-05-01

    Full Text Available The indazole ring system of the title compound, C19H21N3O3S, is almost planar (r.m.s. deviation = 0.0192 Å and forms dihedral angles of 77.99 (15 and 83.9 (3° with the benzene ring and allyl group, respectively. In the crystal, centrosymmetrically related molecules are connected by pairs of N—H...O hydrogen bonds into dimers, which are further linked by C—H...O hydrogen bonds, forming columns parallel to the b axis.

  1. Thermophysical properties and reaction kinetics of γ-irradiated poly allyl diglycol carbonates nuclear track detector

    Science.gov (United States)

    Elmaghraby, Elsayed K.; Seddik, Usama

    2015-07-01

    Kinetic thermogravimetric technique was used to study the effect of gamma irradiation on the poly allyl diglycol carbonates (PADC) within the dose range from 50 to ? Gy. The approach of Coats-Redfern was used to analyze the data. Results showed that low doses around 50 Gy make the polymer slightly more resistive to heat treatment. Higher radiation doses cause severe effects in the samples accompanied by the formation of lower molecular mass species and consequent crosslinking. Results support the domination of re-polymerization and crosslinking for the γ radiation interaction PADC at dose below about ? Gy, while the situation is inverted above ? Gy in which chain secession dominates.

  2. Unusual selectivity-determining factors in the phosphine-free Heck arylation of allyl ethers

    DEFF Research Database (Denmark)

    Ambrogio, I.; Fabrizi, G.; Cacchi, S.

    2008-01-01

    The Heck reaction of aryl iodides and bromides with allyl ethers has been investigated. Using phosphinefree Pd(OAc)(2) in DNIF at 90 degrees C in the presence of Bu4NOAc, the reaction gave cinnamyl derivatives, usually in good to high yields, with a wide range of aryl halides. The reaction...... tolerates a variety of functional groups, including ether, amide, alcohol, aldehyde, ketone, ester, cyano, carboxylic acid, and nitro groups. Ortho-substituted arylating agents afforded moderate yields in some cases, though good to high yields were obtained with o-iodotoluene, iodovanillin, and 1...

  3. Design of the passive personal dosimeter for miners using an allyl diglycol carbonate plastic. Phase 1

    International Nuclear Information System (INIS)

    1983-12-01

    The report summarizes the results of the feasibility study on the design and development of a passive personal dosimeter incorporating an allyl diglycol carbonate plastic (CR39) detector, for use by uranium miners. Based upon the feasibility study, a passive personal dosimeter using a capacitor-type electrostatic enhancement device has been designed. Preliminary tests indicate that the prototype could be used in the mine environment to differentiate radon and thoron daughters with a detection efficiency comparable to that of a typical active device. Further study is required, however, into the possible influence in the mine environment of local variations in charged fraction, upon the calibration of this dosimeter

  4. Non-thermal plasma destruction of allyl alcohol in waste gas: kinetics and modelling

    International Nuclear Information System (INIS)

    Visscher, A de; Dewulf, J; Durme, J van; Leys, C; Morent, R; Langenhove, H Van

    2008-01-01

    Non-thermal plasma treatment is a promising technique for the destruction of volatile organic compounds in waste gas. A relatively unexplored technique is the atmospheric negative dc multi-pin-to-plate glow discharge. This paper reports experimental results of allyl alcohol degradation and ozone production in this type of plasma. A new model was developed to describe these processes quantitatively. The model contains a detailed chemical degradation scheme, and describes the physics of the plasma by assuming that the fraction of electrons that takes part in chemical reactions is an exponential function of the reduced field. The model captured the experimental kinetic data to less than 2 ppm standard deviation

  5. Non-thermal plasma destruction of allyl alcohol in waste gas: kinetics and modelling

    Science.gov (United States)

    DeVisscher, A.; Dewulf, J.; Van Durme, J.; Leys, C.; Morent, R.; Van Langenhove, H.

    2008-02-01

    Non-thermal plasma treatment is a promising technique for the destruction of volatile organic compounds in waste gas. A relatively unexplored technique is the atmospheric negative dc multi-pin-to-plate glow discharge. This paper reports experimental results of allyl alcohol degradation and ozone production in this type of plasma. A new model was developed to describe these processes quantitatively. The model contains a detailed chemical degradation scheme, and describes the physics of the plasma by assuming that the fraction of electrons that takes part in chemical reactions is an exponential function of the reduced field. The model captured the experimental kinetic data to less than 2 ppm standard deviation.

  6. Evaluation of the toxicity of 3-allyl-beta-lapachone against Trypanosoma cruzi bloodstream forms.

    Science.gov (United States)

    Gonçalves, A M; Vasconcellos, M E; Docampo, R; Cruz, F S; de Souza, W; Leon, W

    1980-06-01

    In vitro incubation of Trypanosoma cruzi (Y strain) with 3-allyl-beta-lapachone was followed by: (1) growth inhibition of epimastigotes, (2) damage to cellular membranes, especially of the mitochondria, alterations in the chromatin structure and swelling of mitochondria, (3) increase in the respiratory rate, (4) increase in the rate of H2O2 generation by the epimastigotes, (5) increase of the rate of lipid peroxidation as detected by malonyldialdehyde formation, (6) decrease or total disappearance of trypomastigotes from mouse-infected blood. This drug might therefore be useful in preventing transmission of Chagas' disease during blood transfusion. It is not, however, active against infections in mice.

  7. N-(1-Allyl-3-chloro-4-ethoxy-1H-indazol-5-yl-4-methylbenzenesulfonamide

    Directory of Open Access Journals (Sweden)

    Hakima Chicha

    2014-06-01

    Full Text Available In the title compound, C19H20ClN3O3S, the benzene ring is inclined to the indazole ring system by 51.23 (8°. In the crystal, molecules are linked by pairs of N—H...O hydrogen bonds, forming inversion dimers which stack in columns parallel to [011]. The atoms in the allyl group are disordered over two sets of sites with an occupancy ratio of 0.624 (8:0.376 (8.

  8. Sensitization and desensitization to allyl isothiocyanate (mustard oil) in the nasal cavity.

    Science.gov (United States)

    Brand, Gerard; Jacquot, Laurence

    2002-09-01

    The aim of this study was to investigate the response, acute effects and time-course of sensitization and desensitization to allyl isothiocyanate (mustard oil) nasal stimuli in healthy subjects. Sixty subjects participated in the experiment, which employed psychophysical (intensity ratings) and psychophysiological (skin conductance response) measurements. Nasal stimuli were delivered three times with different inter-stimulus intervals. The results showed that the psychophysical and psycho-physiological data were correlated and that the successive nasal stimuli after a short period of time (3 min produced a markedly decreased intensity of irritation. These findings are in agreement with those obtained with capsaicin, the most frequently used irritant molecule.

  9. [Inhibition of aflatoxin production and fungal growth on stored corn by allyl isothiocyanate vapor].

    Science.gov (United States)

    Okano, Kiyoshi; Ose, Ayaka; Takai, Mitsuhiro; Kaneko, Misao; Nishioka, Chikako; Ohzu, Yuji; Odano, Masayoshi; Sekiyama, Yasushi; Mizukami, Yuichi; Nakamura, Nobuya; Ichinoe, Masakatsu

    2015-01-01

    Studies were conducted to determine the effectiveness of allyl isothiocyanate (AIT) vapor treatment with a commercial mustard seed extract (Wasaouro(®)) in controlling aflatoxin-producing fungi on stored corn. The concentration of AIT in the closed container peaked at 54.6 ng/mL on the 14th day and remained at 21.8 ng/mL on the 42nd day. AIT inhibited visible growth of aflatoxigenic molds in unsterilized corn and in sterilized corn inoculated with various aflatoxigenic fungi. However, fungi such as Aspergillus glaucus group, A. penicillioides and A. restrictus were detected by means of culture methods.

  10. Enantioselective Iridium Catalyzed Carbonyl Allylation from the Alcohol Oxidation Level via Transfer Hydrogenation: Minimizing Pre-Activation for Synthetic Efficiency

    Science.gov (United States)

    Han, Soo Bong; Kim, In Su; Krische, Michael J.

    2010-01-01

    Existing methods for enantioselective carbonyl allylation, crotylation and tert-prenylation require stoichiometric generation of pre-metallated nucleophiles and often employ stoichiometric chiral modifiers. Under the conditions of transfer hydrogenation employing an ortho-cyclometallated iridium C,O-benzoate catalyst, enantioselective carbonyl allylations, crotylations and tert-prenylations are achieved in the absence of stoichiometric metallic reagents or stoichiometric chiral modifiers. Moreover, under transfer hydrogenation conditions, primary alcohols function dually as hydrogen donors and aldehyde precursors, enabling enantioselective carbonyl addition directly from the alcohol oxidation level. PMID:20024203

  11. Weakly Coordinating, Ketone-Directed Cp*Co(III)-Catalyzed C-H Allylation on Arenes and Indoles.

    Science.gov (United States)

    Sk, Md Raja; Bera, Sourav Sekhar; Maji, Modhu Sudan

    2018-01-05

    Weakly coordinating, ketone-directed, regioselective monoallylation of arenes and indoles is reported using a stable and cost-effective high-valent cobalt(III)-catalyst to access several important molecular building blocks. The allylation proceeds smoothly with a variety of substrates in the presence of various electron-rich and -deficient substituents. The method was applied to the formal synthesis of an ancisheynine alkaloid, a highly conjugated azatetracene, and isochroman. The mechanistic study reveals that the allylation reaction follows a base-assisted intermolecular electrophilic substitution pathway.

  12. Further exploration of the heterocyclic diversity accessible from the allylation chemistry of indigo

    Directory of Open Access Journals (Sweden)

    Alireza Shakoori

    2015-04-01

    Full Text Available Diversity-directed synthesis based on the cascade allylation chemistry of indigo, with its embedded 2,2’-diindolic core, has resulted in rapid access to new examples of the hydroxy-8a,13-dihydroazepino[1,2-a:3,4-b']diindol-14(8H-one skeleton in up to 51% yield. Additionally a derivative of the novel bridged heterocycle 7,8-dihydro-6H-6,8a-epoxyazepino[1,2-a:3,4-b']diindol-14(13H-one was produced when the olefin of the allylic substrate was terminally disubstituted. Further optimisation also produced viable one-pot syntheses of derivatives of the spiro(indoline-2,9'-pyrido[1,2-a]indol-3-one (65% and pyrido[1,2,3-s,t]indolo[1,2-a]azepino[3,4-b]indol-17-one (72% heterocyclic systems. Ring-closing metathesis of the N,O-diallylic spiro structure and subsequent Claisen rearrangement gave rise to the new (1R,8aS,17aS-rel-1,2-dihydro-1-vinyl-8H,17H,9H-benz[2',3']pyrrolizino[1',7a':2,3]pyrido[1,2-a]indole-8,17-(2H,9H-dione heterocyclic system.

  13. Combined experimental and theoretical mechanistic investigation of the Barbier allylation in aqueous media.

    Science.gov (United States)

    Dam, Johan Hygum; Fristrup, Peter; Madsen, Robert

    2008-04-18

    The Barbier allylation of a series of para-substituted benzaldehydes with allylbromide in the presence of Zn, In, Sn, Sb, Bi, and Mg was investigated using competition experiments. In all cases, the slope of the Hammett plots indicated a build-up of negative charge in the selectivity-determining step. For Zn, In, Sn, Sb, and Bi, an inverse secondary kinetic isotope effect was found (kH/kD = 0.75-0.95), which was compatible with the formation of a discrete organometallic species prior to allylation via a closed six-membered transition state. With Mg, a significantly larger build-up of negative charge along with a small positive secondary kinetic isotope effect (kH/kD = 1.06) indicated that the selectivity-determining step was the generation of the radical anion of benzaldehyde. The reaction through a six-membered transition state was modeled using density functional theory with the effect of solvent described by a polarized continuum model. The calculated secondary deuterium isotope effects based on this mechanism were found to be in good agreement with experimental values, thus adding further support to this mechanistic scenario.

  14. Iron complexes of tetramine ligands catalyse allylic hydroxyamination via a nitroso–ene mechanism

    Directory of Open Access Journals (Sweden)

    David Porter

    2015-12-01

    Full Text Available Iron(II complexes of the tetradentate amines tris(2-pyridylmethylamine (TPA and N,N′-bis(2-pyridylmethyl-N,N′-dimethylethane-1,2-diamine (BPMEN are established catalysts of C–O bond formation, oxidising hydrocarbon substrates via hydroxylation, epoxidation and dihydroxylation pathways. Herein we report the capacity of these catalysts to promote C–N bond formation, via allylic amination of alkenes. The combination of N-Boc-hydroxylamine with either FeTPA (1 mol % or FeBPMEN (10 mol % converts cyclohexene to the allylic hydroxylamine (tert-butyl cyclohex-2-en-1-yl(hydroxycarbamate in moderate yields. Spectroscopic studies and trapping experiments suggest the reaction proceeds via a nitroso–ene mechanism, with involvement of a free N-Boc-nitroso intermediate. Asymmetric induction is not observed using the chiral tetramine ligand (+-(2R,2′R-1,1′-bis(2-pyridylmethyl-2,2′-bipyrrolidine ((R,R′-PDP.

  15. The behaviour of salt and salt caverns

    NARCIS (Netherlands)

    Fokker, P.A.

    1995-01-01

    Salts are mined for both storage and extraction purposes, either via dry or solution mining techniques. For operational, environmental and geological purposes, it is important to understand and predict the in situ behaviour of salt, in particular the creep and strength characteristics. A

  16. Effect of Low Salt Diet on Insulin Resistance in Salt Sensitive versus Salt Resistant Hypertension

    OpenAIRE

    Garg, Rajesh; Sun, Bei; Williams, Jonathan

    2014-01-01

    Accumulating evidence shows an increase in insulin resistance on salt restriction. We compared the effect of low salt diet on insulin resistance in salt sensitive versus salt resistant hypertensive subjects. We also evaluated the relationship between salt sensitivity of blood pressure and salt sensitivity of insulin resistance in a multivariate regression model. Studies were conducted after one week of high salt (200 mmol/day Na) and one week of low salt (10 mmol/day Na) diet. Salt sensitivit...

  17. Low-salt diet

    Science.gov (United States)

    Low-sodium diet; Salt restriction ... control many functions. Too much sodium in your diet can be bad for you. For most people, ... you limit salt. Try to eat a balanced diet. Buy fresh vegetables and fruits whenever possible. They ...

  18. Copper-Catalyzed Intermolecular Trifluoromethylazidation and Trifluoromethylthiocyanation of Allenes: Efficient Access to CF3-Containing Allyl Azides and Thiocyanates.

    Science.gov (United States)

    Zhu, Na; Wang, Fei; Chen, Pinhong; Ye, Jinxing; Liu, Guosheng

    2015-07-17

    A mild and efficient method for copper-catalyzed trifluoromethylazidation and trifluoromethylthiocyanation of allenes was explored. A series of CF3-containing allyl azides and thiocyanates were obtained with high yields and good stereoselectivities, which can be used for further transformation to some valuable compounds.

  19. A simple approach to unsymmetric atropoisomeric bipyridine N,N'-dioxides and their application in enantioselective allylation of aldehydes

    Czech Academy of Sciences Publication Activity Database

    Hrdina, R.; Valterová, Irena; Hodačová, Jana; Císařová, I.; Kotora, Martin

    2007-01-01

    Roč. 349, č. 6 (2007), s. 822-826 ISSN 1615-4150 R&D Projects: GA ČR(CZ) GA203/05/0102; GA MŠk(CZ) LC06070 Institutional research plan: CEZ:AV0Z40550506 Keywords : allylation * asymmetric catalysis * Lewis bases Subject RIV: CC - Organic Chemistry Impact factor: 4.977, year: 2007

  20. Mechanistic Dichotomy in the Asymmetric Allylation of Aldehydes with Allyltrichlorosilanes Catalyzed by Chiral Pyridine N-Oxides

    Czech Academy of Sciences Publication Activity Database

    Malkov, A. V.; Stončius, S.; Bell, M.; Castelluzzo, F.; Ramírez-López, P.; Biedermannová, Lada; Langer, V.; Rulíšek, Lubomír; Kočovský, P.

    2013-01-01

    Roč. 19, č. 28 (2013), s. 9167-9185 ISSN 0947-6539 R&D Projects: GA MŠk LC512 Institutional support: RVO:61388963 ; RVO:86652036 Keywords : allylation * allylsilanes * calculations * organocatalysis * pyridine N-oxides Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 5.696, year: 2013

  1. Antimicrobial effect of allyl isothiocyanate and modified atmosphere on Pseudomonas aeruginosa in fresh catfish fillet under abuse temperatures

    Science.gov (United States)

    Pseudomonas aeruginosa, a common spoilage microorganism on fresh catfish products, can grow rapidly at temperatures above 4 degree C during storage and transportation. Allyl isothiocyanate (AIT), an extract of horseradish oil, and modified atmosphere (MA) can be used to inhibit the growth of P. aeru...

  2. Effect of allyl isothiocyanate in headspace and modified atmosphere on Pseduomonas Aeruginosa growth in fresh catfish fillets under abuse temperatures

    Science.gov (United States)

    Pseudomonas aeruginosa, a common spoilage microorganism on fresh catfish products, can grow rapidly at temperatures above 4 deg C during storage and transportation. Allyl isothiocyanate (AIT), an extract of horseradish oil, and modified atmosphere (MA) can be used to inhibit the growth of P. aerugin...

  3. Growth behavior prediction of fresh catfish fillet with Pseudomonas aeruginosa under stresses of allyl isothiocyanate, temperature and modified atmosphere

    Science.gov (United States)

    Pseudomonas aeruginosa, a common spoilage microorganism in fish, grows rapidly when temperature rises above 4 degree C. The combination of allyl isothiocyanate (AIT) and modified atmosphere (MA) was applied and proved to be effective to retard the growth of P. aeruginosa. The objective of this resea...

  4. Sulfonamides as new hydrogen atom transfer (HAT) catalysts for photoredox allylic and benzylic C-H arylations.

    Science.gov (United States)

    Tanaka, Hirotaka; Sakai, Kentaro; Kawamura, Atsushi; Oisaki, Kounosuke; Kanai, Motomu

    2018-02-02

    A catalytic amount of a sterically and electronically tuned diarylsulfonamide promoted allylic and benzylic C-H arylations in cooperation with a visible light photoredox catalyst. This is the first example of the catalytic use of a sulfonamidyl radical to promote the hydrogen atom transfer process.

  5. Asymmetric allylic alkylation in combination with ring-closing metathesis for the preparation of chiral N-heterocycles

    NARCIS (Netherlands)

    Teichert, Johannes F.; Zhang, Suyan; Zijl, Anthoni W. van; Slaa, Jan Willem; Minnaard, Adriaan J.; Feringa, Bernard

    2010-01-01

    Asymmetric copper-catalyzed allylic substitution with methylmagnesium bromide is employed in combination with ring-closing olefin metathesis or ene-yne metathesis to achieve the synthesis of chiral, unsaturated nitrogen heterocycles. The resulting six- to eight-membered chiral heterocycles are

  6. Allyl deprotection of galacturonic acid derivatives: mechanistic aspects of mercuric-catalyzed prop-1-enyl acetal cleavage.

    Science.gov (United States)

    Barbier, Maximilien; Grand, Eric; Kovensky, José

    2007-12-10

    Different deallylation methods were assayed for selective deprotection of allyl galactopyranosiduronic acid derivatives. A two-step procedure using DABCO and (Ph(3)P)(3)RhCl followed by mercuric-assisted cleavage gave quantitative yields. Reaction in the presence of [(18)O]water allowed us to obtain evidence about the mechanism of prop-1-enyl cleavage.

  7. Indium-mediated asymmetric barbier-type allylations: additions to aldehydes and ketones and mechanistic investigation of the organoindium reagents.

    Science.gov (United States)

    Haddad, Terra D; Hirayama, Lacie C; Singaram, Bakthan

    2010-02-05

    We report a simple, efficient, and general method for the indium-mediated enantioselective allylation of aromatic and aliphatic aldehydes and ketones under Barbier-type conditions in a one-pot synthesis affording the corresponding chiral alcohol products in very good yield (up to 99%) and enantiomeric excess (up to 93%). Our method is able to tolerate various functional groups, such as esters, nitriles, and phenols. Additionally, more substituted allyl bromides, such as crotyl and cinnamyl bromide, can be used providing moderate enantioselectivity (72% and 56%, respectively) and excellent diastereoselectivity when employing cinnamyl bromide (>95/5 anti/syn). However, the distereoselectivity when using crotyl bromide was poor and other functionalized allyl bromides under our method afforded low enantioselectivities for the alcohol products. In these types of indium-mediated additions, solvent plays a major role in determining the nature of the organoindium intermediate and we observed the susceptibility of some allylindium intermediates to hydrolysis in protic solvents. Under our reaction conditions using a polar aprotic solvent, we suggest that an allylindium(III) species is the active allylating intermediate. In addition, we have observed the presence of a shiny, indium(0) nugget throughout the reaction, irrespective of the stoichiometry, indicating disproportionation of indium halide byproduct formed during the reaction.

  8. Aqueous protocol for allylic arylation of cinnamyl acetates with sodium tetraphenylborate using Bedford-type palladacycle catalyst

    KAUST Repository

    Ghorpade, Seema Arun

    2018-03-19

    Allylic arylation of cinnamyl acetates with sodium tetraphenylborate using 0.002 mol % of Bedford-type palladacycle catalyst is described. The developed methodology is applicable for wide range of cinnamyl acetates furnishing excellent yields up to 93%. Notably all reactions proceed smoothly under mild reaction conditions in water under air atmosphere.

  9. Olefination of Electron-Deficient Alkenes with Allyl Acetate: Stereo- and Regioselective Access to (2Z,4E)-Dienamides.

    Science.gov (United States)

    Li, Feifei; Yu, Chunbing; Zhang, Jian; Zhong, Guofu

    2016-09-16

    A Ru-catalyzed direct olefination of electron-deficient alkenes with allyl acetate via C-H bond activation is disclosed. By using N,N-disubstituted aminocarbonyl as the directing group, this external oxidant-free protocol resulted in high reaction efficiency and good stereo- and regioselectivities, which opens a novel synthetic passway for access to (Z,E)-butadiene skeletons.

  10. Hydroxymethylation beyond Carbonylation: Enantioselective Iridium Catalyzed Reductive Coupling of Formaldehyde with Allylic Acetates via Enantiotopic ?-Facial Discrimination

    OpenAIRE

    Garza, Victoria J.; Krische, Michael J.

    2016-01-01

    Chiral iridium complexes modified by SEGPHOS catalyze the 2-propanol mediated reductive coupling of branched allylic acetates 1a?1o with formaldehyde to form primary homoallylic alcohols 2a?2o with excellent control of regio- and enantioselectivity. These processes, which rely on enantiotopic ?-facial discrimination of ?-allyliridium intermediates, represent the first examples of enantioselective formaldehyde C-C coupling beyond aldol addition.

  11. Modular synthesis of optically active lactones by Ru-catalyzed asymmetric allylic carboxylation and ring-closing metathesis reaction.

    Science.gov (United States)

    Takii, Koichiro; Kanbayashi, Naoya; Onitsuka, Kiyotaka

    2012-04-21

    A new synthetic route to optically active unsaturated γ- and δ-lactones has been demonstrated via asymmetric allylic carboxylation with a planar-chiral Cp'Ru catalyst and ring-closing metathesis reaction with a Grubbs II catalyst, and successfully applied to the enantioselective synthesis of (R)-(-)-massoialactone. This journal is © The Royal Society of Chemistry 2012

  12. Inactivation of Salmonella in tomato stem scars by organic acid wash and chitosan-allyl isothiocyanate coating

    Science.gov (United States)

    The objective of this study was to evaluate inactivation of inoculated Salmonella enterica on tomato stem scars exploiting integrated treatment of organic acid wash (AW) followed by chitosan-allyl isothiocyanate (CT-AIT) coating. The treatment effect on microbial loads and fruit quality during 21 d...

  13. 21 CFR 100.155 - Salt and iodized salt.

    Science.gov (United States)

    2010-04-01

    ... FOR HUMAN CONSUMPTION GENERAL Specific Administrative Rulings and Decisions § 100.155 Salt and iodized salt. (a) For the purposes of this section, the term iodized salt or iodized table salt is designated... 21 Food and Drugs 2 2010-04-01 2010-04-01 false Salt and iodized salt. 100.155 Section 100.155...

  14. Reprint of: Pendant allyl crosslinking as a tunable shape memory actuator for vascular applications.

    Science.gov (United States)

    Boire, Timothy C; Gupta, Mukesh K; Zachman, Angela L; Lee, Sue Hyun; Balikov, Daniel A; Kim, Kwangho; Bellan, Leon M; Sung, Hak-Joon

    2016-04-01

    Thermo-responsive shape memory polymers (SMPs) can be programmed to fit into small-bore incisions and recover their functional shape upon deployment in the body. This property is of significant interest for developing the next generation of minimally-invasive medical devices. To be used in such applications, SMPs should exhibit adequate mechanical strengths that minimize adverse compliance mismatch-induced host responses (e.g. thrombosis, hyperplasia), be biodegradable, and demonstrate switch-like shape recovery near body temperature with favorable biocompatibility. Combinatorial approaches are essential in optimizing SMP material properties for a particular application. In this study, a new class of thermo-responsive SMPs with pendant, photocrosslinkable allyl groups, x%poly(ε-caprolactone)-co-y%(α-allyl carboxylate ε-caprolactone) (x%PCL-y%ACPCL), are created in a robust, facile manner with readily tunable material properties. Thermomechanical and shape memory properties can be drastically altered through subtle changes in allyl composition. Molecular weight and gel content can also be altered in this combinatorial format to fine-tune material properties. Materials exhibit highly elastic, switch-like shape recovery near 37 °C. Endothelial compatibility is comparable to tissue culture polystyrene (TCPS) and 100%PCL in vitro and vascular compatibility is demonstrated in vivo in a murine model of hindlimb ischemia, indicating promising suitability for vascular applications. With the ongoing thrust to make surgeries minimally-invasive, it is prudent to develop new biomaterials that are highly compatible and effective in this workflow. Thermo-responsive shape memory polymers (SMPs) have great potential for minimally-invasive applications because SMP medical devices (e.g. stents, grafts) can fit into small-bore minimally-invasive surgical devices and recover their functional shape when deployed in the body. To realize their potential, it is imperative to devise

  15. Pendant allyl crosslinking as a tunable shape memory actuator for vascular applications.

    Science.gov (United States)

    Boire, Timothy C; Gupta, Mukesh K; Zachman, Angela L; Lee, Sue Hyun; Balikov, Daniel A; Kim, Kwangho; Bellan, Leon M; Sung, Hak-Joon

    2015-09-01

    Thermo-responsive shape memory polymers (SMPs) can be programmed to fit into small-bore incisions and recover their functional shape upon deployment in the body. This property is of significant interest for developing the next generation of minimally-invasive medical devices. To be used in such applications, SMPs should exhibit adequate mechanical strengths that minimize adverse compliance mismatch-induced host responses (e.g. thrombosis, hyperplasia), be biodegradable, and demonstrate switch-like shape recovery near body temperature with favorable biocompatibility. Combinatorial approaches are essential in optimizing SMP material properties for a particular application. In this study, a new class of thermo-responsive SMPs with pendant, photocrosslinkable allyl groups, x%poly(ε-caprolactone)-co-y%(α-allyl carboxylate ε-caprolactone) (x%PCL-y%ACPCL), are created in a robust, facile manner with readily tunable material properties. Thermomechanical and shape memory properties can be drastically altered through subtle changes in allyl composition. Molecular weight and gel content can also be altered in this combinatorial format to fine-tune material properties. Materials exhibit highly elastic, switch-like shape recovery near 37°C. Endothelial compatibility is comparable to tissue culture polystyrene (TCPS) and 100%PCL in vitro and vascular compatibility is demonstrated in vivo in a murine model of hindlimb ischemia, indicating promising suitability for vascular applications. With the ongoing thrust to make surgeries minimally-invasive, it is prudent to develop new biomaterials that are highly compatible and effective in this workflow. Thermo-responsive shape memory polymers (SMPs) have great potential for minimally-invasive applications because SMP medical devices (e.g. stents, grafts) can fit into small-bore minimally-invasive surgical devices and recover their functional shape when deployed in the body. To realize their potential, it is imperative to devise

  16. Not Salt Taste Perception but Self-Reported Salt Eating Habit Predicts Actual Salt Intake

    OpenAIRE

    Lee, Hajeong; Cho, Hyun-Jeong; Bae, Eunjin; Kim, Yong Chul; Kim, Suhnggwon; Chin, Ho Jun

    2014-01-01

    Excessive dietary salt intake is related to cardiovascular morbidity and mortality. Although dietary salt restriction is essential, it is difficult to achieve because of salt palatability. However, the association between salt perception or salt eating habit and actual salt intake remains uncertain. In this study, we recruited 74 healthy young individuals. We investigated their salt-eating habits by questionnaire and salt taste threshold through a rating scale that used serial dilution of a s...

  17. Symmetric Assembly of a Sterically Encumbered Allyl Complex: Mechanochemical and Solution Synthesis of the Tris(allylberyllate, K[BeA′3] (A′ = 1,3-(SiMe32C3H3

    Directory of Open Access Journals (Sweden)

    Nicholas C. Boyde

    2017-05-01

    Full Text Available The ball milling of beryllium chloride with two equivalents of the potassium salt of bis(1,3-trimethylsilylallyl anion, K[A′] (A′ = [1,3-(SiMe32C3H3], produces the tris(allylberyllate K[BeA’3] (1 rather than the expected neutral BeA’2. The same product is obtained from reaction in hexanes; in contrast, although a similar reaction conducted in Et2O was previously shown to produce the solvated species BeA’2(OEt2, it can produce 1 if the reaction time is extended (16 h. The tris(allylberyllate is fluxional in solution, and displays the strongly downfield 9Be NMR shift expected for a three-coordinate Be center (δ22.8 ppm. A single crystal X-ray structure reveals that the three allyl ligands are bound to beryllium in an arrangement with approximate C3 symmetry (Be–C (avg = 1.805(10 Å, with the potassium cation engaging in cation–π interactions with the double bonds of the allyl ligands. Similar structures have previously been found in complexes of zinc and tin, i.e., M[M′A′3L] (M′ = Zn, M = Li, Na, K; M′ = Sn, M = K; L = thf. Density functional theory (DFT calculations indicate that the observed C3-symmetric framework of the isolated anion ([BeA′3]− is 20 kJ·mol−1 higher in energy than a C1 arrangement; the K+ counterion evidently plays a critical role in templating the final conformation.

  18. Enantioselective construction of quaternary N-heterocycles by palladium-catalysed decarboxylative allylic alkylation of lactams

    KAUST Repository

    Behenna, Douglas C.

    2011-12-18

    The enantioselective synthesis of nitrogen-containing heterocycles (N-heterocycles) represents a substantial chemical research effort and resonates across numerous disciplines, including the total synthesis of natural products and medicinal chemistry. In this Article, we describe the highly enantioselective palladium-catalysed decarboxylative allylic alkylation of readily available lactams to form 3,3-disubstituted pyrrolidinones, piperidinones, caprolactams and structurally related lactams. Given the prevalence of quaternary N-heterocycles in biologically active alkaloids and pharmaceutical agents, we envisage that our method will provide a synthetic entry into the de novo asymmetric synthesis of such structures. As an entry for these investigations we demonstrate how the described catalysis affords enantiopure quaternary lactams that intercept synthetic intermediates previously used in the synthesis of the Aspidosperma alkaloids quebrachamine and rhazinilam, but that were previously only available by chiral auxiliary approaches or as racemic mixtures. © 2012 Macmillan Publishers Limited. All rights reserved.

  19. Isomerization of Allylic Alcohols to Ketones Catalyzed by Well-Defined Iron PNP Pincer Catalysts.

    Science.gov (United States)

    Xia, Tian; Wei, Zhihong; Spiegelberg, Brian; Jiao, Haijun; Hinze, Sandra; de Vries, Johannes G

    2018-03-15

    [Fe(PNP)(CO)HCl] (PNP=di-(2-diisopropylphosphanyl-ethyl)amine), activated in situ with KOtBu, is a highly active catalyst for the isomerization of allylic alcohols to ketones without an external hydrogen supply. High reaction rates were obtained at 80 °C, but the catalyst is also sufficiently active at room temperature with most substrates. The reaction follows a self-hydrogen-borrowing mechanism, as verified by DFT calculations. An alternative isomerization through alkene insertion and β-hydride elimination could be excluded on the basis of a much higher barrier. In alcoholic solvents, the ketone product is further reduced to the saturated alcohol. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. Mechanistic Investigation of Palladium–Catalyzed Allylic C–H Activation

    DEFF Research Database (Denmark)

    Engelin, Casper Junker; Jensen, Thomas; Rodríguez-Rodríguez, Sergio

    2013-01-01

    The mechanism for the palladium–catalyzed allylic C–H activation was investigated using a combination of experimental and theoretical methods. A Hammett study revealed a buildup of a partial negative charge in the rate-determining step, while determination of the kinetic isotope effect (KIE......) indicated that the C–H bond is broken in the turnover-limiting transition state. The-se experimental findings were further substantiated by carrying out a detailed density functional theory (DFT) based investigation of the entire catalytic cycle. The DFT modeling supports a mechanism where a coordinated...... acetate acts as a base in an intramolecular fashion during the C–H activation step. The re-oxidation of palladium was found to reach a similar energy level as that of the C–H activation. Calculations of turnover frequencies (TOF) for the entire catalytic cycle for the C–H alkylation were used to acquire...

  1. Highly Diastereoselective Indium-Mediated Allylation of Proline-Derived Hydrazones

    International Nuclear Information System (INIS)

    Satyender, Apuri; Jang, Doo Ok

    2013-01-01

    A highly diastereoselective indium-mediated addition reaction to L-proline-derived hydrazones has been developed. The method affords an efficient and general synthesis of homoallylic amines of high optically purity in high yields and diastereomeric ratios up to 98:2. It is well known that (S)-1-amino-2-methoxymethylpyrro-lidine and (S)-4-isopropyl- or (S)-4-phenylmethyl-oxa-zolidin-2-one-derived hydrazones have been used for metal-mediated diastereoselective allylation additions to produce chiral homoallylic amines. However, the optically pure hydrazine precursors are either commercially expensive and/or involve laborious synthetic procedures employing toxic reagents for their preparation. Thus, the design of novel classes of chiral hydrazines that would further broaden the scope of asymmetric synthesis to access optically pure homoallylic amines is highly desirable

  2. Decarboxylative-coupling of allyl acetate catalyzed by group 10 organometallics, [(phen)M(CH3)]+.

    Science.gov (United States)

    Woolley, Matthew; Ariafard, Alireza; Khairallah, George N; Kwan, Kim Hong-Yin; Donnelly, Paul S; White, Jonathan M; Canty, Allan J; Yates, Brian F; O'Hair, Richard A J

    2014-12-19

    Gas-phase carbon-carbon bond forming reactions, catalyzed by group 10 metal acetate cations [(phen)M(O2CCH3)](+) (where M = Ni, Pd or Pt) formed via electrospray ionization of metal acetate complexes [(phen)M(O2CCH3)2], were examined using an ion trap mass spectrometer and density functional theory (DFT) calculations. In step 1 of the catalytic cycle, collision induced dissociation (CID) of [(phen)M(O2CCH3)](+) yields the organometallic complex, [(phen)M(CH3)](+), via decarboxylation. [(phen)M(CH3)](+) reacts with allyl acetate via three competing reactions, with reactivity orders (% reaction efficiencies) established via kinetic modeling. In step 2a, allylic alkylation occurs to give 1-butene and reform metal acetate, [(phen)M(O2CCH3)](+), with Ni (36%) > Pd (28%) > Pt (2%). Adduct formation, [(phen)M(C6H11O2)](+), occurs with Pt (24%) > Pd (21%) > Ni(11%). The major losses upon CID on the adduct, [(phen)M(C6H11O2)](+), are 1-butene for M = Ni and Pd and methane for Pt. Loss of methane only occurs for Pt (10%) to give [(phen)Pt(C5H7O2)](+). The sequences of steps 1 and 2a close a catalytic cycle for decarboxylative carbon-carbon bond coupling. DFT calculations suggest that carbon-carbon bond formation occurs via alkene insertion as the initial step for all three metals, without involving higher oxidation states for the metal centers.

  3. Copper-Catalyzed Oxidative Dehydrogenative Carboxylation of Unactivated Alkanes to Allylic Esters via Alkenes

    Science.gov (United States)

    2015-01-01

    We report copper-catalyzed oxidative dehydrogenative carboxylation (ODC) of unactivated alkanes with various substituted benzoic acids to produce the corresponding allylic esters. Spectroscopic studies (EPR, UV–vis) revealed that the resting state of the catalyst is [(BPI)Cu(O2CPh)] (1-O2CPh), formed from [(BPI)Cu(PPh3)2], oxidant, and benzoic acid. Catalytic and stoichiometric reactions of 1-O2CPh with alkyl radicals and radical probes imply that C–H bond cleavage occurs by a tert-butoxy radical. In addition, the deuterium kinetic isotope effect from reactions of cyclohexane and d12-cyclohexane in separate vessels showed that the turnover-limiting step for the ODC of cyclohexane is C–H bond cleavage. To understand the origin of the difference in products formed from copper-catalyzed amidation and copper-catalyzed ODC, reactions of an alkyl radical with a series of copper–carboxylate, copper–amidate, and copper–imidate complexes were performed. The results of competition experiments revealed that the relative rate of reaction of alkyl radicals with the copper complexes follows the trend Cu(II)–amidate > Cu(II)–imidate > Cu(II)–benzoate. Consistent with this trend, Cu(II)–amidates and Cu(II)–benzoates containing more electron-rich aryl groups on the benzamidate and benzoate react faster with the alkyl radical than do those with more electron-poor aryl groups on these ligands to produce the corresponding products. These data on the ODC of cyclohexane led to preliminary investigation of copper-catalyzed oxidative dehydrogenative amination of cyclohexane to generate a mixture of N-alkyl and N-allylic products. PMID:25389772

  4. Enantioselective allylations of selected alpha, beta, gamma, delta-unsaturated aldehydes by axially chiral N,N'-dioxides. Synthesis of the left-hand part of papulacandin D

    Czech Academy of Sciences Publication Activity Database

    Vlašaná, K.; Betík, R.; Valterová, Irena; Nečas, D.; Kotora, M.

    2016-01-01

    Roč. 3, č. 3 (2016), s. 301-305 ISSN 2213-3372 Institutional support: RVO:61388963 Keywords : allylation * aldehyde * Lewis base * asymmetric synthesis * organocatalysis * homoallylic alcohol s Subject RIV: CC - Organic Chemistry

  5. Synthesis of Imidazo[1,5-a]quinolines and Imidazo[5,1-a]isoquinolines via the In-Mediated Allylation of Reissert Compounds

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Sung Hwan; Kim, Yu Mi; Park, Bo Ram; Kim, Jae Nyoung [Chonnam National University, Gwangju (Korea, Republic of)

    2010-10-15

    In summary, a facile indium-mediated synthesis of allyl-substituted imidazo[1,5-a]quinoline and its derivatives has been disclosed starting from the Reissert compounds of quinoline and related compounds. Allylindium reagents have been used extensively for the introduction of allyl group in a Barbier type manner to various electrophiles. Although many reactive electrophiles such as aldehydes and imines have been used in the indium-mediated allylations, the reaction of less reactive nitrile has not been reported much except the first successful results of Yamamoto group and our recent papers. Recently, we reported a series of indium-mediated Barbier type allylations of nitrile groups in γ-cyanoesters, γ-ketonitriles, δ-ketonitriles, ortho-cyanobenzoates, and N-(ortho-cyanoaryl) amides.

  6. Modification of Bisphenol-A Based Bismaleimide Resin (BPA-BMI) with an Allyl-Terminated Hyperbranched Polyimide (AT-PAEKI)

    National Research Council Canada - National Science Library

    Qin, Haihu; Mather, Patrick T; Baek, Jong-Beom; Tan, Loon-Seng

    2006-01-01

    As a continuation of previous work involving synthesis of an allyl-functionalized hyperbranched polyimide, AT-PAEKI, we have studied the use of this reactive polymer as a modifier of bisphenol-A based...

  7. Diaza [1,4] Wittig-type rearrangement of N-allylic-N-Boc-hydrazines into γ-amino-N-Boc-enamines.

    Science.gov (United States)

    Tayama, Eiji; Kobayashi, Yoshiaki; Toma, Yuka

    2016-08-18

    Diaza [1,4] Wittig-type rearrangement of N-allylic-N-Boc-hydrazines into γ-amino-N-Boc-enamines was demonstrated. The scope and limitation, experimental mechanistic studies, and a proposed reaction mechanism were also described.

  8. Submarine Salt Karst Terrains

    Directory of Open Access Journals (Sweden)

    Nico Augustin

    2016-06-01

    Full Text Available Karst terrains that develop in bodies of rock salt (taken as mainly of halite, NaCl are special not only for developing in one of the most soluble of all rocks, but also for developing in one of the weakest rocks. Salt is so weak that many surface-piercing salt diapirs extrude slow fountains of salt that that gravity spread downslope over deserts on land and over sea floors. Salt fountains in the deserts of Iran are usually so dry that they flow at only a few cm/yr but the few rain storms a decade so soak and weaken them that they surge at dm/day for a few days. We illustrate the only case where the rates at which different parts of one of the many tens of subaerial salt karst terrains in Iran flows downslope constrains the rates at which its subaerial salt karst terrains form. Normal seawater is only 10% saturated in NaCl. It should therefore be sufficiently aggressive to erode karst terrains into exposures of salt on the thousands of known submarine salt extrusions that have flowed or are still flowing over the floors of hundreds of submarine basins worldwide. However, we know of no attempt to constrain the processes that form submarine salt karst terrains on any of these of submarine salt extrusions. As on land, many potential submarine karst terrains are cloaked by clastic and pelagic sediments that are often hundreds of m thick. Nevertheless, detailed geophysical and bathymetric surveys have already mapped likely submarine salt karst terrains in at least the Gulf of Mexico, and the Red Sea. New images of these two areas are offered as clear evidence of submarine salt dissolution due to sinking or rising aggressive fluids. We suggest that repeated 3D surveys of distinctive features (± fixed seismic reflectors of such terrains could measure any downslope salt flow and thus offer an exceptional opportunity to constrain the rates at which submarine salt karst terrains develop. Such rates are of interest to all salt tectonicians and the many

  9. Comparison of peak shape in hydrophilic interaction chromatography using acidic salt buffers and simple acid solutions.

    Science.gov (United States)

    Heaton, James C; Russell, Joseph J; Underwood, Tim; Boughtflower, Robert; McCalley, David V

    2014-06-20

    The retention and peak shape of neutral, basic and acidic solutes was studied on hydrophilic interaction chromatography (HILIC) stationary phases that showed both strong and weak ionic retention characteristics, using aqueous-acetonitrile mobile phases containing either formic acid (FA), ammonium formate (AF) or phosphoric acid (PA). The effect of organic solvent concentration on the results was also studied. Peak shape was good for neutrals under most mobile phase conditions. However, peak shapes for ionised solutes, particularly for basic compounds, were considerably worse in FA than AF. Even neutral compounds showed deterioration in performance with FA when the mobile phase water concentration was reduced. The poor performance in FA cannot be entirely attributed to the negative impact of ionic retention on ionised silanols on the underlying silica base materials, as results using PA at lower pH (where their ionisation is suppressed) were inferior to those in AF. Besides the moderating influence of the salt cation on ionic retention, it is likely that salt buffers improve peak shape due to the increased ionic strength of the mobile phase and its impact on the formation of the water layer on the column surface. Copyright © 2014 Elsevier B.V. All rights reserved.

  10. Efficient synthesis of α,β-unsaturated alkylimines performed with allyl cations and azides: application to the synthesis of an ant venom alkaloid.

    Science.gov (United States)

    Hayashi, Kyohei; Tanimoto, Hiroki; Zhang, Huan; Morimoto, Tsumoru; Nishiyama, Yasuhiro; Kakiuchi, Kiyomi

    2012-11-16

    An efficient synthesis of α,β-unsaturated alkylimines at low temperature using azides has been developed. Carbocations generated from allyl alcohols helped achieve a rapid conversion under mild conditions with azides to afford reactive α,β-unsaturated imines. Hydroxy or alkoxy groups are essential for these transformations, and utilizing readily accessible allyl alcohols gave a wide extension of substrates. The efficiency of this novel method is demonstrated in the total synthesis of an iminium ant venom alkaloid.

  11. A convenient and stereoselective synthesis of (Z)-allyl selenides via Sm/TMSCl system-promoted coupling of Baylis-Hillman adducts with diselenides*

    Science.gov (United States)

    Liu, Yun-kui; Xu, Dan-qian; Xu, Zhen-yuan; Zhang, Yong-min

    2006-01-01

    A simple and convenient procedure for stereoselective synthesis of (Z)-allyl selenides has been developed by a one-pot reaction of diselenides with Baylis-Hillman adducts in the presence of samarium metal-trimethylsilyl chloride under mild conditions. Presumably, the diselenides are cleaved by Sm/TMSCl system to form selenide anions, which then undergo SN2′ substitution of Baylis-Hillman adducts to produce the (Z)-allyl selenides. PMID:16615170

  12. Oxidation reaction of 4-allyl-4-hydroperoxy-2-methoxycyclohexa-2,5-dienone in the presence of potassium permanganate without a co-oxidant

    Directory of Open Access Journals (Sweden)

    Mehmet Serdar Gültekin

    2016-12-01

    Full Text Available 4-Allyl-4-hydroperoxy-2-methoxycyclohexa-2,5-dienone (5 was synthesized by photooxygenation of commercially available Eugenol in the presence of tetraphenylporphyrin (TPP as a singlet oxygen sensitizer. The brief and one-pot syntheses of some natural product skeletons were conducted using the corresponding allylic hydroperoxide at different temperatures (0 oC and room temperature with potassium permanganate (KMnO 4 in mild condition at N 2(g atm.

  13. A history of salt.

    Science.gov (United States)

    Cirillo, M; Capasso, G; Di Leo, V A; De Santo, N G

    1994-01-01

    The medical history of salt begins in ancient times and is closely related to different aspects of human history. Salt may be extracted from sea water, mineral deposits, surface encrustations, saline lakes and brine springs. In many inland areas, wood was used as a fuel source for evaporation of brine and this practice led to major deafforestation in central Europe. Salt played a central role in the economies of many regions, and is often reflected in place names. Salt was also used as a basis for population censuses and taxation, and salt monopolies were practised in many states. Salt was sometimes implicated in the outbreak of conflict, e.g. the French Revolution and the Indian War of Independence. Salt has also been invested with many cultural and religious meanings, from the ancient Egyptians to the Middle Ages. Man's innate appetite for salt may be related to his evolution from predominantly vegetarian anthropoids, and it is noteworthy that those people who live mainly on protein and milk or who drink salty water do not generally salt their food, whereas those who live mainly on vegetables, rice and cereals use much more salt. Medicinal use tended to emphasize the positive aspects of salt, e.g. prevention of putrefaction, reduction of tissue swelling, treatment of diarrhea. Evidence was also available to ancient peoples of its relationship to fertility, particularly in domestic animals. The history of salt thus represents a unique example for studying the impact of a widely used dietary substance on different important aspects of man's life, including medical philosophy.

  14. Worth its salt?

    Science.gov (United States)

    The idea that all underground salt deposits can serve as storage sites for toxic and nuclear waste does not always hold water—literally. According to Daniel Ronen and Brian Berkowitz of Israel's Weizmann Institute of Science and Yoseph Yechieli of the Geological Survey of Israel, some buried salt layers are in fact highly conductive of liquids, suggesting that wastes buried in their confines could easily leech into groundwater and nearby soil.When drilling three wells into a 10,000-year-old salt layer near the Dead Sea, the researchers found that groundwater had seeped into the layer and had absorbed some of its salt.

  15. Asymmetric allylation of α-ketoester-derived N-benzoylhydrazones promoted by chiral sulfoxides/N-oxides Lewis bases: highly enantioselective synthesis of quaternary α-substituted α-allyl-α-amino acids.

    Science.gov (United States)

    Reyes-Rangel, Gloria; Bandala, Yamir; García-Flores, Fred; Juaristi, Eusebio

    2013-09-01

    Chiral sulfoxides/N-oxides (R)-1 and (R,R)-2 are effective chiral promoters in the enantioselective allylation of α-keto ester N-benzoylhydrazone derivatives 3a-g to generate the corresponding N-benzoylhydrazine derivatives 4a-g, with enantiomeric excesses as high as 98%. Representative hydrazine derivatives 4a-b were subsequently treated with SmI2, and the resulting amino esters 5a-b with LiOH to obtain quaternary α-substituted α-allyl α-amino acids 6a-b, whose absolute configuration was assigned as (S), with fundament on chemical correlation and electronic circular dichroism (ECD) data. © 2013 Wiley Periodicals, Inc.

  16. Olefin cross-metathesis on proteins: investigation of allylic chalcogen effects and guiding principles in metathesis partner selection.

    Science.gov (United States)

    Lin, Yuya A; Chalker, Justin M; Davis, Benjamin G

    2010-12-01

    Olefin metathesis has recently emerged as a viable reaction for chemical protein modification. The scope and limitations of olefin metathesis in bioconjugation, however, remain unclear. Herein we report an assessment of various factors that contribute to productive cross-metathesis on protein substrates. Sterics, substrate scope, and linker selection are all considered. It was discovered during this investigation that allyl chalcogenides generally enhance the rate of alkene metathesis reactions. Allyl selenides were found to be exceptionally reactive olefin metathesis substrates, enabling a broad range of protein modifications not previously possible. The principles considered in this report are important not only for expanding the repertoire of bioconjugation but also for the application of olefin metathesis in general synthetic endeavors.

  17. Crystal structure of (Z-3-allyl-5-(3-bromobenzylidene-2-sulfanylidene-1,3-thiazolidin-4-one

    Directory of Open Access Journals (Sweden)

    Rahhal El Ajlaoui

    2015-12-01

    Full Text Available In the title compound, C13H10BrNOS2, the rhodanine (systematic name: 2-sulfanylidene-1,3-thiazolidin-4-one and the 3-bromobenzylidene ring systems are inclined slightly, forming a dihedral angle of 5.86 (12°. The rhodanine moiety is linked to an allyl group at the N atom and to the 3-bromobenzylidene ring system. The allyl group, C=C—C, is nearly perpendicular to the mean plane through the rhodanine ring, maling a dihedral angle of 87.2 (5°. In the crystal, molecules are linked by pairs of C—H...O hydrogen bonds, forming inversion dimers with an R22(10 ring motif.

  18. Dynamic kinetic resolution of allylic sulfoxides by Rh-catalyzed hydrogenation: a combined theoretical and experimental mechanistic study.

    Science.gov (United States)

    Dornan, Peter K; Kou, Kevin G M; Houk, K N; Dong, Vy M

    2014-01-08

    A dynamic kinetic resolution (DKR) of allylic sulfoxides has been demonstrated by combining the Mislow [2,3]-sigmatropic rearrangement with catalytic asymmetric hydrogenation. The efficiency of our DKR was optimized by using low pressures of hydrogen gas to decrease the rate of hydrogenation relative to the rate of sigmatropic rearrangement. Kinetic studies reveal that the rhodium complex acts as a dual-role catalyst and accelerates the substrate racemization while catalyzing olefin hydrogenation. Scrambling experiments and theoretical modeling support a novel mode of sulfoxide racemization which occurs via a rhodium π-allyl intermediate in polar solvents. In nonpolar solvents, however, the substrate racemization is primarily uncatalyzed. Computational studies suggest that the sulfoxide binds to rhodium via O-coordination throughout the catalytic cycle for hydrogenation.

  19. One-pot synthesis of enantiomerically pure N-protected allylic amines from N-protected α-amino esters

    Directory of Open Access Journals (Sweden)

    Gastón Silveira-Dorta

    2016-05-01

    Full Text Available An improved protocol for the synthesis of enantiomerically pure allylic amines is reported. N-Protected α-amino esters derived from natural amino acids were submitted to a one-pot tandem reduction–olefination process. The sequential reduction with DIBAL-H at −78 °C and subsequent in situ addition of organophosphorus reagents yielded the corresponding allylic amines without the need to isolate the intermediate aldehyde. This circumvents the problem of instability of the aldehydes. The method tolerates well both Wittig and Horner–Wadsworth–Emmons organophosphorus reagents. A better Z-(diastereoselectivity was observed when compared to the previous one-pot method. The (diastereoselectivity of the process was affected neither by the reaction solvent nor by the amount of DIBAL-H employed. The method is compatible with the presence of free hydroxy groups as shown with serine and threonine derivatives.

  20. Low-temperature synthesis of allyl dimethylamine by selective heating under microwave irradiation used for water treatment

    International Nuclear Information System (INIS)

    Tian Binghui; Luan Zhaokun; Li Mingming

    2005-01-01

    Low-temperature synthesis of allyl dimethylamine (ADA) by selective heating under microwave irradiation (MI) used for water treatment is investigated. The effect of MI, ultrasound irradiation (UI) and conventional heating on yield of ADA, reaction time and the flocculation efficiency of polydiallyl dimethylammunion chloride (PDADMAC) prepared form ADA were studied. The results show that by selective heating at low temperature, MI not only increases yield of ADA and reduces reaction time, but also greatly enhances the flocculation efficiency of PDADMAC

  1. Oxidant-free Rh(III)-catalyzed direct C-H olefination of arenes with allyl acetates.

    Science.gov (United States)

    Feng, Chao; Feng, Daming; Loh, Teck-Peng

    2013-07-19

    Rh(III)-catalyzed direct olefination of arenes with allyl acetate via C-H bond activation is described using N,N-disubstituted aminocarbonyl as the directing group. The catalyst undergoes a redox neutral process, and high to excellent yields of trans-products are obtained. This protocol exhibits a wide spectrum of functionality compatibility because of the simple reaction conditions employed and provides a highly effective synthetic method in the realm of C-H olefination.

  2. Hydroxymethylation beyond Carbonylation: Enantioselective Iridium-Catalyzed Reductive Coupling of Formaldehyde with Allylic Acetates via Enantiotopic π-Facial Discrimination.

    Science.gov (United States)

    Garza, Victoria J; Krische, Michael J

    2016-03-23

    Chiral iridium complexes modified by SEGPHOS catalyze the 2-propanol-mediated reductive coupling of branched allylic acetates 1a-1o with formaldehyde to form primary homoallylic alcohols 2a-2o with excellent control of regio- and enantioselectivity. These processes, which rely on enantiotopic π-facial discrimination of σ-allyliridium intermediates, represent the first examples of enantioselective formaldehyde C-C coupling beyond aldol addition.

  3. Rapid assembly of functionalised spirocyclic indolines by palladium-catalysed dearomatising diallylation of indoles with allyl acetate

    OpenAIRE

    Dhankher, P.; Benhamou, L.; Sheppard, T. D.

    2014-01-01

    Herein, we report the application of allyl acetate to the palladium-catalysed dearomatising diallylation of indoles. The reaction can be carried out by using a readily available palladium catalyst at room temperature, and can be applied to a wide range of substituted indoles to provide access to the corresponding 3,3-diallylindolinines. These compounds are versatile synthetic intermediates that readily undergo Ugi reactions or proline-catalysed asymmetric Mannich reactions. Alternatively, acy...

  4. Geomechanics of bedded salt

    International Nuclear Information System (INIS)

    Serata, S.; Milnor, S.W.

    1979-01-01

    Creep data from the literature search is reinterpreted by SGI, resulting in a better understanding of the temperature and stress state dependence of the octahedral creep rate and the octahedral shear strength. The concept of a transition strength between the elastic and the plastic states is in agreement with the data. The elastic and rheological properties of salt are described, and a set of constitutive equations is presented. The dependence of material properties on parameters such as temperature is considered. Findings on the permeability of salt are summarized, and the in-situ behavior of openings in bedded salt is described based on extensive engineering experience. A stress measuring system utilizing a finite element computer code is discussed. Geological factors affecting the stability of salt openings are considered, and the Stress Control Technique for designing stable openings in bedded salt formations is explained

  5. [Salt and cancer].

    Science.gov (United States)

    Strnad, Marija

    2010-05-01

    Besides cardiovascular disease, a high salt intake causes other adverse health effects, i.e., gastric and some other cancers, obesity (risk factor for many cancer sites), Meniere's disease, worsening of renal disease, triggering an asthma attack, osteoporosis, exacerbation of fluid retention, renal calculi, etc. Diets containing high amounts of food preserved by salting and pickling are associated with an increased risk of cancers of the stomach, nose and throat. Because gastric cancer is still the most common cancer in some countries (especially in Japan), its prevention is one of the most important aspects of cancer control strategy. Observations among Japanese immigrants in the U.S.A. and Brazil based on the geographic differences, the trend in cancer incidence with time, and change in the incidence patterns indicate that gastric cancer is closely associated with dietary factors such as the intake of salt and salted food. The findings of many epidemiological studies suggest that high dietary salt intake is a significant risk factor for gastric cancer and this association was found to be strong in the presence of Helicobacter (H.) pylori infection with atrophic gastritis. A high-salt intake strips the lining of the stomach and may make infection with H. pylori more likely or may exacerbate the infection. Salting, pickling and smoking are traditionally popular ways of preparing food in Japan and some parts of Asia. In addition to salt intake, cigarette smoking and low consumption of fruit and vegetables increase the risk of stomach cancer. However, it is not known whether it is specifically the salt in these foods or a combination of salt and other chemicals that can cause cancer. One study identified a mutagen in nitrite-treated Japanese salted fish, and chemical structure of this mutagen suggests that it is derived from methionine and that salt and nitrite are precursors for its formation. Working under conditions of heat stress greatly increased the workers

  6. Resedimented salt deposits

    Energy Technology Data Exchange (ETDEWEB)

    Slaczka, A.; Kolasa, K. (Jagiellonian Univ., Krakow (Poland))

    1988-08-01

    Carparthian foredeep's Wieliczka salt mine, unique gravity deposits were lately distinguished. They are mainly built of salt particles and blocks with a small admixture of fragments of Miocene marls and Carpathian rocks, deposited on precipitated salt. The pattern of sediment distribution is similar to a submarine fan. Gravels are dominant in the upper part and sands in lower levels, creating a series of lobes. Coarse-grained deposits are represented by disorganized, self-supported conglomerates passing into matrix-supported ones, locally with gradation, and pebbly sandstones consisting of salt grains and scattered boulder-size clasts. The latter may show in the upper part of a single bed as indistinct cross-bedding and parallel lamination. These sediments are interpreted as debris-flow and high-density turbidity current deposits. Salt sandstones (saltstones) which build a lower part of the fan often show Bouma sequences and are interpreted as turbidity-current deposits. The fan deposits are covered by a thick series of debrites (olistostromes) which consist of clay matrix with salt grains and boulders. The latter as represented by huge (up to 100,000 m{sup 3}) salt blocks, fragments of Miocene marls and Carpathian rocks. These salt debrites represent slumps and debris-flow deposits. The material for resedimented deposits was derived from the southern part of the salt basin and from the adjacent, advancing Carpathian orogen. The authors believe the distinct coarsening-upward sequence of the series is the result of progressive intensification of tectonic movements with paroxysm during the sedimentation of salt debrites (about 15 Ma).

  7. Water purification using organic salts

    Science.gov (United States)

    Currier, Robert P.

    2004-11-23

    Water purification using organic salts. Feed water is mixed with at least one organic salt at a temperature sufficiently low to form organic salt hydrate crystals and brine. The crystals are separated from the brine, rinsed, and melted to form an aqueous solution of organic salt. Some of the water is removed from the aqueous organic salt solution. The purified water is collected, and the remaining more concentrated aqueous organic salt solution is reused.

  8. Gases in molten salts

    CERN Document Server

    Tomkins, RPT

    1991-01-01

    This volume contains tabulated collections and critical evaluations of original data for the solubility of gases in molten salts, gathered from chemical literature through to the end of 1989. Within the volume, material is arranged according to the individual gas. The gases include hydrogen halides, inert gases, oxygen, nitrogen, hydrogen, carbon dioxide, water vapor and halogens. The molten salts consist of single salts, binary mixtures and multicomponent systems. Included also, is a special section on the solubility of gases in molten silicate systems, focussing on slags and fluxes.

  9. Esterification Mechanism of Bagasse Modified with Glutaric Anhydride in 1-Allyl-3-methylimidazolium Chloride.

    Science.gov (United States)

    Wang, Huihui; Chen, Wei; Zhang, Xueqin; Liu, Chuanfu; Sun, Runcang

    2017-08-18

    The esterification of bagasse with glutaric anhydride could increase surface adhesion compatibility and the surface of derived polymers has the potential of immobilizing peptides or proteins for biomedical application. Due to its complicated components, the esterification mechanism of bagasse esterified with glutaric anhydride in ionic liquids has not been studied. In this paper, the homogenous esterification of bagasse with glutaric anhydride was comparatively investigated with the isolated cellulose, hemicelluloses, and lignin in 1-allyl-3-methylimidazolium chloride (AmimCl) to reveal the reaction mechanism. Fourier transform infrared (FT-IR) indicated that the three components (cellulose, hemicelluloses, and lignin) were all involved in the esterification. The percentage of substitution (PS) of bagasse was gradually improved with the increased dosage of glutaric anhydride (10-40 mmol/g), which was primarily attributed to the increased esterification of cellulose and hemicelluloses. However, the PS fluctuation of lignin led to a decrease in the PS of bagasse at high glutaric anhydride dosage (50 mmol/g). The esterification reactivity of bagasse components followed the order of lignin > hemicelluloses > cellulose. The esterification mechanism was proposed as a nucleophilic substitution reaction. Nuclear magnetic resonance (NMR) analysis indicated that lignin aliphatic hydroxyls were prior to be esterified, and primary hydroxyls were more reactive than secondary hydroxyls in cellulose and hemicelluloses.

  10. Increased presevation of sliced mozzarella cheese by antimibrobial sachet incorporated with allyl isothiocyanate

    Directory of Open Access Journals (Sweden)

    Ana Clarissa dos Santos Pires

    2009-12-01

    Full Text Available There is an increasing tendency to add natural antimicrobials of plant origin into food. The objective of this work was to develop a microbial sachet incorporated with allyl isothiocyanate (AIT, a volatile compound of plant origin, and to test its efficiency against growth of yeasts and molds, Staphylococcus sp. and psychrotrophic bacteria on sliced mozzarella cheese. Another objective was to quantify the concentration of AIT in the headspace of cheese packaging. A reduction of 3.6 log cycles was observed in yeasts and molds counts in the mozzarella packed with the antimicrobial sachet over 15-day storage time. The sachet also showed an antibacterial effect on Staphylococcus sp., reducing 2.4 log cycles after 12-day storage. Psychrotrophic bacteria species were the most resistant to the antimicrobial action. The highest concentration of AIT (0.08µg.mL-1 inside the active packaging system was observed at the 6-day of storage at 12 ºC ± 2 ºC. At the end of the storage time, AIT concentration decreased to only 10% of the initial concentration. Active packaging containing antimicrobial sachet has a potential use for sliced mozzarella, with molds and yeasts being the most sensitive to the antimicrobial effects.

  11. Non-Directed Allylic C–H Acetoxylation in the Presence of Lewis Basic Heterocycles

    Science.gov (United States)

    Malik, Hasnain A.; Taylor, Buck L. H.; Kerrigan, John R.; Grob, Jonathan E.; Houk, K. N.; Du Bois, J.; Hamann, Lawrence G.; Patterson, Andrew W.

    2015-01-01

    We outline a strategy to enable non-directed Pd(II)-catalyzed C–H functionalization in the presence of Lewis basic heterocycles. In a high-throughput screen of two Pd-catalyzed C–H acetoxylation reactions, addition of a variety of N-containing heterocycles is found to cause low product conversion. A pyridine-containing test substrate is selected as representative of heterocyclic scaffolds that are hypothesized to cause catalyst arrest. We pursue two approaches in parallel that allow product conversion in this representative system: Lewis acids are found to be effective in situ blocking groups for the Lewis basic site, and a pre-formed pyridine N-oxide is shown to enable high yield of allylic C–H acetoxylation. Computational studies with density functional theory (M06) of binding affinities of selected heterocycles to Pd(OAc)2 provide an inverse correlation of the computed heterocycle–Pd(OAc)2 binding affinities with the experimental conversions to products. Additionally, 1H NMR binding studies provide experimental support for theoretical calculations. PMID:25685311

  12. Allyl m-Trifluoromethyldiazirine Mephobarbital: An Unusually Potent Enantioselective and Photoreactive Barbiturate General Anesthetic

    Energy Technology Data Exchange (ETDEWEB)

    Savechenkov, Pavel Y.; Zhang, Xi; Chiara, David C.; Stewart, Deirdre S.; Ge, Rile; Zhou, Xiaojuan; Raines, Douglas E.; Cohen, Jonathan B.; Forman, Stuart A.; Miller, Keith W.; Bruzik, Karol S. (Harvard-Med); (Mass. Gen. Hosp.); (UIC)

    2012-12-10

    We synthesized 5-allyl-1-methyl-5-(m-trifluoromethyl-diazirynylphenyl)barbituric acid (14), a trifluoromethyldiazirine-containing derivative of general anesthetic mephobarbital, separated the racemic mixture into enantiomers by chiral chromatography, and determined the configuration of the (+)-enantiomer as S by X-ray crystallography. Additionally, we obtained the {sup 3}H-labeled ligand with high specific radioactivity. R-(-)-14 is an order of magnitude more potent than the most potent clinically used barbiturate, thiopental, and its general anesthetic EC{sub 50} approaches those for propofol and etomidate, whereas S-(+)-14 is 10-fold less potent. Furthermore, at concentrations close to its anesthetic potency, R-(-)-14 both potentiated GABA-induced currents and increased the affinity for the agonist muscimol in human {alpha}1{beta}2/3{gamma}2L GABA{sub A} receptors. Finally, R-(-)-14 was found to be an exceptionally efficient photolabeling reagent, incorporating into both {alpha}1 and {beta}3 subunits of human {alpha}1{beta}3 GABAA receptors. These results indicate R-(-)-14 is a functional general anesthetic that is well-suited for identifying barbiturate binding sites on Cys-loop receptors.

  13. Allyl Isothiocyanate Inhibits Actin-Dependent Intracellular Transport in Arabidopsis thaliana

    Directory of Open Access Journals (Sweden)

    Bjørnar Sporsheim

    2015-12-01

    Full Text Available Volatile allyl isothiocyanate (AITC derives from the biodegradation of the glucosinolate sinigrin and has been associated with growth inhibition in several plants, including the model plant Arabidopsis thaliana. However, the underlying cellular mechanisms of this feature remain scarcely investigated in plants. In this study, we present evidence of an AITC-induced inhibition of actin-dependent intracellular transport in A. thaliana. A transgenic line of A. thaliana expressing yellow fluorescent protein (YFP-tagged actin filaments was used to show attenuation of actin filament movement by AITC. This appeared gradually in a time- and dose-dependent manner and resulted in actin filaments appearing close to static. Further, we employed four transgenic lines with YFP-fusion proteins labeling the Golgi apparatus, endoplasmic reticulum (ER, vacuoles and peroxisomes to demonstrate an AITC-induced inhibition of actin-dependent intracellular transport of or, in these structures, consistent with the decline in actin filament movement. Furthermore, the morphologies of actin filaments, ER and vacuoles appeared aberrant following AITC-exposure. However, AITC-treated seedlings of all transgenic lines tested displayed morphologies and intracellular movements similar to that of the corresponding untreated and control-treated plants, following overnight incubation in an AITC-absent environment, indicating that AITC-induced decline in actin-related movements is a reversible process. These findings provide novel insights into the cellular events in plant cells following exposure to AITC, which may further expose clues to the physiological significance of the glucosinolate-myrosinase system.

  14. A protic ionic liquid as an atom economical solution for palladium catalyzed asymmetric allylic alkylation.

    Science.gov (United States)

    Guerrero-Ríos, Itzel; Ortiz-Ramírez, Alfonso H; van Leeuwen, Piet W N M; Martin, Erika

    2018-03-12

    The asymmetric allylic alkylation of rac-1,3-diphenyl-3-acetoxyprop-1-ene (I) catalysed by palladium and diverse phosphorus containing ligands [(S)-BINAP, (R,R)-Chiraphite and (R,R)-Et-Duphos] in an ionic liquid [HDBU][OAc] was successfully performed, achieving full conversions and up to 96% ee of the (S)-product when (R,R)-Et-Duphos was used as a ligand. The reaction could be performed using an equimolar amount of substrate, malonate and base DBU, in which case the total products sum to the desired alkylated product and the ionic pair [HDBU][OAc]; this system thus produces its own IL solvent as the only co-product. These catalytic systems were active in recycling experiments for up to four cycles, albeit with a loss of activity due to the poor retention of palladium in the ionic liquid. The catalytic performance of each Pd/ligand system was optimized by varying the ratio of the substrate and malonate. Systems based on [HDBU][OAc] were found to be the best.

  15. Hydrolysis of cellulose catalyzed by quaternary ammonium perrhenates in 1-allyl-3-methylimidazolium chloride.

    Science.gov (United States)

    Wang, Jingyun; Zhou, Mingdong; Yuan, Yuguo; Zhang, Quan; Fang, Xiangchen; Zang, Shuliang

    2015-12-01

    Quaternary ammonium perrhenates were applied as catalyst to promote the hydrolysis of cellulose in 1-allyl-3-methylimidazolium chloride ([Amim]Cl). The quaternary ammonium perrhenates displayed good catalytic performance for cellulose hydrolysis. Water was also proven to be effective to promote cellulose hydrolysis. Accordingly, 97% of total reduced sugar (TRS) and 42% of glucose yields could be obtained under the condition of using 5mol% of tetramethyl ammonium perrhenate as catalyst, 70μL of water, ca. 0.6mmol of microcrystalline cellulose (MCC) and 2.0g of [Amim]Cl as solvent under microwave irradiation for 30min at 150°C (optimal conditions). The influence of quaternary ammonium cation on the efficiency of cellulose hydrolysis was examined based on different cation structures of perrhenates. The mechanism on perrhenate catalyzed cellulose hydrolysis is also discussed, whereas hydrogen bonding between ReO4 anion and hydroxyl groups of cellulose is assumed to be the key step for depolymerization of cellulose. Copyright © 2015. Published by Elsevier Ltd.

  16. On the X-ray reflectivity by poly allyl diglycol carbonate (PADC)

    International Nuclear Information System (INIS)

    Ghazaly, M. El

    2011-01-01

    X-ray reflectivity via the poly allyl diglycol carbonate (CR-39 polymer sheet) was investigated. X-ray reflectivity was measured for a pristine and a chemically etched CR-39 detector in 6.25N NaOH at (70 ± 0.5) .deg. C for different durations. Far from the spectral peak, the reflectivity of the CR-39 polymer sheet has a wide peak at 2θ = 20.1 .deg. , and its intensity is decreased by increasing the etching time. Moreover, the integrated counts under the peaks, C(t e ), vary linearly as a function of the etching time t e . Data are fitted using a linear function C(t e ) = A+Bt e , with fitting parameters A = (3271 ± 170) and B = (- 960 ± 84). The reflectivity deterioration is attributed to the increase of CR-39 surface's roughness due to the chemical etching. The rocking curves of X-ray reflectivity were measured for a pristine and an etched CR-39 polymer sheet. Specular reflections are observed, as well as Yoneda wings, which broaden and move away from the specular reflections due to the increase in the CR-39 surface's roughness.

  17. Sustainable and Low Viscous 1-Allyl-3-methylimidazolium Acetate + PEG Solvent for Cellulose Processing

    Directory of Open Access Journals (Sweden)

    Airong Xu

    2017-02-01

    Full Text Available Developing sustainable, low viscous and efficient solvents are always advantageous to the processing/fabricating of cellulose materials in practical applications. To this end, in this work novel solvents were developed; ([Amim][CH3COO]/PEG by dissolving polyethylene glycol 200 (PEG-200 in 1-allyl-3-methylimidazolium acetate ([Amim][CH3COO]. The solubilities of cellulose in [Amim][CH3COO]/PEG solvents were determined as a function of temperature, and the possible dissolution mechanism of cellulose in [Amim][CH3COO]/PEG solvent was investigated. The novel solvent exhibits outstanding advantages for good dissolution capacity of cellulose, such as low viscosity, negligible vapor pressure, and recycling capability. The [CH3COO]− anion and the [Amim]+ cation of [Amim][CH3COO] in [Amim][CH3COO]/PEG-10 are the driving force for cellulose dissolution verified by the 13C NMR spectra. In addition, the regenerated cellulose films from [Amim][CH3COO]/PEG solvent were characterized by scanning electron microscopy (SEM, X-ray diffraction (XRD, attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR, and thermogravimetric analysis (TGA to estimate their morphologies and structures.

  18. What Are Bath Salts?

    Science.gov (United States)

    ... bath salts can produce: feelings of joy increased social interaction increased sex drive paranoia nervousness hallucinations (see or ... and Addiction Drug Overdoses in Youth Viral Infections (HIV, Hepatitis) and Drug Use Real Questions from Real ...

  19. Mass transport in bedded salt and salt interbeds

    International Nuclear Information System (INIS)

    Hwang, Y.; Pigford, T.H.; Chambre, P.L.; Lee, W.W.L.

    1989-08-01

    Salt is the proposed host rock for geologic repositories of nuclear waste in several nations because it is nearly dry and probably impermeable. Although experiments and experience at potential salt sites indicate that salt may contain brine, the low porosity, creep, and permeability of salt make it still a good choice for geologic isolation. In this paper we summarize several mass-transfer and transport analyses of salt repositories. The mathematical details are given in our technical reports

  20. Aspects of the Influence of Light on the Adsorption and Electrooxidation of Allyl Alcohol on Pt/Pt Electrodes in Perchloric Acid Solutions

    Directory of Open Access Journals (Sweden)

    Barin Claudia Smaniotto

    1998-01-01

    Full Text Available The electrooxidation of the adsorbed species produced by allyl alcohol adsorption on platinized platinum electrode has been studied in 1.0 M HClO4 medium. The maximum amount of adsorbed intermediates formed during allyl alcohol adsorption on the electrode surface, was observed at the adsorption potential, Eads = 0.00 V (SCE. Chronoamperometric studies at this potential confirm that the current associated with the hydrogen adsorption process decreases in the presence of the organic compound. Allyl alcohol displaces adsorbed hydrogen at the active sites. The incidence of polychromatic light on the electrode improves this effect as shown by comparison with the same experiments in the darkness. However, the electrooxidation of the adsorbed species comprise a monoelectronic charge transfer step. The anodic current associated with this process was higher under illumination than in the dark. This difference was attributed to a light-induced effect: either on the adsorption process of allyl alcohol on Pt/Pt, or on the electrooxidation of the adsorbed species. The electrooxidation of the adsorbed species formed during allyl alcohol adsorption demands apparent activation energies equivalent to 33.3 kJ mol-1 and 24.9 kJ mol-1 in the dark and under illumination, respectively.

  1. Molten salt reactor type

    International Nuclear Information System (INIS)

    1977-01-01

    This document is one of the three parts of a first volume devoted to the compilations of American data on the molten salt reactor concept. Emphasize is put essentially on the fuel salt of the primary circuit inside which fission reactions occur. The reasons why the (LiF-BeF 2 -ThF 4 -UF 4 ) salt was chosen for the M.S.B.R. concept are examined; the physical, physicochemical and chemical properties of this salt are discussed with its interactions with the structural materials and its evolution in time. An important part of this volume is devoted to the continuous reprocessing of the active salt, the project designers having deemed advisable to take advantage at best from the availability of a continuous purification, in a thermal breeding. The problem of tritium formation and distribution inside the reactor is also envisaged and the fundamentals of the chemistry of the secondary coolant salt are given. The solutions proposed are: the hydrogen scavenging of the primary circuit, a reduction in metal permeability by an oxyde layer deposition on the side in contact with the vapor, and tritium absorption through an isotope exchange with the hydroxifluoroborate [fr

  2. Not salt taste perception but self-reported salt eating habit predicts actual salt intake.

    Science.gov (United States)

    Lee, Hajeong; Cho, Hyun-Jeong; Bae, Eunjin; Kim, Yong Chul; Kim, Suhnggwon; Chin, Ho Jun

    2014-09-01

    Excessive dietary salt intake is related to cardiovascular morbidity and mortality. Although dietary salt restriction is essential, it is difficult to achieve because of salt palatability. However, the association between salt perception or salt eating habit and actual salt intake remains uncertain. In this study, we recruited 74 healthy young individuals. We investigated their salt-eating habits by questionnaire and salt taste threshold through a rating scale that used serial dilution of a sodium chloride solution. Predicted 24-hr urinary salt excretions using Kawasaki's and Tanaka's equations estimated dietary salt intake. Participants' mean age was 35 yr, and 59.5% were male. Salt sense threshold did not show any relationship with actual salt intake and a salt-eating habit. However, those eating "salty" foods showed higher blood pressure (P for trend=0.048) and higher body mass index (BMI; P for trend=0.043). Moreover, a salty eating habit was a significant predictor for actual salt intake (regression coefficient [β] for Kawasaki's equation 1.35, 95% confidence interval [CI] 10-2.69, P=0.048; β for Tanaka's equation 0.66, 95% CI 0.01-1.31, P=0.047). In conclusion, a self-reported salt-eating habit, not salt taste threshold predicts actual salt intake.

  3. Cooperativity of complex salt bridges

    OpenAIRE

    Gvritishvili, Anzor G.; Gribenko, Alexey V.; Makhatadze, George I.

    2008-01-01

    The energetic contribution of complex salt bridges, in which one charged residue (anchor residue) forms salt bridges with two or more residues simultaneously, has been suggested to have importance for protein stability. Detailed analysis of the net energetics of complex salt bridge formation using double- and triple-mutant cycle analysis revealed conflicting results. In two cases, it was shown that complex salt bridge formation is cooperative, i.e., the net strength of the complex salt bridge...

  4. Effect of Low Salt Diet on Insulin Resistance in Salt Sensitive versus Salt Resistant Hypertension

    Science.gov (United States)

    Garg, Rajesh; Sun, Bei; Williams, Jonathan

    2014-01-01

    Accumulating evidence shows an increase in insulin resistance on salt restriction. We compared the effect of low salt diet on insulin resistance in salt sensitive versus salt resistant hypertensive subjects. We also evaluated the relationship between salt sensitivity of blood pressure and salt sensitivity of insulin resistance in a multivariate regression model. Studies were conducted after one week of high salt (200 mmol/day Na) and one week of low salt (10 mmol/day Na) diet. Salt sensitivity was defined as the fall in systolic blood pressure >15mmHg on low salt diet. The study includes 389 subjects (44% Females, 16% Blacks, BMI 28.5±4.2 Kg/m2). As expected, blood pressure was lower on low salt (129±16/78±9 mmHg) as compared to high salt diet (145±18/86±10 mmHg). Fasting plasma glucose, insulin and HOMA were higher on low salt diet (95.4±19.4 mg/dl, 10.8±7.3 mIU/L and 2.6±1.9) as compared to high salt diet (90.6±10.8 mg/dl, 9.4±5.8 mIU/L and 2.1±1.4) (p salt sensitive (N=193) versus salt resistant (N=196) subjects on either diet. Increase in HOMA on low salt diet was 0.5±1.4 in salt sensitive and 0.4±1.5 in salt resistant subjects (p=NS). On multivariate regression analysis, change in systolic blood pressure was not associated with change in HOMA after including age, BMI, sex, change in serum and urine aldosterone and cortisol into the model. We conclude that the increase in insulin resistance on low salt diet is not affected by salt sensitivity of blood pressure. PMID:25185125

  5. Elucidation of the regio- and chemoselectivity of enzymatic allylic oxidations with Pleurotus sapidus – conversion of selected spirocyclic terpenoids and computational analysis

    Directory of Open Access Journals (Sweden)

    Verena Weidmann

    2013-10-01

    Full Text Available Allylic oxidations of olefins to enones allow the efficient synthesis of value-added products from simple olefinic precursors like terpenes or terpenoids. Biocatalytic variants have a large potential for industrial applications, particularly in the pharmaceutical and food industry. Herein we report efficient biocatalytic allylic oxidations of spirocyclic terpenoids by a lyophilisate of the edible fungus Pleurotus sapidus. This ‘’mushroom catalysis’’ is operationally simple and allows the conversion of various unsaturated spirocyclic terpenoids. A number of new spirocyclic enones have thus been obtained with good regio- and chemoselectivity and chiral separation protocols for enantiomeric mixtures have been developed. The oxidations follow a radical mechanism and the regioselectivity of the reaction is mainly determined by bond-dissociation energies of the available allylic CH-bonds and steric accessibility of the oxidation site.

  6. Effects of microencapsulated Allyl isothiocyanate (AITC) on the extension of the shelf-life of Kimchi.

    Science.gov (United States)

    Ko, J A; Kim, W Y; Park, H J

    2012-02-01

    Allyl isothiocyanate (AITC) is a well-recognized antimicrobial agent but, application of AITC to food systems is limited due to its high volatility and strong odor. This study was performed to overcome the volatility of AITC by encapsulation using gum Arabic and chitosan and to investigate the effect of microencapsulated AITC as a natural additive on the shelf-life and quality of Kimchi. AITC loaded microparticles were prepared using gum Arabic and chitosan and were added to Kimchi at various concentrations (0-0.02%, w/w). The titratable acidity, pH, microbial changes, and sensory test of Kimchi were examined for 15days at different fermentation temperatures (4 and 10°C). The pH of Kimchi containing AITC microparticles was significantly higher than that of control and the higher the quantity of added AITC, the higher the pH became. The titratable acidity of Kimchi increased during storage especially, titratable acidity of control increased significantly higher than those of Kimchi with added AITC microparticles. The number of Leuconostoc and Lactobacillus species in Kimchi decreased with an increase in the concentration of AITC. The addition of AITC induced reduction of sour taste and improvement of the texture of Kimchi during fermentation. However, as the content of AITC increased, the scores of overall acceptability decreased due to the odor of AITC. These results indicate that addition of AITC (less than 0.1%) to Kimchi is an effective way of enhancing the shelf-life of Kimchi without reducing quality. Copyright © 2011 Elsevier B.V. All rights reserved.

  7. Proton conductive membranes based on poly (styrene-co-allyl alcohol semi-IPN

    Directory of Open Access Journals (Sweden)

    Felipe Augusto Moro Loureiro

    2014-01-01

    Full Text Available The optimization of fuel cell materials, particularly polymer membranes, for PEMFC has driven the development of methods and alternatives to achieve systems with more adequate properties to this application. The sulfonation of poly (styrene-co-allyl alcohol (PSAA, using sulfonating agent:styrene ratios of 2:1, 1:1, 1:2, 1:4, 1:6, 1:8 and 1:10, was previously performed to obtain proton conductive polymer membranes. Most of those membranes exhibited solubility in water with increasing temperature and showed conductivity of approximately 10-5 S cm-1. In order to optimize the PSAA properties, especially decreasing its solubility, semi-IPN (SIPN membranes are proposed in the present study. These membranes were obtained from the diglycidyl ether of bisphenol A (DGEBA, curing reactions in presence of DDS (4,4-diaminodiphenyl sulfone and PSAA. Different DGEBA/PSAA weight ratios were employed, varying the PSAA concentration between 9 and 50% and keeping the mass ratio of DGEBA:DDS as 1:1. The samples were characterized by FTIR and by electrochemical impedance spectroscopy. Unperturbed bands of PSAA were observed in the FTIR spectra of membranes, suggesting that chemical integrity of the polymer is maintained during the synthesis. In particular, bands involving C-C stretching (1450 cm-1, C=C (aromatic, ~ 3030 cm-1 and C-H (2818 and 2928 cm-1 were observed, unchanged after the synthesis. The disappearance or reduction of the intensity of the band at 916 cm-1, attributed to the DGEBA epoxy ring, is evidenced for all samples, indicating the epoxy ring opening and the DGEBA crosslinking. Conductivity of H3PO4 doped membranes increases with temperature, reaching 10-4 S cm-1.

  8. Rate of Molecular Transfer of Allyl Alcohol across an AOT Surfactant Layer Using Muon Spin Spectroscopy.

    Science.gov (United States)

    Jayasooriya, Upali A; Clayden, Nigel J; Steytler, David C; Oganesyan, Vasily S; Peck, Jamie N T; Khasanov, Rustem; Scheuermann, Robert; Stoykov, Alexey

    2016-01-26

    The transfer rate of a probe molecule across the interfacial layer of a water-in-oil (w/o) microemulsion was investigated using a combination of transverse field muon spin rotation (TF-μSR), avoided level crossing muon spin resonance (ALC-μSR), and Monte Carlo simulations. Reverse microemulsions consist of nanometer-sized water droplets dispersed in an apolar solvent separated by a surfactant monolayer. Although the thermodynamic, static model of these systems has been well described, our understanding of their dynamics is currently incomplete. For example, what is the rate of solute transfer between the aqueous and apolar solvents, and how this is influenced by the structure of the interface? With an appropriate choice of system and probe molecule, μSR offers a unique opportunity to directly probe these interfacial transfer dynamics. Here, we have employed a well characterized w/o microemulsion stabilized by bis(2-ethylhexyl) sodium sulfosuccinate (Aerosol OT), with allyl alcohol (CH2═CH-CH2-OH, AA) as the probe. Resonances due to both muoniated radicals, CMuH2-C*H-CH2-OH and C*H2-CHMu-CH2-OH, were observed with the former being the dominant species. All resonances displayed solvent dependence, with those in the microemulsion observed as a single resonance located at intermediate magnetic fields to those present in either of the pure solvents. Observation of a single resonance is strong evidence for interfacial transfer being in the fast exchange limit. Monte Carlo calculations of the ΔM = 0 ALC resonances are consistent with the experimental data, indicating exchange rates greater than 10(9) s(-1), placing the rate of interfacial transfer at the diffusion limit.

  9. Antibacterial activity of starch/acrylamide/allyl triphenyl phosphonium bromide copolymers synthesized by gamma irradiation

    International Nuclear Information System (INIS)

    Song, Weiqiang; Guo, Zhengchao; Zhang, Linqi; Zheng, Hongjuan; Zhao, Zhiwei

    2013-01-01

    Starch/acrylamide/allyl triphenyl phosphonium bromide (St/AM/TP) copolymers were synthesized by simultaneous gamma irradiation and characterized by FTIR and 1 H NMR techniques, weight measurement and titration method. Moreover, their antibacterial activities against Staphylococcus aureus were explored by the viable cell counting method in sterile distilled water. At St/AM/TP 6:8.4:5.6 g, copolymers with higher graft ratio (G) and higher (AM+TP) graft efficiency (E AM+TP ) were obtained at 3 and 6 kGy, while cationic degree (CD) and TP graft efficiency (E TP ) continuously increased with absorbed dose from 1 to 6 kGy. All of the copolymers were capable of killing >99.75% of 10 7 CFU/ml S. aureus within 30 mins. Moreover, at 3 kGy, G, E AM+TP and E TP increased with AM/TP from 0:14 to 11.2:2.8 g at St/(AM+TP) 6:14 g, while the optimum CD and antibacterial activity were achieved at AM/TP 7:7 and 8.4:5.6 g. In addition, at 3 kGy, G, E AM+TP and CD increased with St/(AM+TP) from 6:3 to 6:18 g at AM/TP 8.4:5.6 g, while the optimum antibacterial activity was achieved at 6:10 to 6:18 g, and the optimum E TP was achieved at 6:14. - Highlights: • Cationic starch is prepared from AM and TP by Gamma irradiation. • Cationic starch is characterized by FTIR, NMR, weight method and titration method. • Grafting ratio and cationic degree depend on absorbed dose and composition. • Cationic starch shows good antibacterial activity against Staphylococcus aureus

  10. Mechanism of copper(I)-catalyzed allylic alkylation of phosphorothioate esters: influence of the leaving group on α regioselectivity.

    Science.gov (United States)

    Sheng, Wenhao; Wang, Mian; Lein, Matthias; Jiang, Linbin; Wei, Wanxing; Wang, Jianyi

    2013-10-11

    The mechanism of Cu(I) -catalyzed allylic alkylation and the influence of the leaving groups (OPiv, SPiv, Cl, SPO(OiPr)2 ; Piv: pivavloyl) on the regioselectivity of the reaction have been explored by using density functional theory (DFT). A comprehensive comparison of many possible reaction pathways shows that [(iPr)2 Cu](-) prefers to bind first oxidatively to the double bond of the allylic substrate at the anti position with respect to the leaving group, and this is followed by dissociation of the leaving group. If the leaving group is not taken into account, the reaction then undergoes an isomerization and a reductive elimination process to give the α- or γ-selective product. If OPiv, SPiv, Cl, or SPO(OiPr)2 groups are present, the optimal route for the formation of both α- and γ-substituted products changes from the stepwise elimination to the direct process, in which the leaving group plays a stabilizing role for the reactant and destabilizes the transition state. The differences to the energy barrier for the α- and γ-substituted products are 2.75 kcal mol(-1) with SPO(OiPr)2 , 2.44 kcal mol(-1) with SPiv, 2.33 kcal mol(-1) with OPiv, and 1.98 kcal mol(-1) with Cl, respectively; these values show that α regioselectivity in the allylic alkylation follows a SPO(OiPr)2 >SPiv>OPiv>Cl trend, which is in satisfactory agreement with the experimental findings. This trend mainly originates in the differences between the attractive electrostatic forces and the repelling steric interactions of the SPO(OiPr)2 , SPiv, OPiv, and Cl groups on the Cu group. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. Facile Preparation of (2Z,4E)-Dienamides by the Olefination of Electron-deficient Alkenes with Allyl Acetate.

    Science.gov (United States)

    Ding, Liyuan; Yu, Chunbing; Zhao, Zhenqiang; Li, Feifei; Zhang, Jian; Zhong, Guofu

    2017-06-21

    Direct cross-coupling between two alkenes via vinylic C-H bond activation represents an efficient strategy for the synthesis of butadienes with high atomic and step economy. However, this functionality-directed cross-coupling reaction has not been developed, as there are still limited directing groups in practical use. In particular, a stoichiometric amount of oxidant is usually required, producing a large amount of waste. Due to our interest in novel 1,3-butadiene synthesis, we describe the ruthenium-catalyzed olefination of electron-deficient alkenes using allyl acetate and without external oxidant. The reaction of 2-phenyl acrylamide and allyl acetate was chosen as a model reaction, and the desired diene product was obtained in 80% isolated yield with good stereoselectivity (Z,E/Z,Z = 88:12) under optimal conditions: [Ru(p-cymene) Cl2]2 (3 mol %) and AgSbF6 (20 mol %) in DCE at 110 ºC for 16 h. With the optimized catalytic conditions in hand, representative α- and/or β-substituted acrylamides were investigated, and all reacted smoothly, regardless of aliphatic or aromatic groups. Also, differently N-substituted acrylamides have proven to be good substrates. Moreover, we examined the reactivity of different allyl derivatives, suggesting that the chelation of acetate oxygen to the metal is crucial for the catalytic process. Deuterium-labeled experiments were also conducted to investigate the reaction mechanism. Only Z-selective H/D exchanges on acrylamide were observed, indicating a reversible cyclometalation event. In addition, a kinetic isotope effect (KIE) of 3.2 was observed in the intermolecular isotopic study, suggesting that the olefinic C-H metalation step is probably involved in the rate-determining step.

  12. Great Salt Lake, Utah

    Science.gov (United States)

    Stephens, Doyle W.; Gardner, Joe F.

    1999-01-01

    This document is intended as a source of general information and facts about Great Salt Lake, Utah. This U.S. Geological Survey information sheet answers frequently asked questions about Great Salt Lake. Topics include: History, salinity, brine shrimp, brine flies, migratory birds, and recreation. Great Salt Lake, the shrunken remnant of prehistoric Lake Bonneville, has no outlet. Dissolved salts accumulate in the lake by evaporation. Salinity south of the causeway has ranged from 6 percent to 27 percent over a period of 22 years (2 to 7 times saltier than the ocean). The high salinity supports a mineral industry that extracts about 2 million tons of salt from the lake each year. The aquatic ecosystem consists of more than 30 species of organisms. Harvest of its best-known species, the brine shrimp, annually supplies millions of pounds of food for the aquaculture industry worldwide. The lake is used extensively by millions of migratory and nesting birds and is a place of solitude for people. All this occurs in a lake that is located at the bottom of a 35,000-square-mile drainage basin that has a human population of more than 1.5 million.

  13. Fundamental Properties of Salts

    Energy Technology Data Exchange (ETDEWEB)

    Toni Y Gutknecht; Guy L Fredrickson

    2012-11-01

    Thermal properties of molten salt systems are of interest to electrorefining operations, pertaining to both the Fuel Cycle Research & Development Program (FCR&D) and Spent Fuel Treatment Mission, currently being pursued by the Department of Energy (DOE). The phase stability of molten salts in an electrorefiner may be adversely impacted by the build-up of fission products in the electrolyte. Potential situations that need to be avoided, during electrorefining operations, include (i) fissile elements build up in the salt that might approach the criticality limits specified for the vessel, (ii) electrolyte freezing at the operating temperature of the electrorefiner due to changes in the liquidus temperature, and (iii) phase separation (non-homogenous solution). The stability (and homogeneity) of the phases can be monitored by studying the thermal characteristics of the molten salts as a function of impurity concentration. Simulated salt compositions consisting of the selected rare earth and alkaline earth chlorides, with a eutectic mixture of LiCl-KCl as the carrier electrolyte, were studied to determine the melting points (thermal characteristics) using a Differential Scanning Calorimeter (DSC). The experimental data were used to model the liquidus temperature. On the basis of the this data, it became possible to predict a spent fuel treatment processing scenario under which electrorefining could no longer be performed as a result of increasing liquidus temperatures of the electrolyte.

  14. Organocatalytic Asymmetric Allylic Alkylation of Morita-Baylis-Hillman Carbonates with Diethyl 2-Aminomalonate Assisted by In Situ Protection.

    Science.gov (United States)

    Zheng, Yu; Wang, Jing; Xia, Peng-Ju; Zhao, Qing-Lan; Xiao, Jun-An; Xiang, Hao-Yue; Chen, Xiao-Qing; Yang, Hua

    2017-12-01

    With the aid of in situ protection by N-(2-formylphenyl)-4-methyl-benzenesulfonamide, enantioselective allylic alkylation of Morita-Baylis-Hillman carbonates with diethyl 2-aminomalonate was successfully realized. The corresponding adducts can be obtained in up to 99% yield with up to 98% ee as well as excellent regioselectivity. Besides, the adducts with opposite configurations were readily prepared by utilizing easily available and inexpensive quinine or quinidine as organocatalyst. Facile deprotection of the resulting adduct provides straightforward access to enantiopure α-methylene-γ-lactam.

  15. Mechanism of the Suzuki–Miyaura Cross-Coupling Reaction Mediated by [Pd(NHC)(allyl)Cl] Precatalysts

    KAUST Repository

    Meconi, Giulia Magi

    2017-05-24

    Density functional theory calculations have been used to investigate the activation mechanism for the precatalyst series [Pd]-X-1–4 derived from [Pd(IPr)(R-allyl)X] species by substitutions at the terminal position of the allyl moiety ([Pd] = Pd(IPr); R = H (1), Me (2), gem-Me2 (3), Ph (4), X = Cl, Br). Next, we have investigated the Suzuki–Miyaura cross-coupling reaction for the active catalyst species IPr-Pd(0) using 4-chlorotoluene and phenylboronic acid as substrates and isopropyl alcohol as a solvent. Our theoretical findings predict an upper barrier trend, corresponding to the activation mechanism for the [Pd]-Cl-1–4 series, in good agreement with the experiments. They indeed provide a quantitative explanation of the low yield (12%) displayed by [Pd]-Cl-1 species (ΔG⧧ ≈ 30.0 kcal/mol) and of the high yields (≈90%) observed in the case of [Pd]-Cl-2–4 complexes (ΔG⧧ ≈ 20.0 kcal/mol). Additionally, the studied Suzuki–Miyaura reaction involving the IPr-Pd(0) species is calculated to be thermodynamically favorable and kinetically facile. Similar investigations for the [Pd]-Br-1–4 series, derived from [Pd(IPr)(R-allyl)Br], indicate that the oxidative addition step for IPr-Pd(0)-mediated catalysis with 4-bromotoluene is kinetically more favored than that with 4-chlorotoluene. Finally, we have explored the potential of Ni-based complexes [Ni((IPr)(R-allyl)X] (X = Cl, Br) as Suzuki–Miyaura reaction catalysts. Apart from a less endergonic reaction energy profile for both precatalyst activation and catalytic cycle, a steep increase in the predicted upper energy barriers (by 2.0–15.0 kcal/mol) is calculated in the activation mechanism for the [Ni]-X-1–4 series compared to the [Pd]-X-1–4 series. Overall, these results suggest that Ni-based precatalysts are expected to be less active than the Pd-based precatalysts for the studied Suzuki–Miyaura reaction.

  16. Chemoenzymatic synthesis of chiral 2,2'-bipyridine ligands and their N-oxide derivatives: applications in the asymmetric aminolysis of epoxides and asymmetric allylation of aldehydes.

    Science.gov (United States)

    Boyd, D R; Sharma, N D; Sbircea, L; Murphy, D; Malone, J F; James, S L; Allen, C C R; Hamilton, J T G

    2010-03-07

    A series of enantiopure 2,2'-bipyridines have been synthesised from the corresponding cis-dihydrodiol metabolites of 2-chloroquinolines. Several of the resulting hydroxylated 2,2'-bipyridines were found to be useful chiral ligands for the asymmetric aminolysis of meso-epoxides leading to the formation of enantioenriched amino alcohols (-->84% ee). N-oxide and N,N'-dioxide derivatives of these 2,2'-bipyridines, including separable atropisomers, have been synthesised and used as enantioselective organocatalysts in the asymmetric allylation of aldehydes to give allylic alcohols (-->86% ee).

  17. Use of Cyclic Allylic Bromides in the Zinc–Mediated Aqueous Barbier–Grignard Reaction

    Directory of Open Access Journals (Sweden)

    Suzanne M. Perala

    2001-07-01

    Full Text Available The zinc–mediated aqueous Barbier–Grignard reaction of cyclic allylic bromide substrates with various aldehydes and ketones to afford homoallylic alcohols was investigated. Aromatic aldehydes and ketones afforded adducts in good yields (66–90% and with good diastereoselectivities. Non–aromatic aldehydes also reacted well under these conditions, but only poor yields were obtained with non–aromatic ketones. Regioselectivity was high when some substituted cyclic allylic bromides were investigated.

  18. Hydrogen-Bond Directed Regioselective Pd-Catalyzed Asymmetric Allylic Alkylation: The Construction of Chiral α-Amino Acids with Vicinal Tertiary and Quaternary Stereocenters.

    Science.gov (United States)

    Wei, Xuan; Liu, Delong; An, Qianjin; Zhang, Wanbin

    2015-12-04

    A Pd-catalyzed asymmetric allylic alkylation of azlactones with 4-arylvinyl-1,3-dioxolan-2-ones was developed, providing "branched" chiral α-amino acids with vicinal tertiary and quaternary stereocenters, in high yields and with excellent selectivities. Mechanistic studies revealed that the formation of a hydrogen bond between the Pd-allylic complex and azlactone isomer is responsible for the excellent regioselectivities. This asymmetric alkylation can be carried out on a gram scale without a loss of catalytic efficiency, and the resulting product can be further transformed to a chiral azetidine in two simple steps.

  19. [bmim][Br] as a solvent and activator for the Ga-mediated Barbier allylation: direct formation of an N-heterocyclic carbene from Ga metal.

    Science.gov (United States)

    Goswami, Dibakar; Chattopadhyay, Angshuman; Sharma, Anubha; Chattopadhyay, Subrata

    2012-12-21

    The room-temperature ionic liquid (RTIL) [bmim][Br] has been found to be an excellent green and inexpensive medium for the Ga-mediated allylation of aromatic and aliphatic aldehydes and ketones. The RTIL activated the metal via formation of a Ga-N-heterocyclic carbene complex that assisted in the completion of the reaction at ambient temperature with only 0.5 equiv of Ga and 1.2 equiv of allyl bromide with respect to the carbonyl substrates. The present protocol required a much shorter time than those reported in the literature using other metals and solvents and proceeded with good yields and excellent selectivity.

  20. Iterative Cr-mediated catalytic asymmetric allylation to synthesize syn/syn- and anti/anti-1,3,5-triols.

    Science.gov (United States)

    Zhang, Zhiyu; Aubry, Sylvain; Kishi, Yoshito

    2008-07-17

    Iterative use of Cr-mediated catalytic asymmetric allylation could give a simple access to 1,3-polyols. Using syn/syn- and anti/anti-1,3,5-triols as representative examples, the feasibility of this approach is studied, thereby demonstrating that (1) the pre-existing TMS-protected alcohol at the beta-position does not give a significant effect on the Cr-mediated catalytic asymmetric allylation and (2) this synthetic route furnishes the expected syn/syn- and anti/anti-1,3,5-triols at the useful level of asymmetric induction and yield.

  1. Mineral resource of the month: salt

    Science.gov (United States)

    Kostick, Dennis S.

    2010-01-01

    The article presents information on various types of salt. Rock salt is either found from underground halite deposits or near the surface. Other types of salt include solar salt, salt brine, and vacuum pan salt. The different uses of salt are also given including its use as a flavor enhancer, as a road deicing agent, and to manufacture sodium hydroxide.

  2. Mechanism for salt scaling

    Science.gov (United States)

    Valenza, John J., II

    Salt scaling is superficial damage caused by freezing a saline solution on the surface of a cementitious body. The damage consists of the removal of small chips or flakes of binder. The discovery of this phenomenon in the early 1950's prompted hundreds of experimental studies, which clearly elucidated the characteristics of this damage. In particular it was shown that a pessimum salt concentration exists, where a moderate salt concentration (˜3%) results in the most damage. Despite the numerous studies, the mechanism responsible for salt scaling has not been identified. In this work it is shown that salt scaling is a result of the large thermal expansion mismatch between ice and the cementitious body, and that the mechanism responsible for damage is analogous to glue-spalling. When ice forms on a cementitious body a bi-material composite is formed. The thermal expansion coefficient of the ice is ˜5 times that of the underlying body, so when the temperature of the composite is lowered below the melting point, the ice goes into tension. Once this stress exceeds the strength of the ice, cracks initiate in the ice and propagate into the surface of the cementitious body, removing a flake of material. The glue-spall mechanism accounts for all of the characteristics of salt scaling. In particular, a theoretical analysis is presented which shows that the pessimum concentration is a consequence of the effect of brine pockets on the mechanical properties of ice, and that the damage morphology is accounted for by fracture mechanics. Finally, empirical evidence is presented that proves that the glue-small mechanism is the primary cause of salt scaling. The primary experimental tool used in this study is a novel warping experiment, where a pool of liquid is formed on top of a thin (˜3 mm) plate of cement paste. Stresses in the plate, including thermal expansion mismatch, result in warping of the plate, which is easily detected. This technique revealed the existence of

  3. Contact and fumigant toxicity of Armoracia rusticana essential oil, allyl isothiocyanate and related compounds to Dermatophagoides farinae.

    Science.gov (United States)

    Yun, Yeon-Kyeong; Kim, Hyun-Kyung; Kim, Jun-Ran; Hwang, Kumnara; Ahn, Young-Joon

    2012-05-01

    The toxicity to adult Dermatophagoides farinae of allyl isothiocyanate identified in horseradish, Armoracia rusticana, oil and another 27 organic isothiocyanates was evaluated using contact + fumigant and vapour-phase mortality bioassays. Results were compared with those of two conventional acaricides, benzyl benzoate and dibutyl phthalate. Horseradish oil (24 h LC(50), 1.54 µg cm(-2)) and allyl isothiocyanate (2.52 µg cm(-2)) were highly toxic. Benzyl isothiocyanate (LC(50) , 0.62 µg cm(-2)) was the most toxic compound, followed by 4-chlorophenyl, 3-bromophenyl, 3,5-bis(trifluoromethyl)phenyl, cyclohexyl, 2-chlorophenyl, 4-bromophenyl and 2-bromophenyl isothiocyanates (0.93-1.41 µg cm(-2)). All were more effective than either benzyl benzoate (LC(50) , 4.58 µg cm(-2)) or dibutyl phthalate (24.49 µg cm(-2)). The structure-activity relationship indicates that types of functional group and chemical structure appear to play a role in determining the isothiocyanate toxicities to adult D. farinae. In the vapour-phase mortality bioassay, these isothiocyanates were consistently more toxic in closed versus open containers, indicating that their mode of delivery was, in part, a result of vapour action. In the light of global efforts to reduce the level of highly toxic synthetic acaricides in indoor environments, the horseradish oil-derived compounds and the isothiocyanates described herein merit further study as potential acaricides for the control of house dust mite populations as fumigants with contact action. Copyright © 2011 Society of Chemical Industry.

  4. Salt repository design approach

    International Nuclear Information System (INIS)

    Matthews, S.C.

    1983-01-01

    This paper presents a summary discussion of the approaches that have been and will be taken in design of repository facilities for use with disposal of radioactive wastes in salt formations. Since specific sites have yet to be identified, the discussion is at a general level, supplemented with illustrative examples where appropriate. 5 references, 1 figure

  5. Crossing the Salt Barrier

    Indian Academy of Sciences (India)

    Fry. RIVER. To cross the salt barrier is, therefore, an obligatory part of every amphihaline fish cycle. Figure 2a. Life Cycle of. Salmon. Adult salmon migrate from sea towards the river. After reaching their hatching ground, the eggs are laid in the gravel. The spawned fishes are called kelts. Alevin is a stage from hatching to fry.

  6. Molten salt reactor concept

    International Nuclear Information System (INIS)

    Sood, D.D.

    1980-01-01

    Molten salt reactor is an advanced breeder concept which is suited for the utilization of thorium for nuclear power production. This reactor is based on the use of solutions of uranium or plutonium fluorides in LiF-BeF 2 -ThF 4 as fuel. Unlike the conventional reactors, no external coolant is used in the reactor core and the fuel salt itself is circulated through heat exchangers to transfer the fission produced heat to a secondary salt (NaF-NaBF 4 ) for steam generation. A part of the fuel stream is continuously processed to isolate 233 Pa, so that it can decay to fissile 233 U without getting converted to 234 Pa, and for the removal of neutron absorbing fission products. This on-line processing scheme makes this reactor concept to achieve a breeding ratio of 1.07 which is the highest for any thermal breeder reactor. Experimental studies at the Bhabha Atomic Research Centre, Bombay, have established the use of plutonium as fuel for this reactor. This molten salt reactor concept is described and the work conducted at the Bhabha Atomic Research Centre is summarised. (auth.)

  7. Salt og forbrugervalg

    DEFF Research Database (Denmark)

    Mørk, Trine; Grunert, Klaus G

    Linket til højre henviser til rapporten i trykt format til download. Dokumentet over linket er selve leveringen til ministeriet med følgebrev. Viden om forbrugernes holdning til og købsintention for saltreducerede fødevarer er central, i forhold til industriens udvikling af nye produkter og...... af saltreducerede fødevarer og deres købsintention af disse. Dette blev undersøgt ved at måle forbrugerens viden om salt, anvendelse af salt, ønske om reduktion af salt og købsintention af saltreducerede fødevarer i en web-baseret undersøgelse. Efter den web-baserede undersøgelse, blev de samme mål...... undersøgt, men i et supermarked, hvor deltagerne blev inddelt i fire grupper for at undersøge effekten af priming og saltmærkning. Desuden blev der foretaget 15 kvalitative interviews, for at studere hvem og hvad der karakteriserer de deltagere i eksperimentet, som enten ender med ingen salt...

  8. Borehole closure in salt

    International Nuclear Information System (INIS)

    Fuenkajorn, K.; Daemen, J.J.K.

    1988-12-01

    Constitutive law parameters are determined from salt behavior characterization experiments. The results are applied to predict creep (time-dependent) closure of boreholes in salt specimens subjected to various loading configurations. Rheological models (linear and nonlinear viscoelastic and viscoplastic models), empirical models, and physical theory models have been formulated from the results of uniaxial creep tests, strain and stress rate controlled uniaxial tests, constant strain rate triaxial tests, cyclic loading tests, and seismic velocity measurements. Analytical solutions for a thick-walled cylinder subjected to internal and external pressures and for a circular hole in an infinite plate subjected to a biaxial or uniaxial stressfield have been derived from each of the linear viscoelastic models and from one of the empirical laws. The experimental results indicate that the salt samples behave as an elastic-viscoplastic material. The elastic behavior tends to be linear and time-independent. The plastic deformation is time-dependent. The stress increment to strain rate increment ratio gradually decreases as the stress level increases. The transient potential creep law seems to give the simplest satisfactory governing equation describing the viscoplastic behavior of salt during the transient phase. 204 refs., 27 figs., 29 tabs

  9. Learning SaltStack

    CERN Document Server

    Myers, Colton

    2015-01-01

    If you are a system administrator who manages multiple servers, then you know how difficult it is to keep your infrastructure in line. If you've been searching for an easier way, this book is for you. No prior experience with SaltStack is required.

  10. Metals removal from spent salts

    Science.gov (United States)

    Hsu, Peter C.; Von Holtz, Erica H.; Hipple, David L.; Summers, Leslie J.; Brummond, William A.; Adamson, Martyn G.

    2002-01-01

    A method and apparatus for removing metal contaminants from the spent salt of a molten salt oxidation (MSO) reactor is described. Spent salt is removed from the reactor and analyzed to determine the contaminants present and the carbonate concentration. The salt is dissolved in water, and one or more reagents may be added to precipitate the metal oxide and/or the metal as either metal oxide, metal hydroxide, or as a salt. The precipitated materials are filtered, dried and packaged for disposal as waste or can be immobilized as ceramic pellets. More than about 90% of the metals and mineral residues (ashes) present are removed by filtration. After filtration, salt solutions having a carbonate concentration >20% can be spray-dried and returned to the reactor for re-use. Salt solutions containing a carbonate concentration ion exchange column, which yields salt solutions that contain less than 1.0 ppm of contaminants.

  11. Actinide removal from spent salts

    Science.gov (United States)

    Hsu, Peter C.; von Holtz, Erica H.; Hipple, David L.; Summers, Leslie J.; Adamson, Martyn G.

    2002-01-01

    A method for removing actinide contaminants (uranium and thorium) from the spent salt of a molten salt oxidation (MSO) reactor is described. Spent salt is removed from the reactor and analyzed to determine the contaminants present and the carbonate concentration. The salt is dissolved in water, and one or more reagents are added to precipitate the thorium as thorium oxide and/or the uranium as either uranium oxide or as a diuranate salt. The precipitated materials are filtered, dried and packaged for disposal as radioactive waste. About 90% of the thorium and/or uranium present is removed by filtration. After filtration, salt solutions having a carbonate concentration >20% can be dried and returned to the reactor for re-use. Salt solutions containing a carbonate concentration salt solutions that contain less than 0.1 ppm of thorium or uranium.

  12. Dietary salt and gastric ulcer.

    OpenAIRE

    Sonnenberg, A

    1986-01-01

    Statistically significant linear correlations between geographic variations in salt consumption and mortality from gastric, but not duodenal ulcer, are reported. It is suggested that dietary consumption of salt is a risk factor in mortality from gastric ulcer.

  13. Should we eat less salt?

    Science.gov (United States)

    Delahaye, François

    2013-05-01

    High blood pressure is a major cardiovascular risk factor. There is overwhelming evidence that high salt consumption is a major cause of increased blood pressure. There is also a link between high salt consumption and risk of stroke, left ventricular hypertrophy, renal disease, obesity, renal stones and stomach cancer. Reducing salt consumption leads to a decrease in blood pressure and the incidence of cardiovascular disease. There are no deleterious effects associated with reducing salt consumption and it is also very cost-effective. Many organizations and state governments have issued recommendations regarding the suitable amount of salt consumption. In France, the objective is a salt consumptionsalt comes from manufactured products in developed countries, reduction of salt consumption requires the participation of the food industry. The other tool is consumer information and education. Salt consumption has already decreased in France in recent years, but efforts must continue. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

  14. Inhibition of bladder cancer cell proliferation by allyl isothiocyanate (mustard essential oil)

    Energy Technology Data Exchange (ETDEWEB)

    Sávio, André Luiz Ventura, E-mail: savio.alv@gmail.com [UNESP – Universidade Estadual Paulista, Faculdade de Medicina de Botucatu, Departamento de Patologia, Botucatu, SP (Brazil); Nicioli da Silva, Glenda [UFOP – Universidade Federal de Ouro Preto, Escola de Farmácia, Departamento de Análises Clínicas, Ouro Preto, MG (Brazil); Salvadori, Daisy Maria Fávero [UNESP – Universidade Estadual Paulista, Faculdade de Medicina de Botucatu, Departamento de Patologia, Botucatu, SP (Brazil)

    2015-01-15

    Highlights: • AITC inhibits mutant and wild-type TP53 cell proliferation. • Morphological changes and cells debris were observed after AITC treatment in both cells. • BAX and BCL2 expression modulation was observed in wild-type TP53 cells. • BCL2, BAX and ANLN increased and S100P decreased expression was detected in mutated TP53 cells. • AITC effects in gene modulation are dependent TP53 gene status. - Abstract: Natural compounds hold great promise for combating antibiotic resistance, the failure to control some diseases, the emergence of new diseases and the toxicity of some contemporary medical products. Allyl isothiocyanate (AITC), which is abundant in cruciferous vegetables and mustard seeds and is commonly referred to as mustard essential oil, exhibits promising antineoplastic activity against bladder cancer, although its mechanism of action is not fully understood. Therefore, the aim of this study was to investigate the effects of AITC activity on bladder cancer cell lines carrying a wild type (wt; RT4) or mutated (T24) TP53 gene. Morphological changes, cell cycle kinetics and CDK1, SMAD4, BAX, BCL2, ANLN and S100P gene expression were evaluated. In both cell lines, treatment with AITC inhibited cell proliferation (at 62.5, 72.5, 82.5 and 92.5 μM AITC) and induced morphological changes, including scattered and elongated cells and cellular debris. Gene expression profiles revealed increased S100P and BAX and decreased BCL2 expression in RT4 cells following AITC treatment. T24 cells displayed increased BCL2, BAX and ANLN and decreased S100P expression. No changes in SMAD4 and CDK1 expression were observed in either cell line. In conclusion, AITC inhibits cell proliferation independent of TP53 status. However, the mechanism of action of AITC differed in the two cell lines; in RT4 cells, it mainly acted via the classical BAX/BCL2 pathway, while in T24 cells, AITC modulated the activities of ANLN (related to cytokinesis) and S100P. These data confirm

  15. Inhibition of bladder cancer cell proliferation by allyl isothiocyanate (mustard essential oil)

    International Nuclear Information System (INIS)

    Sávio, André Luiz Ventura; Nicioli da Silva, Glenda; Salvadori, Daisy Maria Fávero

    2015-01-01

    Highlights: • AITC inhibits mutant and wild-type TP53 cell proliferation. • Morphological changes and cells debris were observed after AITC treatment in both cells. • BAX and BCL2 expression modulation was observed in wild-type TP53 cells. • BCL2, BAX and ANLN increased and S100P decreased expression was detected in mutated TP53 cells. • AITC effects in gene modulation are dependent TP53 gene status. - Abstract: Natural compounds hold great promise for combating antibiotic resistance, the failure to control some diseases, the emergence of new diseases and the toxicity of some contemporary medical products. Allyl isothiocyanate (AITC), which is abundant in cruciferous vegetables and mustard seeds and is commonly referred to as mustard essential oil, exhibits promising antineoplastic activity against bladder cancer, although its mechanism of action is not fully understood. Therefore, the aim of this study was to investigate the effects of AITC activity on bladder cancer cell lines carrying a wild type (wt; RT4) or mutated (T24) TP53 gene. Morphological changes, cell cycle kinetics and CDK1, SMAD4, BAX, BCL2, ANLN and S100P gene expression were evaluated. In both cell lines, treatment with AITC inhibited cell proliferation (at 62.5, 72.5, 82.5 and 92.5 μM AITC) and induced morphological changes, including scattered and elongated cells and cellular debris. Gene expression profiles revealed increased S100P and BAX and decreased BCL2 expression in RT4 cells following AITC treatment. T24 cells displayed increased BCL2, BAX and ANLN and decreased S100P expression. No changes in SMAD4 and CDK1 expression were observed in either cell line. In conclusion, AITC inhibits cell proliferation independent of TP53 status. However, the mechanism of action of AITC differed in the two cell lines; in RT4 cells, it mainly acted via the classical BAX/BCL2 pathway, while in T24 cells, AITC modulated the activities of ANLN (related to cytokinesis) and S100P. These data confirm

  16. Gas phase kinetics and equilibrium of allyl radical reactions with NO and NO2.

    Science.gov (United States)

    Rissanen, Matti P; Amedro, Damien; Krasnoperov, Lev; Marshall, Paul; Timonen, Raimo S

    2013-02-07

    Allyl radical reactions with NO and NO(2) were studied in direct, time-resolved experiments in a temperature controlled tubular flow reactor connected to a laser photolysis/photoionization mass spectrometer (LP-PIMS). In the C(3)H(5) + NO reaction 1 , a dependence on the bath gas density was observed in the determined rate coefficients and pressure falloff parametrizations were performed. The obtained rate coefficients vary between 0.30-14.2 × 10(-12) cm(3) s(-1) (T = 188-363 K, p = 0.39-23.78 Torr He) and possess a negative temperature dependence. The rate coefficients of the C(3)H(5) + NO(2) reaction 2 did not show a dependence on the bath gas density in the range used (p = 0.47-3.38 Torr, T = 201-363 K), and they can be expressed as a function of temperature with k(C(3)H(5) + NO(2)) = (3.97 ± 0.84) × 10(-11) × (T/300 K) (-1.55±0.05) cm(3) s(-1). In the C(3)H(5) + NO reaction, above 410 K the observed C(3)H(5) radical signal did not decay to the signal background, indicating equilibrium between C(3)H(5) + NO and C(3)H(5)NO. This allowed the C(3)H(5) + NO ⇄ C(3)H(5)NO equilibrium to be studied and the equilibrium constants of the reaction between 414 and 500 K to be determined. With the standard second- and third-law analysis, the enthalpy and entropy of the C(3)H(5) + NO ⇄ C(3)H(5)NO reaction were obtained. Combined with the calculated standard entropy of reaction (ΔS°(298) = 137.2 J mol(-1)K(-1)), the third-law analysis resulted in ΔH°(298) = 102.4 ± 3.2 kJ mol(-1) for the C(3)H(5)-NO bond dissociation enthalpy.

  17. Salt ingestion caves.

    Directory of Open Access Journals (Sweden)

    Lundquist Charles A.

    2006-01-01

    Full Text Available Large vertebrate herbivores, when they find a salt-bearing layer of rock, say in a cliff face, can produce sizable voids where, overgenerations, they have removed and consumed salty rock. The cavities formed by this natural animal process constitute a uniqueclass of caves that can be called salt ingestion caves. Several examples of such caves are described in various publications. Anexample in Mississippi U.S.A., Rock House Cave, was visited by the authors in 2000. It seems to have been formed by deer orbison. Perhaps the most spectacular example is Kitum Cave in Kenya. This cave has been excavated to a length over 100 metersby elephants. An ancient example is La Cueva del Milodon in Chile, which is reported to have been excavated by the now extinctmilodon, a giant ground sloth. Still other possible examples can be cited. This class of caves deserves a careful definition. First, thecavity in rock should meet the size and other conventions of the locally accepted definition of a cave. Of course this requirement differsin detail from country to country, particularly in the matter of size. The intent is to respect the local conventions. The characteristicthat human entry is possible is judged to be a crucial property of any recognized cave definition. Second, the cavity should besignificantly the result of vertebrate animal consumption of salt-bearing rock. The defining process is that rock removed to form thecave is carried away in the digestive track of an animal. While sodium salts are expected to be the norm, other salts for which thereis animal hunger are acceptable. Also some other speleogenesis process, such as solution, should not be excluded as long as it issecondary in formation of a cave in question.

  18. Exciton Coupling in Circular Dichroic Spectroscopy as a Tool for Establishing the Absolute Configuration of alpha,beta-Unsaturated Esters of Allylic Alcohols

    DEFF Research Database (Denmark)

    Lauridsen, A.; Cornett, Claus; Christensen, S. B.

    1991-01-01

    alpha-beta-Unsaturated esters of allylic alcohols have been shown to exhibit exciton coupling by circular dichroic spectroscopy. This coupling permits the establishment of the absolute configuration. The method was used to prove the absolute configuration at C-2 of archangelolide. Detailed NMR sp...

  19. Synthesis of New Chiral 2,2'-bipyridine ligands and their application in copper-catalyzed asymmetric allylic oxidation and cyclopropanation

    Czech Academy of Sciences Publication Activity Database

    Malkov, A. V.; Pernazza, D.; Bell, M.; Bella, M.; Massa, A.; Teplý, Filip; Meghani, P.; Kočovský, P.

    2003-01-01

    Roč. 68, č. 12 (2003), s. 4727-4742 ISSN 0022-3263 Institutional research plan: CEZ:AV0Z4055905 Keywords : optically-active bipyridine * enantioselective cyclopropanation * allylic oxidation Subject RIV: CC - Organic Chemistry Impact factor: 3.297, year: 2003

  20. Synthesis of Oxacyclic Scaffolds via Dual Ruthenium Hydride/Brønsted Acid‐Catalyzed Isomerization/Cyclization of Allylic Ethers

    DEFF Research Database (Denmark)

    Ascic, Erhad; Ohm, Ragnhild Gaard; Petersen, Rico

    2014-01-01

    A ruthenium hydride/Brønsted acid‐catalyzed tandem sequence is reported for the synthesis of 1,3,4,9‐tetrahydropyrano[3,4‐b]indoles (THPIs) and related oxacyclic scaffolds. The process was designed on the premise that readily available allylic ethers would undergo sequential isomerization, first...

  1. One single catalyst, Pd(OAc)2, for two sequential very different steps: allylic alcohol oxidation-Heck reaction. Access to functionalised alpha,beta-unsaturated ketones.

    Science.gov (United States)

    Batt, Frédéric; Gozzi, Christel; Fache, Fabienne

    2008-11-30

    A single addition of the catalyst, Pd(OAc)(2), was realised to mediate two transformations as different as allylic alcohol oxidation under O(2) and C-C bond formation of the Heck type, to give substituted alpha,beta-unsaturated ketones without intermediate purification.

  2. Exciton Coupling in Circular Dichroic Spectroscopy as a Tool for Establishing the Absolute Configuration of alpha,beta-Unsaturated Esters of Allylic Alcohols

    DEFF Research Database (Denmark)

    Lauridsen, A.; Cornett, Claus; Christensen, S. B.

    1991-01-01

    alpha-beta-Unsaturated esters of allylic alcohols have been shown to exhibit exciton coupling by circular dichroic spectroscopy. This coupling permits the establishment of the absolute configuration. The method was used to prove the absolute configuration at C-2 of archangelolide. Detailed NMR...

  3. γ‐ and δ-Lactams through Palladium-Catalyzed Intramolecular Allylic Alkylation: Enantioselective Synthesis, NMR Investigation, and DFT Rationalization

    DEFF Research Database (Denmark)

    Bantreil, Xavier; Prestat, Guillaume; Moreno, Aitor

    2011-01-01

    The Pd-catalyzed intramolecular allylic alkylation of unsaturated amides to give gamma- and delta-lactams has been studied in the presence of chiral ligands. Ligand (R)-3,5-tBu-MeOBIPHEP (MeOBIPHEP=6,6'-dimethoxybiphenyl-2,2-diyl)bis(diphenylphosphine)) afforded the best results and allowed the c...

  4. Titanocene Dichloride Complexes Bonded to Carbosilane Dendrimers Via a Spacer of Variable Length – Molecular Dynamics Calculations and Catalysis of Allylic Coupling Reactions

    Czech Academy of Sciences Publication Activity Database

    Strašák, Tomáš; Jaroschik, F.; Malý, M.; Čermák, Jan; Sýkora, Jan; Fajgar, Radek; Karban, Jindřich; Harakat, D.

    2014-01-01

    Roč. 409, SI (2014), s. 137-146 ISSN 0020-1693 R&D Projects: GA MŠk(CZ) LC06070 Grant - others:UJEP(CZ) GA13-06989S Institutional support: RVO:67985858 Keywords : metallodendrimers * titanocene dichloride * allylic homocoupling * molecular dynamics Subject RIV: CC - Organic Chemistry Impact factor: 2.046, year: 2014

  5. Synthesis of N-Boc-Propargylic and Allylic Amines by Reaction of Organomagnesium Reagents with N-Boc-Aminals and Their Oxidation to N-Boc-Ketimines.

    Science.gov (United States)

    Kano, Taichi; Kobayashi, Ryohei; Maruoka, Keiji

    2016-01-15

    Previously inaccessible N-Boc-protected propargylic and allylic amines were synthesized by the reaction between N-Boc-aminals and organomagnesium reagents through the in situ generated N-Boc-imine intermediates. The obtained N-Boc-propargylic amines could be readily converted into unprecedented N-Boc-ketimines by oxidation with manganese dioxide.

  6. The SALT HRS Spectrograph

    Science.gov (United States)

    Tyas, Luke Martin Graham

    2012-05-01

    SALT HRS (Southern African Large Telescope High Resolution Échelle Spectrograph) is a high-resolution, high-efficiency spectrograph for the 11m SALT telescope in Sutherland, South Africa. The initial optical design work was performed at the University of Canterbury, New Zealand. Revisions to the concept, the mechanical design, manufacture, assembly and testing have been handled by the Centre for Advanced Instrumentation, at Durham University in the United Kingdom. SALT HRS is a fibre-fed échelle grating spectrograph with four operational modes: low-, medium- and high-resolution and high-stability modes, having spectral resolutions of R≈16000, 37000, 67000 and 67000 respectively over a wavelength range of 370-890nm. The instrument is of a dual channel, 'white pupil' design, in which the primary mirror acts to collimate light onto a single R4 échelle grating, and also to focus dispersed light to an intermediate focus. A dichroic beam-splitter separates the dispersed light into two separate spectral channels. Spherical pupil mirrors transfer the separated beams via a fold mirror to two wavelength-specific volume-phase holographic gratings (VPHGs) used as cross-dispersers. Cross-dispersed spectra are then imaged by two fully dioptric camera systems onto optimized CCD detectors. This thesis presents the results of the laboratory testing and specification of several critical sub-systems of SALT HRS, as well as the development of key software tools for the design verification and operation at the telescope. In Chapter 1 we first review the technical development of high-resolution spectroscopy and its specific implementation in SALT HRS. In Chapter 2 we develop a comprehensive throughput model of the entire system based on a combination of as-built performance and specific throughput measurements in the laboratory. This is used to make some specific predictions for the on-sky performance of SALT HRS and the magnitude limits for science targets. We also present a

  7. Ultraviolet photochemistry of trichlorovinylsilane and allyltrichlorosilane: vinyl radical (HCCH2) and allyl radical (H2CCHCH2) production in 193 nm photolysis.

    Science.gov (United States)

    DeSain, John D; Jusinski, Leonard E; Taatjes, Craig A

    2006-05-21

    The absolute gas phase ultraviolet absorption spectra of trichlorovinylsilane and allyltrichlorosilane have been measured from 191 to 220 nm. Over this region the absorption spectra of both species are broad and relatively featureless, and their cross sections increase with decreasing wavelength. The electronic transitions of trichlorovinylsilane were calculated by ab initio quantum chemical methods and the observed absorption bands assigned to the A(1)A''<-- X[combining tilde](1)A'' transition. The maximum absorption cross section in the region, at 191 nm, is sigma = (8.50 +/- 0.06) x 10(-18) cm(2) for trichlorovinylsilane and sigma = (2.10 +/- 0.02) x 10(-17) cm(2) for allyltrichlorosilane. The vinyl radical and the allyl radical are formed promptly from the 193 nm photolysis of their respective trichlorosilane precursors. By comparison of the transient visible absorption and the 1315 nm I atom absorption from 266 nm photolysis of vinyl iodide and allyl iodide, the absorption cross sections at 404 nm of vinyl radical ((2.9 +/- 0.4) x 10(-19) cm(2)) and allyl radical ((3.6 +/- 0.8) x 10(-19) cm(2)) were derived. These cross sections are in significant disagreement with literature values derived from kinetic modeling of allyl or vinyl radical self-reactions. Using these cross sections, the vinyl radical yield from trichlorovinylsilane was determined to be phi = (0.9 +/- 0.2) per 193 nm photon absorbed, and the allyl radical yield from allyltrichlorosilane phi = (0.7 +/- 0.2) per 193 nm photon absorbed.

  8. Thermochemical Properties of Nicotine Salts

    Directory of Open Access Journals (Sweden)

    Riggs DM

    2014-12-01

    Full Text Available The thermal gravimetric analysis (TGA and differential scanning calorimetry (DSC results presented in this report clearly show that the thermal stability and the endothermic peak nicotine release temperatures are different for different nicotine salts and these temperatures appear to be linked to the general microstructural details of the salt itself. In addition, the peak nicotine release temperatures are highly dependent upon the sample size used. The heat of vaporization for neat (non-protonated nicotine is also sample-size dependent. The TGA data showed that the least stable of the salts tested at elevated temperatures was the liquid salt nicotine triacetate followed by the crystalline materials (e.g., nicotine gallate and finally, the amorphous salts (e.g., nicotine alginate. The DSC results revealed that the liquid and crystalline salts exhibit nicotine release endotherms that are strongly related to the sample weight being tested. The amorphous salts show nicotine endotherm peak temperatures that are nearly independent of the sample weight. The range of peak nicotine release temperatures varied depending upon the specific salts and the sample size from 83 oC to well over 200 oC. Based on these results, the evolution of nicotine from the nicotine salt should be expected to vary based on the composition of the salt, the details of its microstructure, and the amount of nicotine salt tested.

  9. The material flow of salt

    International Nuclear Information System (INIS)

    Kostick, D.S.

    1993-01-01

    Salt (NaCl) is a universal mineral commodity used by virtually every person in the world. Although a very common mineral today, at one time it was considered as precious as gold in certain cultures. This study traces the material flow of salt from its origin through the postconsumer phase of usage. The final disposition of salt in the estimated 14,000 different uses, grouped into several macrocategories, is traced from the dispersive loss of salt into the environment to the ultimate disposal of salt-base products into the waste stream after consumption. The base year for this study is 1990, in which an estimated 196 million short tons of municipal solid waste was discarded by the US population. Approximately three-fourths of domestic salt consumed is released to the environment and unrecovered while about one-fourth is discharged to landfills and incinerators as products derived from salt. Cumulative historical domestic production, trade, and consumption data have been compiled to illustrate the long-term trends within the US salt industry and the cumulative contribution that highway deicing salt has had on the environment. Salt is an important component of drilling fluids in well drilling. It is used to flocculate and to increase the density of the drilling fluid in order to overcome high down-well gas pressures. Whenever drilling activities encounter salt formations, salt is added to the drilling fluid to saturate the solution and minimize the dissolution within the salt strata. Salt is also used to increase the set rate of concrete in cemented casings. This subsector includes companies engaged in oil, gas, and crude petroleum exploration and in refining and compounding lubricating oil. It includes SIC major groups 13 and 29. 13 refs., 14 figs., 6 tabs

  10. NTP Technical Report on the comparative toxicity studies of allyl acetate (CAS No. 591-87-7), allyl alcohol (CAS No. 107-18-6) and acrolein (CAS No. 107-02-8) administered by gavage to F344/N rats and B6C3F1 mice.

    Science.gov (United States)

    Irwin, Rick D

    2006-07-01

    Allyl acetate, allyl alcohol, and acrolein are used in the manufacture of detergents, plastics, pharmaceuticals, and chemicals and as agricultural agents and food additives. Male and female F344/N rats and B6C3F(1) mice received allyl acetate, allyl alcohol, or acrolein by gavage for 14 weeks. Genetic toxicology studies were conducted in Salmonella typhimurium, Drosophila melanogaster, cultured Chinese hamster ovary cells, rat bone marrow erythrocytes, and mouse peripheral blood erythrocytes. Groups of 10 male and 10 female rats were administered 0, 6, 12, 25, 50, or 100 mg allyl acetate/kg body weight, 0, 1.5, 3, 6, 12, or 25 mg/kg allyl alcohol, or 0, 0.75, 1.25, 2.5, 5, or 10 mg/kg acrolein in 0.5% methylcellulose by gavage, 5 days per week for 14 weeks. Groups of 10 male and 10 female mice were administered 0, 8, 16, 32, 62.5, or 125 mg/kg allyl acetate, 0, 3, 6, 12, 25, or 50 mg/kg allyl alcohol, or 0, 1.25, 2.5, 5, 10, or 20 mg/kg acrolein in 0.5% methylcellulose by gavage, 5 days per week for 14 weeks. In the allyl acetate rat study, all males and females in the 100 mg/kg groups died or were killed moribund by day 8; there were no other deaths. In the allyl alcohol study, all rats survived to the end of the study except one 6 mg/kg female. In the acrolein rat study, eight males and eight females in the 10 mg/kg groups died by week 9 of the study. Two males in the 2.5 and 5 mg/kg groups and one or two females in the 1.25, 2.5, and 5 mg/kg groups also died early; two of these deaths were gavage accidents. In the allyl acetate mouse study, all males and females in the 125 mg/kg group died during the first week of the study. All other early deaths, except five 62.5 mg/kg males and one 32 mg/kg female, were gavage accidents. In the allyl alcohol mouse study, one 50 mg/kg female died due to a gavage accident; all other animals survived to the end of the study. In the acrolein mouse study, all males and females administered 20 mg/kg died during the first week of

  11. Crystal structure of (E-4-(acetoxyimino-N-allyl-3-isopropyl-2,6-diphenylpiperidine-1-carbothioamide

    Directory of Open Access Journals (Sweden)

    T. Mohandas

    2015-08-01

    Full Text Available The title compound, C26H31N3O2S, crystallizes with two molecules (A and B in the asymmetric unit. In each case, the piperidine ring exists in a twist-boat conformation. The dihedral angle between the phenyl rings is 46.16 (12° in molecule A and 44.95 (12° in molecule B. In both molecules, the allyl side chain is disordered over two orientations in a 0.649 (9:0.351 (9 ratio for molecule A and 0.826 (10:0.174 (10 ratio for molecule B. In the crystal, neither molecule forms a hydrogen bond from its N—H group, presumably due to steric hindrance. A+A and B+B inversion dimers are formed, linked by pairs of weak C—H...O hydrogen bonds enclosing R22(22 ring motifs.

  12. Indium-mediated allylation in carbohydrate synthesis: A short and efficient approach towards higher 2-acetamido-2-deoxy sugars

    Directory of Open Access Journals (Sweden)

    Christopher Albler

    2014-09-01

    Full Text Available Higher aminosugars are interesting targets in carbohydrate synthesis since these compounds play important roles in biological systems. However, their availability from natural sources is limited. Thus, in order to investigate their biological function, the development of facile and adaptable routes to this class of compounds is of fundamental importance. Our synthetic route towards these target molecules makes use of readily accessible pentoses and hexoses, which are subjected to indium-mediated two-carbon chain elongation. Subsequent ozonolysis and treatment with base yields α,β-unsaturated aldehydes, which are stereoselectively epoxidized using Jørgenson’s protocol. After Wittig chain elongation the obtained allylic epoxides were regio- and stereoselectively opened with trimethylsilyl azide under palladium catalysis. Finally, a suitable deprotection protocol, starting with acidic acetate cleavage and ozonolysis was established. Peracetylation of the products simplifies purification and subsequent azide reduction followed by final deacetylation using methanolic sodium methoxide furnishes the title compounds.

  13. Crystal structure of (Z-3-allyl-5-(4-chlorobenzylidene-2-sulfanylidene-1,3-thiazolidin-4-one

    Directory of Open Access Journals (Sweden)

    Rahhal El Ajlaoui

    2015-12-01

    Full Text Available In the title compound, C13H10ClNOS2, the dihedral angle between the rhodanine (r.m.s. deviation = 0.008 Å and 4-chlorobenzylidene rings is 1.79 (11°. The allyl group attached to the N atom, which lies almost perpendicular to the rhodanine ring, is disordered over two orientations in a 0.519 (13:0.481 (13 ratio. A short intramolecular C—H...S interaction closes an S(6 ring. In the crystal, molecules are linked by π–π stacking interactions [centroid–centroid separation = 3.600 (15 Å], generating inversion dimers.

  14. Crystal structure of N-(1-allyl-3-chloro-4-ethoxy-1H-indazol-5-yl-4-methoxybenzenesulfonamide

    Directory of Open Access Journals (Sweden)

    Hakima Chicha

    2014-09-01

    Full Text Available In the title compound, C19H20ClN3O4S, the benzene ring is inclined to the indazole ring system (r.m.s. deviation = 0.014 Å by 65.07 (8°. The allyl and ethoxy groups are almost normal to the indazole ring, as indicated by the respective torsion angles [N—N—C—C = 111.6 (2 and C—C—O—C = −88.1 (2°]. In the crystal, molecules are connected by N—H...N hydrogen bonds, forming helical chains propagating along [010]. The chains are linked by C—H...O hydrogen bonds, forming a three-dimensional network.

  15. Ruthenium complexes with dendritic ferrocenyl phosphanes: synthesis, characterization, and application in the catalytic redox isomerization of allylic alcohols.

    Science.gov (United States)

    Neumann, Paul; Dib, Hanna; Sournia-Saquet, Alix; Grell, Toni; Handke, Marcel; Caminade, Anne-Marie; Hey-Hawkins, Evamarie

    2015-04-20

    An efficient system for the catalytic redox isomerization of the allylic alcohol 1-octen-3-ol to 3-octanone is presented. The homogeneous ruthenium(II) catalyst contains a monodentate phosphane ligand with a ferrocene moiety in the backbone and provides 3-octanone in quantitative yields. The activity is increased by nearly 90 % with respect to the corresponding triphenyl phosphane ruthenium(II) complex. By grafting the catalyst at the surface of a dendrimer, the catalytic activity is further increased. By introducing different spacers between ferrocene and phosphorus, the influence on the electronic properties of the complexes is shown by evaluating the electrochemical behavior of the compounds. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Amplification of vacuole-targeting fungicidal activity of antibacterial antibiotic polymyxin B by allicin, an allyl sulfur compound from garlic.

    Science.gov (United States)

    Ogita, Akira; Nagao, Yasuhiro; Fujita, Ken-Ichi; Tanaka, Toshio

    2007-08-01

    A cationic antibacterial peptide, polymyxin B (PMB), was evaluated as an antifungal antibiotic against various yeasts and filamentous fungi when used in combination with allicin, an allyl sulfur compound from garlic. Allicin was not lethal but could markedly amplify the fungicidal activity of PMB, which was weakly detected with the increase in the plasma membrane permeability in Saccharomyces cerevisiae. Their combined actions caused a dynamic structural damage to the yeast vacuole as judged by the disappearance of its swollen spherical architecture. The vacuole-targeting activity of PMB was similarly amplified in medium with t-butyl hydroperoxide as a substitute for the action of allicin. These findings suggest that the allicin-mediated lipoperoxide production in fungal plasma membrane is the cause of the enhancement in the cellular uptake of PMB as well as its action against the vacuole.

  17. Amine-linked diglycosides: Synthesis facilitated by the enhanced reactivity of allylic electrophiles, and glycosidase inhibition assays

    Directory of Open Access Journals (Sweden)

    Ian Cumpstey

    2011-08-01

    Full Text Available Diglycose derivatives, consisting of two monosaccharides linked at non-anomeric positions by a bridging nitrogen atom, have been synthesised. Conversion of one of the precursor monosaccharide coupling components into an unsaturated derivative enhances its electrophilicity at the allylic position, facilitating coupling reactions. Mitsunobu coupling between nosylamides and 2,3-unsaturated-4-alcohols gave the 4-amino-pseudodisaccharides with inversion of configuration as single regio- and diastereoisomers. A palladium-catalysed coupling between an amine and a 2,3-unsaturated 4-trichloroacetimidate gave a 2-amino-pseudodisaccharide as the major product, along with other minor products. Derivatisation of the C=C double bond in pseudodisaccharides allowed the formation of Man(N4–6Glc and Man(N4–6Man diglycosides. The amine-linked diglycosides were found to show weak glycosidase inhibitory activity.

  18. Salt supply to and significance of asymmetric salt diapirs

    DEFF Research Database (Denmark)

    Koyi, H.; Burliga, S.; Chemia, Zurab

    2012-01-01

    Salt diapirs can be asymmetric both internally and externally reflecting their evolution history. As such, this asymmetry bear a significant amount of information about the differential loading (± lateral forces) and in turn the salt supply that have shaped the diapir. In two dimensions...... southeastern overhang due to salt extrusion during Middle Cretaceous followed by its burial in Tertiary. This external asymmetry is also reflected in the internal configuration of the diapir which shows different rates of salt flow on the two halves of the structure. The asymmetric external and internal...... sediments, the diapir extruded an overhang. Using the asymmetric Klodawa Salt Structure (KSS) in central Poland as a prototype, a series of analogue models were carried out to investigate the evolution history and salt supply driven by asymmetric differential loading. During extension of the model, a daipir...

  19. Mechanistic Insights into Solvent and Ligand Dependency in Cu(I)-Catalyzed Allylic Alkylation with gem-Diborylalkanes.

    Science.gov (United States)

    Zhang, Qi; Wang, Bing; Liu, Jia-Qin; Fu, Yao; Wu, Yu-Cheng

    2018-01-19

    The recent Cu-catalyzed allylic substitution reaction between gem-diboryalkane and allyl electrophiles shows intriguing solvent and ligand-controlled regioselectivity. The α-alkylation product was obtained in DMF solvent, while γ-alkylation product was obtained in dioxane solvent and the dioxane and NHC ligand situation. In the present study, density functional theory calculations have been used to investigate the reaction mechanism and origin of the regioselectivity. For both dioxane and DMF, γ-alkylation undergoes successive oxidative addition (CH 2 Bpin trans to leaving group) and direct Cγ-C reductive elimination. The α-alkylation is found to undergo oxidative addition (CH 2 Bpin trans to leaving group), isomerization, and Cα-C reductive elimination rather than the previously proposed oxidative addition (-CH 2 Bpin cis to the leaving group) and Cα-C reductive elimination. The γ-alkylation and α-alkylation is, respectively, favorable for dioxane and DMF solvent, which is consistent with the γ- and α-selectivity in experiment. The solvent interferes the isomerization step, thereby affects the relative facility of the α- and γ-alkylation. Further investigation shows that η 1 -intermediate formation promoted by solvent is the rate-determining step of the isomerization. The stronger electron-donating ability of DMF than dioxane facilitates the η 1 -intermediate formation and finally results in the easier isomerization in DMF. For dioxane and NHC situation, in the presence of neutral NHC ligand, the -PO 4 Et 2 group tightly coordinates with the Cu center after the oxidative addition, preventing the isomerization process. The regioselectivity is determined by the relative facility of the oxidative addition step. Therefore, the favorable oxidative addition (in which -CH 2 Bpin trans to the leaving group) results in the facility of γ-alkylation.

  20. Novel Allyl Cobalt Phosphine Complexes: Synthesis, Characterization and Behavior in the Polymerization of Allene and 1,3-Dienes

    Directory of Open Access Journals (Sweden)

    Giovanni Ricci

    2017-12-01

    Full Text Available Novel allyl cobalt complexes, i.e., (η3-C4H7(η4-C4H6Co(PCyPh2 (1, (η3-C4H7(η4-C4H6Co(PMePh2 (2 and (η3-C5H9(η4-C5H8Co(PMePh2 (3, were synthesized by reacting CoCl2(PRPh22 (R = methyl, cyclohexyl with 1,3-butadiene or isoprene in presence of metallic zinc. The complexes were fully characterized by Nuclear Magnetic Resonance (NMR spectroscopy (1H and 2D experiments; in case of 1, single crystals, suitable for X-ray analysis, were obtained and the molecular structure was determined. The allyl cobalt phosphine complexes alone gave highly crystalline 1,2 polymers from 1,2-propadiene, but they did not polymerize 1,3-dienes. Nevertheless, in the presence of a stoichiometric amount of methylaluminoxane (MAO, they were able to polymerize 1,3-butadiene and substituted 1,3-butadienes such as isoprene, (E-1,3-pentadiene, (E-1,3-hexadiene, and (E-3-methyl-1,3-pentadiene. Specifically, 1/MAO gave predominantly syndiotactic 1,2 polymers from 1,3-butadiene and terminally substituted 1,3-butadienes (e.g., 1,3-pentadiene and 1,3-hexadiene, but it was practically not active in the polymerization of internally substituted 1,3-butadienes (e.g., isoprene and 3-methyl-1,3-pentadiene; 2/MAO and 3/MAO exhibited instead an opposite behavior, giving predominantly isotactic 1,2 polymers from 3-methyl-1,3-pentadiene, and showing very low activity in the polymerization of 1,3-butadiene, 1,3-pentadiene and 1,3-hexadiene. The results obtained are interesting from the mechanistic point of view, and some hypotheses to explain this particular behavior were formulated.

  1. Where Does Road Salt Go - a Static Salt Model

    Science.gov (United States)

    Yu, C. W.; Liu, F.; Moriarty, V. W.

    2017-12-01

    Each winter, more than 15 million tons of road salt is applied in the United States for the de-icing purpose. Considerable amount of chloride in road salt flows into streams/drainage systems with the snow melt runoff and spring storms, and eventually goes into ecologically sensitive low-lying areas in the watershed, such as ponds and lakes. In many watersheds in the northern part of US, the chloride level in the water body has increased significantly in the past decades, and continues an upward trend. The environmental and ecological impact of the elevated chloride level can no longer be ignored. However although there are many studies on the biological impact of elevated chloride levels, there are few investigations on how the spatially distributed road salt application affects various parts of the watershed. In this presentation, we propose a static road salt model as a first-order metric to address spacial distribution of salt loading. Derived from the Topological Wetness Index (TWI) in many hydrological models, this static salt model provides a spatial impact as- sessment of road salt applications. To demonstrate the effectiveness of the static model, National Elevation Dataset (NED) of ten-meter resolution of Lake George watershed in New York State is used to generate the TWI, which is used to compute a spatially dis- tributed "salt-loading coefficient" of the whole watershed. Spatially varying salt applica- tion rate is then aggregated, using the salt-loading coefficients as weights, to provide salt loading assessments of streams in the watershed. Time-aggregated data from five CTD (conductivity-temperature-depth) sensors in selected streams are used for calibration. The model outputs and the sensor data demonstrate a strong linear correlation, with the R value of 0.97. The investigation shows that the static modeling approach may provide an effective method for the understanding the input and transport of road salt to within watersheds.

  2. Reactive halogen species above salt lakes and salt pans

    OpenAIRE

    Holla, Robert

    2013-01-01

    Salt lakes can be found on all continents and saline soils cover 2.5% of the land surface of the earth (FAO, 2012). This thesis investigates the presence of reactive halogen species (RHS) above salt lakes and saline soils to evaluate their relevance for tropospheric chemistry of the planetary boundary layer. Ground-based MAX-DOAS and LP-DOAS measurements were conducted at salt lakes and two other sites with high halogen content. Prior to this work, RHS were found at three salt ...

  3. Rheology of rock salt for salt tectonics modeling

    Directory of Open Access Journals (Sweden)

    Shi-Yuan Li

    2016-10-01

    Full Text Available Abstract Numerical modeling of salt tectonics is a rapidly evolving field; however, the constitutive equations to model long-term rock salt rheology in nature still remain controversial. Firstly, we built a database about the strain rate versus the differential stress through collecting the data from salt creep experiments at a range of temperatures (20–200 °C in laboratories. The aim is to collect data about salt deformation in nature, and the flow properties can be extracted from the data in laboratory experiments. Moreover, as an important preparation for salt tectonics modeling, a numerical model based on creep experiments of rock salt was developed in order to verify the specific model using the Abaqus package. Finally, under the condition of low differential stresses, the deformation mechanism would be extrapolated and discussed according to microstructure research. Since the studies of salt deformation in nature are the reliable extrapolation of laboratory data, we simplified the rock salt rheology to dislocation creep corresponding to power law creep (n = 5 with the appropriate material parameters in the salt tectonic modeling.

  4. Electrolyte salts for nonaqueous electrolytes

    Science.gov (United States)

    Amine, Khalil; Zhang, Zhengcheng; Chen, Zonghai

    2012-10-09

    Metal complex salts may be used in lithium ion batteries. Such metal complex salts not only perform as an electrolyte salt in a lithium ion batteries with high solubility and conductivity, but also can act as redox shuttles that provide overcharge protection of individual cells in a battery pack and/or as electrolyte additives to provide other mechanisms to provide overcharge protection to lithium ion batteries. The metal complex salts have at least one aromatic ring. The aromatic moiety may be reversibly oxidized/reduced at a potential slightly higher than the working potential of the positive electrode in the lithium ion battery. The metal complex salts may also be known as overcharge protection salts.

  5. Organic reactions of sulfur dioxide. IV. A facile regiospecific hydrogen-deuterium exchange in olefins. Consequence of the intermediacy of allylic sulfinic acids in the ene reaction of sulfur dioxide with double bonds

    International Nuclear Information System (INIS)

    Masilamani, D.; Rogic, M.M.

    1978-01-01

    It is reported that the isomerization of the double bond, and presumably the rearrangement of the allylic sulfinic acid intermediates is completely suppressed in the presence of water. The reaction of sulfur dioxide with the double bond and the ene reaction in the resulting dipolar ions are apparently not affected. As a consequence, in the presence of deuterium oxide a very facile exchange of the allylic hydrogens and deuterium takes place

  6. Salt fluoridation and oral health

    Directory of Open Access Journals (Sweden)

    Thomas M. Marthaler

    2013-11-01

    Full Text Available The aim of this paper is to make known the potential of fluoridated salt in community oral health programs, particularly in South Eastern Europe. Since 1922, the addition of iodine to salt has been successful in Switzerland. Goiter is virtually extinct. By 1945, the cariesprotective effect of fluorides was well established. Based on the success of water fluoridation, a gynecologist started adding of fluoride to salt. The sale of fluoridated salt began in 1956 in the Swiss Canton of Zurich, and several other cantons followed suit. Studies initiated in the early seventies showed that fluoride, when added to salt, inhibits dental caries. The addition of fluoride to salt for human consumption was officially authorized in 1980-82. In Switzerland 85% of domestic salt consumed is fluoridated and 67% in Germany. Salt fluoridation schemes are reaching more than one hundred million in Mexico, Colombia, Peru and Cuba. The cost of salt fluoridation is very low, within 0.02 and 0.05 € per year and capita. Children and adults of the low socio-economic strata tend to have substantially more untreated caries than higher strata. Salt fluoridation is by far the cheapest method for improving oral health. Conclusions. Salt fluoridation has cariostatic potential like water fluoridation (caries reductions up to 50%. In Europe, meaningful percentages of users have been attained only in Germany (67% and Switzerland (85%. In Latin America, there are more than 100 million users, and several countries have arrived at coverage of 90 to 99%. Salt fluoridation is by far the cheapest method of caries prevention, and billions of people throughout the world could benefit from this method.

  7. Salt fluoridation and oral health.

    Science.gov (United States)

    Marthaler, Thomas M

    2013-11-01

    The aim of this paper is to make known the potential of fluoridated salt in community oral health programs, particularly in South Eastern Europe. Since 1922, the addition of iodine to salt has been successful in Switzerland. Goiter is virtually extinct. By 1945, the caries-protective effect of fluorides was well established. Based on the success of water fluoridation, a gynecologist started adding of fluoride to salt. The sale of fluoridated salt began in 1956 in the Swiss Canton of Zurich, and several other cantons followed suit. Studies initiated in the early seventies showed that fluoride, when added to salt, inhibits dental caries. The addition of fluoride to salt for human consumption was officially authorized in 1980-82. In Switzerland 85% of domestic salt consumed is fluoridated and 67% in Germany. Salt fluoridation schemes are reaching more than one hundred million in Mexico, Colombia, Peru and Cuba. The cost of salt fluoridation is very low, within 0.02 and 0.05 € per year and capita. Children and adults of the low socio-economic strata tend to have substantially more untreated caries than higher strata. Salt fluoridation is by far the cheapest method for improving oral health. Salt fluoridation has cariostatic potential like water fluoridation (caries reductions up to 50%). In Europe, meaningful percentages of users have been attained only in Germany (67%) and Switzerland (85%). In Latin America, there are more than 100 million users, and several countries have arrived at coverage of 90 to 99%. Salt fluoridation is by far the cheapest method of caries prevention, and billions of people throughout the world could benefit from this method. Copyright © 2013 by Academy of Sciences and Arts of Bosnia and Herzegovina.

  8. Salt, caprock, and sheath study

    International Nuclear Information System (INIS)

    Karably, L.S. Jr.; Jernigan, B.L.; Petre, I.C.; Sullivan, J.M.

    1983-01-01

    Salt domes of the Gulf Coast region of the United States consist of four component parts: 1) a salt stock, 2) caprock material, 3) sheath material, and 4) the surrounding upturned sediments. Salt stock consists of remarkably pure halite (NaCl), which represents 90 to 99% of the total mass, with the major impurity being anhydrite. Salt stocks are markedly homogeneous and continuous with respect to composition, texture and structure. Caprock consists primarily of anhydrite, gypsum and calcite which commonly occur in monomineralic zones oriented roughly parallel to the top of the salt stock. Caprock composition varies markedly over any single salt stock as well as from one salt stock to another. Fracturing, porosity and permeability of caprock material are correspondingly variable, but are usually developed tto a higher degree in the upper portions of caprock; porosity and permeability may also be relatively high at the caprock-salt interface. Caprock is generally believed to form by residual accumulation of anhydrite from the dissolution of salt, with subsequent alteration of the anhydrite to calcite and gypsum. Sheath material, probably a mixture of sedimentary rocks (clastic and evaporite), formed as a result of mechanical interaction between the salt stock and surrounding sediments during diapirism. Sheath material is thought to be distributed throughout an external zone, consisting mainly of disturbed sediment, and an internal zone, consisting mainly of disturbed salt. Sheath material forms along a roughly cylindrical shear zone which encloses thesalt stock. Sheath material may be overpressured and is generally thought to be impermeable. Upturned sediments around the salt diapirs are the result of dome genesis; hovever, these sedimentary beds and other structures are beyond the scope of this report

  9. Zechstein salt Denmark. Vol. 1

    International Nuclear Information System (INIS)

    Lyngsie Jacobsen, F.; Soenderholm, M.; Springer, N.; Gutzon Larsen, J.; Lagoni, P.; Fabricius, J.

    1984-01-01

    The Salt Research Project EFP-81 has mainly been aiming upon an elucidation of the stratigraphy of the Danish Zechstein evaporites. Also an attempt to clarify the connection between the fabric and the strength of the strongly deformed domal rock salt is performed. The unravelling of the stratigraphy is carried out by means of renewed interpretations of new and old data from all the wells drilling in the Danish Permian basin in connection with a revaluation of the core descriptions. By means of trace elements analysis it is possible to some extent to distinguish between Zestein 1 and 2 ''grey salt''. A description of the transition zone between Zechstein 1 and 2 is carried out. New methods of fabric analyses are introduced and the strength measurements of the rock salt are treated statistically in connection with new defined rock salt parameters. An investigation of fluid inclusions in halite and quartz crystals from dome salt has resulted in the determination of salinity and chemical composition of the brines present in the salt. Temperatures and corresponding pressures during the evolution of the salt pillow and salt dome have been established. The dehydration conditions of natural carnallite in situ are clarified. (author)

  10. Salt formations offer disposal alternative

    International Nuclear Information System (INIS)

    Funderburk, R.

    1990-01-01

    This paper discusses how three U.S. firms are spending millions to permit and build underground disposal sites in salt formations. These companies claim salt is the ideal geological medium for holding hazardous wastes. Two Texas locations and one in Michigan have been targeted as future sites for hazardous waste disposal. The Michigan site, outside Detroit, is a former salt mine 2,000 feet beneath the Ford Motor Co. (Detroit) assembly works in Dearborn. Both Texas sites are atop salt domes---one east and one west of Houston

  11. Pathophysiology of salt sensitivity hypertension.

    Science.gov (United States)

    Ando, Katsuyuki; Fujita, Toshiro

    2012-06-01

    Dietary salt intake is the most important factor contributing to hypertension, but the salt susceptibility of blood pressure (BP) is different in individual subjects. Although the pathogenesis of salt-sensitive hypertension is heterogeneous, it is mainly attributable to an impaired renal capacity to excrete sodium (Na(+) ). We recently identified two novel mechanisms that impair renal Na(+) -excreting function and result in an increase in BP. First, mineralocorticoid receptor (MR) activation in the kidney, which facilitates distal Na(+) reabsorption through epithelial Na(+) channel activation, causes salt-sensitive hypertension. This mechanism exists not only in models of high-aldosterone hypertension as seen in conditions of obesity or metabolic syndrome, but also in normal- or low-aldosterone type of salt-sensitive hypertension. In the latter, Rac1 activation by salt excess causes MR stimulation. Second, renospecific sympathoactivation may cause an increase in BP under conditions of salt excess. Renal beta2 adrenoceptor stimulation in the kidney leads to decreased transcription of the gene encoding WNK4, a negative regulator of Na(+) reabsorption through Na(+) -Cl (-) cotransporter in the distal convoluted tubules, resulting in salt-dependent hypertension. Abnormalities identified in these two pathways of Na(+) reabsorption in the distal nephron may present therapeutic targets for the treatment of salt-sensitive hypertension.

  12. Fused salt electrolysis

    International Nuclear Information System (INIS)

    Ares, Osvaldo; Botbol, Jose.

    1989-01-01

    Working conditions for zirconium preparation by fused salt electrolysis were studied. For such purpose, a cell was built for operation under argon atmosphere. A graphite crucible served as anode, with steel cathodes. Proper design allowed cathode rechange under the inert atmosphere. Cathodic deposits of zirconium powder occluded salts from the bath. After washing with both water and hydrochloric acid, the metallic powder was consolidated by fusion. Optimum operating conditions were found to arise from an electrolyte of 12% potassium hexafluorzirconate -88% sodium chloride, at 820 deg C and 5 A/cm 2 cathodic current density. Deposits contained 35% of metal and current efficiency reached 66%. The powder contained up to 600 ppm of chlorine and 1.700 ppm of fluorine; after fusion, those amounts decreased to 2 ppm and 3 ppm respectively, with low proportion of metallic impurities. Though oxygen proportion was 4.500 ppm, it should be lowered by improving working conditions, as well as working on an ampler scale. (Author)

  13. Experiments in connection with Salt Domes

    NARCIS (Netherlands)

    Escher, B.G.; Kuenen, Ph.H.

    1928-01-01

    The different theories concerning the origin of Salt Domes in Roumania, Germany, Texas, Louisiana, Colorado and Utah are discussed. In Roumania the salt occurs in cores of “Diapir” anticlines. The existance of hills of salt indicates, that the salt is still pushing upwards. In Germany the salt

  14. Theory Of Salt Effects On Protein Solubility

    Science.gov (United States)

    Dahal, Yuba; Schmit, Jeremy

    Salt is one of the major factors that effects protein solubility. Often, at low salt concentration regime, protein solubility increases with the salt concentration(salting in) whereas at high salt concentration regime, solubility decreases with the increase in salt concentration(salting out). There are no quantitative theories to explain salting in and salting out. We have developed a model to describe the salting in and salting out. Our model accounts for the electrostatic Coulomb energy, salt entropy and non-electrostatic interaction between proteins. We analytically solve the linearized Poisson Boltzmann equation modelling the protein charge by a first order multipole expansion. In our model, protein charges are modulated by the anion binding. Consideration of only the zeroth order term in protein charge doesn't help to describe salting in phenomenon because of the repulsive interaction. To capture the salting in behaviour, it requires an attractive electrostatic interaction in low salt regime. Our work shows that at low salt concentration, dipole interaction is the cause for salting in and at high salt concentration a salt-dependent depletion interaction dominates and gives the salting out. Our theoretical result is consistent with the experimental result for Chymosin protein NIH Grant No R01GM107487.

  15. An Efficient Protocol for the Palladium-catalyzed Asymmetric Decarboxylative Allylic Alkylation Using Low Palladium Concentrations and a Palladium(II) Precatalyst.

    Science.gov (United States)

    Marziale, Alexander N; Duquette, Douglas C; Craig, Robert A; Kim, Kelly E; Liniger, Marc; Numajiri, Yoshitaka; Stoltz, Brian M

    2015-07-06

    Enantioselective catalytic allylic alkylation for the synthesis of 2-alkyl-2-allylcycloalkanones and 3,3-disubstituted pyrrolidinones, piperidinones and piperazinones has been previously reported by our laboratory. The efficient construction of chiral all-carbon quaternary centers by allylic alkylation was previously achieved with a catalyst derived in situ from zero valent palladium sources and chiral phosphinooxazoline (PHOX) ligands. We now report an improved reaction protocol with broad applicability among different substrate classes in industry-compatible reaction media using loadings of palladium(II) acetate as low as 0.075 mol % and the readily available chiral PHOX ligands. The novel and highly efficient procedure enables facile scale-up of the reaction in an economical and sustainable fashion.

  16. Structure and stability of acrolein and allyl alcohol networks on Ag(111) from density functional theory based calculations with dispersion corrections

    Science.gov (United States)

    Ferullo, Ricardo M.; Branda, Maria Marta; Illas, Francesc

    2013-11-01

    The interaction of acrolein and allyl alcohol with the Ag(111) surface has been studied by means of periodic density functional theory based calculations including explicitly dispersion terms. Different coverage values have been explored going from isolated adsorbed molecules to isolated dimers, interacting dimers or ordered overlayers. The inclusion of the dispersion terms largely affects the calculated values of the adsorption energy and also the distance between adsorbed molecule and the metallic surface but much less the adsorbate-adsorbate interactions. Owing to the large dipole moment of acrolein, the present calculations predict that at high coverage this molecule forms a stable extensive two-dimensional network on the surface, caused by the alignment of the adsorbate dipoles. For the case of allyl alcohol, dimers and complex networks exhibit similar stability.

  17. Remarkable rate acceleration of SmI3-mediated iodination of acetates of Baylis-Hillman adducts in ionic liquid: facile synthesis of (Z)-allyl iodides*

    Science.gov (United States)

    Liu, Yun-Kui; Zheng, Hui; Xu, Dan-Qian; Xu, Zhen-Yuan; Zhang, Yong-Min

    2006-01-01

    Stereoselective transformation of Baylis-Hillman acetates 1 into corresponding (Z)-allyl iodides 2 has been achieved by treatment of 1 with samarium triiodide in THF. Remarkable rate acceleration of samarium triiodide-mediated iodination of 1 was found when ionic liquid 1-n-butyl-3-methyl-imidazolium tetrafluroborate ([bmim]BF4) was used as reaction media in stead of THF. This novel approach proceeds readily at 50 °C within a few minutes to afford (Z)-allyl iodides 2 in excellent yields. A mechanism involving stereoselective iodination of the acetates of Baylis-Hillman adducts by samarium triiodide is described, in which a six-membered ring transition state played a key role in the stereoselective formation of 2. PMID:16502505

  18. Caenorhabditis elegans response to salt

    NARCIS (Netherlands)

    O.O. Umuerri (Oluwatoroti Omowayewa)

    2012-01-01

    textabstractThis thesis describes my work, where I used genetic methods to identify new genes involved in salt taste in C. elegans. In addition, I used calcium imaging to characterize the cellular response of C. elegans to salt. The thesis is divided into five sections and each section is summarized

  19. SYNTHESIS AND ANTITUMOR ACTIVITY OF COPPER, NICKEL AND COBALT COORDINATION COMPOUNDS WITH 1-(2-HYDROXYPHENYL)ETHANONE N(4)-ALLYL-3-THIOSEMICARBAZONE

    OpenAIRE

    Vasilii GRAUR; Serghei SAVCIN; Victor TSAPKOV; Aurelian GULEA

    2015-01-01

    The paper presents the synthesis of the ligand 1-(2-hydroxyphenyl)ethanone N(4)-allyl-3-thiosemicarbazone (H2L) and six coordination compounds of copper, nickel and cobalt with this ligand. The structure of thiosemicarbazone H2L was studied using 1H and 13С NMR spectroscopy. The synthesized coordination compounds were studied using elemental analysis, gravimetric analysis of water content, molar conductivity, and magnetochemistry. For H2L the antitumor activity towards human leukemia HL-60 ce...

  20. Palladium-Catalyzed Asymmetric Allylic Alkylation of 4-Substituted Isoxazolidin-5-ones: Straightforward Access to β2,2 -Amino Acids.

    Science.gov (United States)

    Nascimento de Oliveira, Marllon; Arseniyadis, Stellios; Cossy, Janine

    2018-04-03

    We report here an unprecedented and highly enantioselective palladium-catalyzed allylic alkylation applied to 4-substituted isoxazolidin-5-ones. Ultimately, the process provides a straightforward access to β 2,2 -amino acids bearing an all-carbon quaternary stereogenic center in great yields and a high degree of enantioselectivity. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. Intramolecular carbolithiation of N-allyl-ynamides: an efficient entry to 1,4-dihydropyridines and pyridines – application to a formal synthesis of sarizotan

    Directory of Open Access Journals (Sweden)

    Wafa Gati

    2012-12-01

    Full Text Available We have developed a general synthesis of polysubstituted 1,4-dihydropyridines and pyridines based on a highly regioselective lithiation/6-endo-dig intramolecular carbolithiation from readily available N-allyl-ynamides. This reaction, which has been successfully applied to the formal synthesis of the anti-dyskinesia agent sarizotan, further extends the use of ynamides in organic synthesis and further demonstrates the synthetic efficiency of carbometallation reactions.

  2. Atmospheric oxidation of vinyl and allyl acetate: product distribution and mechanisms of the OH-initiated degradation in the presence and absence of NO(x).

    Science.gov (United States)

    Blanco, María B; Bejan, Iustinian; Barnes, Ian; Wiesen, Peter; Teruel, Mariano A

    2012-08-21

    The products formed from the reactions of OH radicals with vinyl acetate and allyl acetate have been studied in a 1080 L quartz-glass chamber in the presence and absence of NO(x) using in situ FTIR spectroscopy to monitor the reactant decay and product formation. The yields of the primary products formed in the reaction of OH with vinyl acetate were: formic acetic anhydride (84 ± 11)%; acetic acid (18 ± 3)% and formaldehyde (99 ± 15)% in the presence of NO(x) and formic acetic anhydride (28 ± 5)%; acetic acid (87 ± 12)% and formaldehyde (52 ± 8)% in the absence of NO(x). For the reaction of OH with allyl acetate the yields of the identified products were: acetoxyacetaldehyde (96 ± 15)% and formaldehyde (90 ± 12)% in the presence of NO(x) and acetoxyacetaldehyde (26 ± 4)% and formaldehyde (12 ± 3)% in the absence of NO(x). The present results indicate that in the absence of NO(x) the main fate of the 1,2-hydroxyalkoxy radicals formed after addition of OH to the double bond in the compounds is, in the case of vinyl acetate, an α-ester rearrangement to produce acetic acid and CH(2)(OH)CO(•) radicals and in the case of allyl acetate reaction of the radical with O(2) to form acetic acid 3-hydroxy-2-oxo-propyl ester (CH(3)C(O)OCH(2)C(O)CH(2)OH). In contrast, in the presence of NO(x) the main reaction pathway for the 1,2-hydroxyalkoxy radicals is decomposition. The results are compared with the available literature data and implications for the atmospheric chemistry of vinyl and allyl acetate are assessed.

  3. Cu(II)-catalyzed allylic silylation of Morita-Baylis-Hillman alcohols via dual activation of Si-B bond and hydroxyl group.

    Science.gov (United States)

    Xuan, Qing-Qing; Zhong, Neng-Jun; Ren, Chuan-Li; Liu, Li; Wang, Dong; Chen, Yong-Jun; Li, Chao-Jun

    2013-11-01

    The reaction of Morita-Baylis-Hillman (MBH) alcohols with Me2PhSiBpin under the catalysis of Cu(OTf)2/pyridine in methanol has been developed. The direct silylation of allylic alcohols via dual activation of the Si-B bond and the hydroxyl group of the MBH alcohol provides an efficient and convenient method for the synthesis of functionalized allylsilanes.

  4. Morita-Baylis-Hillman Reaction of α,β-Unsaturated Ketones with Allylic Acetates by the Combination of Transition-Metal Catalysis and Organomediation.

    Science.gov (United States)

    Li, Ya-Qiong; Wang, Hai-Jun; Huang, Zhi-Zhen

    2016-06-03

    An intermolecular Morita-Baylis-Hillman (MBH) reaction of α,β-unsaturated ketones with allylic acetates under the catalysis of 10 mol % of tetrakis(triphenylphosphine)palladium(0) and mediation of tributylphosphine has been developed in the presence of acetic acid, affording the desired α-coupling products. The MBH reaction has the advantages of good tolerance to many functional groups, excellent regioselectivity and E-stereoselectivity, and moderate to good yields.

  5. The Salt II Treaty

    International Nuclear Information System (INIS)

    Caldwell, D.

    1991-01-01

    The first strategic arms limitation talks resulted in two agreements: the Anti-Ballistic Missile Treaty and the Interim Agreement to Limit Strategic Offensive Arms. Senator Henry M. (Scoop) Jackson (D-Wa.) was concerned about the numerical advantage granted to the USSR by the Latter agreement and proposed an amendment that would prohibit future negotiators from granting the Soviet Union similar terms. This paper discusses the second round of SALT negotiations which opened in November 1972 and continued under presidents Richard M. Nixon, Gerald Ford, and Jimmy Carter. As the negotiators met, U.S. and Soviet scientists and engineers continued their work to develop new nuclear weapons and launchers. Particularly problematic were modern, large ballistic missiles, cruise missiles, and the Soviet Backfire bomber

  6. Salt resistant crop plants

    KAUST Repository

    Roy, Stuart J.

    2014-04-01

    Soil salinity is a major constraint to agriculture. To improve salinity tolerance of crops, various traits can be incorporated, including ion exclusion, osmotic tolerance and tissue tolerance. We review the roles of a range of genes involved in salt tolerance traits. Different tissues and cells are adapted for specific and often diverse function, so it is important to express the genes in specific cell-types and to pyramid a range of traits. Modern biotechnology (marker- assisted selection or genetic engineering) needs to be increasingly used to introduce the correct combination of genes into elite crop cultivars. Importantly, the effects of introduced genes need to be evaluated in the field to determine their effect on salinity tolerance and yield improvement.

  7. THE CM-, MM-, AND SUB-MM-WAVE SPECTRUM OF ALLYL ISOCYANIDE AND RADIOASTRONOMICAL OBSERVATIONS IN ORION KL AND THE SgrB2 LINE SURVEYS

    Energy Technology Data Exchange (ETDEWEB)

    Haykal, I.; Margulès, L.; Huet, T. R.; Motyienko, R. A. [Laboratoire de Physique des Lasers, Atomes, et Molécules, UMR CNRS 8523, Université de Lille 1, F-59655 Villeneuve d' Ascq Cédex (France); Écija, P.; Cocinero, E. J.; Basterretxea, F.; Fernández, J. A.; Castaño, F. [Departamento de Química Física, Facultad de Ciencia y Tecnología, Universidad del País Vasco, Barrio Sarriena s/n, E-48940 Leioa (Spain); Lesarri, A. [Departamento de Química Física y Química Inorgánica, Facultad de Ciencias, Universidad de Valladolid, E-47011 Valladolid (Spain); Guillemin, J. C. [Institut des Sciences Chimiques de Rennes, Ecole Nationale Supérieure de Chimie de Rennes, CNRS, UMR 6226, Allèe de Beaulieu, CS 50837, F-35708 Rennes Cedex 7 (France); Tercero, B.; Cernicharo, J., E-mail: laurent.margules@univ-lille1.fr [Centro de Astrobiología (CSIC-INTA), Laboratory of Molecular Astrophysics, Department of Astrophysics, Ctra. De Ajalvir, km 4, E-28850 Torrejón de Ardoz, Madrid (Spain)

    2013-11-10

    Organic isocyanides have an interesting astrochemistry and some of these molecules have been detected in the interstellar medium (ISM). However, rotational spectral data for this class of compounds are still scarce. We provide laboratory spectra of the four-carbon allyl isocyanide covering the full microwave region, thus allowing a potential astrophysical identification in the ISM. We assigned the rotational spectrum of the two cis (synperiplanar) and gauche (anticlinal) conformations of allyl isocyanide in the centimeter-wave region (4-18 GHz), resolved its {sup 14}N nuclear quadrupole coupling (NQC) hyperfine structure, and extended the measurements into the millimeter and submillimeter-wave (150-900 GHz) ranges for the title compound. Rotational constants for all the monosubstituted {sup 13}C and {sup 15}N isotopologues are additionally provided. Laboratory observations are supplemented with initial radioastronomical observations. Following analysis of an extensive dataset (>11000 rotational transitions), accurate ground-state molecular parameters are reported for the cis and gauche conformations of the molecule, including rotational constants, NQC parameters, and centrifugal distortion terms up to octic contributions. Molecular parameters have also been obtained for the two first excited states of the cis conformation, with a dataset of more than 3300 lines. The isotopic data allowed determining substitution and effective structures for the title compound. We did not detect allyl isocyanide either in the IRAM 30 m line survey of Orion KL or in the PRIMOS survey toward SgrB2. Nevertheless, we provided an upper limit to its column density in Orion KL.

  8. Thin film of Poly(acrylic acid-co-allyl acrylate as a Sacrificial Protective Layer for Hydrophilic Self Cleaning Glass

    Directory of Open Access Journals (Sweden)

    Jānis Lejnieks

    2010-05-01

    Full Text Available Poly(acrylic acid-co-allyl acrylate statistical copolymers were synthesized in a controlled manner in two steps: first tert.butyl acrylate and allyl acrylate were polymerized via atom transfer radical polymerization (ATRP and afterwords the tert.butyl protective groups were removed via hydrolysis. Samples of self cleaning glass (SCG were coated with thin films of poly(acrylic acid-co-allyl acrylate and cross-linked afterwards by UV irradiation (in the presence of a photoinitiator and an accelerator. Solution cast thin films were transparent and homogeneous before and after UV cross-linking. The irradiated samples were found to be hydrophilic (Θ < 20° and water insoluble. The coating prevented the spontaneous hydrophobization of the SCG by residual silicon exhaled from the sealing material. The TiO2 photocatalyst that covers the glass surface was found to strip the protective coating. The rate of the photooxidation process was measured by IR spectroscopy. The real field performance of the protective coating was also tested.

  9. Iodized Salt Sales in the United States

    Directory of Open Access Journals (Sweden)

    Joyce Maalouf

    2015-03-01

    Full Text Available Iodized salt has been an important source of dietary iodine, a trace element important for regulating human growth, development, and metabolic functions. This analysis identified iodized table salt sales as a percentage of retail salt sales using Nielsen ScanTrack. We identified 1117 salt products, including 701 salt blends and 416 other salt products, 57 of which were iodized. When weighted by sales volume in ounces or per item, 53% contained iodized salt. These findings may provide a baseline for future monitoring of sales of iodized salt.

  10. Dietary Salt Exacerbates Experimental Colitis.

    Science.gov (United States)

    Tubbs, Alan L; Liu, Bo; Rogers, Troy D; Sartor, R Balfour; Miao, Edward A

    2017-08-01

    The Western diet is characterized by high protein, sugar, fat, and low fiber intake, and is widely believed to contribute to the incidence and pathogenesis of inflammatory bowel disease (IBD). However, high sodium chloride salt content, a defining feature of processed foods, has not been considered as a possible environmental factor that might drive IBD. We set out to bridge this gap. We examined murine models of colitis on either a high salt diet (HSD) or a low salt diet. We demonstrate that an HSD exacerbates inflammatory pathology in the IL-10-deficient murine model of colitis relative to mice fed a low salt diet. This was correlated with enhanced expression of numerous proinflammatory cytokines. Surprisingly, sodium accumulated in the colons of mice on an HSD, suggesting a direct effect of salt within the colon. Similar to the IL-10-deficient model, an HSD also enhanced cytokine expression during infection by Salmonella typhimurium This occurred in the first 3 d of infection, suggesting that an HSD potentiates an innate immune response. Indeed, in cultured dendritic cells we found that high salt media potentiates cytokine expression downstream of TLR4 activation via p38 MAPK and SGK1. A third common colitis model, administration of dextran sodium sulfate, was hopelessly confounded by the high sodium content of the dextran sodium sulfate. Our results raise the possibility that high dietary salt is an environmental factor that drives increased inflammation in IBD. Copyright © 2017 by The American Association of Immunologists, Inc.

  11. Young Stars with SALT

    Science.gov (United States)

    Riedel, Adric R.; Alam, Munazza K.; Rice, Emily L.; Cruz, Kelle L.; Henry, Todd J.

    2017-05-01

    We present a spectroscopic and kinematic analysis of 79 nearby M dwarfs in 77 systems. All of these dwarfs are low-proper-motion southern hemisphere objects and were identified in a nearby star survey with a demonstrated sensitivity to young stars. Using low-resolution optical spectroscopy from the Red Side Spectrograph on the South African Large Telescope, we have determined radial velocities, H-alpha, lithium 6708 Å, and potassium 7699 Å equivalent widths linked to age and activity, and spectral types for all of our targets. Combined with astrometric information from literature sources, we identify 44 young stars. Eighteen are previously known members of moving groups within 100 pc of the Sun. Twelve are new members, including one member of the TW Hydra moving group, one member of the 32 Orionis moving group, 9 members of Tucana-Horologium, one member of Argus, and two new members of AB Doradus. We also find 14 young star systems that are not members of any known groups. The remaining 33 star systems do not appear to be young. This appears to be evidence of a new population of nearby young stars not related to the known nearby young moving groups. Based on observations made with the Southern African Large Telescope (SALT).

  12. Reaction of zearalenone and α-zearalenol with allyl isothiocyanate, characterization of reaction products, their bioaccessibility and bioavailability in vitro.

    Science.gov (United States)

    Bordin, K; Saladino, F; Fernández-Blanco, C; Ruiz, M J; Mañes, J; Fernández-Franzón, M; Meca, G; Luciano, F B

    2017-02-15

    This study investigates the reduction of zearalenone (ZEA) and α-zearalenol (α-ZOL) on a solution model using allyl isothiocyanate (AITC) and also determines the bioaccessibility and bioavailability of the reaction products isolated and identified by MS-LIT. Mycotoxin reductions were dose-dependent, and ZEA levels decreased more than α-ZOL, ranging from 0.2 to 96.9% and 0 to 89.5% respectively, with no difference (p⩽0.05) between pH 4 and 7. Overall, simulated gastric bioaccessibility was higher than duodenal bioaccessibility for both mycotoxins and mycotoxin-AITC conjugates, with duodenal fractions representing ⩾63.5% of the original concentration. Simulated bioavailability of reaction products (α-ZOL/ZEA-AITC) were lower than 42.13%, but significantly higher than the original mycotoxins. The cytotoxicity of α-ZOL and ZEA in Caco-2/TC7 cells was also evaluated, with toxic effects observed at higher levels than 75μM. Further studies should be performed to evaluate the toxicity and estrogenic effect of α-ZOL/ZEA-AITC. Copyright © 2016 Elsevier Ltd. All rights reserved.

  13. Fabrication of Cellulose Film with Enhanced Mechanical Properties in Ionic Liquid 1-Allyl-3-methylimidaxolium Chloride (AmimCl

    Directory of Open Access Journals (Sweden)

    Jinhui Pang

    2013-03-01

    Full Text Available More and more attention has been paid to environmentally friendly bio-based renewable materials as the substitution of fossil-based materials, due to the increasing environmental concerns. In this study, regenerated cellulose films with enhanced mechanical property were prepared via incorporating different plasticizers using ionic liquid 1-allyl-3-methylimidazolium chloride (AmimCl as the solvent. The characteristics of the cellulose films were investigated by scanning electron microscopy (SEM, atomic force microscopy (AFM, thermal analysis (TG, X-ray diffraction (XRD, 13C Solid-state cross-polarization/magic angle spinning nuclear magnetic resonance (CP/MAS NMR and tensile testing. The results showed that the cellulose films exhibited a homogeneous and smooth surface structure. It was noted that the thermal stability of the regenerated cellulose film plasticized with glycerol was increased compared with other regenerated cellulose films. Furthermore, the incorporation of plasticizers dramatically strengthened the tensile strength and improved the hydrophobicity of cellulose films, as compared to the control sample. Therefore, these notable results exhibited the potential utilization in producing environmentally friendly cellulose films with high performance properties.

  14. Fumigation of Brazil nuts with allyl isothiocyanate to inhibit the growth of Aspergillus parasiticus and aflatoxin production.

    Science.gov (United States)

    Lopes, Lucas F; Bordin, Keliani; de Lara, Gabriel Hc; Saladino, Federica; Quiles, Juan M; Meca, Giuseppe; Luciano, Fernando B

    2018-01-01

    Brazil produces approximately 40 000 tons of Brazil nuts annually, which is commonly contaminated with fungi and mycotoxins. Gaseous allyl isothiocyanate (AITC) was used to inhibit the growth of Aspergillus parasiticus and its production of aflatoxins (AFs) in Brazil nuts. Nuts were inoculated with 10 4 spores g -1 of A. parasiticus and placed in airtight glass jars with controlled relative humidity (RH = 95 or 85%). Samples were treated with 0, 0.5, 1.0 or 2.5 µL L -1 of gaseous AITC and analyzed after 30 days to determine the fungal population and AFs content. Samples were also submitted to sensory evaluation. AITC at 2.5 µL L -1 could completely inhibit the fungal growth and AFs production in both the RH tested. AITC at 0.5 and 1 µL L -1 did not affect the microbial growth at RH = 95%, but 1 µL L -1 reduced the production of AFs by ∼50%. All AITC treatments reduced the fungal population and AFs to undetectable levels at RH = 85%. None of the concentrations altered sensory characteristics of Brazil nuts. Gaseous AITC could be used as an alternative to inhibit the growth of A. parasiticus during storage and transport of Brazil nuts. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

  15. Allyl isothiocyanate arrests cancer cells in mitosis, and mitotic arrest in turn leads to apoptosis via Bcl-2 protein phosphorylation.

    Science.gov (United States)

    Geng, Feng; Tang, Li; Li, Yun; Yang, Lu; Choi, Kyoung-Soo; Kazim, A Latif; Zhang, Yuesheng

    2011-09-16

    Allyl isothiocyanate (AITC) occurs in many commonly consumed cruciferous vegetables and exhibits significant anti-cancer activities. Available data suggest that it is particularly promising for bladder cancer prevention and/or treatment. Here, we show that AITC arrests human bladder cancer cells in mitosis and also induces apoptosis. Mitotic arrest by AITC was associated with increased ubiquitination and degradation of α- and β-tubulin. AITC directly binds to multiple cysteine residues of the tubulins. AITC induced mitochondrion-mediated apoptosis, as shown by cytochrome c release from mitochondria to cytoplasm, activation of caspase-9 and caspase-3, and formation of TUNEL-positive cells. Inhibition of caspase-9 blocked AITC-induced apoptosis. Moreover, we found that apoptosis induction by AITC depended entirely on mitotic arrest and was mediated via Bcl-2 phosphorylation at Ser-70. Pre-arresting cells in G(1) phase by hydroxyurea abrogated both AITC-induced mitotic arrest and Bcl-2 phosphorylation. Overexpression of a Bcl-2 mutant prevented AITC from inducing apoptosis. We further showed that AITC-induced Bcl-2 phosphorylation was caused by c-Jun N-terminal kinase (JNK), and AITC activates JNK. Taken together, this study has revealed a novel anticancer mechanism of a phytochemical that is commonly present in human diet.

  16. Transcriptional responses to exposure to the brassicaceous defence metabolites camalexin and allyl-isothiocyanate in the necrotrophic fungus Alternaria brassicicola.

    Science.gov (United States)

    Sellam, Adnane; Dongo, Anita; Guillemette, Thomas; Hudhomme, Piétrick; Simoneau, Philippe

    2007-03-01

    SUMMARY Alternaria brassicicola is the causative agent of black spot disease of Brassicaceae belonging to the genera Brassica and Raphanus. During host infection, A. brassicicola is exposed to high levels of antimicrobial defence compounds such as indolic phytoalexins and glucosinolate breakdown products. To investigate the transcriptomic response of A. brassicicola when challenged with brassicaceous defence metabolites, suppression subtractive hybridization (SSH) was performed to generate two cDNA libraries from germinated conidia treated either with allyl isothiocyanate (Al-ITC) or with camalexin. Following exposure to Al-ITC, A. brassicicola displayed a response similar to that experienced during oxidative stress. Indeed, a substantial subset of differentially expressed genes was related to cell protection against oxidative damage. Treatment of A. brassicicola conidia with the phytoalexin camalexin appeared to activate a compensatory mechanism to preserve cell membrane integrity and, among the camalexin-elicited genes, several were involved in sterol and sphingolipid biosynthesis. The transcriptomic analysis suggested that protection against the two tested compounds also involved mechanisms aimed at limiting their intracellular accumulation, such as melanin biosynthesis (in the case of camalexin exposure only) and drug efflux. From the Al-ITC and the camalexin differentially expressed genes identified here, 25 were selected to perform time-course studies during interactions with brassicaceous hosts. In planta, up-regulation of all the selected genes was observed during infection of Raphanus sativus whereas only a subset were over-expressed during the incompatible interaction with Arabidopsis thaliana ecotype Columbia.

  17. Structure formation of soil dispersions in the presence of polyelectrolytes on the basis of allyl alcohol and acryl acid derivatives

    Directory of Open Access Journals (Sweden)

    Amankait Asanov

    2015-09-01

    Full Text Available Some changes of structural composition and surface properties of soil dispersions in the presence of polyelectrolytes, based on allyl alcohol and acryl acid derivatives, have been studied. The results show, that the changes in the structure of soil dispersions composition are connected with the added concentration and pH value, that depend on mole ratio and nature of functional groups, as well as on the nature of counterions and concomitant electrolytes, changing with the conditions of polymer analogous conversion and neutralization reaction. Experimental data show, that the change in the conformational state and the length of the macromolecule has a significant impact on the structure-forming effect and the amount of polyelectrolyte, needed to achieve the same degree of structure-forming effect of soil dispersions. The causes for the revealed reasons are shown on the basis of the results of the experiment. Along with this, it was found that particular changes of structural composition and surface properties of the soil dispersions depend on the type and concentration of the added polyelectrolyte.

  18. Isolation and recovery of cellulose from waste nylon/cotton blended fabrics by 1-allyl-3-methylimidazolium chloride.

    Science.gov (United States)

    Lv, Fangbing; Wang, Chaoxia; Zhu, Ping; Zhang, Chuanjie

    2015-06-05

    Development of a simple process for separating cellulose and nylon 6 from their blended fabrics is indispensable for recycling of waste mixed fabrics. An efficient procedure of dissolution of the fabrics in an ionic liquid 1-allyl-3-methylimidazolium chloride ([AMIM]Cl) and subsequent filtration separation has been demonstrated. Effects of treatment temperature, time and waste fabrics ratio on the recovery rates were investigated. SEM images showed that the cotton cellulose dissolved in [AMIM]Cl while the nylon 6 fibers remained. The FTIR spectrum of regenerated cellulose (RC) was similar with that of virgin cotton fibers, which verified that no other chemical reaction occurred besides breakage of hydrogen bonds during the processes of dissolution and separation. TGA curves indicated that the regenerated cellulose possessed a reduced thermal stability and was effectively removed from waste nylon/cotton blended fabrics (WNCFs). WNCFs were sufficiently reclaimed with high recovery rate of both regenerated cellulose films and nylon 6 fibers. Copyright © 2015 Elsevier Ltd. All rights reserved.

  19. Structural Changes of Bagasse dusring the Homogeneous Esterification with Maleic Anhydride in Ionic Liquid 1-Allyl-3-methylimidazolium Chloride

    Directory of Open Access Journals (Sweden)

    Huihui Wang

    2018-04-01

    Full Text Available The maleation of bagasse could greatly increase the compatibility between bagasse and composite matrixes, and the percentage of substitution (PS of bagasse maleates could be regulated in the homogeneous system. However, due to the complicated components and the linkages of bagasse, it was difficult to control the reaction behaviors of each component. In this paper, the detailed structural changes of bagasse during the homogeneous maleation in ionic liquid 1-allyl-3-methylimidazolium chloride (AmimCl were comparatively investigated with the three main components (cellulose, hemicelluloses, and lignin from bagasse. The PS of the maleated bagasse was 12.52%, and the PS of the maleated cellulose, hemicelluloses, and lignin were 13.50%, 10.89%, and 14.03%, respectively. Fourier translation infrared (FT-IR and NMR analyses confirmed that the three main components were all involved in the homogeneous maleation. 1H-13C HSQC analysis indicated that the predominant monoesterification of cellulose, diesterification of hemicelluloses and lignin, and the degradation of the three main components simultaneously occurred. Besides, the quantitative analysis from 1H-13C HSQC revealed the relative PS of reactive sites in each component. 31P NMR results showed that the reactivity of lignin aliphatic hydroxyls was higher than that of phenolic ones, and the reactivity of phenolic hydroxyls followed the order of p-hydroxyphenyl hydroxyls > guaiacyl hydroxyls > syringyl hydroxyls.

  20. Palladium-catalyzed asymmetric allylic substitution of 2-arylcyclohexenol derivatives: asymmetric total syntheses of (+)-crinamine, (-)-haemanthidine, and (+)-pretazettine.

    Science.gov (United States)

    Nishimata, Toyoki; Sato, Yoshihiro; Mori, Miwako

    2004-03-19

    Much interest has been shown in Amaryllidaceae alkaloids as synthetic targets due to their wide range of biological activities. Over 100 alkaloids have been isolated from members of the Amaryllidaceae family; most of them can be classified into eight skeletally homogeneous groups. We have succeeded in the first asymmetric total syntheses of the crinane-type alkaloids (+)-crinamine (1), (-)-haemanthidine (2), and (+)-pretazettine (3). The starting cyclohexenylamine 14 was obtained from allyl phosphonate 11c by palladium-catalyzed asymmetric amination in 82% yield and with 74% ee. The product was recrystallized from MeOH. Interestingly, (-)-14 with 99% ee was obtained from the mother liquor (74% recovery). Intramolecular carbonyl-ene reaction of (-)-10 proceeds in a highly stereoselective manner to give hexahydroindole derivative 9 as the sole product. In the Lewis-acid-catalyzed carbonyl-ene reaction, an interesting rearrangement product, 20, was isolated in high yield. From 9, (+)-crinamine was synthesized. Thus, the asymmetric total synthesis of (+)-crinamine was achieved in 10 steps from 11c, and the overall yield is 19%. The total synthesis of (-)-haemanthidine was also achieved from 9 by a short sequence of steps.

  1. Rapid assembly of functionalised spirocyclic indolines by palladium-catalysed dearomatising diallylation of indoles with allyl acetate.

    Science.gov (United States)

    Dhankher, Persis; Benhamou, Laure; Sheppard, Tom D

    2014-10-06

    Herein, we report the application of allyl acetate to the palladium-catalysed dearomatising diallylation of indoles. The reaction can be carried out by using a readily available palladium catalyst at room temperature, and can be applied to a wide range of substituted indoles to provide access to the corresponding 3,3-diallylindolinines. These compounds are versatile synthetic intermediates that readily undergo Ugi reactions or proline-catalysed asymmetric Mannich reactions. Alternatively, acylation of the 3,3-diallylindolinines with an acid chloride or a chloroformate, followed by treatment with aluminium chloride, enables 2,3-diallylindoles to be prepared. By using ring-closing metathesis, functionalised spirocyclic indoline scaffolds can be accessed from the Ugi products, and a dihydrocarbazole can be prepared from the corresponding 2,3-diallylindole. © 2014 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.

  2. A dioxygenase of Pleurotus sapidus transforms (+)-valencene regio-specifically to (+)-nootkatone via a stereo-specific allylic hydroperoxidation.

    Science.gov (United States)

    Krügener, Sven; Krings, Ulrich; Zorn, Holger; Berger, Ralf G

    2010-01-01

    A selective and highly efficient allylic oxidation of the sesquiterpene (+)-valencene to the grapefruit flavour compound (+)-nootkatone was achieved with lyophilisate of the edible mushroom Pleurotus sapidus. The catalytic reaction sequence was elucidated through the identification of intermediate, (+)-valencene derived hydroperoxides. A specific staining of hydroperoxides allowed the semi-preparative isolation of two secondary (+)-valencene hydroperoxides, 6(R)-Isopropenyl-4(R),4a(S)-dimethyl-2,3,4,4a,5,6,7,8-octahydro-naphthalen-4(S)-yl-hydroperoxide and 6(R)-Isopropenyl-4(R),4a(S)-dimethyl-2,3,4,4a,5,6,7,8-octahydro-naphthalen-2(R)-yl-hydroperoxide. Chemical reduction of the biotransformation products yielded a tertiary alcohol identified as 2(R)-Isopropenyl-8(R),8a(S)-dimethyl-1,3,4,7,8,8a-hexahydro-2H-naphthalen-4a(R)-ol. This suggested a lipoxygenase-type oxidation of (+)-valencene via secondary and tertiary hydroperoxides and confirmed homology data of the key enzyme obtained previously from amino acid sequencing.

  3. Sodium (Salt or Sodium Chloride)

    Science.gov (United States)

    ... pick up the salt shaker. Get tips on cutting back and how to build a healthier relationship ... from the start. Healthy Eating • Healthy Eating Home • Nutrition AHA Diet and Lifestyle Recommendations Making Healthy Choices ...

  4. Lowering Salt in Your Diet

    Science.gov (United States)

    ... and salt that cooks add to foods at restaurants and other food service establishments. Q. What are ... State & Local Officials Consumers Health Professionals Science & Research Industry Scroll back to top Popular Content Home Latest ...

  5. Microbiology of solar salt ponds

    Science.gov (United States)

    Javor, B.

    1985-01-01

    Solar salt ponds are shallow ponds of brines that range in salinity from that of normal seawater (3.4 percent) through NaCl saturation. Some salterns evaporate brines to the potash stage of concentration (bitterns). All the brines (except the bitterns, which are devoid of life) harbor high concentrations of microorganisms. The high concentrations of microorganisms and their adaptation to life in the salt pond are discussed.

  6. Hydrogen-bonding catalysis of sulfonium salts

    OpenAIRE

    Kaneko, Shiho; Kumatabara, Yusuke; Shimizu, Shoichi; Maruoka, Keiji; Shirakawa, Seiji

    2017-01-01

    Although quaternary ammonium and phosphonium salts are known as important catalysts in phase-transfer catalysis, the catalytic ability of tertiary sulfonium salts has not yet been well demonstrated. Herein, we demonstrate the catalytic ability of trialkylsulfonium salts as hydrogen-bonding catalysts on the basis of the characteristic properties of the acidic α hydrogen atoms on alkylsulfonium salts.

  7. Opinion on Salt intake of Dutch children

    OpenAIRE

    Netherlands Food and Consumer Product Safety Authority

    2009-01-01

    The amount of salt in many, especially commercially prepared, food is too high. Reducing salt intake can contribute positively to public health. A reduction in salt intake at a young age reduces the risk of hypertension and cardiovascular disease in later life. The salt intake of 2-6 year old Dutch children was estimated using the Dutch Food Consumption Survey, which was aimed at children in 2005/2006. The foods that contributed most to the total salt intake were determined.

  8. A theoretical study of the reaction of O(3P) with an allyl radical C3H5

    Science.gov (United States)

    Park, Jong-Ho; Lee, Hohjai; Choi, Jong-Ho

    2003-11-01

    Ab initio calculations of the reaction of ground-state atomic oxygen [O(3P)] with an allyl radical (C3H5) have been carried out using the density functional method and the complete basis set model. On the calculated lowest doublet potential energy surface, the barrierless association of O(3P) to C3H5 forms three energy-rich addition intermediates, which are predicted to undergo subsequent isomerization and decomposition steps leading to various products: C3H4O+H, CH2O+C2H3, C2H4+CHO, C2H2O+CH3, C2H5+CO, C3H4+OH, and C2H4O+CH. The respective reaction mechanisms through the three addition intermediates are presented, and it has been found that the barrier height, reaction enthalpy, and the number of intermediates involved along the reaction coordinate are of extreme importance in understanding such reactive scattering processes. With the aid of Rice-Ramsperger-Kassel-Marcus calculations, the major reaction pathway is predicted to be the formation of acrolein (C3H4O)+H, which is consistent with the previous gas-phase bulk kinetic experiment performed by Gutman et al. [J. Phys. Chem. 94, 3652 (1990)]. For the minor C3H4+OH channel, which has been newly found in the recent crossed beam investigations, a second barrierless, direct H-atom abstraction from the central carbon of C3H5 is calculated to compete with the addition process due to the little C-H bond dissociation energy and the formation of a stable allene product. The dynamic and kinetic characteristics of the reaction mechanism are discussed on the basis of the comparison of prior statistical calculations to the nascent internal distributions of the observed OH product.

  9. Modifying responses of allyl sulfide, indole-3-carbinol and germanium in a rat multi-organ carcinogenesis model.

    Science.gov (United States)

    Jang, J J; Cho, K J; Lee, Y S; Bae, J H

    1991-04-01

    The modifying potential of allyl sulfide (AS), indole-3-carbinol (I3C) and carboxyethylgermanium sesquioxide (GE) on lesion development was examined in a wide-spectrum initiation model. Groups 1-4 were treated sequentially with diethylnitrosamine (DEN) (100 mg/kg, i.p., single dose), N-methylnitrosourea (MNU) (20 mg/kg, i.p., four doses at days 2, 5, 8 and 11), and N,N-dibutylnitrosamine (DBN) (0.05% in drinking water during weeks 3 and 4). Groups 5-7 received vehicles without carcinogens during the initiation period. Group 8 served as the untreated control. After this initiating procedure, groups 2-7 were administered a diet containing 0.5% AS or I3C and 0.05% GE. All surviving animals were killed 40 weeks after the beginning of the experiment and the target organs were examined. The induction of GST-P+ hepatic foci in rats treated with carcinogens was significantly inhibited by treatment with all three compounds. AS treatment significantly decreased the incidence of hepatic hyperplastic nodules, adenoma of the lung and thyroid, and papillary or nodular hyperplasia of the urinary bladder. Administration of GE also significantly inhibited the development of hepatic nodules and adenoma of the lung and thyroid. However, I3C only inhibited the hyperplastic nodules of the liver. These results demonstrated that this multi-organ initiation model could be useful in confirming organ-specific modification potential and, in addition, the inhibitory effect of AS, I3C and GE on liver, lung, thyroid and urinary bladder carcinogenesis.

  10. Biosynthesis of a linoleic acid allylic epoxide: mechanistic comparison with its chemical synthesis and leukotriene A biosynthesiss⃞

    Science.gov (United States)

    Niisuke, Katrin; Boeglin, William E.; Murray, John J.; Schneider, Claus; Brash, Alan R.

    2009-01-01

    Biosynthesis of the leukotriene A (LTA) class of epoxide is a lipoxygenase-catalyzed transformation requiring a fatty acid hydroperoxide substrate containing at least three double bonds. Here, we report on biosynthesis of a dienoic analog of LTA epoxides via a different enzymatic mechanism. Beginning with homolytic cleavage of the hydroperoxide moiety, a catalase/peroxidase-related hemoprotein from Anabaena PCC 7120, which occurs in a fusion protein with a linoleic acid 9R-lipoxygenase, dehydrates 9R-hydroperoxylinoleate to a highly unstable epoxide. Using methods we developed for isolating extremely labile compounds, we prepared and purified the epoxide and characterized its structure as 9R,10R-epoxy-octadeca-11E,13E-dienoate. This epoxide hydrolyzes to stable 9,14-diols that were reported before in linoleate autoxidation (Hamberg, M. 1983. Autoxidation of linoleic acid: Isolation and structure of four dihydroxy octadecadienoic acids. Biochim. Biophys. Acta 752: 353–356) and in incubations with the Anabaena enzyme (Lang, I., C. Göbel, A. Porzel, I. Heilmann, and I. Feussner. 2008. A lipoxygenase with linoleate diol synthase activity from Nostoc sp. PCC 7120. Biochem. J. 410: 347–357). We also prepared an equivalent epoxide from 13S-hydroperoxylinoleate using a “biomimetic” chemical method originally described for LTA4 synthesis and showed that like LTA4, the C18.2 epoxide conjugates readily with glutathione, a potential metabolic fate in vivo. We compare and contrast the mechanisms of LTA-type allylic epoxide synthesis by lipoxygenase, catalase/peroxidase, and chemical transformations. These findings provide new insights into the reactions of linoleic acid hydroperoxides and extend the known range of catalytic activities of catalase-related hemoproteins. PMID:19244216

  11. Study of preparation of radioiodinated allyl diprenorphine as an single photon emission computed tomographic imaging agent for mapping opioid receptors

    International Nuclear Information System (INIS)

    He Xiaokun; Wang Rongfu; Zhang Chunli

    2004-01-01

    Purpose: To prepare and evaluate radioiodinated allyl diprenorphine (DPN) as a new opioid receptor imaging agent for SPECT study. Methods: 7α-O-stannyl-DPN was obtained from DPN by acetylated it to protect the phenolic 3-OH group of DPN and then introduced the vinylstannane into the tertiary alcohol of the 7α-side chain. [ 125 I]-7α-O-iodoallyl diprenorphine (7α-O-IA-DPN) was prepared by radioiododestannylation under acidic condition using iodobead as an oxidant reagent, and in vitro and in vivo opioid receptor binding assays, metabolism were performed with Kunming mouse brains. Study of distribution in the Wistar rat's brain and naloxone inhibition was carried out. The data were analyzed by statistical method. Results: The radiochemical yields of I-125-7α-O-IA-DPN were more than 90%. In TLC, Rf of 7α-O-IA-DPN and I-125-7α-O-IA-DPN was 0.83 and 0.93, respectively. In ambient temperature the radiochemical purity of I-125-7α-O-IA-DPN in rats showed higher in anterior and posterior colliculi, striatum and hippocampus. It was low in frontal lobe, temporal lobe and brain stem and was low in cerebellum and the other parts of the brain. Among the clearance from the structures in brain, it was fastest in cerebellum. At 20 min when the uptake reached to the peak, the ratio of anterior and posterior colliculi, striatum and hippocampus to the cerebellum was 4.36, 3.7 and 3.12, respectively. There were significant differences between the inhibition experimental group using the naloxone and control. Conclusions: I-125-7α-O-IA-DPN appears to be a potential opioid receptor imaging agent for SPECT study. (authors)

  12. Combinatorial materials research applied to the development of new surface coatings XIII: an investigation of polysiloxane antimicrobial coatings containing tethered quaternary ammonium salt groups.

    Science.gov (United States)

    Majumdar, Partha; Lee, Elizabeth; Gubbins, Nathan; Christianson, David A; Stafslien, Shane J; Daniels, Justin; Vanderwal, Lyndsi; Bahr, James; Chisholm, Bret J

    2009-01-01

    High-throughput biological assays were used to develop structure - antimicrobial relationships for polysiloxane coatings containing chemically bound (tethered) quaternary ammonium salt (QAS) moieties. The QAS-functional polysiloxanes were derived from solution blends of a silanol-terminated polydimethylsiloxane, a trimethoxysilane-functional QAS (QAS-TMS), and methylacetoxysilane. Since the QAS moieties provide antimicrobial activity through interaction with the microorganism cell wall, most of the compositional variables that were investigated were associated with the chemical structure of the QAS-TMS. Twenty different QAS-TMS were synthesized for the study and the antimicrobial activity of sixty unique polysiloxane coatings derived from these QAS-TMS determined toward Escherichia coli , Staphylococcus aureus , and Candida albicans . The results of the study showed that essentially all of the compositional variables significantly influenced antimicrobial activity. Surface characterization of these moisture-cured coatings using atomic force microscopy as well as water contact angle and water contact angle hysteresis measurements indicated that the compositional variables significantly affected coating surface morphology and surface chemistry. Overall, compositional variables that produced heterogeneous surface morphologies provided the highest antimicrobial activity suggesting that the antimicrobial activity was primarily derived from the relationship between coating chemical composition and self-assembly of QAS moieties at the coating/air interface. Using data modeling software, a narrow region of the compositional space was identified that provided broad-spectrum antimicrobial activity.

  13. Structural analysis by reductive cleavage with LiAlH4 of an allyl ether choline-phospholipid, archaetidylcholine, from the hyperthermophilic methanoarchaeon Methanopyrus kandleri

    Directory of Open Access Journals (Sweden)

    Masateru Nishihara

    2002-01-01

    Full Text Available A choline-containing phospholipid (PL-4 in Methanopyrus kandleri cells was identified as archaetidylcholine, which has been described by Sprott et al. (1997. The PL-4 consisted of a variety of molecular species differing in hydrocarbon composition. Most of the PL-4 was acid-labile because of its allyl ether bond. The identity of PL-4 was confirmed by thin-layer chromatography (TLC followed by positive staining with Dragendorff-reagent and fast-atom bombardment–mass spectrometry. A new method of LiAlH4 hydrogenolysis was developed to cleave allyl ether bonds and recover the corresponding hydrocarbons. We confirmed the validity of the LiAlH4 method in a study of the model compound synthetic unsaturated archaetidic acid (2,3-di-O-geranylgeranyl-sn-glycerol-1-phosphate. Saturated ether bonds were not cleaved by the LiAlH4 method. The hydrocarbons formed following LiAlH4 hydrogenolysis of PL-4 were identified by gas–liquid chromatography and mass spectrometry. Four kinds of hydrocarbons with one to four double bonds were detected: 47% of the hydrocarbons had four double bonds; 11% had three double bonds; 14% had two double bonds; 7% had one double bond; and 6% were saturated species. The molecular species composition of PL-4 was also estimated based on acid lability: 77% of the molecular species had two acid-labile hydrocarbons; 11% had one acid-labile and one acid-stable hydrocarbon; and 11% had two acid-stable hydrocarbons. To our knowledge, this is the first report of a specific chemical degradation method for the structural analysis of allyl ether phospholipid in archaea.

  14. Fracture and Healing of Rock Salt Related to Salt Caverns

    International Nuclear Information System (INIS)

    Chan, K.S.; Fossum, A.F.; Munson, D.E.

    1999-01-01

    In recent years, serious investigations of potential extension of the useful life of older caverns or of the use of abandoned caverns for waste disposal have been of interest to the technical community. All of the potential applications depend upon understanding the reamer in which older caverns and sealing systems can fail. Such an understanding will require a more detailed knowledge of the fracture of salt than has been necessary to date. Fortunately, the knowledge of the fracture and healing of salt has made significant advances in the last decade, and is in a position to yield meaningful insights to older cavern behavior. In particular, micromechanical mechanisms of fracture and the concept of a fracture mechanism map have been essential guides, as has the utilization of continuum damage mechanics. The Multimechanism Deformation Coupled Fracture (MDCF) model, which is summarized extensively in this work was developed specifically to treat both the creep and fracture of salt, and was later extended to incorporate the fracture healing process known to occur in rock salt. Fracture in salt is based on the formation and evolution of microfractures, which may take the form of wing tip cracks, either in the body or the boundary of the grain. This type of crack deforms under shear to produce a strain, and furthermore, the opening of the wing cracks produce volume strain or dilatancy. In the presence of a confining pressure, microcrack formation may be suppressed, as is often the case for triaxial compression tests or natural underground stress situations. However, if the confining pressure is insufficient to suppress fracture, then the fractures will evolve with time to give the characteristic tertiary creep response. Two first order kinetics processes, closure of cracks and healing of cracks, control the healing process. Significantly, volume strain produced by microfractures may lead to changes in the permeability of the salt, which can become a major concern in

  15. Ir-Catalyzed Asymmetric and Regioselective Hydrogenation of Cyclic Allylsilanes and Generation of Quaternary Stereocenters via the Hosomi-Sakurai Allylation.

    Science.gov (United States)

    Rabten, Wangchuk; Margarita, Cristiana; Eriksson, Lars; Andersson, Pher G

    2018-02-01

    A number of cyclic dienes containing the allylsilane moiety were prepared by a Birch reduction and subjected to iridium-catalyzed regioselective and asymmetric hydrogenation, which provided chiral allylsilanes in high conversion and enantiomeric excess (up to 99 % ee). The compounds were successively used in the Hosomi-Sakurai allylation with various aldehydes employing TiCl 4 as Lewis acid, providing adducts with two additional stereogenic centers in excellent diastereoselectivity. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Practical metal-free C(sp(3))-H functionalization: construction of structurally diverse α-substituted N-benzyl and N-allyl carbamates.

    Science.gov (United States)

    Xie, Zhiyu; Liu, Lei; Chen, Wenfang; Zheng, Hongbo; Xu, Qingqing; Yuan, Huiqing; Lou, Hongxiang

    2014-04-07

    Described is a practical and universal CH functionalization of readily removable N-benzyl and N-allyl carbamates, with a wide range of nucleophiles at ambient temperature promoted by Ph3 CClO4 . The metal-free reaction has an excellent functional-group tolerance, and displays a broad scope with respect to both N-carbamates and nucleophile partners (a variety of organoboranes and CH compounds). The synthetic utility in target- as well as diversity-oriented syntheses is demonstrated. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. Polycyclization Enabled by Relay Catalysis: One-Pot Manganese-Catalyzed C-H Allylation and Silver-Catalyzed Povarov Reaction.

    Science.gov (United States)

    Chen, Shi-Yong; Li, Qingjiang; Liu, Xu-Ge; Wu, Jia-Qiang; Zhang, Shang-Shi; Wang, Honggen

    2017-06-09

    In this study, a Mn I /Ag I -based relay catalysis process is described for the one-pot synthesis of polycyclic products by a formal [3+2] and [4+2] cycloaddition reaction cascade. A manganese(I) complex catalyzed the first example of directed C-H allylation with allenes, setting the stage for an in situ Povarov cyclization catalyzed by silver(I). The reaction proceeds with high bond-forming efficiency (three C-C bonds), broad substrate scope, high regio- and stereoselectivity, and 100 % atom economy. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. Palladium-Catalyzed Asymmetric Construction of Vicinal Tertiary and All-Carbon Quaternary Stereocenters by Allylation of β-Ketocarbonyls with Morita-Baylis-Hillman Adducts.

    Science.gov (United States)

    Liu, Jiawang; Han, Zhaobin; Wang, Xiaoming; Meng, Fanye; Wang, Zheng; Ding, Kuiling

    2017-04-24

    Palladium-catalyzed regio-, diastereo-, and enantioselective allylic alkylation of β-ketocarbonyls with Morita-Baylis-Hillman adducts has been developed using a spiroketal-based diphosphine (SKP) as the ligand, thus affording a range of densely functionalized products bearing vicinal tertiary and all-carbon quaternary stereodyad in high selectivities. The utility of the protocol was demonstrated by the facile synthesis of some complex molecules by simple product transformations. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. Crystal structure of methyl 1-allyl-4-methyl-1H-benzo[c][1,2]thiazine-3-carboxylate 2,2-dioxide

    Directory of Open Access Journals (Sweden)

    Liliana Azotla-Cruz

    2016-11-01

    Full Text Available In the title compound, C14H15NO4S, the dihydrothiazine ring adopts a distorted sofa conformation with the S atom displaced from the mean plane through the N and C ring atoms by 0.767 (1 Å. The allyl substituent (C—C=C is inclined to this mean plane by 78.5 (7° and the acetate group [C(=O—O—C] by 66.5 (3°. In the crystal, molecules are linked by C—H...π interactions forming chains propagating along the a-axis direction.

  20. Expression of liver functions following sub-lethal and non-lethal doses of allyl alcohol and acetaminophen in the rat

    DEFF Research Database (Denmark)

    Tygstrup, N; Jensen, S A; Krog, B

    1997-01-01

    , doses producing no and about 30% mortality, respectively, within 2 days. In the morning 2, 6, 12, 24, and 36 h after intoxication, RNA was extracted from liver tissue. By slot blot hybridization mRNA levels were determined for acute phase proteins, enzymes involved in ammonia elimination and urea...... synthesis, and for proteins related to liver regeneration. RESULTS: After allyl alcohol, mRNA of "positive" acute phase proteins was higher than after acetaminophen and increased with the dose, whereas after acetaminophen it decreased with the dose. The mRNA of the urea cycle enzymes and glutamine...

  1. Synthesis of 2-(2-R1-Hydrazino-5-(R2-benzyl-2-thiazolines on the Basis of Meerweins Arylation Products of Allyl Isothiocyanate

    Directory of Open Access Journals (Sweden)

    Mykola I. Ganushchak

    2003-02-01

    Full Text Available 3-Aryl-2-chloropropylisothiocyanates (1 are formed by interaction of arenediazonium chlorides with allyl isothiocyanate. Adducts 1 react with monoacylhydrazines to form 1-acyl-4-(3-aryl-2-chloropropylthiosemicarbazides (2a–d. Thiosemicarbazides 2a–d in the presence of bases selectively transform into 2-(2-R1-hydrazino-5-(R2-benzyl-2-thiazolines (3a–d.

  2. Disposal of Radioactive Wastes in Natural Salt

    International Nuclear Information System (INIS)

    Parker, F.L.; Boegly, W.J.; Bradshaw, R.L.; Empson, F.M.; Hemphill, L.; Struxness, E.G.; Tamura, T.

    1960-01-01

    The proposed use of cavities in salt formations as a disposal site for radioactive wastes is based upon : 1. Existence of salt for geologic time periods, 2. The impermeability of salt to the passage of water; 3. The widespread geographical distribution of salt; 4. The extremely large quantities of salt available; 5. The structural strength of salt; 6. The relatively high thermal conductivity of salt in comparison with other general geologic formations; 7. The possible recovery of valuable fission products in the wastes injected into the salt; 8. The relative ease of forming cavities in salt by mining, and the even greater ease and low cost of developing solution cavities in salt; and 9. The low seismicity in the areas of major salt deposits. Radioactive liquid wastes can be stored in cavities in natural salt formations if the structural properties of the salt are not adversely affected by chemical interaction, pressure, temperature, and radiation. Analytical studies show that it is possible to-store 2-year-old 10,000 MWD/T, 800 gal/ton waste in a sphere of 10 ft diameter without exceeding a temperature of 200° F. Laboratory tests show that the structural properties and thermal conductivity of rock salt are not greatly altered by high radiation doses, although high temperatures increase the creep rate for both irradiated and unirradiated samples. Chemical interaction of liquid wastes with salt produces chlorine and other chlorine compound gases, but the volumes are not excessive. The migration of nuclides through the salt and deformation of the cavity and chamber can only be studied in undisturbed salt in situ. One-fifth-scale models have been run in a bedded salt deposit in Hutchinson, Kansas, and full-scale field tests are in progress. (author) [fr

  3. Simulation of salt production process

    Science.gov (United States)

    Muraveva, E. A.

    2017-10-01

    In this paper an approach to the use of simulation software iThink to simulate the salt production system has been proposed. The dynamic processes of the original system are substituted by processes simulated in the abstract model, but in compliance with the basic rules of the original system, which allows one to accelerate and reduce the cost of the research. As a result, a stable workable simulation model was obtained that can display the rate of the salt exhaustion and many other parameters which are important for business planning.

  4. Production of chlorine from chloride salts

    Science.gov (United States)

    Rohrmann, Charles A.

    1981-01-01

    A process for converting chloride salts and sulfuric acid to sulfate salts and elemental chlorine is disclosed. A chloride salt and sulfuric acid are combined in a furnace where they react to produce a sulfate salt and hydrogen chloride. Hydrogen chloride from the furnace contacts a molten salt mixture containing an oxygen compound of vanadium, an alkali metal sulfate and an alkali metal pyrosulfate to recover elemental chlorine. In the absence of an oxygen-bearing gas during the contacting, the vanadium is reduced, but is regenerated to its active higher valence state by separately contacting the molten salt mixture with an oxygen-bearing gas.

  5. Thermodynamic characterization of salt components for Molten Salt Reactor fuel

    NARCIS (Netherlands)

    Capelli, E.

    2016-01-01

    The Molten Salt Reactor (MSR) is a promising future nuclear fission reactor technology with excellent performance in terms of safety and reliability, sustainability, proliferation resistance and economics. For the design and safety assessment of this concept, it is extremely important to have a

  6. Relationship Between Salt Intake, Salt-Taste Threshold and Blood ...

    African Journals Online (AJOL)

    Conclusion: Sodium intake measured as 24-hour urinary sodium is increased in subjects with hypertension attesting to sodium intake as a risk factor for the development of high blood pressure. Subjects with high salt taste threshold also have increased urinary sodium excretion which may predispose them to deveploment ...

  7. Molten salt thermal energy storage systems: salt selection

    Energy Technology Data Exchange (ETDEWEB)

    Maru, H.C.; Dullea, J.F.; Huang, V.S.

    1976-08-01

    A research program aimed at the development of a molten salt thermal energy storage system commenced in June 1976. This topical report describes Work performed under Task I: Salt Selection is described. A total of 31 inorganic salts and salt mixtures, including 9 alkali and alkaline earth carbonate mixtures, were evaluated for their suitability as heat-of-fusion thermal energy storage materials at temperatures of 850 to 1000/sup 0/F. Thermophysical properties, safety hazards, corrosion, and cost of these salts were compared on a common basis. We concluded that because alkali carbonate mixtures show high thermal conductivity, low volumetric expansion on melting, low corrosivity and good stability, they are attractive as heat-of-fusion storage materials in this temperature range. A 35 wt percent Li/sub 2/CO/sub 3/-65 wt percent K/sub 2/CO/sub 3/ (50 mole percent Li/sub 2/CO/sub 3/-50 mole percent K/sub 2/CO/sub 3/) mixture was selected as a model system for further experimental work. This is a eutectoid mixture having a heat of fusion of 148 Btu/lb (82 cal/g) that forms an equimolar compound, LiKCO/sub 3/. The Li/sub 2/CO/sub 3/-K/sub 2/CO/sub 3/ mixture is intended to serve as a model system to define heat transfer characteristics, potential problems, and to provide ''first-cut'' engineering data required for the prototype system. The cost of a thermal energy storage system containing this mixture cannot be predicted until system characteristics are better defined. However, our comparison of different salts indicated that alkali and alkaline earth chlorides may be more attractive from a salt cost point of view. The long-term corrosion characteristics and the effects of volume change on melting for the chlorides should be investigated to determine their overall suitability as a heat-of-fusion storage medium.

  8. Sources of household salt in South Africa.

    Science.gov (United States)

    Jooste, Pieter L

    2005-01-01

    Marketing of non-iodized salt through unconventional distribution channels is one of the factors weakening the national salt iodization program in South Africa. The aim of this study was therefore to quantify the various sources of household salt, and to relate this information to socio-economic status. Questionnaire information was collected by personal interview during home visits from a multistage, cluster, probability sample of 2164 adults representative of the adult population. Nationally 77.7% of households obtained their table salt from the typical food shops distributing iodized salt. However, in the nine different provinces between 8 and 37.3% of households used unconventional sources, distributing mainly non-iodized salt, to obtain their household salt. These alternative sources include distributors of agricultural salt, small general dealer shops called spaza shops, in peri-urban and rural townships, street vendors and salt saches placed in the packaging of maize meal bags. Country-wide around 30% of low socio-economic households obtained their salt from unconventional sources compared to less than 5% in high socio-economic households, emphasizing the vulnerability of low socio-economic groups to the use of non-iodized salt. Intervention strategies should mobilize all role players involved in unconventional marketing channels of household salt to provide only iodized salt to consumers, as required by law.

  9. Poly(allyl methacrylate) functionalized hydroxyapatite nanocrystals via the combination of surface-initiated RAFT polymerization and thiol-ene protocol: a potential anticancer drug nanocarrier.

    Science.gov (United States)

    Bach, Long Giang; Islam, Md Rafiqul; Vo, Thanh-Sang; Kim, Se-Kwon; Lim, Kwon Taek

    2013-03-15

    Hydroxyapatite nanocrystals (HAP NCs) were encapsulated by poly(allyl methacrylate) (PolyAMA) employing controlled surface-initiated reversible addition-fragmentation chain transfer (SI-RAFT) polymerization of allyl methacrylate to afford HAP-PolyAMA nanohybrids. The subsequent thiol-ene coupling of nanohybrids with 2-mercaptosuccinic acid resulted HAP-Poly(AMA-COOH) possessing multicarboxyl group. The formation of the nanohybrids was confirmed by FT-IR and EDS analyses. The TGA and FE-SEM investigation were further suggested the grafting of PolyAMA onto HAP NCs. The utility of the HAP-PolyAMA nanohybrid as drug carrier was also explored. The pendant carboxyl groups on the external layers of nanohybrids were conjugated with anticancer drug cisplatin to afford HAP-Poly(AMA-COOH)/Pt complex. The formation of the complex was confirmed by FT-IR, XPS, and FE-SEM. In vitro evaluation of the synthesized complex as nanomedicine revealed its potential chemotherapeutic efficacy against cancer cell lines. Copyright © 2012 Elsevier Inc. All rights reserved.

  10. Recent Advances in the Synthesis of β-Functionalized Ketones via Radical-Mediated 1,2-Rearrangement of Allylic Alcohols.

    Science.gov (United States)

    Weng, Wei-Zhi; Zhang, Bo

    2018-02-22

    β-Functionalized ketones are a highly important and valuable class of compounds, which have gained increasing attention from organic chemists due to their intensive uses as versatile synthetic intermediates and building blocks in complex molecule assembly and natural product synthesis. Accordingly, there is continuing interest in the development of new approaches for the synthesis of β-functionalized ketones. In recent years, radical-mediated 1,2-rearrangement reactions of allylic alcohols, which proceed through cationic (semipinacol) rearrangements or radical (neophyl) rearrangements, have presented an attractive and powerful strategy to access various diversely β-functionalized ketones. Interestingly, this strategy allows directly installing a variety of valuable functional groups into the β-position of cyclic and acyclic ketones by employing different radical precursors. However, a review focusing on the preparation of β-functionalized ketones via radical-mediated 1,2-rearrangement reactions of allylic alcohols has not been summarized to date. This Minireview highlights recent progress made in this highly active and interesting research area, and the corresponding mechanism will be discussed. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. Interception and characterization of catalyst species in rhodium bis(diazaphospholane)-catalyzed hydroformylation of octene, vinyl acetate, allyl cyanide, and 1-phenyl-1,3-butadiene.

    Science.gov (United States)

    Nelsen, Eleanor R; Brezny, Anna C; Landis, Clark R

    2015-11-11

    In the absence of H2, reaction of [Rh(H) (CO)2(BDP)] [BDP = bis(diazaphospholane)] with hydroformylation substrates vinyl acetate, allyl cyanide, 1-octene, and trans-1-phenyl-1,3-butadiene at low temperatures and pressures with passive mixing enables detailed NMR spectroscopic characterization of rhodium acyl and, in some cases, alkyl complexes of these substrates. For trans-1-phenyl-1,3-butadiene, the stable alkyl complex is an η(3)-allyl complex. Five-coordinate acyl dicarbonyl complexes appear to be thermodynamically preferred over the four-coordinate acyl monocarbonyls at low temperatures and one atmosphere of CO. Under noncatalytic (i.e., no H2 present) reaction conditions, NMR spectroscopy reveals the kinetic and thermodynamic selectivity of linear and branched acyl dicarbonyl formation. Over the range of substrates investigated, the kinetic regioselectivity observed at low temperatures under noncatalytic conditions roughly predicts the regioselectivity observed for catalytic transformations at higher temperatures and pressures. Thus, kinetic distributions of off-cycle acyl dicarbonyls constitute reasonable models for catalytic selectivity. The Wisconsin high-pressure NMR reactor (WiHP-NMRR) enables single-turnover experiments with active mixing; such experiments constitute a powerful strategy for elucidating the inherent selectivity of acyl formation and acyl hydrogenolysis in hydroformylation reactions.

  12. thermic oil and molten salt

    African Journals Online (AJOL)

    Boukelia T.E, Mecibah M.S and Laouafi A

    1 mai 2016 ... [27] Zavoico, AB. Solar Power Tower Design Basis Document. Tech. rep, Sandia National. Laboratories, SAND2001-2100, 2001. How to cite this article: Boukelia T.E, Mecibah M.S and Laouafi A. Performance simulation of parabolic trough solar collector using two fluids (thermic oil and molten salt).

  13. Salt effects in electromembrane extraction

    DEFF Research Database (Denmark)

    Seip, Knut Fredrik; Jensen, Henrik; Kieu, Thanh Elisabeth

    2014-01-01

    Electromembrane extraction (EME) was performed on samples containing substantial amounts of NaCl to investigate how the presence of salts affected the recovery, repeatability, and membrane current in the extraction system. A group of 17 non-polar basic drugs with various physical chemical...

  14. Dietary salt reduction for control of hypertension

    Directory of Open Access Journals (Sweden)

    Richard Tjan

    2016-02-01

    Full Text Available In developed as well as developing countries, the four main factors affecting blood pressure are high salt intake, low potassium intake, overweight, and low physical activity level. This is also true for the increase in blood pressure with advancing age, occurring in all societies. It is now accepted that excess dietary salt raises blood pressure levels, whereas dietary salt reduction reduces blood pressure and prevents vascular complications.(1 The effect of salt on blood pressure is presumably due to the inability of the kidneys to excrete large amounts of salt, as humans are evolutionary adapted to ingest and excrete less than 1 gram of salt per day.(2 In this connection it should be noted that the more important element in common salt (sodium chloride is the sodium ion, and any restrictions applying to common salt also apply to all food items that contain sodium ions, such as sodium glutamate and baking soda.

  15. Investigation of the O+allyl addition/elimination reaction pathways from the OCH2CHCH2 radical intermediate

    International Nuclear Information System (INIS)

    FitzPatrick, Benjamin L.; Lau, K.-C.; Butler, Laurie J.; Lee, S.-H.; Lin, Jim Jr-Min

    2008-01-01

    These experiments study the preparation of and product channels resulting from OCH 2 CHCH 2 , a key radical intermediate in the O+allyl bimolecular reaction. The data include velocity map imaging and molecular beam scattering results to probe the photolytic generation of the radical intermediate and the subsequent pathways by which the radicals access the energetically allowed product channels of the bimolecular reaction. The photodissociation of epichlorohydrin at 193.3 nm produces chlorine atoms and c-OCH 2 CHCH 2 radicals; these undergo a facile ring opening to the OCH 2 CHCH 2 radical intermediate. State-selective resonance-enhanced multiphoton ionization (REMPI) detection resolves the velocity distributions of ground and spin-orbit excited state chlorine independently, allowing for a more accurate determination of the internal energy distribution of the nascent radicals. We obtain good agreement detecting the velocity distributions of the Cl atoms with REMPI, vacuum ultraviolet (VUV) photoionization at 13.8 eV, and electron bombardment ionization; all show a bimodal distribution of recoil kinetic energies. The dominant high recoil kinetic energy feature peaks near 33 kcal/mol. To elucidate the product channels resulting from the OCH 2 CHCH 2 radical intermediate, the crossed laser-molecular beam experiment uses VUV photoionization and detects the velocity distribution of the possible products. The data identify the three dominant product channels as C 3 H 4 O (acrolein)+H, C 2 H 4 +HCO (formyl radical), and H 2 CO (formaldehyde)+C 2 H 3 . A small signal from C 2 H 2 O (ketene) product is also detected. The measured velocity distributions and relative signal intensities at m/e=27, 28, and 29 at two photoionization energies show that the most exothermic product channel, C 2 H 5 +CO, does not contribute significantly to the product branching. The higher internal energy onset of the acrolein+H product channel is consistent with the relative barriers en route to

  16. Investigation of the O+allyl addition/elimination reaction pathways from the OCH2CHCH2 radical intermediate

    Science.gov (United States)

    Fitzpatrick, Benjamin L.; Lau, Kai-Chung; Butler, Laurie J.; Lee, Shih-Huang; Lin, Jim-Min, Jr.

    2008-08-01

    These experiments study the preparation of and product channels resulting from OCH2CHCH2, a key radical intermediate in the O+allyl bimolecular reaction. The data include velocity map imaging and molecular beam scattering results to probe the photolytic generation of the radical intermediate and the subsequent pathways by which the radicals access the energetically allowed product channels of the bimolecular reaction. The photodissociation of epichlorohydrin at 193.3 nm produces chlorine atoms and c-OCH2CHCH2 radicals; these undergo a facile ring opening to the OCH2CHCH2 radical intermediate. State-selective resonance-enhanced multiphoton ionization (REMPI) detection resolves the velocity distributions of ground and spin-orbit excited state chlorine independently, allowing for a more accurate determination of the internal energy distribution of the nascent radicals. We obtain good agreement detecting the velocity distributions of the Cl atoms with REMPI, vacuum ultraviolet (VUV) photoionization at 13.8 eV, and electron bombardment ionization; all show a bimodal distribution of recoil kinetic energies. The dominant high recoil kinetic energy feature peaks near 33 kcal/mol. To elucidate the product channels resulting from the OCH2CHCH2 radical intermediate, the crossed laser-molecular beam experiment uses VUV photoionization and detects the velocity distribution of the possible products. The data identify the three dominant product channels as C3H4O (acrolein)+H, C2H4+HCO (formyl radical), and H2CO (formaldehyde)+C2H3. A small signal from C2H2O (ketene) product is also detected. The measured velocity distributions and relative signal intensities at m/e=27, 28, and 29 at two photoionization energies show that the most exothermic product channel, C2H5+CO, does not contribute significantly to the product branching. The higher internal energy onset of the acrolein+H product channel is consistent with the relative barriers en route to each of these product channels

  17. Inactivation of Salmonella in grape tomato stem scars by organic acid wash and chitosan-allyl isothiocyanate coating.

    Science.gov (United States)

    Mukhopadhyay, Sudarsan; Sokorai, Kimberly; Ukuku, Dike O; Jin, Tony; Fan, Xuetong; Olanya, Modesto; Juneja, Vijay

    2018-02-02

    The objective of this study was to evaluate inactivation of inoculated Salmonella enterica on grape tomato stem scars exploiting integrated treatment of organic acid wash (AW) followed by chitosan-allyl isothiocyanate (CT-AIT) coating. The treatment effect on microbial loads and fruit quality during 21days storage at 10°C was also determined. A bacterial cocktail containing three serotypes of Salmonella enterica was used for this study based on their association with produce-related outbreaks. Tomatoes were spot inoculated on stem scars and then immersed in an organic acid solution (700ml) containing 0.5% (v/v) each of acetic (AA) and formic acid (FA) to wash under mild agitation for 1min at ambient temperature (22°C) followed by 1min dipping in a coating solution containing 6mlAIT/g CT. AW in 0.5% organic acid (AA+FA) for 1min reduced Salmonella population by 2.7logCFU/g from an initial load of 7.8logCFU/g, while additional coating treatment of AW tomatoes reduced the pathogens on stem scars to undetectable levels (7logCFU/g reduction for the pathogen. Although the populations of Salmonella in the controls (approx. 7.8logCFU/g stem scar) did not change significantly during 21days of storage at 10°C, the populations were reduced to undetectable level in the integrated (AW plus CT-AIT) treated stem scars on day 1 and no regrowth was observed during storage. The treatment significantly (p<0.05) reduced background bacterial loads to approx. 1.3logCFU/g and the population remained unchanged through day 21 at 10°C. The treatment also completely inactivated mold and yeast on day 1 with no growth reoccurrence. These results indicate that the integrated treatment can provide a safe and effective intervention strategy for grape tomatoes. Published by Elsevier B.V.

  18. Reconsolidated Salt as a Geotechnical Barrier

    Energy Technology Data Exchange (ETDEWEB)

    Hansen, Francis D. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Gadbury, Casey [USDOE Carlsbad Field Office, NM (United States)

    2015-11-01

    Salt as a geologic medium has several attributes favorable to long-term isolation of waste placed in mined openings. Salt formations are largely impermeable and induced fractures heal as stress returns to equilibrium. Permanent isolation also depends upon the ability to construct geotechnical barriers that achieve nearly the same high-performance characteristics attributed to the native salt formation. Salt repository seal concepts often include elements of reconstituted granular salt. As a specific case in point, the Waste Isolation Pilot Plant recently received regulatory approval to change the disposal panel closure design from an engineered barrier constructed of a salt-based concrete to one that employs simple run-of-mine salt and temporary bulkheads for isolation from ventilation. The Waste Isolation Pilot Plant is a radioactive waste disposal repository for defense-related transuranic elements mined from the Permian evaporite salt beds in southeast New Mexico. Its approved shaft seal design incorporates barrier components comprising salt-based concrete, bentonite, and substantial depths of crushed salt compacted to enhance reconsolidation. This paper will focus on crushed salt behavior when applied as drift closures to isolate disposal rooms during operations. Scientific aspects of salt reconsolidation have been studied extensively. The technical basis for geotechnical barrier performance has been strengthened by recent experimental findings and analogue comparisons. The panel closure change was accompanied by recognition that granular salt will return to a physical state similar to the halite surrounding it. Use of run-of-mine salt ensures physical and chemical compatibility with the repository environment and simplifies ongoing disposal operations. Our current knowledge and expected outcome of research can be assimilated with lessons learned to put forward designs and operational concepts for the next generation of salt repositories. Mined salt

  19. Tetraalkylammonium Salts as Hydrogen-Bonding Catalysts

    OpenAIRE

    Shirakawa, Seiji; Liu, Shiyao; Kaneko, Shiho; Kumatabara, Yusuke; Fukuda, Airi; Omagari, Yumi; Maruoka, Keiji

    2015-01-01

    Although the hydrogen-bonding ability of the α hydrogen atoms on tetraalkylammonium salts is often discussed with respect to phase-transfer catalysts, catalysis that utilizes the hydrogen-bond-donor properties of tetraalkylammonium salts remains unknown. Herein, we demonstrate hydrogen-bonding catalysis with newly designed tetraalkylammonium salt catalysts in Mannich-type reactions. The structure and the hydrogen-bonding ability of the new ammonium salts were investigated by X-ray diffraction...

  20. Reconsolidated Salt as a Geotechnical Barrier

    International Nuclear Information System (INIS)

    Hansen, Francis D.; Gadbury, Casey

    2015-01-01

    Salt as a geologic medium has several attributes favorable to long-term isolation of waste placed in mined openings. Salt formations are largely impermeable and induced fractures heal as stress returns to equilibrium. Permanent isolation also depends upon the ability to construct geotechnical barriers that achieve nearly the same high-performance characteristics attributed to the native salt formation. Salt repository seal concepts often include elements of reconstituted granular salt. As a specific case in point, the Waste Isolation Pilot Plant recently received regulatory approval to change the disposal panel closure design from an engineered barrier constructed of a salt-based concrete to one that employs simple run-of-mine salt and temporary bulkheads for isolation from ventilation. The Waste Isolation Pilot Plant is a radioactive waste disposal repository for defense-related transuranic elements mined from the Permian evaporite salt beds in southeast New Mexico. Its approved shaft seal design incorporates barrier components comprising salt-based concrete, bentonite, and substantial depths of crushed salt compacted to enhance reconsolidation. This paper will focus on crushed salt behavior when applied as drift closures to isolate disposal rooms during operations. Scientific aspects of salt reconsolidation have been studied extensively. The technical basis for geotechnical barrier performance has been strengthened by recent experimental findings and analogue comparisons. The panel closure change was accompanied by recognition that granular salt will return to a physical state similar to the halite surrounding it. Use of run-of-mine salt ensures physical and chemical compatibility with the repository environment and simplifies ongoing disposal operations. Our current knowledge and expected outcome of research can be assimilated with lessons learned to put forward designs and operational concepts for the next generation of salt repositories. Mined salt

  1. Salt loading affects cortisol metabolism in normotensive subjects : Relationships with salt sensitivity

    NARCIS (Netherlands)

    Kerstens, MN; van der Kleij, FGH; Boonstra, AH; Sluiter, WJ; Koerts, J; Navis, G; Dullaart, RPF

    We studied cortisol metabolism together with insulin sensitivity [homeostatic model assessment (HOMA)] and renal hemodynamics in 19 salt-resistant (sr) and nine salt-sensitive ( ss) normotensive subjects after a low-and high-salt diet. Results are described as high- vs. low-salt diet. Sum of urinary

  2. Salt-assisted and salt-suppressed sol-gel transitions of methylcellulose in water.

    Science.gov (United States)

    Xu, Y; Wang, C; Tam, K C; Li, L

    2004-02-03

    The effects of various salts on the sol-gel transition of aqueous methylcellulose (MC) solutions have been studied systematically by means of a micro differential scanning calorimeter. It was found that the heating process was endothermic while the cooling process was exothermic for both MC solutions with and without salts. The addition of salts did not change the patterns of gelation and degelation of MC. However, the salts could shift the sol-gel transition and the gel-sol transition to lower or higher temperatures from a pure MC solution, depending on the salt type. These opposite effects were termed the salt-assisted and salt-suppressed sol-gel transitions. Either the salt-assisted transition or the salt-suppressed sol-gel transition was a function of salt concentration. In addition, each salt was found to have its own concentration limit for producing a stable aqueous solution of MC at a given concentration of MC, which was related to the anionic charge density of the salt. Cations were proved to have weaker effects than anions. The "salt-out strength", defined as the salt effect per mole of anion, was obtained for each anion studied. The thermodynamic mechanisms involved in the salt-assisted and salt-suppressed sol-gel transitions are discussed.

  3. Cardiovascular and other effects of salt consumption

    OpenAIRE

    Cappuccio, Francesco P

    2013-01-01

    Salt is one of the most important determinants of high blood pressure and increased cardiovascular risk worldwide. However, a high salt intake has other adverse effects beyond those involving the cardiovascular system, so that there is renewed interest in the relationships between high salt intake and other diseases.

  4. Effect of low salt diet on insulin resistance in salt-sensitive versus salt-resistant hypertension.

    Science.gov (United States)

    Garg, Rajesh; Sun, Bei; Williams, Jonathan

    2014-12-01

    Accumulating evidence shows an increase in insulin resistance on salt restriction. We compared the effect of low salt diet on insulin resistance in salt-sensitive versus salt-resistant hypertensive subjects. We also evaluated the relationship between salt sensitivity of blood pressure and salt sensitivity of insulin resistance in a multivariate regression model. Studies were conducted after 1 week of high salt (200 mmol per day sodium) and 1 week of low salt (10 mmol per day sodium) diet. Salt sensitivity was defined as the fall in systolic blood pressure>15 mm Hg on low salt diet. The study includes 389 subjects (44% women; 16% blacks; body mass index, 28.5±4.2 kg/m2). As expected, blood pressure was lower on low salt (129±16/78±9 mm Hg) as compared with high salt diet (145±18/86±10 mm Hg). Fasting plasma glucose, insulin, and homeostasis model assessment were higher on low salt diet (95.4±19.4 mg/dL; 10.8±7.3 mIU/L; 2.6±1.9) as compared with high salt diet (90.6±10.8 mg/dL; 9.4±5.8 mIU/L; 2.1±1.4; Psalt-sensitive (n=193) versus salt-resistant (n=196) subjects on either diet. Increase in homeostasis model assessment on low salt diet was 0.5±1.4 in salt-sensitive and 0.4±1.5 in salt-resistant subjects (P=NS). On multivariate regression analysis, change in systolic blood pressure was not associated with change in homeostasis model assessment after including age, body mass index, sex, change in serum and urine aldosterone, and cortisol into the model. We conclude that the increase in insulin resistance on low salt diet is not affected by salt sensitivity of blood pressure. © 2014 American Heart Association, Inc.

  5. A Modular Approach to Aryl-C-ribonucleosides via the Allylic Substitution and Ring-Closing Metathesis Sequence. A Stereocontrolled Synthesis of All Four alpha-/beta- and D-/L-C-Nucleoside Stereoisomers

    Czech Academy of Sciences Publication Activity Database

    Štambaský, J.; Kapras, V.; Štefko, Martin; Kysilka, O.; Hocek, Michal; Malkov, A. V.; Kočovský, P.

    2011-01-01

    Roč. 76, č. 19 (2011), s. 7781-7803 ISSN 0022-3263 R&D Projects: GA MŠk LC512; GA AV ČR IAA400550902 Institutional research plan: CEZ:AV0Z40550506 Keywords : C-nucleosides * allylic substitution * metathesis * dihydroxylation Subject RIV: CC - Organic Chemistry Impact factor: 4.450, year: 2011

  6. Carcinogenesis Studies of Allyl Isovalerate (CAS No. 2835-39-4) in F344/N Rats and B6C3F1 Mice (Gavage Studies).

    Science.gov (United States)

    1983-05-01

    Allyl isovalerate, a synthetic fragrance and flavoring ingredient in use since the 1950's, may be found in various products at the following concentrations: soap, 30 ppm; detergent, 3 ppm; creams, 15 ppm; perfume, 50 ppm; nonalcoholic beverages, 9 ppm; ice cream, 18 ppm; candy, 22 ppm; baked goods, 15-48 ppm; and gelatins and puddings, 1 ppm. A colorless liquid with an apple-like odor and taste, allyl isovalerate is approved by the U.S. Food and Drug Administration for use in foods. Specific production figures are not available, but U.S. production in 1980 exceeded 1,000 pounds. Carcinogenesis studies of allyl isovalerate (96% pure) were conducted by administering the test chemical in corn oil gavage to groups of 50 male and 50 female F344/N rats and to groups of 50 male and 50 female B6C3F1 mice at doses of 31 or 62 mg/kg. The doses selected were based on the chemically-induced toxic effects and depressed weight gains obtained from the 13-week studies. Doses were administered five times per week for 103 weeks. Groups of 50 rats and 50 mice of each sex received corn oil by gavage on the same dosing schedule and served as vehicle controls. Survival and mean body weight gain of rats of each sex and male mice were not adversely affected by the administration of allyl isovalerate. The significantly lower survival (P=0.001) and the lower mean body weight of low-dose female as compared with controls are likely consequences of the high incidence of a genital tract infection in the low-dose females. This infection was probably responsible for the deaths of 11/19 control, 22/33 low-dose, and 13/25 high-dose female mice that died before the end of the study. Squamous cell papillomas and epithelial hyperplasia of the nonglandular stomach were observed in dosed male mice in the 2-year studies (squamous cell papillomas: 0/50, 1/50, 2%, 3/48, 6%; epithelial hyperplasia: 1/50, 2%, 1/50, 2%, 7/48, 15%). The papillomas occurred with a significant positive trend (P<0.05). The

  7. Thermophysical properties of reconsolidating crushed salt.

    Energy Technology Data Exchange (ETDEWEB)

    Bauer, Stephen J. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Urquhart, Alexander [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2014-03-01

    Reconsolidated crushed salt is being considered as a backfilling material placed upon nuclear waste within a salt repository environment. In-depth knowledge of thermal and mechanical properties of the crushed salt as it reconsolidates is critical to thermal/mechanical modeling of the reconsolidation process. An experimental study was completed to quantitatively evaluate the thermal conductivity of reconsolidated crushed salt as a function of porosity and temperature. The crushed salt for this study came from the Waste Isolation Pilot Plant (WIPP). In this work the thermal conductivity of crushed salt with porosity ranging from 1% to 40% was determined from room temperature up to 300°C, using two different experimental methods. Thermal properties (including thermal conductivity, thermal diffusivity and specific heat) of single-crystal salt were determined for the same temperature range. The salt was observed to dewater during heating; weight loss from the dewatering was quantified. The thermal conductivity of reconsolidated crushed salt decreases with increasing porosity; conversely, thermal conductivity increases as the salt consolidates. The thermal conductivity of reconsolidated crushed salt for a given porosity decreases with increasing temperature. A simple mixture theory model is presented to predict and compare to the data developed in this study.

  8. Novel Paradigms of Salt and Hypertension.

    Science.gov (United States)

    Feng, Wenguang; Dell'Italia, Louis J; Sanders, Paul W

    2017-05-01

    Salt resistance/sensitivity refers specifically to the effect of dietary sodium chloride (salt) intake on BP. Increased dietary salt intake promotes an early and uniform expansion of extracellular fluid volume and increased cardiac output. To compensate for these hemodynamic changes and maintain constant BP in salt resistance, renal and peripheral vascular resistance falls and is associated with an increase in production of nitric oxide. In contrast, the decline in peripheral vascular resistance and the increase in nitric oxide are impaired or absent in salt sensitivity, promoting an increase in BP in these individuals. Endothelial dysfunction may pose a particularly significant risk factor in the development of salt sensitivity and subsequent hypertension. Vulnerable salt-sensitive populations may have in common underlying endothelial dysfunction due to genetic or environmental influences. These individuals may be very sensitive to the hemodynamic stress of increased effective blood volume, setting in motion untoward molecular and biochemical events that lead to overproduction of TGF- β , oxidative stress, and limited bioavailable nitric oxide. Finally, chronic high-salt ingestion produces endothelial dysfunction, even in salt-resistant subjects. Thus, the complex syndrome of salt sensitivity may be a function of the endothelium, which is integrally involved in the vascular responses to high salt intake. Copyright © 2017 by the American Society of Nephrology.

  9. Salt Intake: ¿Risk or Need?

    Directory of Open Access Journals (Sweden)

    Emiliano Nicolás Diez y Martínez de la Cotera

    2011-11-01

    Full Text Available A literary review on salt intake and its uses throughout the different stages in the history of mankind was conducted. It addresses issues related to salt concentrations in the human body, its physiological functions that are essential for homeostatic control, as well as the complications when salt levels are below or over the physiological limits. Different studies were analyzed including the contradictions they all present on the damage that salt intake can cause to human health. Population groups are defined as salt sensitive (SS and salt resistant (SR according to study that was conducted as well as to the possible causes for their variations. Conclusions are drawn on the risks and benefits of salt intake. Intervention is recommended for balanced consumption, both for individuals and for populations.

  10. Mixing of zeolite powders and molten salt

    International Nuclear Information System (INIS)

    Pereira, C.; Zyryanov, V.N.; Lewis, M.A.; Ackerman, J.P.

    1996-01-01

    Transuranics and fission products in a molten salt can be incorporated into zeolite A by an ion exchange process and by a batch mixing or blending process. The zeolite is then mixed with glass and consolidated into a monolithic waste form for geologic disposal. Both processes require mixing of zeolite powders with molten salt at elevated temperatures (>700 K). Complete occlusion of salt and a uniform distribution of chloride and fission products are desired for incorporation of the powders into the final waste form. The relative effectiveness of the blending process was studied over a series of temperature, time, and composition profiles. The major criteria for determining the effectiveness of the mixing operations were the level and uniformity of residual free salt in the mixtures. High operating temperatures (>775 K) improved salt occlusion. Reducing the chloride levels in the mixture to below 80% of the full salt capacity of the zeolite significantly reduced the free salt level in the final product

  11. Early Holocene Great Salt Lake

    Science.gov (United States)

    Oviatt, Charles G.; Madsen, David B.; Miller, David; Thompson, Robert S.; McGeehin, John P.

    2015-01-01

    Shorelines and surficial deposits (including buried forest-floor mats and organic-rich wetland sediments) show that Great Salt Lake did not rise higher than modern lake levels during the earliest Holocene (11.5–10.2 cal ka BP; 10–9 14C ka BP). During that period, finely laminated, organic-rich muds (sapropel) containing brine-shrimp cysts and pellets and interbedded sodium-sulfate salts were deposited on the lake floor. Sapropel deposition was probably caused by stratification of the water column — a freshwater cap possibly was formed by groundwater, which had been stored in upland aquifers during the immediately preceding late-Pleistocene deep-lake cycle (Lake Bonneville), and was actively discharging on the basin floor. A climate characterized by low precipitation and runoff, combined with local areas of groundwater discharge in piedmont settings, could explain the apparent conflict between evidence for a shallow lake (a dry climate) and previously published interpretations for a moist climate in the Great Salt Lake basin of the eastern Great Basin.

  12. Renal arteriolar injury by salt intake contributes to salt memory for the development of hypertension.

    Science.gov (United States)

    Oguchi, Hideyo; Sasamura, Hiroyuki; Shinoda, Kazunobu; Morita, Shinya; Kono, Hidaka; Nakagawa, Ken; Ishiguro, Kimiko; Hayashi, Kaori; Nakamura, Mari; Azegami, Tatsuhiko; Oya, Mototsugu; Itoh, Hiroshi

    2014-10-01

    The role of salt intake in the development of hypertension is prominent, but its mechanism has not been fully elucidated. Our aim was to examine the effect of transient salt intake during the prehypertensive period in hypertensive model animals. Dahl salt-sensitive rats and spontaneously hypertensive rats were fed from 6 to 14 weeks with low-salt (0.12% NaCl), normal-salt (0.8% NaCl), high-salt (7% NaCl), or high-sodium/normal-chloride diet and returned to normal-salt diet for 3 months. Rats in the high-salt group saw elevations in blood pressure (BP) not only during the treatment period but also for the 3 months after returning to normal-salt diet. We named this phenomenon salt memory. Renal arteriolar injury was found in the high-salt group at the end of experiment. Dahl salt-sensitive rats were fed from 6 to 14 weeks with high-salt diet with angiotensin receptor blocker, vasodilator, calcium channel blocker, and calcium channel blocker+angiotensin receptor blocker and returned to normal-salt diet. Although BP was suppressed to control levels by vasodilator or calcium channel blocker, elevated renal angiotensin II and renal arteriolar injury were observed, and salt memory did not disappear because of sustained renal arteriolar injury. Calcium channel blocker+angiotensin receptor blocker suppressed renal arteriolar injury, resulting in the disappearance of salt memory. Cross-transplantation of kidneys from Dahl salt-sensitive rats on high salt to control rats caused increase of BP, whereas control kidneys caused reduction in BP of hypertensive rats, inducing the central role of the kidney. These results suggest that renal arteriolar injury through BP and renal angiotensin II elevation plays important roles in the development of salt memory for hypertension. © 2014 American Heart Association, Inc.

  13. Ultrasonic characterization of pork meat salting

    International Nuclear Information System (INIS)

    García-Pérez, J V; De Prados, M; Pérez-Muelas, N; Cárcel, J A; Benedito, J

    2012-01-01

    Salting process plays a key role in the preservation and quality of dry-cured meat products. Therefore, an adequate monitoring of salt content during salting is necessary to reach high quality products. Thus, the main objective of this work was to test the ability of low intensity ultrasound to monitor the salting process of pork meat. Cylindrical samples (diameter 36 mm, height 60±10 mm) of Biceps femoris were salted (brine 20% NaCl, w/w) at 2 °C for 1, 2, 4 and 7 days. During salting and at each experimental time, three cylinders were taken in order to measure the ultrasonic velocity at 2 °C. Afterwards, the cylinders were split in three sections (height 20 mm), measuring again the ultrasonic velocity and determining the salt and the moisture content by AOAC standards. In the whole cylinders, moisture content was reduced from 763 (g/kg sample) in fresh samples to 723 (g/kg sample) in samples salted for 7 days, while the maximum salt gain was 37.3 (g/kg sample). Although, moisture and salt contents up to 673 and 118 (g/kg sample) were reached in the sections of meat cylinders, respectively. During salting, the ultrasonic velocity increased due to salt gain and water loss. Thus, significant (p 2 = 0.975) and moisture (R 2 = 0.863) contents. In addition, the change of the ultrasonic velocity with the increase of the salt content showed a good agreement with the Kinsler equation. Therefore, low intensity ultrasound emerges as a potential technique to monitor, in a non destructive way, the meat salting processes carried out in the food industry.

  14. Salt bridges: geometrically specific, designable interactions.

    Science.gov (United States)

    Donald, Jason E; Kulp, Daniel W; DeGrado, William F

    2011-03-01

    Salt bridges occur frequently in proteins, providing conformational specificity and contributing to molecular recognition and catalysis. We present a comprehensive analysis of these interactions in protein structures by surveying a large database of protein structures. Salt bridges between Asp or Glu and His, Arg, or Lys display extremely well-defined geometric preferences. Several previously observed preferences are confirmed, and others that were previously unrecognized are discovered. Salt bridges are explored for their preferences for different separations in sequence and in space, geometric preferences within proteins and at protein-protein interfaces, co-operativity in networked salt bridges, inclusion within metal-binding sites, preference for acidic electrons, apparent conformational side chain entropy reduction on formation, and degree of burial. Salt bridges occur far more frequently between residues at close than distant sequence separations, but, at close distances, there remain strong preferences for salt bridges at specific separations. Specific types of complex salt bridges, involving three or more members, are also discovered. As we observe a strong relationship between the propensity to form a salt bridge and the placement of salt-bridging residues in protein sequences, we discuss the role that salt bridges might play in kinetically influencing protein folding and thermodynamically stabilizing the native conformation. We also develop a quantitative method to select appropriate crystal structure resolution and B-factor cutoffs. Detailed knowledge of these geometric and sequence dependences should aid de novo design and prediction algorithms. Copyright © 2010 Wiley-Liss, Inc.

  15. DFT Mechanistic Study of the Selective Terminal C-H Activation of n-Pentane with a Tungsten Allyl Nitrosyl Complex

    KAUST Repository

    Lee, Richmond

    2017-01-17

    Mechanistic insights into the selective C-H terminal activation of n-pentane with tungsten allyl nitrosyl complex reported by Legzdins were gained by employing density functional theory with B3LYP hybrid functional. Using Bader’s atom in molecules (AIM) analysis on the elementary steps of the hydrogen transfer process, TS1 and TS2, it was observed that the calculated H-transfer models were closely similar to Hall’s metal-assisted σ-bond metathesis through bond critical point (BCP) comparisons. One distinguishable feature was the fact that the formal oxidation state of the W changed in the concerted H-transfer process. To better differentiate, we term these processes as ‘Formal Reductive Hydrogen Transfer’ (FRHT) for TS1 and ‘Formal Oxidative Hydrogen Transfer’ (FOHT) for TS2.

  16. Enantioselective synthesis of alkyne-substituted quaternary carbon stereogenic centers through NHC-Cu-catalyzed allylic substitution reactions with (i-Bu)2(alkynyl)aluminum reagents.

    Science.gov (United States)

    Dabrowski, Jennifer A; Gao, Fang; Hoveyda, Amir H

    2011-04-06

    A catalytic enantioselective method for the formation of alkyne-substituted all-carbon quaternary stereogenic centers is reported. Additions of alkynylaluminums to alkyl-, aryl-, carboxylic ester-, or silyl-substituted allylic phosphates are promoted by 1.0-5.0 mol % loadings of NHC-Cu complexes derived from air-stable and commercially available CuCl(2)·2H(2)O. The requisite Al-based reagents are prepared through treatment of the corresponding aryl-, heteroaryl-, alkyl-, or alkenyl-substituted terminal alkynes with diisobutylaluminum hydride in the presence of 5.0 mol % Et(3)N at ambient temperature. The desired 1,4-enynes are obtained in up to 98% yield and >99:1 enantiomeric ratio. Selected Au-catalyzed cyclizations involving the alkyne unit of the enantiomerically enriched products are presented as a demonstration of the method's utility in chemical synthesis. © 2011 American Chemical Society

  17. Enantioselective Synthesis of Alkyne-Substituted Quaternary Carbon Stereogenic Centers through NHC–Cu-Catalyzed Allylic Substitution Reactions with (i-Bu)2(Alkynyl)aluminum Reagents

    Science.gov (United States)

    Dabrowski, Jennifer A.; Gao, Fang; Hoveyda, Amir H.

    2011-01-01

    A catalytic enantioselective method for formation of alkyne-substituted all-carbon quaternary carbon stereogenic centers is reported. Additions of alkynylaluminums to alkyl-, aryl-, carboxylic ester-, or silyl-substituted allylic phosphates are promoted by 1.0–5.0 mol % of NHC–Cu complexes derived from air stable and commercially available CuCl2•2H2O. The requisite Al-based reagents are prepared through treatment of the corresponding aryl-, heteroaryl-, alkyl-, or alkenyl-substituted terminal alkynes with di-iso-butylaluminum hydride in the presence of 5.0 mol % Et3N at ambient temperature. The desired 1,4-enynes are obtained in up to >98% yield and >99:1 enantiomeric ratio. Selected Au-catalyzed cyclizations involving the alkyne unit of the enantiomerically enriched products are presented as a demonstration of the method’s utility in chemical synthesis. PMID:21384918

  18. Catalytic isomerization of ethylenic hydrocarbons. XII. Isomerization of 2-butenes selectively deuterated in the allylic and vinylic positions over alumina and silica-alumina

    International Nuclear Information System (INIS)

    Perot, G.; Guisnet, M.; Maurel, R.

    1976-01-01

    The isomerization of 2,3-d 2 - and 1,4-d 6 -cis-butenes was carried out on alumina and silica-alumina catalysts. Over both catalysts, double-bond shift is closely related to exchange between the allylic hydrogens of the reactant and the catalyst. On the other hand, it becomes apparent from the reported data that cis-trans isomerization proceeds through two different paths: a mechanism (I) involving exchange between the catalyst and the vinylic hydrogens of the reactant and an ''intramolecular'' mechanism (II) without any exchange between the reactant and the catalyst. It is shown that both double-bond shift and cis-trans reaction by mechanism I can occur on the two catalysts by a stereospecific carbonium ion mechanism while mechanism II is not fully understood

  19. DFT mechanistic study of the selective terminal C–H activation of n-pentane with a tungsten allyl nitrosyl complex

    Directory of Open Access Journals (Sweden)

    Richmond Lee

    2017-07-01

    Full Text Available Mechanistic insights into the selective C–H terminal activation of n-pentane with tungsten allyl nitrosyl complex reported by Legzdins were gained by employing density functional theory with B3LYP hybrid functional. Using Bader’s atom in molecules (AIM analysis on the elementary steps of the hydrogen transfer process, TS1 and TS2, it was observed that the calculated H-transfer models were closely similar to Hall’s metal-assisted σ-bond metathesis through bond critical point (BCP comparisons. One distinguishable feature was the fact that the formal oxidation state of the W changed in the concerted H-transfer process. To better differentiate, we term these processes as ‘Formal Reductive Hydrogen Transfer’ (FRHT for TS1 and ‘Formal Oxidative Hydrogen Transfer’ (FOHT for TS2.

  20. Synthesis and Crystal Structure of 1-(4-Nitrobenzyl-3-allyl-1H-benzo[d]imidazol-2(3H-one

    Directory of Open Access Journals (Sweden)

    Dounia Belaziz

    2013-01-01

    Full Text Available A functionalized benzimidazole, 1-(4-nitrobenzyl-3-allyl-1H-benzo[d]imidazol-2(3H-one, has been synthesized, and the crystal structure was determined and analyzed. This compound crystallizes in the monoclinic, space group P21/n (number 14 c with cell parameters, a=7.12148(8 Å, b=16.12035(17 Å, c=13.04169(17 Å, β=93.3043(11, V=1494.71(3 Å3, and Dcalc = 1.375 g/mm3. The solid state geometry is stabilized by intermolecular π–π interactions along with the van der Waals interactions which contribute to the stability of the crystal packing. Computational calculations have been used to properly understand the main intermolecular interactions present in the crystal.

  1. Preformulation investigation of some clopidogrel addition salts.

    Science.gov (United States)

    Zupančič, Vinko; Smrkolj, Matej; Benkič, Promož; Simonič, Igor; Plevnik, Miha; Ritlop, Gregor; Kristl, Albin; Vrečer, Franc

    2010-06-01

    Physico-chemical properties of active substances such as solubility, dissolution rate, chemical stability, pharmaceutical processibility, etc. can be improved by salt formation of active substances. Characterization of physical properties of such salts is important for selection of an optimal salt having required biopharmaceutical properties, stability and manufacturability. The present study deals with the preformulation study of selected clopidogrel acid addition salts, i.e. hydrogen sulfate, hydrochloride (HCl), hydrobromide (HBr), besylate and (-)-camphor-10-sulfonate salt (CSA) and two commercially available polymorphic forms of hydrogen sulphate salt, i.e. form 1 (HS F1) and form 2 (HS F2). Clopidogrel salts were characterized by means of thermal analysis (TG, DSC), X-ray powder diffraction (XRPD), infrared spectroscopy (FTIR), nuclear magnetic resonance (NMR), dynamic vapor sorption (DVS), true density, scanning electron microscopy (SEM) and solubility. Distinct differences in tested parameters were found among acid addition salts and crystalline forms of clopidogrel. Higher melting point of both hydrogen sulphate salt was attributed to presence of hydrogen bonds among HS anions, connecting them into a chain. All salts included in the present study were anhydrous, except HBr which was in the form of monohydrate. The two tested polymorphic forms of clopidogrel HS salt are enantiotropically related to each other and showed the highest hygroscopicity among the tested salts. This is important for development of solid dosage form containing both polymorphic forms and for selection of primary packaging. Solubility studies in different aqueous media showed comparable solubility for clopidogrel hydrogen sulfate (polymorphic forms 1 and 2), hydrochloride (form 1) and hydrobromide hydrate (form 1) whereas clopidogrel camphorsulfonate (CSA) and besylate salt showed slightly lower solubility.

  2. Investigation of total phenolic, total flavonoid, antioxidant and allyl isothiocyanate content in the different organs of Wasabi japonica grown in an organic system.

    Science.gov (United States)

    Shin, Seong Woo; Ghimeray, Amal Kumar; Park, Cheol Ho

    2014-01-01

    This study was carried out to investigate the total polyphenol (TP), total flavonoid (TF), antioxidative effect and allyl isothyocyanate (ITC) content in different organs of wasabi plant grown in an organic system. Invitro study of methanol and boiled water extracts of wasabi were conducted by analyzing the 1-1-diphenyl-2-picryl hydrozyl (DPPH) radial scavenging activity, metal chelating activity and total antioxidant capacity in a comparative manner. The result revealed that methanol extract showed higher TP in flower (3644 mg TAE/100 g dw), leaf (3201 mg TAE/100 g dw) and fruit (3025 mg TAE/100 g dw) as compared to the boiled water extract. Similarly, TF content was also higher in methanol extracts of flower (1152 mg QE/100 g dw) and leaf (325 mg QE/100 g dw), however, the other parts showed ignorable value. Results of antioxidant activity were found at different magnitude of potency. The methanol extract of different parts of wasabi exhibited higher activity in total antioxidant capacity and DPPH radical scavenging assay as compared to water extract. In metal chelating assay, the boiled water extracts of leaf showed higher (76.9%) activity, followed by fruit (68.8%) and flower (62.8%). Ally ITC detected by gas chromatography was present in all of the tissues of wasabi plant but the content was found to be varied in different tissues. Overall, this study will allow consumers and processors to understand the possibility for medical application of wasabi plant by knowing the level of total polyphenol distribution, Ally ITC content and antioxidant property distributed in different parts and tissues.Key words: Allyl ITC, antioxidant, flavonoid, polyphenol, Wasabi japonica.

  3. Seismic anisotropy in deforming salt bodies

    Science.gov (United States)

    Prasse, P.; Wookey, J. M.; Kendall, J. M.; Dutko, M.

    2017-12-01

    Salt is often involved in forming hydrocarbon traps. Studying salt dynamics and the deformation processes is important for the exploration industry. We have performed numerical texture simulations of single halite crystals deformed by simple shear and axial extension using the visco-plastic self consistent approach (VPSC). A methodology from subduction studies to estimate strain in a geodynamic simulation is applied to a complex high-resolution salt diapir model. The salt diapir deformation is modelled with the ELFEN software by our industrial partner Rockfield, which is based on a finite-element code. High strain areas at the bottom of the head-like strctures of the salt diapir show high amount of seismic anisotropy due to LPO development of halite crystals. The results demonstrate that a significant degree of seismic anisotropy can be generated, validating the view that this should be accounted for in the treatment of seismic data in, for example, salt diapir settings.

  4. 168 Hours Salt Fog Test

    International Nuclear Information System (INIS)

    Nur Ubaidah Saidin; Muhamad Daud; Siti Radiah Mohd Kamarudin

    2011-01-01

    This report explained the test conducted in salt fog chamber to evaluate the effectiveness of mild steel, coated with rust converter, for 168 hours in artificial seawater exposure. The samples were compared with mild steel coated with commercial primer. The tests were conducted followed ASTM B117. Individual pictures were taken of each sample before the tests began, at 24, 48, 72, 96, 120, 144 and 168 hours to see the progression of the corrosion. Results showed that the samples coated with rust converter provide a good significant protection against corrosion phenomenon than the samples coated with commercial primer that available in the market. (author)

  5. Physical Properties Data for Rock Salt

    Science.gov (United States)

    1981-01-01

    foreign substances, such as oil . Other characteristics of Rock salt is a coarsely crystalline, sedimentary rock rock salt, specifically porosity and...225Permian """ 280 - , Pennsyl vani an-. ’, ~320---.. Mississippian 345 Paleozoic Devonian 395- . Silurian 430... Silurian salt-bearing Salina Formation of Michi- well into the Gulf of Mexico to the Sigsbee knolls, which gan, northern Ohio, Ontario, New York

  6. Impact of slope inclination on salt accumulation

    Science.gov (United States)

    Nachshon, Uri

    2017-04-01

    Field measurements indicated on high variability in salt accumulation along natural and cultivated slopes, even for relatively homogeneous soil conditions. It was hypothesised that slope inclination has an impact on the location of salt accumulation along the slope. A set of laboratory experiments and numerical models were used to explore the impact of slope inclination on salt accumulation. It was shown, experimentally, that for conditions of saline water source at the lower boundary of the slope - salt accumulates in low concentrations and homogeneously along the entire slope, for moderate slopes. However, as inclination increases high salt concentrations were observed at the upper parts of the slope, leaving the lower parts of the slope relatively free of salt. The traditional flow and transport models did not predict the experimental observations as they indicated also for the moderate slopes on salt accumulation in the elevated parts of the slope, away of the saline water source. Consequently - a conceptual model was raised to explain the laboratory observations. It was suggested that the interactions between slope angle, evaporation rates, hydraulic conductivity of the medium and distribution of wetness along the slope affect the saline water flow path through the medium. This lead to preferential flow path close to the soil-atmosphere interface for the steep slopes, which leads to constant wash of the salts from the evaporation front upward towards the slope upper parts, whereas for the moderate slopes, flow path is below the soil-atmosphere interface, therefore salt that accumulates at the evaporation front is not being transported upward. Understanding of salt dynamics along slopes is important for agricultural and natural environments, as well as for civil engineering purposes. Better understanding of the salt transport processes along slopes will improve our ability to minimize and to cope with soil salinization processes. The laboratory experiments and

  7. Evaluation of salt content in school meals

    Directory of Open Access Journals (Sweden)

    Cláudia Alexandra Colaço Lourenço Viegas

    2015-04-01

    Full Text Available OBJECTIVE: High blood pressure is a major rick factor for cardiovascular disease, and it is closely associated with salt intake. Schools are considered ideal environments to promote health and proper eating habits. Therefore the objective of this study was to evaluate the amount of salt in meals served in school canteens and consumers' perceptions about salt. METHODS: Meals, including all the components (bread, soup, and main dish were retrieved from school canteens. Salt was quantified by a portable salt meter. For food perception we constructed a questionnaire that was administered to high school students. RESULTS: A total of 798 food samples were analysed. Bread had the highest salt content with a mean of 1.35 g/100 g (SD=0.12. Salt in soups ranged from 0.72 g/100 g to 0.80 g/100 g (p=0.05 and, in main courses, from 0.71 g/100 to 0.97 g/100g (p=0.05. The salt content of school meals is high with a mean value of 2.83 to 3.82 g of salt per meal. Moreover, a high percentage of students consider meals neither salty nor bland, which shows they are used to the intensity/amount of salt consumed. CONCLUSION: The salt content of school meals is high, ranging from 2 to 5 times more than the Recommended Dietary Allowances for children, clearly exceeding the needs for this population, which may pose a health risk. Healthy choices are only possible in environments where such choices are possible. Therefore, salt reduction strategies aimed at the food industry and catering services should be implemented, with children and young people targeted as a major priority.

  8. Salt Bridges: Geometrically Specific, Designable Interactions

    OpenAIRE

    Donald, Jason E.; Kulp, Daniel W.; DeGrado, William F.

    2011-01-01

    Salt bridges occur frequently in proteins, providing conformational specificity and contributing to molecular recognition and catalysis. We present a comprehensive analysis of these interactions in protein structures by surveying a large database of protein structures. Salt bridges between Asp or Glu and His, Arg, or Lys display extremely well-defined geometric preferences. Several previously observed preferences are confirmed and others that were previously unrecognized are discovered. Salt ...

  9. Fluorinated benzamide neuroleptics--III. Development of (S)-N-[(1-allyl-2-pyrrolidinyl)methyl]-5-(3-[{sup 18}F]fluoropropyl)-2,3- dimethoxybenzamide as an improved dopamine D-2 receptor tracer

    Energy Technology Data Exchange (ETDEWEB)

    Mukherjee, Jogeshwar; Yang Zhiying; Das, Malay K.; Brown, Terry

    1995-04-01

    We have prepared five new analogs (n-propyl, iso-propyl, allyl, n-butyl, and iso-butyl) of the dopamine D-2 receptor antagonist, FPMB which result from modifications of the ethyl group at the pyrrolidine nitrogen in FPMB. As expected, all new derivatives showed higher apparent lipophilicity (log k{sub w}), with iso-butyl being the most lipophilic (log k{sub w} = 2.52), followed by the allyl derivative (log k{sub w} = 2.43). The allyl group showed the largest increase in affinity (from 0.26 nM for the ethyl substituent to 0.03 nM for the allyl substituent, almost 10-fold), followed by the n-propyl substituent which showed approximately five-fold better affinity than did the ethyl substituent. Radiosynthesis of S-N-[(1-allyl-2-pyrrolidinyl)methyl]-5-(3-[{sup 18}F]fluoropropyl)-2,3-dimethoxybenzamide ([{sup 18}F]fallypride) was carried out by nucleophilic substitution reaction of (S)-N-[(1-allyl-2-pyrrolidinyl)methyl]-5-(3-tosyloxypropyl)-2,3- dimethoxybenzamide with no carrier added {sup 18}F{sup -}. [{sup 18}F]Fallypride was obtained in approximately 20-40% yields (EOS/EOB, decay corrected) in specific activities of 900-1700 Ci/mmol after reverse phase HPLC purification in 60 min from EOB. High striatal uptake (upto 2.5% injected dose/g) of [{sup 18}F]fallypride in rats was observed with striatal/cerebellar ratios of 17, 42, 63 and 122 at 30, 60, 90 and 120 min post-injection, respectively. PET experiments with [{sup 18}F]fallypride in a cebus monkey showed a brain uptake of 0.10% injected dose/cc. In rhesus monkeys [{sup 18}F]fallypride showed rapid specific uptake in the striata (0.04-0.06% injected dose/cc) with striata/cerebellum ratios of approx. 3.0 at 14 min, 5.0 at 35 min and 8 at 70 min post-injection. Specifically bound [{sup 18}F]fallypride was displaced with haloperidol (1 mg/kg) with a half-life of 18 min in the rhesus monkey.

  10. Molten salt safety study. Final report

    Energy Technology Data Exchange (ETDEWEB)

    1980-01-01

    The considerations concerning safety in using molten salt (40% potassium nitrate, 60% sodium nitrate) in a solar central receiver plant are addressed. The considerations are of a general nature and do not cover any details of equipment or plant operation. The study includes salt chemical reaction, experiments with molten salt, dry storage and handling constraints, and includes data from the National Fire Protection Association. The contents of this report were evaluated by two utility companies and they concluded that no major safety problems exist in using a molten salt solar system.

  11. Granular Salt Summary: Reconsolidation Principles and Applications

    Energy Technology Data Exchange (ETDEWEB)

    Hansen, Frank; Popp, Till; Wieczorek, Klaus; Stuehrenberg, Dieter

    2014-07-01

    The purposes of this paper are to review the vast amount of knowledge concerning crushed salt reconsolidation and its attendant hydraulic properties (i.e., its capability for fluid or gas transport) and to provide a sufficient basis to understand reconsolidation and healing rates under repository conditions. Topics covered include: deformation mechanisms and hydro-mechanical interactions during reconsolidation; the experimental data base pertaining to crushed salt reconsolidation; transport properties of consolidating granulated salt and provides quantitative substantiation of its evolution to characteristics emulating undisturbed rock salt; and extension of microscopic and laboratory observations and data to the applicable field scale.

  12. Applications of molten salts in plutonium processing

    International Nuclear Information System (INIS)

    Bowersox, D.F.; Christensen, D.C.; Williams, J.D.

    1987-01-01

    Plutonium is efficiently recovered from scrap at Los Alamos by a series of chemical reactions and separations conducted at temperatures ranging from 700 to 900 0 C. These processes usually employ a molten salt or salt eutectic as a heat sink and/or reaction medium. Salts for these operations were selected early in the development cycle. The selection criteria are being reevaluated. In this article we describe the processes now in use at Los Alamos and our studies of alternate salts and eutectics

  13. Brine Transport Experiments in Granular Salt

    Energy Technology Data Exchange (ETDEWEB)

    Jordan, Amy B. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Boukhalfa, Hakim [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Caporuscio, Florie Andre [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Stauffer, Philip H. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-06-06

    To gain confidence in the predictive capability of numerical models, experimental validation must be performed to ensure that parameters and processes are correctly simulated. The laboratory investigations presented herein aim to address knowledge gaps for heat-generating nuclear waste (HGNW) disposal in bedded salt that remain after examination of prior field and laboratory test data. Primarily, we are interested in better constraining the thermal, hydrological, and physicochemical behavior of brine, water vapor, and salt when moist salt is heated. The target of this work is to use run-of-mine (RoM) salt; however during FY2015 progress was made using high-purity, granular sodium chloride.

  14. Anaglyph, Salt Lake City, Utah

    Science.gov (United States)

    2002-01-01

    The 2002 Winter Olympics are hosted by Salt Lake City at several venues within the city, in nearby cities, and within the adjacent Wasatch Mountains. This anaglyph image provides a stereoscopic map view of north central Utah that includes all of these Olympic sites. In the south, next to Utah Lake, Provo hosts the ice hockey competition. In the north, northeast of the Great Salt Lake, Ogden hosts curling and the nearby Snowbasin ski area hosts the downhill events. In between, southeast of the Great Salt Lake, Salt Lake City hosts the Olympic Village and the various skating events. Further east, across the Wasatch Mountains, the Park City ski resort hosts the bobsled, ski jumping, and snowboarding events. The Winter Olympics are always hosted in mountainous terrain. This view shows the dramatic landscape that makes the Salt Lake City region a world-class center for winter sports.The stereoscopic effect of this anaglyph was created by first draping a Landsat satellite image over a Shuttle Radar Topography Mission digital elevation model and then generating two differing perspectives, one for each eye. When viewed through special glasses, the result is a vertically exaggerated view of Earth's surface in its full three dimensions. Anaglyph glasses cover the left eye with a red filter and cover the right eye with a blue filter.Landsat has been providing visible and infrared views of the Earth since 1972. SRTM elevation data matches the 30-meter (98-foot) resolution of most Landsat images and will substantially help in analyzing the large and growing Landsat image archive, managed by the U.S. Geological Survey (USGS).Elevation data used in this image was acquired by the Shuttle Radar Topography Mission (SRTM) aboard the Space Shuttle Endeavour, launched on Feb. 11, 2000. SRTM used the same radar instrument that comprised the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) that flew twice on the Space Shuttle Endeavour in 1994. SRTM was designed

  15. ERG review of salt constitutive law, salt stress determinations, and salt corrosion and modeling studies

    International Nuclear Information System (INIS)

    Balon, J.E.

    1986-03-01

    The Engineering Review Group (ERG) was established by the Office of Nuclear Waste Isolation (ONWI) to help evaluate engineering-related issues in the US Department of Energy's nuclear waste repository program. The August 1983 meeting of the ERG reviewed a RE/SPEC technical report containing a review of eight constitutive laws that have been proposed to model the creep of salt over the ranges of stress and temperature anticipated in a nuclear repository. This report documents the ERG's comments and recommendations on this subject and the ONWI responses to the specific points raised by the ERG

  16. Balancing sub- and supra-salt strain in salt-influenced rifts: Implications for extension estimates

    Science.gov (United States)

    Coleman, Alexander J.; Jackson, Christopher A.-L.; Duffy, Oliver B.

    2017-09-01

    The structural style of salt-influenced rifts may differ from those formed in predominantly brittle crust. Salt can decouple sub- and supra-salt strain, causing sub-salt faults to be geometrically decoupled from, but kinematically coupled to and responsible for, supra-salt forced folding. Salt-influenced rifts thus contain more folds than their brittle counterparts, an observation often ignored in extension estimates. Fundamental to determining whether sub- and supra-salt structures are kinematically coherent, and the relative contributions of thin- (i.e. gravity-driven) and thick-skinned (i.e. whole-plate stretching) deformation to accommodating rift-related strain, is our ability to measure extension at both structural levels. We here use published physical models of salt-influenced extension to show that line-length estimates yield more accurate values of sub- and supra-salt extension compared to fault-heave, before applying these methods to seismic data from the Halten Terrace, offshore Norway. We show that, given the abundance of ductile deformation in salt-influenced rifts, significant amounts of extension may be ignored, leading to the erroneous interpretations of thin-skinned, gravity-gliding. If a system is kinematically coherent, supra-salt structures can help predict the occurrence and kinematics of sub-salt faults that may be poorly imaged and otherwise poorly constrained.

  17. Salt Reductions in Some Foods in The Netherlands: Monitoring of Food Composition and Salt Intake.

    NARCIS (Netherlands)

    Temme, Elisabeth H M; Hendriksen, Marieke A H; Milder, Ivon E J; Toxopeus, Ido B; Westenbrink, Susanne; Brants, Henny A M; van der A, Daphne L

    2017-01-01

    High salt intake increases blood pressure and thereby the risk of chronic diseases. Food reformulation (or food product improvement) may lower the dietary intake of salt. This study describes the changes in salt contents of foods in the Dutch market over a five-year period (2011-2016) and

  18. Comparative effects of neutral salt and alkaline salt stress on seed ...

    African Journals Online (AJOL)

    Comparative effects of neutral salt and alkaline salt stress on seed germination, early seedling growth and physiological response of a halophyte species Chenopodium glaucum. ... Relative water content (RWC) of C. glaucum remained high even under the highest salt or alkali stress. No obvious increase of osmolytes ...

  19. Zinc or indium-mediated Barbier-type allylation of aldehydes with 3-bromomethyl-5H-furan-2-one in aqueous media: an efficient synthesis method for α-methylene-γ-butyrolactone.

    Science.gov (United States)

    Gao, YuZhe; Wang, Xue; Sun, LiDong; Xie, LongGuan; Xu, XiaoHua

    2012-05-28

    A zinc or indium-mediated Barbier-type allylation of aldehydes with 3-bromomethyl-5H-furan-2-one in aqueous solvents was developed to provide an efficient route to α-methylene-γ-butyrolactone, which is synthetically very useful. The desired products were obtained in moderate to high yields in aqueous solvents. Excellent drs were achieved, among which the best diastereomeric ratios of products were found when water was used in the indium-mediated reaction, and THF-NH(4)Cl (sat, aq) (2 : 1) mixture in the zinc-mediated reaction. Furthermore, the allylation can be induced by chiral centers, especially those in the α-position, as a substrate-controlled reaction to obtain the enantioselective homoallylation alcohols.

  20. Mined salt storage feasibility: Engineering study report

    International Nuclear Information System (INIS)

    1987-07-01

    This study addresses a method of eliminating the surface storage of mined salt at the Deaf Smith repository site. It provides rough estimates of the logistics and costs of transporting 3.7 million tons of salt from the repository to the salt disposal site near Carlsbad, New Mexico and returning it to the repository for decommissioning backfill. The study assumes that a railcar/truck system will be installed and that the excavated salt will be transported from the repository to an existing potash mine located near Carlsbad, New Mexico approximately 300 miles from the repository. The 3.7 million tons of salt required for repository decommissioning backfill can be stored in the potash mines along with the excess salt, with no additional capital costs required for either a railcar or a truck transportation system. The capital cost for facilities to reclaim the 3.7 million tons of salt from the potash mine is estimated to be $4,400,000 with either a rail or truck transportation system. Segregating the 3.7 million tons of backfill salt in a surface storage area at the potash mine requires a capital cost of $13,900,000 with a rail system or $11,400,000 with a truck system. Transportation costs are estimated at $0.08/ton-mile for rail and $0.13/ton-mile for truck. 2 figs., 5 tabs

  1. vinyltriphenylphosphonium salt-mediated preparation of thiophene ...

    African Journals Online (AJOL)

    Preferred Customer

    phosphonium salts are usually made from phosphine and an alkyl halide [10-16], and they are also obtained by the ... novel reaction of dialkyl acetylenedicarboxylates (DAAD), triphenylphosphine (TPP) and acids ... concomitant protonation of the intermediate by an acid leads to vinyltriphenylphosphonium salts [18-28].

  2. Specific investigations related to salt rock behaviour

    International Nuclear Information System (INIS)

    Vons, L.H.

    1985-01-01

    In this paper results are given of work in various countries in rather unrelated areas of research. Nevertheless, since the studies have been undertaken to better understand salt behaviour, both from mechanical and chemical points of view, some connection between the studies can be found. In the French contribution the geological conditions have been investigated that might promote or prevent the formation of salt domes from layers in view of possible use of the latter type of formation. This was done theoretically by the finite element method, and a start was made with centrifuge tests. The density of a number of samples from salt and overburden from the Bresse basin was measured and it was shown that a favourable condition exists in this region for waste disposal. In the German contribution various subjects are touched upon, one being the effect of water on the mobility in the early stages of salt dome formation. Evidence was found for an anisotropy in salt. One Dutch contribution describes results of studies on the effect of small amounts of water on the rheology of salt. The results imply that flow laws obtained for salt at rapid strain rates and/or low confining pressure cannot be reliably extrapolated to predict the long term behaviour of wet or even very dry material under natural conditions. Preliminary results on the effect of water upon ion-mobility indicate a certain pseudo-absorptive capacity of salt e.g. for Sr

  3. Asymmetric Hydrogenation of 3-Substituted Pyridinium Salts

    NARCIS (Netherlands)

    Renom-Carrasco, Marc; Gajewski, Piotr; Pignataro, Luca; de Vries, Johannes G.; Piarulli, Umberto; Gennari, Cesare; Lefort, Laurent

    2016-01-01

    The use of an equivalent amount of an organic base leads to high enantiomeric excess in the asymmetric hydrogenation of N-benzylated 3-substituted pyridinium salts into the corresponding piperidines. Indeed, in the presence of Et3N, a Rh-JosiPhos catalyst reduced a range of pyridinium salts with ee

  4. Metal salt catalysts for enhancing hydrogen spillover

    Science.gov (United States)

    Yang, Ralph T; Wang, Yuhe

    2013-04-23

    A composition for hydrogen storage includes a receptor, a hydrogen dissociating metal doped on the receptor, and a metal salt doped on the receptor. The hydrogen dissociating metal is configured to spill over hydrogen to the receptor, and the metal salt is configured to increase a rate of the spill over of the hydrogen to the receptor.

  5. Public health impact of salt reduction

    NARCIS (Netherlands)

    Hendriksen, M.A.H.

    2015-01-01

    The health and economic burden related to cardiovascular diseases is substantial and prevention of these diseases remains a challenge. There is convincing evidence that high salt intake affects blood pressure and the risk of cardiovascular diseases. As salt intake is far above the recommended

  6. Nonlinear Analysis of Cavities in Rock Salt

    DEFF Research Database (Denmark)

    Ottosen, N. S.; Krenk, Steen

    1979-01-01

    The paper covers some material and computational aspects of the rock mechanics of leached cavities in salt. A material model is presented in which the instantaneous stiffness of the salt is obtained by interpolation between the unloaded state and a relevant failure state. The model enables predic...

  7. Secondary Aluminum Processing Waste: Salt Cake ...

    Science.gov (United States)

    Thirty-nine salt cake samples were collected from 10 SAP facilities across the U.S. The facilities were identified by the Aluminum Association to cover a wide range of processes. Results suggest that while the percent metal leached from the salt cake was relatively low, the leachable metal content may still pose a contamination concern and potential human and ecological exposure if uncontrollably released to the environment. As a result, salt cake should always be managed at facilities that utilize synthetic liner systems with leachate collection (the salt content of the leachate will increase the hydraulic conductivity of clay liners within a few years of installation). The mineral phase analysis showed that various species of aluminum are present in the salt cake samples with a large degree of variability. The relative abundance of various aluminum species was evaluated but it is noted that the method used is a semi-quantitative method and as a result there is a limitation for the data use. The analysis only showed a few aluminum species present in salt cake which does not exclude the presence of other crystalline species especially in light of the variability observed in the samples. Results presented in this document are of particular importance when trying to understand concerns associated with the disposal of salt cake in MSW landfills. From the end-of-life management perspective, data presented here suggest that salt cake should not be size reduce

  8. The effect of the salt viscosity on future evolution of the Gorleben salt diapir, Germany

    DEFF Research Database (Denmark)

    Chemia, Zurab; Schmeling, H.; Koyi, H.

    2009-01-01

    for various salt rheologies. It is shown that the rheology of the salt plays a significant role in how and at which rate the anhydrite blocks sink within the diapir. The mobility of anhydrite blocks depends on the effective viscosity of salt which has to be lower than threshold value of around 1018–1019 Pa s....... Decreasing salt viscosity allows the previously “stationary” anhydrite blocks to sink. If the effective viscosity of salt in post-depositional stage of the Gorleben diapir falls below this threshold value, induced internal flow due to the present anhydrite layer might disturb any repository within the diapir....

  9. Actinide removal from molten salts by chemical oxidation and salt distillation

    Energy Technology Data Exchange (ETDEWEB)

    McNeese, J.A.; Garcia, E.; Dole, V.R. [Los Alamos National Laboratory, NM (United States)] [and others

    1995-10-01

    Actinide removal from molten salts can be accomplished by a two step process where the actinide is first oxidized to the oxide using a chemical oxidant such as calcium carbonate or sodium carbonate. After the actinide is precipitated as an oxide the molten salt is distilled away from the actinide oxides leaving a oxide powder heel and an actinide free distilled salt that can be recycled back into the processing stream. This paper discusses the chemistry of the oxidation process and the physical conditions required to accomplish a salt distillation. Possible application of an analogous process sequence for a proposed accelerator driven transmutation molten salt process is also discussed.

  10. Conformational analysis of a Chlamydia-specific disaccharide {alpha}-Kdo-(2{sup {yields}}8)-{alpha}-Kdo-(2{sup {yields}}O)-allyl in aqueous solution and bound to a monoclonal antibody: Observation of intermolecular transfer NOEs

    Energy Technology Data Exchange (ETDEWEB)

    Sokolowski, Tobias; Haselhorst, Thomas; Scheffler, Karoline [Medizinische Universitaet, Institut fuer Chemie (Germany); Weisemann, Ruediger [Bruker Analytik GmbH, Silberstreifen (Germany); Kosma, Paul [Institut fuer Chemie der Universitaet fuer Bodenkultur Wien (Austria); Brade, Helmut; Brade, Lore [Forschungszentrum Borstel, Zentrum fuer Medizin und Biowissenschaften Parkallee 22 (Germany); Peters, Thomas [Medizinische Universitaet, Institut fuer Chemie (Germany)

    1998-07-15

    The disaccharide {alpha}-Kdo-(2{sup {yields}}8)-{alpha}-Kdo (Kdo: 3-deoxy-d-manno-oct-2-ulosonic acid) represents a genus-specific epitope of the lipopolysaccharide of the obligate intracellular human pathogen Chlamydia. The conformation of the synthetically derived disaccharide {alpha}-Kdo-(2{sup {yields}}8)-{alpha}-Kdo-(2{sup {yields}}O)-allyl was studied in aqueous solution, and complexed to a monoclonal antibody S25-2. Various NMR experiments based on the detection of NOEs (or transfer NOEs) and ROEs (or transfer ROEs) were performed. A major problem was the extensive overlap of almost all {sup 1}H NMR signals of {alpha}-Kdo-(2{sup {yields}}8)-{alpha}-Kdo-(2{sup {yields}}O)-allyl. To overcome this difficulty, HMQC-NOESY and HMQC-trNOESY experiments were employed. Spin diffusion effects were identified using trROESY experiments, QUIET-trNOESY experiments and MINSY experiments. It was found that protein protons contribute to the observed spin diffusion effects. At 800 MHz, intermolecular trNOEs were observed between ligand protons and aromatic protons in the antibody binding site. From NMR experiments and Metropolis Monte Carlo simulations, it was concluded that {alpha}-Kdo-(2{sup {yields}}8)-{alpha}-Kdo-(2{sup {yields}}O)-allyl in aqueous solution exists as a complex conformational mixture. Upon binding to the monoclonal antibody S25-2, only a limited range of conformations is available to {alpha}-Kdo-(2{sup {yields}}8)-{alpha}-Kdo-(2{sup {yields}}O)-allyl. These possible bound conformations were derived from a distance geometry analysis using transfer NOEs as experimental constraints. It is clear that a conformation is selected which lies within a part of the conformational space that is highly populated in solution. This conformational space also includes the conformation found in the crystal structure. Our results provide a basis for modeling studies of the antibody-disaccharide complex.

  11. Dam construction in salt rock

    International Nuclear Information System (INIS)

    Stockmann, N.; Beinlich, A.; Flach, D.; Jockwer, N.; Klarr, K.; Krogmann, P.; Miehe, R.; Schmidt, M.W.; Schwaegermann, H.F.; Walter, F.; Yaramanci, U.

    1991-11-01

    Barriers are a major component of the satefy concept for the Gorleben repository. The construction and performance of dams are currently tested within the framework of a project carried out in the Asse salt mine. A measuring programme has been established to give evidence of the sealing capacities of a barrier consisting of an abatement, long-term sealing material, and a hydraulic sealing system. Tests are to be made to verify the barrier's performance for shorter of long time periods (up to about 500 years). The tests are assisted by computed models established for the project. The long-term safety aspects to be studied include such conditions as permeability changes due to mechanical impacts, circulation conditions at the roadside, and the serviceable life and efficiency of the sealing components. (DG) [de

  12. Whitecaps, sea-salt aerosols, and climate

    Science.gov (United States)

    Anguelova, Magdalena Dimitrova

    Oceanic whitecaps are the major source of sea-salt aerosols. Because these aerosols are dominant in remote marine air, they control the radiative properties of the clean background atmosphere by scattering sunlight, changing cloud properties and lifetime, and providing media for chemical reactions. Including sea-salt effects in climate models improves predictions, but simulating their generation is first necessary. To make the sea-salt generation function currently used in climate models more relevant for aerosol investigations, this study proposes two modifications. First, the conventional relation between whitecap coverage, W, and the 10-meter wind speed, U10, used in typical generation functions is expanded to include additional factors that affect whitecaps and sea-salt aerosol formation. Second, the sea-salt generation function is extended to smaller sizes; sea-salt aerosol with initial radii from 0.4 to 20 mum can now be modeled. To achieve these goals, this thesis develops a new method for estimating whitecap coverage on a global scale using satellite measurements of the brightness temperature of the ocean surface. Whitecap coverage evaluated with this method incorporates the effects of atmospheric stability, sea-surface temperature, salinity, wind fetch, wind duration, and the amount of surface-active material. Assimilating satellite-derived values for whitecap coverage in the sea-salt generation function incorporates the effects of all environmental factors on sea-salt production and predicts realistic sea-salt aerosol loadings into the atmosphere. An extensive database of whitecap coverage and sea-salt aerosol fluxes has been compiled with the new method and is used to investigate their spatial and temporal characteristics. The composite effect of all environmental factors suggests a more uniform latitudinal distribution of whitecaps and sea-salt aerosols than that predicted from wind speed alone. The effect of sea-surface temperature, TS, is

  13. SEPARATION OF METAL SALTS BY ADSORPTION

    Science.gov (United States)

    Gruen, D.M.

    1959-01-20

    It has been found that certain metal salts, particularly the halides of iron, cobalt, nickel, and the actinide metals, arc readily absorbed on aluminum oxide, while certain other salts, particularly rare earth metal halides, are not so absorbed. Use is made of this discovery to separate uranium from the rare earths. The metal salts are first dissolved in a molten mixture of alkali metal nitrates, e.g., the eutectic mixture of lithium nitrate and potassium nitrate, and then the molten salt solution is contacted with alumina, either by slurrying or by passing the salt solution through an absorption tower. The process is particularly valuable for the separation of actinides from lanthanum-group rare earths.

  14. Alternative methods of salt disposal at the seven salt sites for a nuclear waste repository

    International Nuclear Information System (INIS)

    1987-02-01

    This study discusses the various alternative salt management techniques for the disposal of excess mined salt at seven potentially acceptable nuclear waste repository sites: Deaf Smith and Swisher Counties, Texas; Richton and Cypress Creek Domes, Mississippi; Vacherie Dome, Louisiana; and Davis and Lavender Canyons, Utah. Because the repository development involves the underground excavation of corridors and waste emplacement rooms, in either bedded or domed salt formations, excess salt will be mined and must be disposed of offsite. The salt disposal alternatives examined for all the sites include commercial use, ocean disposal, deep well injection, landfill disposal, and underground mine disposal. These alternatives (and other site-specific disposal methods) are reviewed, using estimated amounts of excavated, backfilled, and excess salt. Methods of transporting the excess salt are discussed, along with possible impacts of each disposal method and potential regulatory requirements. A preferred method of disposal is recommended for each potentially acceptable repository site. 14 refs., 5 tabs

  15. Synthesis, Molecular Structure and Characterization of Allylic Derivatives of 6-Amino-3-methyl-1,2,4-triazolo[3,4-f][1,2,4]-triazin-8(7H-one

    Directory of Open Access Journals (Sweden)

    Gene-Hsiang Lee

    2006-06-01

    Full Text Available 1-Allyl- (2 and 7-allyl-6-amino-3-methyl-1,2,4-triazolo[3,4-f][1,2,4]triazin-8(7H-one (3 were obtained via the 18-crown-6-ether catalyzed room temperature reactionof 6-amino-3-methyl-1,2,4-triazolo[3,4-f][1,2,4]triazin-8(7H-one (1 with potassiumcarbonate and allyl bromide in dry acetone. The structures of these two derivatives wereverified by 2D-NMR measurements, including gHSQC and gHMBC measurements. Theminor compound 2 may possess aromatic character. A single crystal X-ray diffractionexperiment indicated that the major compound 3 crystallizes from dimethyl sulfoxide in themonoclinic space group P21/n and its molecular structure includes an attached dimethylsulfoxide molecule, resulting in the molecular formula C10H16N6O2S. Molecular structuresof 3 are linked by extensive intermolecular N-H···N hydrogen bonding [graph set C 1 (7]. 1Each molecule is attached to the dimethyl sulfoxide oxygen via N-H···O intermolecularhydrogen bonding. The structure is further stabilized by π-π stacking interactions.

  16. Ion beam-induced topographical and chemical modification on the poly(styrene-co-allyl alcohol) and its effect on the molecular interaction between the modified surface and liquid crystals

    International Nuclear Information System (INIS)

    Jeong, Hae-Chang; Park, Hong-Gyu; Lee, Ju Hwan; Jang, Sang Bok; Oh, Byeong-Yun; Seo, Dae-Shik

    2016-01-01

    We demonstrated uniform liquid crystal (LC) alignment on ion beam (IB)-irradiated poly(styrene-co-allyl alcohol) by modifying the chemical bonding on the surface. An IB-irradiated copolymer was used for the alignment layer. We used physico-chemical analysis to determine the IB-irradiated surface modification and LC alignment mechanism on the surface. During IB treatment on poly(styrene-co-allyl alcohol), IB irradiation induces breaking of chemical bonds on the surface to give rise to new bonds with oxygen atoms. This causes a strong Van der Waals interaction between LCs and the modified surface, thereby resulting in uniform LC alignment. The results of contact angle (CA) studies of the copolymer support the chemical bonding changes that were investigated by XPS. We achieved uniform homogeneous LC alignment and obtained stable electro-optical performance by controlling the IB energy. Therefore, the LC cells with IB-irradiated poly(styrene-co-allyl alcohol) exhibited a good potential for alternative alignment of layers in LC applications.

  17. Ion beam-induced topographical and chemical modification on the poly(styrene-co-allyl alcohol) and its effect on the molecular interaction between the modified surface and liquid crystals

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Hae-Chang [Information Display Device Laboratory, Department of Electrical and Electronic Engineering, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, Seoul, 120-749 (Korea, Republic of); Park, Hong-Gyu [School of Electrical, Electronic & Control Engineering, Changwon National University, 20 Changwondaehak-ro, Uichang-gu, Changwon-si, Gyeongsangnam-do, 51140 (Korea, Republic of); Lee, Ju Hwan; Jang, Sang Bok [Information Display Device Laboratory, Department of Electrical and Electronic Engineering, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, Seoul, 120-749 (Korea, Republic of); Oh, Byeong-Yun [ZeSHTech Co., Ltd., Business Incubator, Gwangju Institute of Science and Technology, 123, Cheomdangwagi-ro, Buk-gu, Gwangju, 500-712 (Korea, Republic of); Seo, Dae-Shik, E-mail: dsseo@yonsei.ac.kr [Information Display Device Laboratory, Department of Electrical and Electronic Engineering, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, Seoul, 120-749 (Korea, Republic of)

    2016-10-01

    We demonstrated uniform liquid crystal (LC) alignment on ion beam (IB)-irradiated poly(styrene-co-allyl alcohol) by modifying the chemical bonding on the surface. An IB-irradiated copolymer was used for the alignment layer. We used physico-chemical analysis to determine the IB-irradiated surface modification and LC alignment mechanism on the surface. During IB treatment on poly(styrene-co-allyl alcohol), IB irradiation induces breaking of chemical bonds on the surface to give rise to new bonds with oxygen atoms. This causes a strong Van der Waals interaction between LCs and the modified surface, thereby resulting in uniform LC alignment. The results of contact angle (CA) studies of the copolymer support the chemical bonding changes that were investigated by XPS. We achieved uniform homogeneous LC alignment and obtained stable electro-optical performance by controlling the IB energy. Therefore, the LC cells with IB-irradiated poly(styrene-co-allyl alcohol) exhibited a good potential for alternative alignment of layers in LC applications.

  18. The Strategy of Welfare Improvement for Salt Farmers in Indonesia

    Directory of Open Access Journals (Sweden)

    Sudaryana Bambang

    2018-01-01

    Full Text Available Until now, production of salt in Indonesia is done by salt farmers and PT. Garam Indonesia as the only state company that produces salt. As the perpetrators of production which contribute greatly to the national salt production, salt farmer is considered not prosperous. In general, they depend on marine and coastal resources, use requires large investment and rely heavily on season. Climate and weather conditions that are often hostile, the price mechanism and the salt market tend to be contrast to the condition of farmers, this is what makes salt business is risky. The goals of this research are: 1. Improving the Welfare of salt farmers through a focused and effective empowerment. 2. Improving government’spolicies on salt. To conclude, Empowerment of salt farmers in Indonesia should be focused and effective, salt governance and policy revisions significantly affect the welfare of salt farmers.

  19. Systematic Evaluation of Salt Cavern Well Integrity

    Science.gov (United States)

    Roberts, B. L.; Lord, D. L.; Lord, A. S.; Bettin, G.; Sobolik, S. R.; Park, B. Y.

    2017-12-01

    The U.S. Strategic Petroleum Reserve (SPR) holds a reserve of crude oil ( 700 million barrels) to help ease any interruptions in oil import to the United States. The oil is stored in a set of 63 underground caverns distributed across four sites along the U.S. Gulf Coast. The caverns were solution mined into salt domes at each of the four sites. The plastic nature of the salt is beneficial for the storage of crude oil as it heals any fractures that may occur in the salt. The SPR is responsible for operating and maintaining the nearly 120 wells used to access the storage caverns over operational lifetimes spanning decades. Salt creep can induce deformation of the well casing which must be remediated to insure cavern and well integrity. This is particularly true at the interface between the plastic salt and the rigid caprock. The Department of Energy, the SPR Management and Operations contractor, and Sandia National Laboratories has developed a multidimensional well-grading system for the salt cavern access wells. This system is designed to assign numeric grades to each well indicating its risk of losing integrity and remediation priority. The system consists of several main components which themselves may consist of sub-components. The main components consider such things as salt cavern pressure history, results from geomechanical simulations modeling salt deformation, and measurements of well casing deformation due to salt creep. In addition, the geology of the salt domes and their overlying caprock is also included in the grading. These multiple factors are combined into summary values giving the monitoring and remediation priority for each well. Sandia National Laboratories is a multimission laboratory managed and operated by National Technology and Engineering Solutions of Sandia LLC, a wholly owned subsidiary of Honeywell International Inc. for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-NA0003525.

  20. Molten salt oxidation of organic hazardous waste with high salt content.

    Science.gov (United States)

    Lin, Chengqian; Chi, Yong; Jin, Yuqi; Jiang, Xuguang; Buekens, Alfons; Zhang, Qi; Chen, Jian

    2018-02-01

    Organic hazardous waste often contains some salt, owing to the widespread use of alkali salts during industrial manufacturing processes. These salts cause complications during the treatment of this type of waste. Molten salt oxidation is a flameless, robust thermal process, with inherent capability of destroying the organic constituents of wastes, while retaining the inorganic ingredients in the molten salt. In the present study, molten salt oxidation is employed for treating a typical organic hazardous waste with a high content of alkali salts. The hazardous waste derives from the production of thiotriazinone. Molten salt oxidation experiments have been conducted using a lab-scale molten salt oxidation reactor, and the emissions of CO, NO, SO 2 , HCl and dioxins are studied. Impacts are investigated from the composition of the molten salts, the types of feeding tube, the temperature of molten carbonates and the air factor. Results show that the waste can be oxidised effectively in a molten salt bath. Temperature of molten carbonates plays the most important role. With the temperature rising from 600 °C to 750 °C, the oxidation efficiency increases from 91.1% to 98.3%. Compared with the temperature, air factor has but a minor effect, as well as the composition of the molten salts and the type of feeding tube. The molten carbonates retain chlorine with an efficiency higher than 99.9% and the emissions of dioxins are below 8 pg TEQ g -1 sample. The present study shows that molten salt oxidation is a promising alternative for the disposal of organic hazardous wastes containing a high salt content.

  1. Pressure Effects on Product Channels of the Allyl Radical Reactions; C3H5+C3H5 and C3H5+CH3

    Science.gov (United States)

    Halpern, J. B.; N'Doumi, M.; Fahr, A.

    2011-12-01

    Relatively large hydrocarbon molecules (C4, C6 and larger) have been detected in several planetary environments. The mechanism for the formation of such large molecular species and detailed mechanism for their potential destruction are not well understood and are of considerable current interest. Previously we have studied the kinetics and product channels of small unsaturated hydrocarbon radical (C2 and C3s) reactions relevant to planetary atmospheric modeling. Reactions of C2 radicals (such as vinyl, H2CCH and ethynyl C2H) and C3 radicals (such as propargyl, HCCCH2) can affect the abundances of a large number of stable observable C3, C4, C5, C6 and larger molecules, including linear, aromatic and even poly aromatic molecules. Pressure-dependent product yields have been determined experimentally for the self- and cross-radical reactions performed at 298 K and at pressures between ~4 Torr (0.5 kPa) and 760 Torr (101 kPa). Final reaction products were quantitatively determined using a gas chromatograph with mass spectrometry/flame ionization detection (GC/MS/FID). In some cases complementary computational studies extended the pressure and temperature range of the experiments and provided valuable information on the complex reaction mechanisms. Theses studies provide a systematic framework so that important energetic and structural parameters for radical-radical reactions can be assessed. Here we report recent results for the allyl radical reactions H2CCCH3+ H2CCCH3 and H2CCCH3+CH3. For the allyl radical self-reaction, at high pressures the "head -to-head", combination channel forming 1,5-hexadiene is dominant with a combination/disproportionation = 1,5-hexadiene/propyne ratio of about 24 at 500 Torr (67 kPa, T=298K). At low pressures the ratio is substantially reduced to about 1.2 (at 0.3 kPa) and other major products are observed including allene, propene, 1-butene and propyne.

  2. Permanent Disposal of Nuclear Waste in Salt

    Science.gov (United States)

    Hansen, F. D.

    2016-12-01

    Salt formations hold promise for eternal removal of nuclear waste from our biosphere. Germany and the United States have ample salt formations for this purpose, ranging from flat-bedded formations to geologically mature dome structures. Both nations are revisiting nuclear waste disposal options, accompanied by extensive collaboration on applied salt repository research, design, and operation. Salt formations provide isolation while geotechnical barriers reestablish impermeability after waste is placed in the geology. Between excavation and closure, physical, mechanical, thermal, chemical, and hydrological processes ensue. Salt response over a range of stress and temperature has been characterized for decades. Research practices employ refined test techniques and controls, which improve parameter assessment for features of the constitutive models. Extraordinary computational capabilities require exacting understanding of laboratory measurements and objective interpretation of modeling results. A repository for heat-generative nuclear waste provides an engineering challenge beyond common experience. Long-term evolution of the underground setting is precluded from direct observation or measurement. Therefore, analogues and modeling predictions are necessary to establish enduring safety functions. A strong case for granular salt reconsolidation and a focused research agenda support salt repository concepts that include safety-by-design. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000. Author: F. D. Hansen, Sandia National Laboratories

  3. Site characterization plan: Gulf Coast salt domes

    International Nuclear Information System (INIS)

    1983-12-01

    The National Waste Terminal Storage (NWTS) program of the US Department of Energy (DOE) is responsible for developing technology and providing facilities for safe, environmentally acceptable, permanent disposal of high-level nuclear waste. The Office of Nuclear Waste Isolation has been intensively investigating Gulf Coast Salt Dome Basin salt domes and bedded salt in Texas and Utah since 1978. In the Gulf Coast, the application of screening criteria in the region phase led to selection of eight domes for further study in the location phase. Further screening in the area phase identified four domes for more intensive study in the location phase: Oakwood Dome, Texas; Vacherie Dome, Louisiana; and Richton Dome and Cypress Creek Dome, Mississippi. For each dome, this Site Characterization Plan identifies specific hydrologic, geologic, tectonic, geochemical, and environmental key issues that are related to the DOE/NWTS screening criteria or affect the feasibility of constructing an exploratory shaft. The Site Characterization Plan outlines studies need to: (1) resolve issues sufficiently to allow one or more salt domes to be selected and compared to bedded salt sites in order to determine a prime salt site for an exploratory shaft; (2) conduct issue-related studies to provide a higher level of confidence that the preferred salt dome site is viable for construction of an exploratory shaft; and (3) provide a vehicle for state input to issues. Extensive references, 7 figures, 20 tables

  4. Salted fish and nasopharyngeal carcinoma in Malaysia.

    Science.gov (United States)

    Armstrong, R W; Eng, A C

    1983-01-01

    The evidence for a hypothesis that eating salted fish is associated with nasopharyngeal carcinoma (NPC) is reviewed. The hypothesis was tested among Malaysian Chinese using a matched case-control design. The kinds of salted fish and patterns of use were also investigated in a control group comprising 100 Chinese, 50 Malay and 50 Indian households. During 1980, in Selangor, Malaysia, interviews with 100 Chinese cases of NPC and 100 non-disease controls indicated that salted fish consumption during childhood was a significant risk (relative risk = 3.0, P = 0.04), with an elevated risk for daily as opposed to less frequent consumption. Salted fish consumption during adolescence was a less significant risk, and current consumption not at all. There were 19 kinds of fishes reported as being eaten as salted fish by the 200 control households. There were marked differences between ethnic groups in preference for different kinds: Chinese preferred red snapper (74% of households), Malay jewfish (54%) and Indian red snapper (28%). Salted fish was hardly ever eaten daily by any household; weekly was a moderate frequency in all ethnic groups; less than weekly most common. There were no statistically significant differences between Chinese NPC case and non-disease control participants in kind of salted fish eaten. Results were the same when the data were analyzed by sex, subethnic group and income.

  5. Spectroscopic Characterization of Omeprazole and Its Salts

    Directory of Open Access Journals (Sweden)

    Tomislav Vrbanec

    2017-01-01

    Full Text Available During drug development, it is important to have a suitable crystalline form of the active pharmaceutical ingredient (API. Mostly, the basic options originate in the form of free base, acid, or salt. Substances that are stable only within a certain pH range are a challenge for the formulation. For the prazoles, which are known to be sensitive to degradation in an acid environment, the formulation is stabilized with alkaline additives or with the application of API formulated as basic salts. Therefore, preparation and characterization of basic salts are needed to monitor any possible salinization of free molecules. We synthesized salts of omeprazole from the group of alkali metals (Li, Na, and K and alkaline earth metals (Mg, Ca. The purpose of the presented work is to demonstrate the applicability of vibrational spectroscopy to discriminate between the OMP and OMP-salt molecules. For this reason, the physicochemical properties of 5 salts were probed using infrared and Raman spectroscopy, NMR, TG, DSC, and theoretical calculation of vibrational frequencies. We found out that vibrational spectroscopy serves as an applicable spectroscopic tool which enables an accurate, quick, and nondestructive way to determine the characteristic of OMP and its salts.

  6. Modeling of Salt Solubilities in Mixed Solvents

    DEFF Research Database (Denmark)

    Chiavone-Filho, O.; Rasmussen, Peter

    2000-01-01

    A method to correlate and predict salt solubilities in mixed solvents using a UNIQUAC+Debye-Huckel model is developed. The UNIQUAC equation is applied in a form with temperature-dependent parameters. The Debye-Huckel model is extended to mixed solvents by properly evaluating the dielectric...... constants and the liquid densities of the solvent media. To normalize the activity coefficients, the symmetric convention is adopted. Thermochemical properties of the salt are used to estimate the solubility product. It is shown that the proposed procedure can describe with good accuracy a series of salt...... solubility measurements in aqueous organic solvent mixtures....

  7. Evaluation of constitutive models for crushed salt

    Energy Technology Data Exchange (ETDEWEB)

    Callahan, G.D.; Loken, M.C. [RE/SPEC, Inc., Rapid City, SD (United States); Hurtado, L.D.; Hansen, F.D.

    1996-05-01

    Three constitutive models are recommended as candidates for describing the deformation of crushed salt. These models are generalized to three-dimensional states of stress to include the effects of mean and deviatoric stress and modified to include effects of temperature, grain size, and moisture content. A database including hydrostatic consolidation and shear consolidation tests conducted on Waste Isolation Pilot Plant (WIPP) and southeastern New Mexico salt is used to determine material parameters for the models. To evaluate the capability of the models, parameter values obtained from fitting the complete database are used to predict the individual tests. Finite element calculations of a WIPP shaft with emplaced crushed salt demonstrate the model predictions.

  8. Evaluation of Allyl Isothiocyanate as a Soil Fumigant against Soil-borne Diseases in Commercial Tomato (Lycopersicon esculentum Mill.) Production in China.

    Science.gov (United States)

    Ren, Zongjie; Li, Yuan; Fang, Wensheng; Yan, Dongdong; Huang, Bin; Zhu, Jiahong; Wang, Xiaoning; Wang, Xianli; Wang, Qiuxia; Guo, Meixia; Cao, Aocheng

    2018-03-12

    Root-knot nematodes (Meloidogyne spp.), soil-borne diseases and weeds seriously reduce the commercial yield of tomatoes grown under protected cultivation in China. Allyl isothiocyanate (AITC), a natural product obtained from damaged Brassica tissues, was evaluated as a potential replacement for the fumigant methyl bromide (MB) for use in the greenhouse production of tomatoes in China. The dose-response assay indicates that AITC has high biological activity against major bacterial and fungal pathogens (EC 50 of 0.225 - 4.199 mg L -1 ). The bioassay results indicate that AITC has good efficacy against root-knot nematodes (LC 50 of 18.046 mg kg -1 ), moderate efficacy against fungal pathogens (LC 50 of 27.999 - 29.497 mg kg -1 ), and weeds (LC 50 of 17.300 - 47.660 mg kg -1 ). The potting test indicates AITC had significantly improved plant vigor. The field trials indicate that AITC showed good efficacy against Meloidogyne spp. and Fusarium spp. (both about 80%) as well as Phytophthora spp. and Pythium spp. (both about 70%), and improved plant vigor and marketable yield. AITC used as a soil fumigant (30 - 50g m -2 ) effectively controlled major bacterial and fungal pathogens, root-knot nematode, weeds and increased plant vigor, yield and farmers' income in tomato cultivated under protected agriculture in China. This article is protected by copyright. All rights reserved.

  9. Encapsulation of vanadium complexes in inorganic or hybrid matrices via the sol-gel method: application to the epoxidation of allylic alcohols

    International Nuclear Information System (INIS)

    Pellegrino, Rodolfo B.; Buffon, Regina

    2004-01-01

    Vanadium complexes have been encapsulated in inorganic (based on hydrolysis/condensation of tetramethyl orthosilicate - TMOS) and hybrid matrices (TMOS plus a co-condensation agent) using the sol-gel method. The resulting solids were tested in the epoxidation of allylic alcohols in the presence of tert-butyl hydroperoxide (TBHP) as the oxidant agent at 70 deg C. When the catalyst was based on [VO(salen)], the hybrid matrix led to higher initial turnover frequencies than the inorganic one for all tested alcohols (trans-3-phenyl-2-methyl-2-propen-1-ol, trans-2-hexen-1-ol, cis-2-hexen-1-ol, 1-octen-3-ol), which might be related to its higher pore diameter. Although no vanadium leaching was observed during the catalytic reactions, recycling experiments with the hybrid catalyst and trans-2-hexen-1-ol showed that some loss of vanadium took place at every Soxhlet washing (performed after every run, using CH 2 Cl 2 ): a total of 1.5 wt.% after three reactions. In four successive runs, keeping the initial molar ratios, conversions decreased from 100% to 85%, 65% and 40% (in 5h). (author)

  10. Extraction of allyl isothiocyanate from horseradish (Armoracia rusticana) and its fumigant insecticidal activity on four stored-product pests of paddy.

    Science.gov (United States)

    Wu, Hua; Zhang, Guo-An; Zeng, Shuiyun; Lin, Kai-chun

    2009-09-01

    Isothiocyanates (ITCs) extracted from Armoracia rusticana Gaertn., May & Scherb. have been shown previously to have insecticidal activity. Allyl isothiocyanate (AITC), a major component of ITCs with high volatility, was therefore extracted using different methods and tested as a fumigant against four major pest species of stored products, maize weevil Sitophilus zeamais (Motsch.), lesser grain borer Rhizopertha dominica (F.), Tribolium ferrugineum (F.) and book louse Liposcelis entomophila (Enderlein). Whereas there was no significant difference between hydrodistillation and supercritical carbon dioxide fluid extraction in extraction rate for AITC from A. rusticana, both methods resulted in higher extraction efficiency than water extraction. AITC fumigation showed strong toxicity to the four species of stored-product pests. Adult mortality of 100% of all four pest species, recorded after 72 h exposure to AITC fumes at an atmospheric concentration of 3 microg mL(-1), showed no significant difference from that of insects exposed to phosphine at 5 microg mL(-1), the recommended dose for phosphine. The results suggest good insecticidal efficacy of AITC against the four stored-product pests, with non-gaseous residuals on stored products. AITC obtained from A. rusticana may be an alternative to phosphine and methyl bromide against the four pest species. Copyright 2009 Society of Chemical Industry.

  11. CASSCF Calculations Reveal Competitive Chair (Pericyclic) and Boat (Pseudopericyclic) Transition States for the [3,3] Sigmatropic Rearrangement of Allyl Esters.

    Science.gov (United States)

    Kreiman, Henry W; Batali, Mackenzie E; Jamieson, Cooper S; Lyon, Molly A; Duncan, James A

    2018-02-16

    (10,8)CASPT2/6-31G**//(10,8)CASSCF/6-31G** and CCSD(T)/cc-pVDZ//(10,8)-CASSCF/6-31G** calculations have been performed on the potential surface for the [3,3] sigmatropic allyl ester rearrangements of cis-3-penten-2-yl acetate (16) to trans-3-penten-2-yl acetate (17) and 3-buten-2-yl acetate (21) to trans-2-buten-1-yl acetate (22). The results are compared to DFT (B3LYP/6-31G**) calculations on the known 16 → 17 rearrangement that reported it to be concerted and pseudopericyclic through a boat-shaped transition structure ( Birney, D. M. et al. J. Am. Chem. Soc. 2009 , 131 , 528 - 537 ). The CASSCF calculations, on the other hand, uncovered competitive concerted pathways for both the 16 → 17 and 21 → 22 rearrangements, though it was necessary to apply certain approximations in the former case. While one CASSCF pathway in each case involves a boat-shaped transition structure, similar to the one located through DFT calculations, the other pathway involves a chair-shaped transition structure. Preference for chair or boat is shown to be method dependent. Moreover, examination of the CASSCF active-space orbitals clearly confirms that the boat-shaped transition structures are pseudopericyclic but significantly also established that the chair-shaped transition structures are clearly pericyclic. Conclusions based on these results, and regarding our understanding of pericyclic vs pseudopericyclic reactions, are proffered.

  12. Catalytic enantioselective allyl- and crotylboration of aldehydes using chiral diol x SnCl4 complexes. optimization, substrate scope and mechanistic investigations.

    Science.gov (United States)

    Rauniyar, Vivek; Zhai, Huimin; Hall, Dennis G

    2008-07-02

    We report a novel class of C2-symmetric chiral diols derived from the hydrobenzoin skeleton. The combination of these diols with SnCl4 under Yamamoto's concept of Lewis acid assisted Brønsted acidity (LBA catalysis) leads to high levels of asymmetric induction in the allylboration of aldehydes by commercially available allylboronic acid pinacol ester 1a. The corresponding homoallylic alcohol products of synthetically useful aliphatic aldehydes are obtained in excellent yields with up to 98:2 er. This combined acid manifold is also efficient in catalyzing the diastereo- and enantioselective crotylboration of aldehydes, thus providing the propionate units in >95:5 dr and up to 98:2 er. The X-ray crystal structure of the optimal diol x SnCl4 complex, Vivol (4m) x SnCl4, unambiguously shows the Brønsted acidic character of this LBA catalyst and its highly dissymmetrical environment. Further controls have ruled out a possible boron trans-esterification mechanism with the chiral diol and point to LBA catalyst-derived activation of the pinacol allylic boronates 1. Due to slow dissociation of the diol x SnCl4 complex, a small excess of diol is required in order to suppress a competing racemic cycle catalyzed by free SnCl4.

  13. Reaction Behavior of Cellulose in the Homogeneous Esterification of Bagasse Modified with Phthalic Anhydride in Ionic Liquid 1-Allyl-3-methylimidazium Chloride

    Directory of Open Access Journals (Sweden)

    Hui-Hui Wang

    2016-01-01

    Full Text Available In order to elucidate the reaction behavior of cellulose component in bagasse, the homogeneous phthalation of bagasse was investigated comparatively with the isolated cellulose in 1-allyl-3-methylimidazium chloride (AmimCl with phthalic anhydride (PA at the dosage of 10–50 mmol/g. The phthalation degrees of bagasse and the isolated cellulose were in the range of 5.66% to 22.71% and 11.61% to 44.11%, respectively. A phthalation degree increase of cellulose was proportional to phthalic anhydride dosage due to its regular macromolecular structure and followed the equation yPDI=0.004x-0.02. FT-IR and 2D HSQC NMR analyses confirmed the attachment of phthaloyl group. The phthalation reactivity of the three hydroxyls in the isolated cellulose followed the order of C-6 > C-2 > C-3, and the more selective phthalation to C-6 position was found in the cellulose component in bagasse. These results provide detailed understanding of the homogenous modification mechanism of lignocellulose.

  14. In vitro antifungal activity of allyl isothiocyanate (AITC) against Aspergillus parasiticus and Penicillium expansum and evaluation of the AITC estimated daily intake.

    Science.gov (United States)

    Manyes, L; Luciano, F B; Mañes, J; Meca, G

    2015-09-01

    Isothiocyanates (ITCs) are natural compounds derived from cruciferous vegetables produced by enzymatic conversion of metabolites called glucosinolates. They are potentially useful antimicrobial compounds for food applications have been shown to be promising agents against cancer in human cell culture, animal models, and in epidemiological studies. In this study, the antifungal activity of the allyl isothiocyanate (AITC) was evaluated on two mycotoxigenic fungi as Aspergillus parasiticus and Penicillium expnsum, aflatoxins (AFs) and patulin (PAT) producers, employing an assay on solid medium. Also an approximation of the risk evaluation associated to the intake of food treated with the AITC to reduce the risk of fungi spoilage has been evaluated. On solid medium and after 20 days incubation the strain of Penicillium expansum was inhibited with AITC quantities highest than 50 mg, whereas the strain of A. parasiticus was sensible to AITC doses highest than 5 mg. The analysis of the risk assessment associated to the intake of several food classes treated with the bioactive compound AITC to prevent fungi spoilage evidenced that this product can be considered as safe due that the estimated daily intakes (EDIs) are always lower than the AITC Admissible Daily intake (ADI). Copyright © 2015 Elsevier Ltd. All rights reserved.

  15. BAIA VERDE - SLANIC PRAHOVA SALTED LAKES COMPLEX

    Directory of Open Access Journals (Sweden)

    Monica SAVA

    2009-12-01

    Full Text Available Baia Verde – Slanic Prahova Lakes Complex have been formed by water accumulation resulted out of infiltrated salted water from bell shaped surface salt mines dated XVII century (1685. Such lakes, as per their method of formation, can be also found in other places from the SubCarpathians area (Telega – Prahova, Ocnele Mari – Valcea, Transilvanian Depression (Ocna Sibiului, Turda, Sovata, Ocna Dejului, etc.. Water contact with diapires, in the places where have always existed such mining explorations and exploitation, has determined the formation of salted lakes having balneary and therapeutically qualities and sometimes the development of a heliothermic / mezothermic bed. At Slanic – Prahova besides the three lakes known as Baia Verde 1, 2 and 3, there is also the lake Baia Baciului situated at the border of “Salt Mountain” which represented the first objective for capitalization of the balnear and therapeutically potential of the area.

  16. Coordination chemistry in fused-salt solutions

    Science.gov (United States)

    Gruen, D. M.

    1969-01-01

    Spectrophotometric work on structural determinations with fused-salt solutions is reviewed. Constraints placed on the method, as well as interpretation of the spectra, are discussed with parallels drawn to aqueous spectrophotometric curves of the same materials.

  17. Immobilization of IFR salt wastes in mortar

    International Nuclear Information System (INIS)

    Fisher, D.F.; Johnson, T.R.

    1988-01-01

    Portland cement-base mortars are being considered for immobilizing chloride salt wastes from the fuel cycle of an integral fast reactor (IFR). The IFR is a sodium-cooled fast reactor with metal fuel. It has a close-coupled fuel cycle in which fission products are separated from the actinides in an electrochemical cell operating at 500 degrees C. This cell has a cadmium anode and a liquid salt electrolyte. The salt will be a low-melting mixture of alkaline and alkaline earth chlorides. This paper discusses one method being considered for immobilizing this treated salt, to disperse it in a portland cement-base motar, which would then be sealed in corrosion-resistant containers. For this application, the grout must be sufficiently fluid that it can be pumped into canisters where it will solidify into a strong, leach-resistant material

  18. Assessment of Jordanian salt using nuclear techniques

    International Nuclear Information System (INIS)

    Al-Saleh, K.A.; Arafah, D.E.; Jabr, I.J.; Saleh, N.S.

    1987-01-01

    Elemental study and concentration determinations have been conducted on Jordanian crude salt using Rutherford Back-Scattering (RBS) and X-ray Fluorescence (SRF) spectrometry techniques. Analysis have also been carried out on different purified salt samples available in the local market. The concentration of some elements, in particular bromide, content and its significance on human health and nutrition is discussed. Results reveal relatively high traces of elemental concentrations in crude salt. For example, bromide concentration ranges from 178 to 384 ppm in comparison to a tolerance limit of 30 ppm set by the Unites States Food and Drug Administration (USDA) and other International Agencies like FAO/WHO. It is suggested that refining crude salt may result in a reduction of bromide concentration and other traces considerably, thus making it feasible for human consumption

  19. Sodium: How to Tame Your Salt Habit

    Science.gov (United States)

    ... with the transition. After a few weeks of cutting back on salt, you probably won't miss ... Original article: http://www.mayoclinic.org/healthy-lifestyle/nutrition-and-healthy-eating/in-depth/sodium/art-20045479 . ...

  20. Liquid salt environment stress-rupture testing

    Science.gov (United States)

    Ren, Weiju; Holcomb, David E.; Muralidharan, Govindarajan; Wilson, Dane F.

    2016-03-22

    Disclosed herein are systems, devices and methods for stress-rupture testing selected materials within a high-temperature liquid salt environment. Exemplary testing systems include a load train for holding a test specimen within a heated inert gas vessel. A thermal break included in the load train can thermally insulate a load cell positioned along the load train within the inert gas vessel. The test specimen can include a cylindrical gage portion having an internal void filled with a molten salt during stress-rupture testing. The gage portion can have an inner surface area to volume ratio of greater than 20 to maximize the corrosive effect of the molten salt on the specimen material during testing. Also disclosed are methods of making a salt ingot for placement within the test specimen.

  1. Nitrate salt immobilization process development and implementation

    International Nuclear Information System (INIS)

    Petersen, R.D.; Johnson, A.J.; Peter, K.G.

    1986-01-01

    The waste nitrate salts generated at the Rocky Flats Plant (RFP) were determined to be unacceptable in their present form for shipment to and storage at the Nevada Test Site, according to the recently implemented Waste Acceptance Criteria. A reduction in the dispersibility and oxidizing potential of the salt was necessary. Various methods of immobilization were investigated to determine the waste form with the highest possible waste loading and the most cost effective processing. Portland cement was selected as the most effective binder (in terms of cost and performance), with a 55 wt % waste loading and a 1.5 water-to-cement ratio. A nitrate salt immobilization process has been installed in the liquid waste processing building. The process uses dry nitrate salts from the existing spray dryer, spray dryer feed solution, and Portland cement. The resulting waste grout is packaged in a plastic lined, corrugated fiberboard tri-wall box, and shipped to the Nevada Test Site for burial

  2. Oregon Salt Marshes: How Blue are They?

    Science.gov (United States)

    Two important ecosystem services of wetlands are carbon sequestration and filtration of nutrients and particulates. We quantified the carbon and nitrogen accumulation rates in salt marshes at 135 plots distributed across eight estuaries located in Oregon, USA. Net carbon and ...

  3. Plutonium and americium separation from salts

    International Nuclear Information System (INIS)

    Hagan, P.G.; Miner, F.J.

    1976-01-01

    Salts or materials containing plutonium and americium are dissolved in hydrochloric acid, heated, and contacted with an alkali metal carbonate solution to precipitate plutonium and americium carbonates which are thereafter readily separable from the solution

  4. Potential for creation of a salt dome following disposal of radioactive waste in a salt layer

    International Nuclear Information System (INIS)

    Charo, L.; Habib, P.

    1987-01-01

    The study aims at quantifying the possibility of creation of a salt dome from a salt layer in which heat-emitting radioactive waste would be buried. Volume 1 describes the results of numerical computer simulations, and of laboratory-scale models in centrifuges. Volume 2 envisages, in a geological perspective, the origin of salt domes, the mechanisms of their formation, and the associated parameters [fr

  5. SALT4: a two-dimensional displacement discontinuity code for thermomechanical analysis in bedded salt deposits

    International Nuclear Information System (INIS)

    1983-04-01

    SALT4 is a two-dimensional analytical/displacement-discontinuity code designed to evaluate temperatures, deformation, and stresses associated with underground disposal of radioactive waste in bedded salt. This code was developed by the University of Minnesota. This documentation describes the mathematical equations of the physical system being modeled, the numerical techniques utilized, and the organization of the computer code, SALT4. The SALT4 code takes into account: (1) viscoelastic behavior in the pillars adjacent to excavations; (2) transversely isotropic elastic moduli such as those exhibited by bedded or stratified rock; and (2) excavation sequence. Major advantages of the SALT4 code are: (1) computational efficiency; (2) the small amount of input data required; and (3) a creep law consistent with laboratory experimental data for salt. The main disadvantage is that some of the assumptions in the formulation of SALT4, i.e., temperature-independent material properties, render it unsuitable for canister-scale analysis or analysis of lateral deformation of the pillars. The SALT4 code can be used for parameter sensitivity analyses of two-dimensional, repository-scale, thermal and thermomechanical response in bedded salt during the excavation, operational, and post-closure phases. It is especially useful in evaluating alternative patterns and sequences of excavation or waste canister placement. SALT4 can also be used to verify fully numerical codes. This is similar to the use of analytic solutions for code verification. Although SALT4 was designed for analysis of bedded salt, it is also applicable to crystalline rock if the creep calculation is suppressed. In Section 1.5 of this document the code custodianship and control is described along with the status of verification, validation and peer review of this report

  6. Potential for creation of a salt dome following disposal of radioactive waste in a salt layer

    International Nuclear Information System (INIS)

    Fries, G.

    1987-01-01

    The study aims at quantifying the possibility of creation of a salt dome from a salt layer in which heat-emitting radioactive waste would be buried. Volume 1 describes the results of numerical computer simulations, and of laboratory-scale models in centrifuges. Volume 2 envisages, in a geological perspective, the origin of salt domes, the mechanisms of thei formation, and the associated parameters [fr

  7. Cum grano salis - NAA of selected salts

    International Nuclear Information System (INIS)

    Steinhauser, G.; Sterba, J.H.; Poljanc, K.; Bichler, M.; Buchtela, K.

    2006-01-01

    The aim of this study was to investigate the trace element concentrations of salt samples from different regions, in particular Austria, Germany, Pakistan, Poland, Switzerland, and Ukraine. Investigated types of salt were Rock-, Sea-, Lake-, and Evaporated Salt. The main objective was to find out whether the consumption of salt can contribute significantly to the daily human requirements of trace elements. Therefore, trace element concentrations in the untreated samples were compared to those of specially treated samples, simulating digestive uptake using a simple model. Salt is a non-trivial matrix for Neutron Activation Analysis (NAA) because of very high background activities from 38 Cl and 24 Na, as well as the bremsstrahlung of 32 P (originating from 35 Cl(n,α) 32 P). Because of this fact, detection limits in salt are higher compared to other matrices. Nevertheless, several elements could be detected, namely Al, Ba, Br, (Ca), Ce, Cl, Co, Cr, Cs, Eu, Fe, Hf, La, Mn, Na, Rb, Sb, Sc, Sm, Sr, Ta, Tb, Th, and Zn, some of them only in single samples. In most samples the concentrations of trace elements in salt were too low to show biological effects. Salt can therefore only significantly contribute the essential elements sodium, chlorine, and, if added on purpose, fluorine and iodine to human nutrition. The contribution of all other traces in salt to the average daily human requirements can be neglected. Thus, from an analytical point of view, there is no health reason to use unpurified salt. There are, however, a few drawbacks to the use of unpurified salt, as hygroscopic compounds like MgCl 2 , and even toxic heavy metals like chromium or thorium. Especially rare earth element (REE) concentrations can often be used to obtain a chemical fingerprint, which can be used to identify the origin of an unknown sample. In the case of this study, the sample number from each region was too small to collect significant data. Therefore more analytical information is needed

  8. Monitoring change in Great Salt Lake

    Science.gov (United States)

    Naftz, David L.; Angeroth, Cory E.; Freeman, Michael L.; Rowland, Ryan C.; Carling, Gregory

    2013-01-01

    Despite the ecological and economic importance of Great Salt Lake, only limited water quality monitoring has occurred historically. To change this, new monitoring stations and networks—gauges of lake level height and rate of inflow, moored buoys, and multiple lake-bottom sensors—will provide important information that can be used to make informed decisions regarding future management of the Great Salt Lake ecosystem.

  9. Molten salts processes and generic simulation

    International Nuclear Information System (INIS)

    Ogawa, Toru; Minato, Kazuo

    2001-01-01

    Development of dry separation process (pyrochemical process) using molten salts for the application of spent-nuclear fuel reprocessing requires a rather complete fundamental database as well as process simulation technique with wide applicability. The present report concerns recent progress and problems in this field taking behaviors of co-electrodeposition of UO 2 and PuO 2 in molten salts as an example, and using analytical simulation of local equilibrium combined with generic diffusion. (S. Ohno)

  10. Molten salts processes and generic simulation

    Energy Technology Data Exchange (ETDEWEB)

    Ogawa, Toru; Minato, Kazuo [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    2001-12-01

    Development of dry separation process (pyrochemical process) using molten salts for the application of spent-nuclear fuel reprocessing requires a rather complete fundamental database as well as process simulation technique with wide applicability. The present report concerns recent progress and problems in this field taking behaviors of co-electrodeposition of UO{sub 2} and PuO{sub 2} in molten salts as an example, and using analytical simulation of local equilibrium combined with generic diffusion. (S. Ohno)

  11. DNA nanosensor surface grafting and salt dependence

    Science.gov (United States)

    Carvalho, B. G.; Fagundes, J.; Martin, A. A.; Raniero, L.; Favero, P. P.

    2013-02-01

    In this paper we investigated the Paracoccidoides brasiliensis fungus nanosensor by simulations of simple strand DNA grafting on gold nanoparticle. In order to improve the knowledge of nanoparticle environment, the addiction of salt solution was studied at the models proposed by us. Nanoparticle and DNA are represented by economic models validated by us in this paper. In addition, the DNA grafting and salt influences are evaluated by adsorption and bond energies calculations. This theoretical evaluation gives support to experimental diagnostics techniques of diseases.

  12. Electrochemical ion separation in molten salts

    Energy Technology Data Exchange (ETDEWEB)

    Spoerke, Erik David; Ihlefeld, Jon; Waldrip, Karen; Wheeler, Jill S.; Brown-Shaklee, Harlan James; Small, Leo J.; Wheeler, David R.

    2017-12-19

    A purification method that uses ion-selective ceramics to electrochemically filter waste products from a molten salt. The electrochemical method uses ion-conducting ceramics that are selective for the molten salt cations desired in the final purified melt, and selective against any contaminant ions. The method can be integrated into a slightly modified version of the electrochemical framework currently used in pyroprocessing of nuclear wastes.

  13. Managing mainland salt marshes for breeding birds

    OpenAIRE

    Maier, Martin

    2014-01-01

    The Wadden Sea region is one of the most important breeding areas in Western Europe for coastal breeding bird species. It is expected that management of salt marshes is important for successful conservation of breeding bird populations but the impact of management on the habitat quality for breeding birds is still not fully understood. In this study the effects of management on the three crucial habitat characteristics for breeding birds were studied on mainland salt marshes: effects of manag...

  14. Salt toxicosis in waterfowl in North Dakota

    Science.gov (United States)

    Windingstad, Ronald M.; Kartch, Fred X.; Stroud, Richard K.; Smith, Milton R.

    1987-01-01

    About 150 waterfowl died and another 250 became weak and lethargic from suspected salt poisoning after using White Lake, a highly saline lake in Mountrail County, North Dakota. Frigid temperatures made fresh water unavailable, forcing the birds to ingest the saline waters with resultant toxic effects. Sick birds recovered when removed from the salt water and released into fresh water marshes. Brain sodium levels were higher in dead geese submitted for necropsy than in controls.

  15. Salt on roads and the environment (VB)

    DEFF Research Database (Denmark)

    Hessberg, Philipp von; Jørgensen, Michael Søgaard

    2000-01-01

    This report descripes the extent of use of salt on roads in Denmark and the environmental consequences of this. Alternative strategies for reducing the risk of greasy roads and different ways of alleviating the vegetation are also discussed.The different consequences for the environment that this...... that this report discusses are:- The ground water.- Lakes and streams.- Plants and trees along roads.The consequences for the economy through usage of salt on roads has not been carried out....

  16. Water and salt balance of Great Salt Lake, Utah, and simulation of water and salt movement through the causeway

    Science.gov (United States)

    Wold, Steven R.; Thomas, Blakemore E.; Waddell, Kidd M.

    1997-01-01

    The water and salt balance of Great Salt Lake primarily depends on the amount of inflow from tributary streams and the conveyance properties of a causeway constructed during 1957-59 that divides the lake into the south and north parts. The conveyance properties of the causeway originally included two culverts, each 15 feet wide, and the permeable rock-fill material.During 1980-86, the salt balance changed as a result of record high inflow that averaged 4,627,000 acre-feet annually and modifications made to the conveyance properties of the causeway that included opening a 300-foot-wide breach. In this study, a model developed in 1973 by Waddell and Bolke to simulate the water and salt balance of the lake was revised to accommodate the high water-surface altitude and modifications made to the causeway. This study, done by the U.S. Geological Survey in cooperation with the Utah Department of Natural Resources, Division of State Lands and Forestry, updates the model with monitoring data collected during 1980-86. This report describes the calibration of the model and presents the results of simulations for three hypothetical 10-year periods.During January 1, 1980, to July 31, 1984, a net load of 0.5 billion tons of dissolved salt flowed from the south to the north part of the lake primarily as a result of record inflows. From August 1, 1984, when the breach was opened, to December 31,1986, a net load of 0.3 billion tons of dissolved salt flowed from the north to the south part of the lake primarily as a result of the breach.For simulated inflow rates during a hypothetical 10-year period resulting in the water-surface altitude decreasing from about 4,200 to 4,192 feet, there was a net movement of about 1.0 billion tons of dissolved salt from the south to the north part, and about 1.7 billion tons of salt precipitated in the north part. For simulated inflow rates during a hypothetical 10-year period resulting in a rise in water-surface altitude from about 4,200 to 4

  17. Assessment of crushed salt consolidation and fracture healing processes in a nuclear waste repository in salt

    International Nuclear Information System (INIS)

    1984-11-01

    For a nuclear waste repository in salt, two aspects of salt behavior are expected to contribute to favorable conditions for waste isolation. First, consolidation of crushed salt backfill due to creep closure of the underground openings may result in a backfill barrier with low permeability. Second, fractures created in the salt by excavation may heal under the influence of stress and temperature following sealing. This report reviews the status of knowledge regarding crushed salt consolidation and fracture healing, provides analyses which predict the rates at which the processes will occur under repository conditions, and develops requirements for future study. Analyses of the rate at which crushed salt will consolidate are found to be uncertain because of unexplained wide variation in the creep properties of crushed salt obtained from laboratory testing, and because of uncertainties in predictions of long term closure rates of openings in salt. This uncertainty could be resolved to a large degree by additional laboratory testing of crushed salt. Similarly, additional testing of fracture healing processes is required to confirm that healing will be effective under repository conditions. Extensive references, 27 figures, 5 tables

  18. 238Pu recovery and salt disposition from the molten salt oxidation process

    International Nuclear Information System (INIS)

    Remerowski, M.L.; Stimmel, Jay J.; Wong, Amy S.; Ramsey, Kevin B.

    2000-01-01

    We have begun designing and optimizing our recovery and recycling processes by experimenting with samples of 'spent salt' produced by MSO treatment of surrogate waste in the reaction vessel at the Naval Surface Warfare Center-Indian Head. One salt was produced by treating surrogate waste containing pyrolysis ash spiked with cerium. The other salt contains residues from MSO treatment of materials similar to those used in 238 Pu processing, e.g., Tygon tubing, PVC bagout bags, HDPE bottles. Using these two salt samples, we will present results from our investigations

  19. 238Pu recovery and salt disposition from the molten salt oxidation process

    Science.gov (United States)

    Remerowski, M. L.; Stimmel, Jay J.; Wong, Amy S.; Ramsey, Kevin B.

    2000-07-01

    We have begun designing and optimizing our recovery and recycling processes by experimenting with samples of "spent salt" produced by MSO treatment of surrogate waste in the reaction vessel at the Naval Surface Warfare Center-Indian Head. One salt was produced by treating surrogate waste containing pyrolysis ash spiked with cerium. The other salt contains residues from MSO treatment of materials similar to those used in 238Pu processing, e.g., Tygon tubing, PVC bagout bags, HDPE bottles. Using these two salt samples, we will present results from our investigations.

  20. Autophagy Is Rapidly Induced by Salt Stress and Is Required for Salt Tolerance in Arabidopsis

    Directory of Open Access Journals (Sweden)

    Liming Luo

    2017-08-01

    Full Text Available Salinity stress challenges agriculture and food security globally. Upon salt stress, plant growth slows down, nutrients are recycled, osmolytes are produced, and reallocation of Na+ takes place. Since autophagy is a high-throughput degradation pathway that contributes to nutrient remobilization in plants, we explored the involvement of autophagic flux in salt stress response of Arabidopsis with various approaches. Confocal microscopy of GFP-ATG8a in transgenic Arabidopsis showed that autophagosome formation is induced shortly after salt treatment. Immunoblotting of ATG8s and the autophagy receptor NBR1 confirmed that the level of autophagy peaks within 30 min of salt stress, and then settles to a new homeostasis in Arabidopsis. Such an induction is absent in mutants defective in autophagy. Within 3 h of salt treatment, accumulation of oxidized proteins is alleviated in the wild-type; however, such a reduction is not seen in atg2 or atg7. Consistently, the Arabidopsis atg mutants are hypersensitive to both salt and osmotic stresses, and plants overexpressing ATG8 perform better than the wild-type in germination assays. Quantification of compatible osmolytes further confirmed that the autophagic flux contributes to salt stress adaptation. Imaging of intracellular Na+ revealed that autophagy is required for Na+ sequestration in the central vacuole of root cortex cells following salt treatment. These data suggest that rapid protein turnover through autophagy is a prerequisite for salt stress tolerance in Arabidopsis.