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Sample records for dechalcogenative allylic selenosulfide

  1. CATALYTIC ENANTIOSELECTIVE ALLYLIC OXIDATION

    NARCIS (Netherlands)

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

    1995-01-01

    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%.

  2. Regiospecific decarboxylative allylation of nitriles

    Science.gov (United States)

    Recio, Antonio; Tunge, Jon A.

    2009-01-01

    Palladium-catalyzed decarboxylative α-allylation of nitriles readily occurs using Pd2(dba)3 and rac-BINAP. This catalyst mixture also allows the highly regiospecific α-allylation of nitriles in the presence of much more acidic α-protons. Thus, the reported method provides access to compounds that are not readily available via base-mediated allylation chemistries. Lastly, mechanistic investigations indicate that there is a competition between C- and N-allylation of an intermediate nitrile-stabilized anion and that N-allylation is followed by a rapid [3,3]-sigmatropic rearrangement. PMID:19921827

  3. Allyl 4-hydroxyphenyl carbonate

    Directory of Open Access Journals (Sweden)

    Víctor Hugo Flores Ahuactzin

    2009-07-01

    Full Text Available The title molecule, C10H10O4, is a functionalized carbonate used in the synthetic route to organic glasses. The central CH fragment of the allyl group is disordered over two positions, with occupancies in a 0.758 (10:0.242 (10ratio. This disorder reflects the torsional flexibility of the oxygen–allyl group, although both disordered parts present the expected anticlinal conformation, with O—CH2—CH=CH2 torsion angles of −111 (2 and 119.1 (4°. The crystal structure is based on chains parallel to [010], formed by O...H—O hydrogen bonds involving hydroxyl and carbonyl groups as donors and acceptors, respectively. The molecular packing is further stabilized by two weak C—H...π contacts from the benzene ring of the asymmetric unit with two benzene rings of neighboring molecules.

  4. Copper-Catalyzed Enantioselective Allyl-Allyl Cross-Coupling

    NARCIS (Netherlands)

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

    2013-01-01

    A Cu(I)-phosphoramidite-based catalytic system that allows asymmetric allyl-allyl cross-coupling with high enantioselectivity is reported. This transformation tolerates a large variety of functionalized substrates. The versatility of this new reaction is illustrated in the catalytic asymmetric

  5. Preconditioning with subneurotoxic allyl nitrile: protection against allyl nitrile neurotoxicity.

    Science.gov (United States)

    Tanii, H; Higashi, T; Saijoh, K

    2010-02-01

    High-dose cruciferous allyl nitrile can induce behavioral abnormalities in rodents, while repeated exposure to allyl nitrile at subneurotoxic levels can increase phase 2 detoxification enzymes in many tissues, although the brain has not been investigated yet. In the present study, we examined the effect of 5 days repeated exposure to subneurotoxic allyl nitrile (0-400 micromol/kg/day) on the brain. Elevated glutathione S-transferase activity was recorded in the striatum, hippocampus, medulla oblongata plus pons, and cortex. Enhancement of quinone reductase activity was observed in the medulla oblongata plus pons, hippocampus, and cortex. In the medulla oblongata plus pons, elevated glutathione levels were recorded. Following repeated subneurotoxic allyl nitrile exposure (0-400 micromol/kg/day), mice were administered a high-dose allyl nitrile (1.2 mmol/kg) which alone led to appearance of behavioral abnormalities. Compared with the 0 micromol/kg/day group, animals in the 200 and 400 micromol/kg/day pre-treatment groups exhibited decreased behavioral abnormalities and elevated GABA-positive cell counts in the substantia nigra pars reticulata and the interpeduncular nucleus. These data suggest that repeated exposure to subneurotoxic levels of allyl nitrile can induce phase 2 enzymes in the brain, which together with induction in other tissues, may contribute to protection against allyl nitrile neurotoxicity. Copyright 2009 Elsevier Ltd. All rights reserved.

  6. 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.

  7. Allylation of Aromatic Aldehyde under Microwave Irradiation

    Institute of Scientific and Technical Information of China (English)

    ZHANG,Yu-Mei; JIA,Xue-Feng; WANG,Jin-Xian

    2004-01-01

    @@ Allylation of carbonyl compounds is one of the most interesting processes for the preparation of homoallylic alcohols. Over the past few decades, many reagents have been developed for such reactions[1~3]. In this paper, we first report allylic zinc reagent 1, which can be prepared from zinc dust and allyl bromide conveniently in THF, and reacted with aromatic aldehyde to give homo-allylic alcohols under microwave irradiation.

  8. Palladium-catalyzed amination of allyl alcohols.

    Science.gov (United States)

    Ghosh, Raju; Sarkar, Amitabha

    2011-10-21

    An efficient catalytic amination of aryl-substituted allylic alcohols has been developed. The complex [(η(3)-allyl)PdCl](2) modified by a bis phosphine ligand, L, has been used as catalyst in the reaction that afforded a wide range of allyl amines in good to excellent yield under mild conditions.

  9. Iridium-Catalyzed Allylic Substitution

    Science.gov (United States)

    Hartwig, John F.; Pouy, Mark J.

    Iridium-catalyzed asymmetric allylic substitution has become a valuable method to prepare products from the addition of nucleophiles at the more substituted carbon of an allyl unit. The most active and selective catalysts contain a phosphoramidite ligand possessing at least one arylethyl substituent on the nitrogen atom of the ligand. In these systems, the active catalyst is generated by a base-induced cyclometalation at the methyl group of this substituent to generate an iridium metalacycle bound by the COD ligand of the [Ir(COD)Cl]2 precursor and one additional labile dative ligand. Such complexes catalyze the reactions of linear allylic esters with alkylamines, arylamines, phenols, alcohols, imides, carbamates, ammonia, enolates and enolate equivalents, as well as typical stabilized carbon nucleophiles generated from malonates and cyanoesters. Iridium catalysts for enantioselective allylic substitution have also been generated from phosphorus ligands with substituents bound by heteroatoms, and an account of the studies of such systems, along with a description of the development of iridium catalysts is included.

  10. Allyl nitrile: Toxicity and health effects.

    Science.gov (United States)

    Tanii, Hideji

    2017-03-28

    Allyl nitrile (3-butenenitrile) occurs naturally in the environment, in particular, in cruciferous vegetables, indicating a possible daily intake of the compound. There is no report on actual health effects of allyl nitrile in humans, although it is possible that individuals in the environment are at a risk of exposure to allyl nitrile. However, little is known about its quantitative assessment for the environment and bioactivity in the body. This study provides a review of previous accumulated studies on allyl nitrile. Published literature on allyl nitrile was examined for findings on toxicity, metabolism, risk of various cancers, generation, intake estimates, and low-dose effects in the body. High doses of allyl nitrile produce toxicity characterized by behavioral abnormalities, which are considered to be produced by an active metabolite, 3,4-epoxybutyronitrile. Cruciferous vegetables have been shown to have a potential role in reducing various cancers. Hydrolysis of the glucosinolate sinigrin, rich in cruciferous vegetables, results in the generation of allyl nitrile. An intake of allyl nitrile is estimated at 0.12 μmol/kg body weight in Japan. Repeated exposure to low doses of allyl nitrile upregulates antioxidant/phase II enzymes in various tissues; this may contribute to a reduction in neurotoxicity and skin inflammation. These high and low doses are far more than the intake estimate. Allyl nitrile in the environment is a compound with diverse bioactivities in the body, characterized by inducing behavioral abnormalities at high doses and some antioxidant/phase II enzymes at low doses.

  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

    2010-01-01

    Summary 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. PMID:21283554

  13. Interplay of metal-allyl and metal-metal bonding in dimolybdenum allyl complexes

    Energy Technology Data Exchange (ETDEWEB)

    John, Kevin D [Los Alamos National Laboratory; Martin, Richard L [Los Alamos National Laboratory; Obrey, Steven J [Los Alamos National Laboratory; Scott, Brian L [Los Alamos National Laboratory

    2008-01-01

    Addition of PMe{sub 3} to Mo{sub 2}(allyl){sub 4} afforded Mo{sub 2}(allyl){sub 4}(PMe{sub 3}){sub 2}, in which two of the allyl groups adopt an unprecedented {mu}{sub 2{sup -}}{eta}{sup 1}, {eta}{sup 3} bonding mode; theoretical studies elucidate the role sof the {sigma}- and {pi}-donor ligands in the interplay of metal-allyl and metal-metal bonding.

  14. 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.

  15. Regio- and Stereospecific Formation of Protected Allylic Alcohols via Zirconium-Mediated SN2' Substitution of Allylic Chlorides

    OpenAIRE

    Fox, Richard J; Lalic, Gojko; Bergman, Robert G.

    2007-01-01

    A new, highly regio- and stereospecific SN2' substitution reaction between a zirconium oxo complex and allylic chloride has been achieved. The resulting allylic alcohol or TBS-protected allylic ether products were isolated in good to excellent yields with a wide range of E-allylic chlorides. A mechanism for the SN2' allylic substitution consistent with kinetic, stereochemical and secondary isotope effect studies was proposed.

  16. 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 ...

  17. Synthesis of 3-Allyl-4-phosphachromones by Cyclized Coupling of Ethyl o-Hydroxyphenyl(ethynyl)phosphinate with Allyl Bromide

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    3-Allyl-4-phosphachromones as the phosphorus analogues of chromone were firstly prepared in good yields and high regioselectivity by the palladium(Ⅱ)-catalyzed cyclized coupling reaction of ethyl o-hydroxyphenyl(ethynyl)-phosphinate with allyl bromide.

  18. Rh-Catalyzed Chemo- and Enantioselective Hydrogenation of Allylic Hydrazones.

    Science.gov (United States)

    Hu, Qiupeng; Hu, Yanhua; Liu, Yang; Zhang, Zhenfeng; Liu, Yangang; Zhang, Wanbin

    2017-01-23

    A highly efficient P-stereogenic diphosphine-rhodium complex was applied to the chemo- and enantioselective hydrogenation of allylic hydrazones for the synthesis of chiral allylic hydrazines in 89-96 % yields and with 82-99 % ee values. This methodology was successfully applied to the preparation of versatile chiral allylic amine derivatives.

  19. The Allyl Intermediate in Regioselective and Enantioselective Iridium-Catalyzed Asymmetric Allylic Substitution Reactions

    OpenAIRE

    Madrahimov, Sherzod T.; Markovic, Dean; Hartwig, John F.

    2009-01-01

    The isolation and structural characterization of metallacyclic allyl (2a) and crotyl (2b) iridium complexes are reported. Complexes 2a and 2b are rare examples of iriduim allyl complexes that undergo nucleophilic attack at terminal position, rather than the central position, of the allyl unit. Structures of 2a and 2b were obtained by X-ray diffraction. Nucleophilic attack was observed at the carbon that is bound to iridium trans to phosphorus through a longer Ir-C bond. However, the effect of...

  20. Elementary reaction allyl radical with oxygen

    Institute of Scientific and Technical Information of China (English)

    DONG Feng; KONG Fanao

    2003-01-01

    The elementary reaction between allyl radical with oxygen molecule wasexperimentally investigated. The allyl radical was produced via laser photolysis of C3H5Br in gaseous phase. Nascent vibrational excited products HCO, CO2, CH3CHO and HCOOH were recorded by the time- resolved Fourier transform infrared spectroscopy. The product channels of C2H5+CO2, CH3CHO+HCO, and HCOOH + C2H3 have been identified. The vibrational populations of product CO2 are obtained by spectral simulation. A mechanism forming a series of three-membered ring-struc- ture intermediates is suggested.

  1. The allyl intermediate in regioselective and enantioselective iridium-catalyzed asymmetric allylic substitution reactions.

    Science.gov (United States)

    Madrahimov, Sherzod T; Markovic, Dean; Hartwig, John F

    2009-06-03

    The isolation and structural characterization of metallacyclic allyl (2a) and crotyl (2b) iridium complexes are reported. Complexes 2a and 2b are rare examples of iriduim allyl complexes that undergo nucleophilic attack at terminal position, rather than the central position, of the allyl unit. Structures of 2a and 2b were obtained by X-ray diffraction. Nucleophilic attack was observed at the carbon that is bound to iridium trans to phosphorus through a longer Ir-C bond. However, the effect of the trans phosphine ligand on the Ir-C bond lengths was smaller than the effect of the substituent on the allyl group in 2b. The competence of complexes 2a and 2b to be intermediates in the catalytic asymmetric allylic substitutions was evaluated by studying their reactivity toward stabilized carbon and heteroatom nucleophiles and comparing the rates and selectivities to those of the catalytic reactions. The stereoselectivity and regioselectivity of stoichiometric reactions of 2b were similar to those of reactions catalyzed by the previously reported iridium catalysts, supporting their intermediacy in the catalytic reactions. On the basis of the structural data, a model is proposed for the origin of stereoselectivity in iridium-catalyzed asymmetric allylic substitution reactions.

  2. 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.

  3. 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.

  4. Catalytic Asymmetric Generation of (Z)-Disubstituted Allylic Alcohols

    OpenAIRE

    Salvi, Luca; Jeon, Sang-Jin; Fisher, Ethan L.; Carroll, Patrick J.; Walsh, Patrick J.

    2007-01-01

    A one-pot method for the direct preparation of enantioenriched (Z)-disubstituted allylic alcohols is introduced. Hydroboration of 1-halo-1-alkynes with dicyclohexylborane, reaction with t-BuLi, and transmetallation with dialkylzinc reagents generates (Z)-disubstituted vinylzinc intermediates. In situ reaction of these reagents with aldehydes in the presence of a catalyst derived from (−)-MIB generates (Z)-disubstituted allylic alcohols. It was found that the resulting allylic alcohols were ra...

  5. Cp*Co(III)-Catalyzed Dehydrative C-H Allylation of 6-Arylpurines and Aromatic Amides Using Allyl Alcohols in Fluorinated Alcohols.

    Science.gov (United States)

    Bunno, Youka; Murakami, Nanami; Suzuki, Yudai; Kanai, Motomu; Yoshino, Tatsuhiko; Matsunaga, Shigeki

    2016-05-01

    Cp*Co(III)-catalyzed C-H allylation of various aromatic C-H bonds using allyl alcohols as allylating reagents is described. Improved reaction conditions using fluorinated alcohol solvents afforded efficient directed C-H allylation of 6-arylpurines, benzamides, and a synthetically useful Weinreb amide with good functional group compatibility.

  6. Amination of allylic alcohols in water at room temperature.

    Science.gov (United States)

    Nishikata, Takashi; Lipshutz, Bruce H

    2009-06-04

    The "trick" to carrying out regiocontrolled aminations of allylic alcohols in water as the only medium is use of a nanomicelle's interior as the organic reaction solvent. When HCO(2)Me is present, along with the proper base and source of catalytic Pd, allylic amines are cleanly formed at room temperature.

  7. 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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Lopez-V, D., E-mail: dlopez@siu.buap.m [Facultad de Ciencias Quimicas, Benemerita Universidad Autonoma de Puebla, Antiguo Edificio de la Fac. de Cs., Quimica. Av. San Claudio y Boulevard de la 14 sur, Col. San Manuel, Puebla, Pue., CP 72500 (Mexico); Herrera-G, A.M., E-mail: mherrera@uaeh.reduaeh.m [Centro de Inv. en Materiales y Metalurgia, UAEH. Km 4.5, C.U., CP 42184, Pachuca de S. Hidalgo (Mexico); Castillo-Rojas, S., E-mail: castillo@nucleares.unam.m [Instituto de Ciencias Nucleares, Universidad Nacional Autonoma de Mexico, Circuito Exterior, Ciudad Universitaria, 04510 DF (Mexico)

    2011-03-15

    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 {sup 1}H NMR spectroscopy.

  9. Palladium Catalyzed Allylic C-H Alkylation

    DEFF Research Database (Denmark)

    Engelin, Casper Junker; Fristrup, Peter

    2011-01-01

    -H alkylation reaction which is the topic of the current review. Particular emphasis is put on current mechanistic proposals for the three reaction types comprising the overall transformation: C-H activation, nucleophillic addition, and re-oxidation of the active catalyst. Recent advances in C-H bond activation...... 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...

  10. Enantioselective Synthesis of All-Carbon Quaternary Stereogenic Centers via Copper-Catalyzed Asymmetric Allylic Alkylation of (Z)-Allyl Bromides with Organolithium Reagents

    NARCIS (Netherlands)

    Fananas-Mastral, Martin; Vitale, Romina; Perez, Manuel; Feringa, Ben L.

    2015-01-01

    A copper/phosphoramidite catalyzed asymmetric allylic alkylation of Z trisubstituted allyl bromides with organolithium reagents is reported. The reaction affords all-carbon quaternary stereogenic centers in high yields and very good regio- and enantioselectivity. This systematic study illustrates

  11. 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

    2009-07-02

    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 K(3)PO(4) in the presence of a metalacyclic iridium catalyst containing a labile ethylene ligand. The reactions of aryl-, heteroaryl-, and alkyl-substituted allylic carbonates with BocNH(2), FmocNH(2), CbzNH(2), TrocNH(2), TeocNH(2), and 2-oxazolidinone occur in good yields, with high selectivity for the branched isomer and high enantioselectivities (98% average ee).

  12. Chiral allylic and allenic metal reagents for organic synthesis.

    Science.gov (United States)

    Marshall, James A

    2007-10-26

    This account traces the evolution of our work on the synthesis of chiral allylic and allenic organometal compounds of tin, silicon, zinc, and indium and their application to natural product synthesis over the past quarter century.

  13. 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....

  14. 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....

  15. Copper-catalyzed regioselective allylic substitution reactions with indium organometallics.

    Science.gov (United States)

    Rodríguez, David; Sestelo, José Pérez; Sarandeses, Luis A

    2003-03-21

    The first nucleophilic allylic substitution reactions of triorganoindium compounds with allylic halides and phosphates are reported. The reactions of trialkyl- and triarylindium reagents with cinnamyl and geranyl halides and phosphates, with the aid of copper catalysis [Cu(OTf)(2)/P(OEt)(3)], are described. In general, the reaction proceeds efficiently to give good yields and regioselectively to afford the S(N)2' product.

  16. 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.

  17. Transition metal catalysed Grignard-like allylic activation across tetragonal tin(II) oxide

    Indian Academy of Sciences (India)

    Pradipta Sinha; Moloy Banerjee; Abhijit Kundu; Sujit Roy

    2002-08-01

    The reaction of allyl halide and a carbonyl compound under the aegis of tetragonal tin(II) oxide and catalytic 8, 10 metal complexes provides the corresponding homoallylic alcohol, via a novel allyl tin intermediate.

  18. Structurally defined allyl compounds of main group metals: coordination and reactivity.

    Science.gov (United States)

    Lichtenberg, Crispin; Okuda, Jun

    2013-05-10

    Organometallic allyl compounds are important as allylation reagents in organic synthesis, as polymerization catalysts, and as volatile metal precursors in material science. Whereas the allyl chemistry of synthetically relevant transition metals such as palladium and of the lanthanoids is well-established, that of main group metals has been lagging behind. Recent progress on allyl complexes of Groups 1, 2, and 12-16 now provides a more complete picture. This is based on a fundamental understanding of metal-allyl bonding interactions in solution and in the solid state. Furthermore, reactivity trends have been rationalized and new types of allyl-specific reactivity patterns have been uncovered. Key features include 1) the exploitation of the different types of metal-allyl bonding (highly ionic to predominantly covalent), 2) the use of synergistic effects in heterobimetallic compounds, and 3) the adjustment of Lewis acidity by variation of the charge of allyl compounds.

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

    African Journals Online (AJOL)

    A convenient method for lactonization of α-allyl esters using iodine in dimethyl- sulphoxide. ... KEY WORDS: γ-Butyrolactones, α-Allyl esters, Iodine, Dimethyl sulphoxide. Bull. Chem. Soc. Ethiop. 2014, 28(3) ... Article Metrics. Metrics Loading .

  20. Scalable and sustainable electrochemical allylic C-H oxidation

    Science.gov (United States)

    Horn, Evan J.; Rosen, Brandon R.; Chen, Yong; Tang, Jiaze; Chen, Ke; Eastgate, Martin D.; Baran, Phil S.

    2016-05-01

    New methods and strategies for the direct functionalization of C-H bonds are beginning to reshape the field of retrosynthetic analysis, affecting the synthesis of natural products, medicines and materials. The oxidation of allylic systems has played a prominent role in this context as possibly the most widely applied C-H functionalization, owing to the utility of enones and allylic alcohols as versatile intermediates, and their prevalence in natural and unnatural materials. Allylic oxidations have featured in hundreds of syntheses, including some natural product syntheses regarded as “classics”. Despite many attempts to improve the efficiency and practicality of this transformation, the majority of conditions still use highly toxic reagents (based around toxic elements such as chromium or selenium) or expensive catalysts (such as palladium or rhodium). These requirements are problematic in industrial settings; currently, no scalable and sustainable solution to allylic oxidation exists. This oxidation strategy is therefore rarely used for large-scale synthetic applications, limiting the adoption of this retrosynthetic strategy by industrial scientists. Here we describe an electrochemical C-H oxidation strategy that exhibits broad substrate scope, operational simplicity and high chemoselectivity. It uses inexpensive and readily available materials, and represents a scalable allylic C-H oxidation (demonstrated on 100 grams), enabling the adoption of this C-H oxidation strategy in large-scale industrial settings without substantial environmental impact.

  1. Catalytic asymmetric generation of (Z)-disubstituted allylic alcohols.

    Science.gov (United States)

    Salvi, Luca; Jeon, Sang-Jin; Fisher, Ethan L; Carroll, Patrick J; Walsh, Patrick J

    2007-12-26

    A one-pot method for the direct preparation of enantioenriched (Z)-disubstituted allylic alcohols is introduced. Hydroboration of 1-halo-1-alkynes with dicyclohexylborane, reaction with t-BuLi, and transmetalation with dialkylzinc reagents generate (Z)-disubstituted vinylzinc intermediates. In situ reaction of these reagents with aldehydes in the presence of a catalyst derived from (-)-MIB generates (Z)-disubstituted allylic alcohols. It was found that the resulting allylic alcohols were racemic, most likely due to a rapid addition reaction promoted by LiX (X = Br and Cl). To suppress the LiX-promoted reaction, a series of inhibitors were screened. It was found that 20-30 mol % tetraethylethylenediamine inhibited LiCl without inhibiting the chiral zinc-based Lewis acid. In this fashion, (Z)-disubstituted allylic alcohols were obtained with up to 98% ee. The asymmetric (Z)-vinylation could be coupled with tandem diastereoselective epoxidation reactions to provide epoxy alcohols and allylic epoxy alcohols with up to three contiguous stereogenic centers, enabling the rapid construction of complex building blocks with high levels of enantio- and diastereoselectivity.

  2. Catalytic Enantioselective Allylic Amination of Olefins for the Synthesis of ent-Sitagliptin.

    Science.gov (United States)

    Bao, Hongli; Bayeh, Liela; Tambar, Uttam K

    2013-11-01

    The presence of nitrogen atoms in most chiral pharmaceutical drugs has motivated the development of numerous strategies for the synthesis of enantioenriched amines. Current methods are based on the multi-step transformation of pre-functionalized allylic electrophiles into chiral allylic amines. The enantioselective allylic amination of unactivated olefins represents a more direct and attractive strategy. We report the enantioselective synthesis of ent-sitagliptin via an allylic amination of an unactivated terminal olefin.

  3. 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-CF3-substituted allylic carbonate is described. This reaction provides direct access to linear CF3-allyl frameworks with complete trans-selectivity. In particular, a rhodium catalyst provided Heck-type γ-CF3-allylation products via the β-O-elimination of rhodacycle intermediate and subsequent olefin migration process.

  4. A convenient procedure for the synthesis of allyl and benzyl ethers from alcohols and phenols

    Indian Academy of Sciences (India)

    H Surya Prakash Rao; S P Senthilkumar

    2001-06-01

    Allyl and benzyl ethers of alcohols can be prepared conveniently and in high yield with allyl and benzyl bromide in the presence of solid potassium hydroxide without use of any solvent. Phenols can be converted to allyl ethers but are inert to benzylation under above conditions.

  5. 40 CFR 721.7000 - Polymer of disodium maleate, allyl ether, and ethylene oxide.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Polymer of disodium maleate, allyl... New Uses for Specific Chemical Substances § 721.7000 Polymer of disodium maleate, allyl ether, and... substance identified generically as a polymer of disodium maleate, allyl ether, and ethylene oxide (P-91...

  6. Titanium-promoted Allyl Transfer to Carbon Monoxide and Other Unsaturated Molecules

    NARCIS (Netherlands)

    Klei, Bert; Teuben, Jan H.; Liefde Meijer, Henk J. de

    1981-01-01

    Carbonylation of Cp2Ti-(π-allyl) yields Cp2Ti(CO)2 and triallylmethanol; reactions of Cp2Ti-(π-allyl) and Cp2Ti-(π-1-methylallyl) with other ligands proceed via insertion or allyl-elimination pathways.

  7. PHOTOINDUCED GRAFTING OF ACRYLIC AND ALLYL MONOMERS ON POLYETHYLENE SURFACE

    Institute of Scientific and Technical Information of China (English)

    ZHANG Zhenfeng; HU Xingzhou; YAN Qing

    1995-01-01

    Photoinduced grafting of acrylic and allyl monomers on polyethylene surface was generally studied by using benzophenone (BP) as a photoinitiator. The grafting process was carried out either in vapor-phase or in solution of the monomers. In the vapor-phase reaction with a filter used to cut off the short wavelength UV light, allyl amine is the most reactive of the four monomers used and acrylic amide is comparatively more reactive than acrylic acid and allyl alcohol. Acetone, as a solvent and carrier for initiator and monomers, however, shows its reactivity to participate the reaction. The solution grafting with a filter is much faster than the corresponding vapor-phase reaction, and a fully covered surface by the grafted polymer can be achieved in this way.

  8. Direct activation of allylic alcohols in palladium catalyzed coupling reactions

    OpenAIRE

    Gümrükçü, Y.

    2014-01-01

    The direct use of allylic alcohols in substitution reactions without pre-activation of the hydroxyl-group into a better leaving group or the use of additional stoichiometric in situ activators remains challenging due to the poor leaving group ability of the hydroxyl-group. Hence, it is important to develop new methods to activate (bio-mass derived) allyl-alcohols, which allow ‘green’ chemical processes for a broad substrate range. This may have a considerable impact on the methodology for fin...

  9. Direct activation of allylic alcohols in palladium catalyzed coupling reactions

    NARCIS (Netherlands)

    Gümrükçü, Y.

    2014-01-01

    The direct use of allylic alcohols in substitution reactions without pre-activation of the hydroxyl-group into a better leaving group or the use of additional stoichiometric in situ activators remains challenging due to the poor leaving group ability of the hydroxyl-group. Hence, it is important to

  10. Sulfonium-based Ionic Liquids Incorporating the Allyl Functionality

    Directory of Open Access Journals (Sweden)

    Paul J. Dyson

    2007-04-01

    Full Text Available A series of sulfonium halides bearing allyl groups have been prepared andcharacterized. Anion metathesis with Li[Tf2N] and Ag[N(CN2] resulted in sulfonium-basedionic liquids which exhibit low viscosities at room temperature. The solid state structure ofone of the halide salts was determined by single crystal X-ray diffraction.

  11. Single pulse shock tube study of allyl radical recombination.

    Science.gov (United States)

    Fridlyand, Aleksandr; Lynch, Patrick T; Tranter, Robert S; Brezinsky, Kenneth

    2013-06-13

    The recombination and disproportionation of allyl radicals has been studied in a single pulse shock tube with gas chromatographic measurements at 1-10 bar, 650-1300 K, and 1.4-2 ms reaction times. 1,5-Hexadiene and allyl iodide were used as precursors. Simulation of the results using derived rate expressions from a complementary diaphragmless shock tube/laser schlieren densitometry study provided excellent agreement with precursor consumption and formation of all major stable intermediates. No significant pressure dependence was observed at the present conditions. It was found that under the conditions of these experiments, reactions of allyl radicals in the cooling wave had to be accounted for to accurately simulate the experimental results, and this unusual situation is discussed. In the allyl iodide experiments, higher amounts of allene, propene, and benzene were found at lower temperatures than expected. Possible mechanisms are discussed and suggest that iodine containing species are responsible for the low temperature formation of allene, propene, and benzene.

  12. Electrochemical Allylic Oxidation of Olefins: Sustainable and Safe.

    Science.gov (United States)

    Waldvogel, Siegfried R; Selt, Maximilian

    2016-10-01

    The power you're supplying: With the application of an optimized electrochemical approach, the allylic oxidation of olefins, which is an important C-H activation process that provides access to enones, becomes a sustainable, versatile, and potent key reaction for organic synthesis.

  13. 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.

  14. Radiation initiated copolymerization of allyl alcohol with acrylonitrile

    Energy Technology Data Exchange (ETDEWEB)

    Solpan, Dilek; Guven, Olgun [Hacettepe Univ., Ankara (Turkey). Dept. of Chemistry

    1996-07-01

    Copolymerization of allyl alcohol (AA) with acrylonitrile (AN) initiated by {gamma}-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).

  15. Radiation initiated copolymerization of allyl alcohol with acrylonitrile

    Science.gov (United States)

    Şolpan, Dilek; Güven, Olgun

    1996-07-01

    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-Tüdös (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.

  16. 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.

  17. Rh2(esp)2-catalyzed allylic and benzylic oxidations.

    Science.gov (United States)

    Wang, Yi; Kuang, Yi; Wang, Yuanhua

    2015-04-07

    The dirhodium(II) catalyst Rh2(esp)2 allows direct solvent-free allylic and benzylic oxidations by T-HYDRO with a remarkably low catalyst loading. This method is operationally simple and scalable at ambient temperature without the use of any additives. The high catalyst stability in these reactions may be attributed to a dirhodium(II,II) catalyst resting state, which is less prone to decomposition.

  18. Gold(I)-Assisted α-Allylation of Enals and Enones with Alcohols.

    Science.gov (United States)

    Mastandrea, Marco Michele; Mellonie, Niall; Giacinto, Pietro; Collado, Alba; Nolan, Steven P; Miscione, Gian Pietro; Bottoni, Andrea; Bandini, Marco

    2015-12-01

    The intermolecular α-allylation of enals and enones occurs by the condensation of variously substituted allenamides with allylic alcohols. Cooperative catalysis by [Au(ItBu)NTf2] and AgNTf2 enables the synthesis of a range of densely functionalized α-allylated enals, enones, and acyl silanes in good yield under mild reaction conditions. DFT calculations support the role of an α-gold(I) enal/enone as the active nucleophilic species.

  19. An Unexpected Reaction of Allylic Propynoate under Palladium(Ⅱ) Catalysis

    Institute of Scientific and Technical Information of China (English)

    ZHANG,Zhao-Guo(张兆国); LU,Xi-Yan(陆熙炎); LANG,Shen-Hui(郎深慧)

    2002-01-01

    Palladium (Ⅱ) catalyzed reactions of allyl propynoate in the presence of excess halide ions with or without allyl halide or acrolein were studied, yielding (E)-3-halo-2-allyl-acrylic acid as the sole product. A mechanism involving halopalladation, carbopalladation, ring opening and β-heteroatom elimination was prioposed and was further justified by the reaction with deuterated substrate.keywords palladium, enyne, halopalladation, carbopalladation,β-heteroatom elimination was proposed and was further justified by the reaction with deuterated substrate.

  20. Silver-Catalyzed Decarboxylative Allylation of Aliphatic Carboxylic Acids in Aqueous Solution.

    Science.gov (United States)

    Cui, Lei; Chen, He; Liu, Chao; Li, Chaozhong

    2016-05-06

    Direct decarboxylative radical allylation of aliphatic carboxylic acids is described. With K2S2O8 as the oxidant and AgNO3 as the catalyst, the reactions of aliphatic carboxylic acids with allyl sulfones in aqueous CH3CN solution gave the corresponding alkenes in satisfactory yields under mild conditions. This site-specific allylation method is applicable to all primary, secondary, and tertiary alkyl acids and exhibits wide functional group compatibility.

  1. Allyl strontium compounds: synthesis, molecular structure and properties.

    Science.gov (United States)

    Jochmann, Phillip; Davin, Julien P; Maslek, Stefanie; Spaniol, Thomas P; Sarazin, Yann; Carpentier, Jean-Francois; Okuda, Jun

    2012-08-14

    The synthesis and attempted isolation of neutral bis(allyl)strontium [Sr(C(3)H(5))(2)] (1) resulted in the isolation of potassium tris(allyl)strontiate K[Sr(C(3)H(5))(3)] (2). In situ generated 1 shows a pronounced Brønsted basicity, inducing polymerisation of THF. Ate complex 2 crystallises as [K(THF)(2){Sr(C(3)H(5))(3)}(THF)](∞) (2·(THF)(3)). The salt-like solid state structure of 2·(THF)(3) comprises a two-dimensional network of (μ(2)-η(3):η(3)-C(3)H(5))(-) bridged potassium and strontium centres. Synthesis of allyl complexes 1 and 2 utilised SrI(2), [Sr(TMDS)(2)] (3) (TMDS = tetramethyldisilazanide), and [Sr(HMDS)(2)] (HMDS = hexamethyldisilazanide) as strontium precursors. The solid state structure of previously reported [Sr(TMDS)(2)] (3) was established by X-ray single crystal analysis as a dissymmetric dimer of [Sr(2)(TMDS)(4)(THF)(3)] (3·(THF)(3)) with multiple Si-HSr agostic interactions. The presence of ether ligands (THF, 18-crown-6) influenced the Si-HSr resonances in the NMR spectra of the amido complex 3.

  2. Catalyst-free synthesis of skipped dienes from phosphorus ylides, allylic carbonates, and aldehydes via a one-pot SN2' allylation-Wittig strategy.

    Science.gov (United States)

    Xu, Silong; Zhu, Shaoying; Shang, Jian; Zhang, Junjie; Tang, Yuhai; Dou, Jianwei

    2014-04-18

    A catalyst-free allylic alkylation of stabilized phosphorus ylides with allylic carbonates via a regioselective SN2' process is presented. Subsequent one-pot Wittig reaction with both aliphatic and aromatic aldehydes as well as ketenes provides structurally diverse skipped dienes (1,4-dienes) in generally high yields and moderate to excellent stereoselectivity with flexible substituent patterns. This one-pot SN2' allylation-Wittig strategy constitutes a convenient and efficient synthetic method for highly functionalized skipped dienes from readily available starting materials.

  3. Memory effects in palladium-catalyzed allylic Alkylations of 2-cyclohexen-1-yl acetate

    DEFF Research Database (Denmark)

    Svensen, Nina; Fristrup, Peter; Tanner, David Ackland

    2007-01-01

    The objective of this work was to characterize the enantiospecificity of the allylic alkylation of enantioenriched 2-cyclohexen-1-yl acetate with the enolate ion of dimethyl malonate catalyzed by unsymmetrical palladium catalysts. The precatalysts employed were (eta(3)-allyl)PdLCl, where L...

  4. Corn oil and milk enhance the absorption of orally administered allyl isothiocyanate in rats.

    Science.gov (United States)

    Ippoushi, Katsunari; Ueda, Hiroshi; Takeuchi, Atsuko

    2013-11-15

    Allyl isothiocyanate, a chief component of mustard oil, exhibits anticancer effects in both cultured cancer cells and animal models. The accumulation of the N-acetylcysteine conjugate of allyl isothiocyanate, the final metabolite of allyl isothiocyanate, in urine was evaluated in rats that were orally coadministered allyl isothiocyanate with fluids (e.g., water, green tea, milk, and 10% ethanol) or corn oil. The N-acetylcysteine conjugate of allyl isothiocyanate content in urine when allyl isothiocyanate (2 or 4μmol) was coadministered with corn oil or milk showed a greater increase (1.4±0.22 or 2.7±0.34μmol or 1.2±0.32 or 2.5±0.36μmol, 1.6- to 1.8-fold or 1.5-fold, respectively) than when allyl isothiocyanate (2 or 4μmol) was coadministered with water (0.78±0.10 or 1.7±0.17μmol). This result demonstrates that corn oil and milk enhance the absorption of allyl isothiocyanate in rats.

  5. 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.

  6. 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.

  7. P ' CP '-Pincer palladium complex-catalyzed allylation of N,N-dimethylsulfamoyl-protected aldimines

    NARCIS (Netherlands)

    Li, Jie; Minnaard, Adriaan J.; Gebbink, Robertus J. M. Klein; van Koten, Gerard

    2009-01-01

    The P'CP'-pincer palladium complex-catalyzed allylation of N,N-dimethylsulfamoyl-protected aldimines with allyl(tributyl)stannane is investigated for the preparation of N-homoallylic sulfamides. The desired N,N-dimethylsulfamoyl-protected products are obtained in moderate to high yields in DMF under

  8. Reactivity of Phenol Allylation Using Phase-Transfer Catalysis in Ion-Exchange Membrane Reactor

    Directory of Open Access Journals (Sweden)

    Ho Shing Wu

    2012-01-01

    Full Text Available This study investigates the reactivity of phenol allylation using quaternary ammonium salt as a phase-transfer catalyst in three types of membrane reactors. Optimum reactivity and turnover of phenol allylation were obtained using a respond surface methodology. The contact angle, water content, and degree of crosslinkage were measured to understand the microenvironment in the ion exchange membrane.

  9. Copper-Catalyzed SN2'-Selective Allylic Substitution Reaction of gem-Diborylalkanes.

    Science.gov (United States)

    Zhang, Zhen-Qi; Zhang, Ben; Lu, Xi; Liu, Jing-Hui; Lu, Xiao-Yu; Xiao, Bin; Fu, Yao

    2016-03-04

    A Cu/(NHC)-catalyzed SN2'-selective substitution reaction of allylic electrophiles with gem-diborylalkanes is reported. Different substituted gem-diborylalkanes and allylic electrophiles can be employed in this reaction, and various synthetic valuable functional groups can be tolerated. The asymmetric version of this reaction was initially researched with chiral N-heterocyclic carbene (NHC) ligands.

  10. Green Synthesis and Regioselective Control of Sn/I2 Mediated Allylation of Carbonyl Compounds with Crotyl Halide in Water

    Institute of Scientific and Technical Information of China (English)

    ZHANG,Yan; ZHA,Zhang-Gen; ZHOU,Yu-Qing; WANG,Zhi-Yong

    2004-01-01

    @@ Barbier-type carbonyl allylation is particularly useful due to ease of operation and the availability and tractability of allylic substrates,[1] Metals such as indium, zinc and tin are often used as the mediator. Here we present a green approach toward the synthesis, that is, Sn/I2 mediated allylation of carbonyl compounds with crotyl halide in water.

  11. Construction of an Asymmetric Quaternary Carbon Center via Allylation of Hydrazones

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jin Bum; Satyender, Apuri; Jang, Doo Ok [Yonsei Univ., Wonju (Korea, Republic of)

    2013-11-15

    Asymmetric indium-mediated allylation of imine derivatives bearing a chiral auxiliary is a reliable strategy for the synthesis of chiral homoallylic amines. Various techniques for indium-mediated stereoselective allylation of imines bearing a chiral auxiliary have been reported. In 1997 Loh and co-workers reported indium-mediated allylation with imines derived from L-valine methyl ester. Since then, many forms of indium-mediated allylation bearing a chiral auxiliary have been reported, including imines derived from (S)-valinol, (R)-phenylglycinol, uracil, (R)-phenylglycinol methyl ester, N-tert-butanesufinamide, and (1R,2S)-1-amino-2-indanol. However, the synthesis of chiral auxiliaries often involves a laborious multi-step synthesis with expensive reagents. Therefore, the development of readily accessible chiral auxiliaries for asymmetric indium-mediated all-ylation is in high demand.

  12. Palladium Catalyzed Allylic C-H Alkylation: A Mechanistic Perspective

    Directory of Open Access Journals (Sweden)

    Casper Junker Engelin

    2011-01-01

    Full Text Available The atom-efficiency of one of the most widely used catalytic reactions for forging C-C bonds, the Tsuji-Trost reaction, is limited by the need of preoxidized reagents. This limitation can be overcome by utilization of the recently discovered palladium-catalyzed C-H activation, the allylic C-H alkylation reaction which is the topic of the current review. Particular emphasis is put on current mechanistic proposals for the three reaction types comprising the overall transformation: C-H activation, nucleophillic addition, and re-oxidation of the active catalyst. Recent advances in C-H bond activation are highlighted with emphasis on those leading to C-C bond formation, but where it was deemed necessary for the general understanding of the process closely related C-H oxidations and aminations are also included. It is found that C-H cleavage is most likely achieved by ligand participation which could involve 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 of the benzoquinone/hydroquinone redox couple. Alternative methods for re-oxidation that does not rely on benzoquinone could be able to alleviate this limitation.

  13. Allylation of intraerythrocytic hemoglobin by raw garlic extracts.

    Science.gov (United States)

    Bonaventura, Joseph; Rodriguez, Eva N; Beyley, Veronica; Vega, Irving E

    2010-08-01

    Recent studies have shown that deoxygenated human red blood cells (RBCs) converted garlic-derived polysulfides into hydrogen sulfide, which in turn produced vasorelaxation in aortic ring preparations. The vasoactivity was proposed to occur via glucose- and thiol-dependent acellular reactions. In the present study, we investigated the interaction of garlic extracts with human deoxygenated RBCs and its effect on intracellular hemoglobin molecules. The results showed that garlic extract covalently modified intraerythrocytic deoxygenated hemoglobin. The modification identified consisted of an addition of 71 atomic mass units, suggesting allylation of the cysteine residues. Consistently, purified human deoxyhemoglobin reacted with chemically pure diallyl disulfide, showing the same modification as garlic extracts. Tandem mass spectrometry analysis demonstrated that garlic extract and diallyl disulfide modified hemoglobin's beta-chain at cysteine-93 (beta-93C) or cysteine-112 (beta-112C). These results indicate that garlic-derived organic disulfides as well as pure diallyl disulfide must permeate the RBC membrane and modified deoxyhemoglobin at beta-93C or beta-112C. Although the physiological role of the reported garlic extract-induced allyl modification on human hemoglobin warrants further study, the results indicate that constituents of natural products, such as those from garlic extract, modify intracellular proteins.

  14. Do garlic-derived allyl sulfides scavenge peroxyl radicals?

    Science.gov (United States)

    Amorati, Riccardo; Pedulli, Gian Franco

    2008-03-21

    The chain-breaking antioxidant activities of two garlic-derived allyl sulfides, i.e. diallyl disulfide (1), the main component of steam-distilled garlic oil, and allyl methyl sulfide (3) were evaluated by studying the thermally initiated autoxidation of cumene or styrene in their presence. Although the rate of cumene oxidation was reduced by addition of both 1 and 3, the dependence on the concentration of the two sulfides could not be explained on the basis of the classic antioxidant mechanism as with phenolic antioxidants. The rate of oxidation of styrene, on the other hand, did not show significant changes upon addition of either 1 or 3. This unusual behaviour was explained in terms of the co-oxidant effect, consisting in the decrease of the autoxidation rate of a substrate forming tertiary peroxyl radicals (i.e. cumene) upon addition of little amounts of a second oxidizable substrate giving rise instead to secondary peroxyl radicals. The relevant rate constants for the reaction of ROO(.) with 1 and 3 were measured as 1.6 and 1.0 M(-1) s(-1), respectively, fully consistent with the H-atom abstraction from substituted sulfides. It is therefore concluded that sulfides 1 and 3 do not scavenge peroxyl radicals and therefore cannot be considered chain-breaking antioxidants.

  15. Preparation of Stereodefined Homoallylic Amines from the Reductive Cross-Coupling of Allylic Alcohols with Imines

    Science.gov (United States)

    Chen, Ming Z.; McLaughlin, Martin; Takahashi, Masayuki; Tarselli, Michael A.; Yang, Dexi; Umemura, Shuhei; Micalizio, Glenn C.

    2010-01-01

    Regio-, diastereo-, and enantioselective coupling reactions between imines and allylic alcohols have been developed. These coupling reactions deliver complex homoallylic amine products through a convergent C–C bond forming process that does not proceed through intermediate allylic organometallic reagents. In general, convergent coupling, by exposure of an allylic alkoxide to a preformed Ti–imine complex, occurs with allylic transposition in a predictable and stereocontrolled manner. While simple diastereoselection in these reactions is high, delivering anti-products with ≥ 20:1 selectivity, the organometallic transformation described is compatible with a diverse range of functionality and substrates (including: aliphatic and aromatic imines, allylic silanes, trisubstituted alkenes, vinyl- and aryl halides, trifluoromethyl groups, thioethers, and aromatic heterocycles). Alkene geometry of the products is a complex function of the allylic alcohol structure, and is consistent with a mechanistic proposal based on syn-carbometalation followed by syn-elimination by way of a boat-like transition state geometry. Single asymmetric coupling reactions provide a means to translate the stereochemical information of the allylic alcohol to the homoallylic amine with very high levels of fidelity, or to control diastereoselection in the coupling reactions of achiral allylic alcohols with chiral imines. Double asymmetric coupling reactions are also described that afford a unique means to control stereoselection in these complex convergent coupling processes. Finally, empirical models are proposed that are consistent with the observed stereochemical course of these coupling reactions en route to chiral homoallylic amines possessing di- or trisubstituted alkenes, and anti- or syn- relative stereochemistry at the allylic and homoallylic positions. Overall, the bond construction enabled by this Ti-mediated reductive cross-coupling is unmatched by available methods in organic

  16. A Mechanistic Study of Direct Activation of Allylic Alcohols in Palladium Catalyzed Amination Reactions

    OpenAIRE

    Yasemin Gumrukcu; Bas de Bruin; Reek, Joost N. H.

    2015-01-01

    We here report a computational approach on the mechanism of allylicamination reactions using allyl-alcohols and amines as the substrates and phosphoramidite palladium catalyst 1a, which operates in the presence of catalytic amount of 1,3-diethylurea as a co-catalyst. DFT calculations showed a cooperative hydrogen-bonding array between the urea moiety and the hydroxyl group of the allyl alcohol, which strengthens the hydrogen bond between the O-H moiety of the coordinated allyl-alcohol and th...

  17. Highly stereoselective synthesis of functionalized 1,3-dienes from a new allyl bromide

    Directory of Open Access Journals (Sweden)

    Asma Fray

    2014-05-01

    Full Text Available New and highly functionalized 1,3-dienes 3 and 4 have been synthesized via two different pathways starting from allyl bromide 1. Firstly, the reaction of allyl bromide 1 with triethylphosphite leads to an allylphosphonate 2, which undergoes the Wittig-Horner reaction with a range of saturated and unsaturated aldehydes gives rise to the corresponding 1,3-dienes 3. Secondly, a highly stereoselective reaction between allyl bromide 1 and nitroalkane salts, offers the possibility to obtaining functionalized (E-1,3-dienes 4.

  18. Highly selective allylborations of aldehydes using α,α-disubstituted allylic pinacol boronic esters.

    Science.gov (United States)

    Hesse, Matthew J; Essafi, Stéphanie; Watson, Charlotte G; Harvey, Jeremy N; Hirst, David; Willis, Christine L; Aggarwal, Varinder K

    2014-06-10

    α,α-Disubstituted allylic pinacol boronic esters undergo highly selective allylborations of aldehydes to give tetrasubstituted homoallylic alcohols with exceptional levels of anti-Z-selectivity (>20:1). The scope of the reaction includes both acyclic and cyclic allylic boronic esters which lead to acyclic and exocyclic tetrasubstituted homoallylic alcohols. The use of β-borylated allylic boronic esters gave fully substituted alkenes bearing a boronic ester which underwent further cross-coupling enabling a highly modular and stereoselective approach to the synthesis of diaryl tetrasubstituted alkenes. Computational analysis revealed the origin of the remarkable selectivity observed. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. Chemoselective allylation of ketones in ionic liquids containing sulfonate anions.

    Science.gov (United States)

    Galletti, Paola; Moretti, Fabio; Samorì, Chiara; Tagliavini, Emilio

    2009-01-01

    The chemoselective addition of tetraallyltin to dialkyl, alkenyl-alkyl, and alkynyl-alkyl ketones can be performed with high yields in N-methyl-N-butylpyrrolidinium trifuoromethansulfonate (MBP-Tf). Other room temperature ionic liquids (RTILs) can also be successfully employed if some sulfonic acid is added. The reaction is very sensitive to the electronic properties of the substrate. Aryl alkyl ketones bearing electron-withdrawing substituents behave like dialkyl ketones and react promptly; on the contrary, electron-rich aryl alkyl ketones react sluggishly, which allows selective competitive allylation of dialkyl substrates to occur. The ionic liquid solvent can be easily recycled, which meets the green chemistry principles of selectivity and reuse of chemicals. NMR spectroscopic data support the formation of tin-triflate catalysts in situ.

  20. Sequence-defined polymers via orthogonal allyl acrylamide building blocks.

    Science.gov (United States)

    Porel, Mintu; Alabi, Christopher A

    2014-09-24

    Biological systems have long recognized the importance of macromolecular diversity and have evolved efficient processes for the rapid synthesis of sequence-defined biopolymers. However, achieving sequence control via synthetic methods has proven to be a difficult challenge. Herein we describe efforts to circumvent this difficulty via the use of orthogonal allyl acrylamide building blocks and a liquid-phase fluorous support for the de novo design and synthesis of sequence-specific polymers. We demonstrate proof-of-concept via synthesis and characterization of two sequence-isomeric 10-mer polymers. (1)H NMR and LCMS were used to confirm their chemical structure while tandem MS was used to confirm sequence identity. Further validation of this methodology was provided via the successful synthesis of a sequence-specific 16-mer polymer incorporating nine different monomers. This strategy thus shows promise as an efficient approach for the assembly of sequence-specific functional polymers.

  1. Aerobic Linear Allylic C-H Amination: Overcoming Benzoquinone Inhibition.

    Science.gov (United States)

    Pattillo, Christopher C; Strambeanu, Iulia I; Calleja, Pilar; Vermeulen, Nicolaas A; Mizuno, Tomokazu; White, M Christina

    2016-02-03

    An efficient aerobic linear allylic C-H amination reaction is reported under palladium(II)/bis-sulfoxide/Brønsted base catalysis. The reaction operates under preparative, operationally simple conditions (1 equiv of olefin, 1 atm O2 or air) with reduced Pd(II)/bis-sulfoxide catalyst loadings while providing higher turnovers and product yields than systems employing stoichiometric benzoquinone (BQ) as the terminal oxidant. Pd(II)/BQ π-acidic interactions have been invoked in various catalytic processes and are often considered beneficial in promoting reductive functionalizations. When such electrophilic activation for functionalization is not needed, however, BQ at high concentrations may compete with crucial ligand (bis-sulfoxide) binding and inhibit catalysis. Kinetic studies reveal an inverse relationship between the reaction rate and the concentration of BQ, suggesting that BQ is acting as a ligand for Pd(II) which results in an inhibitory effect on catalysis.

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

    Science.gov (United States)

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

    2013-06-01

    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 1H 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.

  3. Facile synthesis of allyl resinate monomer in an aqueous solution under microwave irradiation

    Indian Academy of Sciences (India)

    Yanju Lu; Mixia Wang; Zhendong Zhao; Yuxiang Chen; Shichao Xu; Jing Wang; Liangwu Bi

    2015-07-01

    We have developed a facile method for production of allyl resinate monomer (allyl rosin ester) via a phase transfer reaction under microwave irradiation. The synthesis of allyl resinate was conducted using allyl chloride and sodium resinate as starting materials in aqueous solution at 50°C for 30 min with a yield of 94.7%, which is 20% higher than conventional heating method. The products precipitated spontaneously from the aqueous phase after reaction, which significantly facilitated the subsequent separation of monomer products. The synthesized monomer product appeared as a viscous liquid, with a viscosity of 460 mPa·s at 25°C and a density of 1.0469 g/cm3. The physical and chemical properties suggested that the synthesized monomer has great potential for free radical polymerization.

  4. 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...

  5. Origins of Enantioselectivity during Allylic Substitution Reactions Catalyzed by Metallacyclic Iridium Complexes

    OpenAIRE

    Madrahimov, Sherzod T.; Hartwig, John F.

    2012-01-01

    In depth mechanistic studies of iridium catalyzed regioselective and enantioselective allylic substitution reactions are presented. A series of cyclometallated allyliridium complexes that are kinetically and chemically competent to be intermediates in the allylic substitution reactions was prepared and characterized by 1D and 2D NMR spectroscopies and solid state structural analysis. The rates of epimerization of the less thermodynamically stable diastereomeric allyliridium complexes to the t...

  6. Diene-ligated iridium catalyst for allylation reactions of ketones and imines.

    Science.gov (United States)

    Barker, Timothy J; Jarvo, Elizabeth R

    2009-03-05

    [Ir(cod)Cl](2) is a highly reactive catalyst for allylation reactions of ketones using allylboronic ester. Mechanistic experiments are consistent with formation of a nucleophilic allyliridium(I) complex that is activated by the diene ligand toward attack of a ketone. Aryl and alkyl ketones react smoothly at room temperature. Aldimines also undergo allylation under these reaction conditions, requiring increased reaction times relative to the corresponding ketones.

  7. Direct use of allylic alcohols for platinum-catalyzed monoallylation of amines.

    Science.gov (United States)

    Utsunomiya, Masaru; Miyamoto, Yoshiki; Ipposhi, Junji; Ohshima, Takashi; Mashima, Kazushi

    2007-08-16

    A new direct catalytic amination of allylic alcohols promoted by the combination of platinum and a large bite-angle ligand DPEphos was developed in which the allylic alcohol was effectively converted to a pi-allylplatinum intermediate without the use of an activating reagent. The use of the DPEphos ligand was essential for obtaining high catalyst activity and high monoallylation selectivity of primary amines, allowing the formation of a variety of monoallylation products in good to excellent yield.

  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. A concomitant allylic azide rearrangement/intramolecular azide-alkyne cycloaddition sequence.

    Science.gov (United States)

    Vekariya, Rakesh H; Liu, Ruzhang; Aubé, Jeffrey

    2014-04-04

    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.

  10. 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.)

  11. Catalytic allylic oxidation of internal alkenes to a multifunctional chiral building block

    Science.gov (United States)

    Bayeh, Liela; Le, Phong Q.; Tambar, Uttam K.

    2017-07-01

    The stereoselective oxidation of hydrocarbons is one of the most notable advances in synthetic chemistry over the past fifty years. Inspired by nature, enantioselective dihydroxylations, epoxidations and other oxidations of unsaturated hydrocarbons have been developed. More recently, the catalytic enantioselective allylic carbon-hydrogen oxidation of alkenes has streamlined the production of pharmaceuticals, natural products, fine chemicals and other functional materials. Allylic functionalization provides a direct path to chiral building blocks with a newly formed stereocentre from petrochemical feedstocks while preserving the olefin functionality as a handle for further chemical elaboration. Various metal-based catalysts have been discovered for the enantioselective allylic carbon-hydrogen oxidation of simple alkenes with cyclic or terminal double bonds. However, a general and selective allylic oxidation using the more common internal alkenes remains elusive. Here we report the enantioselective, regioselective and E/Z-selective allylic oxidation of unactivated internal alkenes via a catalytic hetero-ene reaction with a chalcogen-based oxidant. Our method enables non-symmetric internal alkenes to be selectively converted into allylic functionalized products with high stereoselectivity and regioselectivity. Stereospecific transformations of the resulting multifunctional chiral building blocks highlight the potential for rapidly converting internal alkenes into a broad range of enantioenriched structures that can be used in the synthesis of complex target molecules.

  12. 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.

  13. Cp*Rh(III)-Catalyzed Low Temperature C-H Allylation of N-Aryl-trichloro Acetimidamide.

    Science.gov (United States)

    Debbarma, Suvankar; Bera, Sourav Sekhar; Maji, Modhu Sudan

    2016-12-02

    The readily synthesized trichloro acetimidamide was found to be an excellent directing group for the directed C-H-allylation reactions. Depending on the allylating agent used, selectively either mono- or diallylated products were readily synthesized. Moreover, the trichloro acetimidamide directing group was found to be highly efficient even at lower temperature for the C-H-allylation reaction. Due to mildness of the reaction conditions, double bond isomerization or cyclization to indole side product was not observed.

  14. Gold-catalyzed intermolecular coupling of sulfonylacetylene with allyl ethers: [3,3]- and [1,3]-rearrangements

    Directory of Open Access Journals (Sweden)

    Jungho Jun

    2013-08-01

    Full Text Available Gold-catalyzed intermolecular couplings of sulfonylacetylenes with allyl ethers are reported. A cooperative polarization of alkynes both by a gold catalyst and a sulfonyl substituent resulted in an efficient intermolecular tandem carboalkoxylation. Reactions of linear allyl ethers are consistent with the [3,3]-sigmatropic rearrangement mechanism, while those of branched allyl ethers provided [3,3]- and [1,3]-rearrangement products through the formation of a tight ion–dipole pair.

  15. Chiral Phosphoric Acid Catalyzed Enantioselective Allylation of Aldehydes with Allyltrichlorosilane%Chiral Phosphoric Acid Catalyzed Enantioselective Allylation of Aldehydes with Allyltrichlorosilane

    Institute of Scientific and Technical Information of China (English)

    程柯; 范甜甜; 孙健

    2011-01-01

    Easily accessible chiral phosphoric acid lb has been applied as efficient organocatalyst for the asymmetric al- lylation of aldehydes with allyltrichlorosilane. In the presence of 20 mol% of lb, the allylation of a broad range of aldehydes proceeded smoothly to give the corresponding homoallylic alcohol with up to 87% ee and 97% yield.

  16. Origins of Regioselectivity in Iridium Catalyzed Allylic Substitution.

    Science.gov (United States)

    Madrahimov, Sherzod T; Li, Qian; Sharma, Ankit; Hartwig, John F

    2015-12-02

    Detailed studies on the origin of the regioselectivity for formation of branched products over linear products have been conducted with complexes containing the achiral triphenylphosphite ligand. The combination of iridium and P(OPh)3 was the first catalytic system shown to give high regioselectivity for the branched product with iridium and among the most selective for forming branched products among any combination of metal and ligand. We have shown the active catalyst to be generated from [Ir(COD)Cl]2 and P(OPh)3 by cyclometalation of the phenyl group on the ligand and have shown such species to be the resting state of the catalyst. A series of allyliridium complexes ligated by the resulting P,C ligand have been generated and shown to be competent intermediates in the catalytic system. We have assessed the potential impact of charge, metal-iridium bond length, and stability of terminal vs internal alkenes generated by attack at the branched and terminal positions of the allyl ligand, respectively. These factors do not distinguish the regioselectivity for attack on allyliridium complexes from that for attack on allylpalladium complexes. Instead, detailed computational studies suggest that a series of weak, attractive, noncovalent interactions, including interactions of H-bond acceptors with a vinyl C-H bond of the alkene ligand, favor formation of the branched product with the iridium catalyst. This conclusion underscores the importance of considering attractive interactions, as well as repulsive steric interactions, when seeking to rationalize selectivities.

  17. 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.

  18. SN2 reactions with allylic substrates--Trends in reactivity

    Science.gov (United States)

    Ochran, Richard A.; Uggerud, Einar

    2007-09-01

    The gas-phase identity SN2 reactions of allylic substrates has been studied by systematic altering of the nucleophile/nucleofuge X, the remote substituent Y, and the number of methyl substituents at the reaction centre: X- + YCHCHCZ2X --> YCHCHCZ2X + X- (X = H, CH3, NH2, F, Cl; Y = F, OH, H, CHO, BH2; Z = H, CH3). Key regions of the potential energy surfaces have been explored by MP2, B3LYP, G3B3 and G3 calculations; the latter two methods providing accurate estimates of the reaction barrier. The calculations show that irrespective of theoretical level, for the second row of the periodic table (X = CH3, NH2, OH, and F), the tendency is that the barrier height decreases in going from left to right in agreement with the previously observed trend for identity SN2 reactions at methyl. The barrier height decreases by introduction a [pi] electron withdrawing substituents, Y, remote 6rom the reaction centre. The barrier height increases by introducing methyl groups (Z = CH3) next to the reaction centre, but the effect is less than half of that of changing the remote substituent from Y = CHO to Y = OH. The trends cannot be explained by simplified valence bond theory and are discussed in light of a simple electrostatic bonding model of the transition structure.

  19. Allyl isothiocyanate enhances shelf life of minimally processed shredded cabbage.

    Science.gov (United States)

    Banerjee, Aparajita; Penna, Suprasanna; Variyar, Prasad S

    2015-09-15

    The effect of allyl isothiocyanate (AITC), in combination with low temperature (10°C) storage on post harvest quality of minimally processed shredded cabbage was investigated. An optimum concentration of 0.05μL/mL AITC was found to be effective in maintaining the microbial and sensory quality of the product for a period of 12days. Inhibition of browning was shown to result from a down-regulation (1.4-fold) of phenylalanine ammonia lyase (PAL) gene expression and a consequent decrease in PAL enzyme activity and o-quinone content. In the untreated control samples, PAL activity increased following up-regulation in PAL gene expression that could be linearly correlated with enhanced o-quinone formation and browning. The efficacy of AITC in extending the shelf life of minimally processed shredded cabbage and its role in down-regulation of PAL gene expression resulting in browning inhibition in the product is reported here for the first time. Copyright © 2015 Elsevier Ltd. All rights reserved.

  20. 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

  1. Bis(μ-N,N-di-allyl-dithio-carbamato)bis[(N,N-di-allyl-dithio-carbamato)cadmium].

    Science.gov (United States)

    Onwudiwe, Damian C; Hrubaru, Madalina; Hosten, Eric C; Arderne, Charmaine

    2017-09-01

    The title compound, [Cd2(C7H10NS2)4], is a neutral dinuclear cadmium(II) complex bearing four bis N,N-di-allyl-di-thio-carbamate ligands coordinating to two Cd(II) cations. In each of the monomeric subunits, there are four S atoms of two di-thio-carbamate ligands [Cd-S = 2.5558 (3), 2.8016 (3), 2.6050 (3) and 2.5709 (3) Å] that coordinate to one Cd(II) atom in a bidentate mode. The dimers are located over an inversion centre bridged by two additional bridging Cd-S bonds [2.6021 (3) Å], leading to a substantial distortion of the geometry of the monomeric subunit from the expected square-planar geometry. The five-coordinate environment around each of the Cd(II) ions in the dimer is best described as substanti-ally tetra-gonally distorted square pyramidal. The di-thio-carbamate groups are themselves planar and are also coplanar with the Cd(II) ions. The negative charge on these groups is delocalized by resonance across the S atoms bound to the Cd(II) cation. This delocalization of the π electrons in the di-thio-carbamate groups also extends to the C-N bonds as they reveal significant double bond character [C-N = 1.3213 (16) and 1.3333 (15) Å].

  2. Formation and reaction of allylic species on silver surfaces: bond-order conservation Morse-potential analysis

    Science.gov (United States)

    Shustorovich, Evgeny

    1992-12-01

    The reaction energetics, particularly the intrinsic activation barriers for possible reactions involving allylic species C 3H 5X, X = H, OH, O, Cl on clean and oxygen-preadsorbed Ag surfaces, have been calculated by using the bond-order conservation Morse-potential (BOC-MP) method. The calculations were made for low coverages of C 3H 5X with qualitative corrections for higher coverages. On clean Ag surfaces, propylene C 3H 6 and allyl alcohol C 3H 5OH are projected to desorb without dissociation, in contrast to allyl chloride C 3H 5C1, which is projected to desorb only at high coverages but to dissociate at low coverages forming a stable π-allyl (and atomic chlorine). It is found that the intrinsic activation barrier for dimerization of π-allyl into 1,5-hexadiene is very small and the apparent barrier should be mainly of diffusional character. In the presence of preadsorbed hydroxyl OH s, π-allyl is projected to undergo various transformations producing allyl alcohol, allyl alkoxide, acrolein, and propylene, when most recombination and disproportionation reactions have low intrinsic activation barriers. The BOC-MP model projections are in good agreement with experiment, particularly with the recent HREEL and TPD studies of C 3H 5C1.

  3. Catalyst-Free Imidation of Allyl Sulfides with Chloramine-T and Subsequent [2,3]-Sigmatropic Rearrangement

    Institute of Scientific and Technical Information of China (English)

    江玉波; 莫凡洋; 邱迪; 匡春香; 张艳; 王剑波

    2012-01-01

    A facile synthesis of various allyl sulfonamides based on imidation of allyl sulfides with chloramine-T and sub- sequent [2,3]-sigmatropic rearrangement has been achieved without metal catalysts. The reaction completes smoothly within 10 min, providing excellent yields in environment friendly solvent of alcohol. Functional groups such as bromine, hydroxyl, protected amido and aldehyde are tolerant under this condition.

  4. An Efficient Synthesis of de novo Imidates via Aza-Claisen Rearrangements of N-Allyl Ynamides.

    Science.gov (United States)

    Dekorver, Kyle A; North, Troy D; Hsung, Richard P

    2010-10-01

    A novel thermal 3-aza-Claisen rearrangement of N-allyl ynamides for the synthesis of α-allyl imidates is described. Also, a sequential aza-Claisen, Pd-catalyzed Overman rearrangement is described for the synthesis of azapine-2-ones.

  5. A Mechanistic Study of Direct Activation of Allylic Alcohols in Palladium Catalyzed Amination Reactions

    Directory of Open Access Journals (Sweden)

    Yasemin Gumrukcu

    2015-03-01

    Full Text Available We here report a computational approach on the mechanism of allylicamination reactions using allyl-alcohols and amines as the substrates and phosphoramidite palladium catalyst 1a, which operates in the presence of catalytic amount of 1,3-diethylurea as a co-catalyst. DFT calculations showed a cooperative hydrogen-bonding array between the urea moiety and the hydroxyl group of the allyl alcohol, which strengthens the hydrogen bond between the O-H moiety of the coordinated allyl-alcohol and the carbonyl-moiety of the ligand. This hydrogen bond pattern facilitates the (rate-limiting C-O oxidative addition step and leads to lower energy isomers throughout the catalytic cycle, clarifying the role of the urea-moiety.

  6. 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.

  7. 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.

  8. 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

    by asymmetric HWE reactions into mixtures of two major $alpha@,$beta@-unsaturated esters, possessing opposite configurations at their allylic stereocenters as well as opposite alkene geometry. Subsequently, these isomeric mixtures of alkenes could be subjected to palladium-catalyzed allylic substitution...... reactions with carbon, nitrogen, and oxygen nucleophiles. In this latter step, the respective (E) and (Z) alkene substrate isomers were observed to react with opposite stereospecificity: the (E) alkene reacted with retention and the (Z) alkene with inversion of stereochemistry with respect to both...... the allylic stereocenter and the alkene geometry. Thus, a single $gamma@-substituted ester was obtained as the overall product, in high isomeric purity. The method was applied to a synthesis of a subunit of the iejimalides, a group of cytotoxic macrolides....

  9. Allyl isothiocyanate sensitizes TRPV1 to heat stimulation.

    Science.gov (United States)

    Alpizar, Yeranddy A; Boonen, Brett; Gees, Maarten; Sanchez, Alicia; Nilius, Bernd; Voets, Thomas; Talavera, Karel

    2014-03-01

    The powerful plant-derived irritant allyl isothiocyanate (AITC, aka mustard oil) induces hyperalgesia to heat in rodents and humans through mechanisms that are not yet fully understood. It is generally believed that AITC activates the broadly tuned chemosensory cation channel transient receptor potential cation channel subfamily A member 1 (TRPA1), triggering an inflammatory response that sensitizes the heat sensor transient receptor potential cation channel subfamily V member 1 (TRPV1). In the view of recent data demonstrating that AITC can directly activate TRPV1, we here explored the possibility that this compound sensitizes TRPV1 to heat stimulation in a TRPA1-independent manner. Patch-clamp recordings and intracellular Ca(2+) imaging experiments in HEK293T cells over-expressing mouse TRPV1 revealed that the increase in channel activation induced by heating is larger in the presence of AITC than in control conditions. The analysis of the effects of AITC and heat on the current-voltage relationship of TRPV1 indicates that the mechanism of sensitization is based on additive shifts of the voltage dependence of activation towards negative voltages. Finally, intracellular Ca(2+) imaging experiments in mouse sensory neurons isolated from Trpa1 KO mice yielded that AITC enhances the response to heat, specifically in the subpopulation expressing TRPV1. Furthermore, this effect was strongly reduced by the TRPV1 inhibitor capsazepine and virtually absent in neurons isolated from double Trpa1/Trpv1 KO mice. Taken together, these findings demonstrate that TRPV1 is a locus for cross sensitization between AITC and heat in sensory neurons and may help explaining, at least in part, the role of this channel in AITC-induced hyperalgesia to heat.

  10. Biphilic Organophosphorus Catalysis: Regioselective Reductive Transposition of Allylic Bromides via PIII/PV Redox Cycling

    Science.gov (United States)

    Reichl, Kyle D.; Dunn, Nicole L.; Fastuca, Nicholas J.; Radosevich, Alexander T.

    2016-01-01

    We report that a regioselective reductive transposition of primary allylic bromides is catalyzed by a biphilic organophosphorus (phosphetane) catalyst. Spectroscopic evidence supports the formation of a pentacoordinate (σ5-P) hydridophosphorane as a key reactive intermediate. Kinetics experiments and computational modeling are consistent with a unimolecular decomposition of the σ5-P hydridophosphorane via a concerted cyclic transition structure that delivers the observed allylic transposition and completes a novel PIII/PV redox catalytic cycle. These results broaden the growing repertoire of reactions catalyzed within the PIII/PV redox couple and suggest additional opportunities for organophosphorus catalysis in a biphilic mode. PMID:25874950

  11. Origins of enantioselectivity during allylic substitution reactions catalyzed by metallacyclic iridium complexes.

    Science.gov (United States)

    Madrahimov, Sherzod T; Hartwig, John F

    2012-05-16

    In depth mechanistic studies of iridium catalyzed regioselective and enantioselective allylic substitution reactions are presented. A series of cyclometalated allyliridium complexes that are kinetically and chemically competent to be intermediates in the allylic substitution reactions was prepared and characterized by 1D and 2D NMR spectroscopies and single-crystal X-ray difraction. The rates of epimerization of the less thermodynamically stable diastereomeric allyliridium complexes to the thermodynamically more stable allyliridium stereoisomers were measured. The rates of nucleophilic attack by aniline and by N-methylaniline on the isolated allyliridium complexes were also measured. Attack on the thermodynamically less stable allyliridium complex was found to be orders of magnitude faster than attack on the thermodynamically more stable complex, yet the major enantiomer of the catalytic reaction is formed from the more stable diastereomer. Comparison of the rates of nucleophilic attack to the rates of epimerization of the diastereomeric allyliridium complexes containing a weakly coordinating counterion showed that nucleophilic attack on the less stable allyliridium species is much faster than conversion of the less stable isomer to the more stable isomer. These observations imply that Curtin-Hammett conditions are not met during iridium catalyzed allylic substitution reactions by η(3)-η(1)-η(3) interconversion. Rather, these data imply that when these conditions exist for this reaction, they are created by reversible oxidative addition, and the high selectivity of this oxidative addition step to form the more stable diastereomeric allyl complex leads to the high enantioselectivity. The stereochemical outcome of the individual steps of allylic substitution was assessed by reactions of deuterium-labeled substrates. The allylic substitution was shown to occur by oxidative addition with inversion of configuration, followed by an outer sphere nucleophilic attack

  12. Chemoselective and stereoselective lithium carbenoid mediated cyclopropanation of acyclic allylic alcohols.

    Science.gov (United States)

    Durán-Peña, M J; Flores-Giubi, M E; Botubol-Ares, J M; Harwood, L M; Collado, I G; Macías-Sánchez, A J; Hernández-Galán, R

    2016-03-01

    The reaction of geraniol with different lithium carbenoids generated from n-BuLi and the corresponding dihaloalkane has been evaluated. The reaction occurs in a chemo and stereoselective manner, which is consistent with a directing effect from the oxygen of the allylic moiety. Furthermore, a set of polyenes containing allylic hydroxyl or ether groups were chemoselectively and stereoselectively converted into the corresponding gem-dimethylcyclopropanes in one single step in moderate to good yields mediated by a lithium carbenoid generated in situ by the reaction of n-BuLi and 2,2-dibromopropane.

  13. 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

  14. Additive-Free Pd-Catalyzed α-Allylation of Imine-Containing Heterocycles.

    Science.gov (United States)

    Kljajic, Marko; Puschnig, Johannes G; Weber, Hansjörg; Breinbauer, Rolf

    2017-01-06

    An additive-free Pd-catalyzed α-allylation of different imino-group-ontaining heterocycles is reported. The activation of α-CH pronucleophiles (pKa (DMSO) > 25) occurs without the addition of strong bases or Lewis acids using only the Pd/Xantphos catalyst system. The reaction scope has been studied for various 5- and 6-membered nitrogen-containing heterocycles (yields up to 96%). Mechanistic investigations suggest an initial allylation of the imine-N followed by a Pd-catalyzed formal aza-Claisen rearrangement.

  15. FeCl3 catalysed regioselective allylation of phenolic substrates with (-hydroxy)allylphosphonates

    Indian Academy of Sciences (India)

    Mandala Anitha; Ramesh Kotikalapudi; K C Kumara Swamy

    2015-08-01

    Electrophilic allylation of phenolic substrates including salicylaldehydes with (-hydroxy) allylphosphonates is presented. It is observed that catalytic FeCl3 is sufficient to accomplish the allylation. Interestingly, the reaction led to the formation of allylphosphonates in addition to vinylphosphonates, depending upon the substituent. The vinylphosphonates obtained here are -isomers. More importantly, the reaction occurred regioselectively with respect to the phenolic substrates. Substituted allylphosphonates are formed when salicylaldehyde or (2-hydroxy-phenyl)arylmethanones are used. Conclusive proof for the formation of allylphosphontates as well as vinylphosphonates has been provided by single crystal X-ray crystallography.

  16. Highly selective palladium–benzothiazole carbene-catalyzed allylation of active methylene compounds under neutral conditions

    Directory of Open Access Journals (Sweden)

    Antonio Monopoli

    2015-06-01

    Full Text Available The Pd–benzothiazol-2-ylidene complex I was found to be a chemoselective catalyst for the Tsuji–Trost allylation of active methylene compounds carried out under neutral conditions and using carbonates as allylating agents. The proposed protocol consists in a simplified procedure adopting an in situ prepared catalyst from Pd2dba3 and 3-methylbenzothiazolium salt V as precursors. A comparison of the performance of benzothiazole carbene with phosphanes and an analogous imidazolium carbene ligand is also proposed.

  17. Asymmetric Catalysis with CO2 : The Direct α-Allylation of Ketones.

    Science.gov (United States)

    Pupo, Gabriele; Properzi, Roberta; List, Benjamin

    2016-05-10

    Quaternary stereocenters are found in numerous bioactive molecules. The Tsuji-Trost reaction has proven to be a powerful C-C bond forming process, and, at least in principle, should be well suited to access quaternary stereocenters via the α-allylation of ketones. However, while indirect approaches are known, the direct, catalytic asymmetric α-allylation of branched ketones has been elusive until today. By combining "enol catalysis" with the use of CO2 as a formal catalyst for asymmetric catalysis, we have now developed a solution to this problem: we report a direct, highly enantioselective and highly atom-economic Tsuji-Trost allylation of branched ketones with allylic alcohol. Our reaction delivers products bearing quaternary stereocenters with high enantioselectivity and water as the sole by-product. We expect our methodology to be of utility in asymmetric catalysis and inspire the design of other highly atom-economic transformations. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. 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...

  19. A Novel, One-Step Palladium and Phenylsilane Activated Amidation from Allyl Ester on Solid Support

    Directory of Open Access Journals (Sweden)

    Zheming Ruan

    2008-01-01

    Full Text Available The direct conversion of solid-supported carboxylic acid allyl esters to carboxamides through the use of phenylsilane and catalytic Pd(PPh34 under mild reaction conditions is reported. The use of this methodology for the generation of a 48 compound solid-phase array is described herein.

  20. Reductive coupling reaction of benzyl, allyl and alkyl halides in aqueous medium promoted by zinc

    Directory of Open Access Journals (Sweden)

    Sá Ana C. P. F. de

    2003-01-01

    Full Text Available Organic halides undergo reductive dimerization (Wurtz-type coupling promoted by zinc at room temperature in aqueous medium. The reaction yields are strongly enhanced by copper catalysis. This coupling procedure provides an efficient and simple method for the homocoupling of benzylic and allylic bromides and primary alkyl iodides.

  1. Asymmetric synthesis of N,O-heterocycles via enantioselective iridium-catalysed intramolecular allylic amidation

    NARCIS (Netherlands)

    Zhao, Depeng; Fananas-Mastral, Martin; Chang, Mu-Chieh; Otten, Edwin; Feringa, Ben L.

    2014-01-01

    Chiral N,O-heterocycles were synthesized in high yields and excellent enantioselectivity up to 97% ee via iridium-catalysed intramolecular allylic substitution with nucleophilic attack by the amide oxygen atom. The resulting benzoxazine derivatives were further transformed into challenging chiral

  2. Catalytic allylation of phenols : chloride-free route towards epoxy resins

    NARCIS (Netherlands)

    Rijn, Jimmy Antonius van

    2010-01-01

    An industrially applicable process was developed for the synthesis of epoxy resin components. A catalytic reaction was explored towards allyl phenyl ethers that prevents the use of chloride-containing starting materials and thus formation of chloride-containing side products. The preferred allylatin

  3. 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) indi...

  4. A convenient method for lactonization of α-allyl esters using iodine in dimethyl- sulphoxide

    Directory of Open Access Journals (Sweden)

    B. R. Nawghare

    2014-09-01

    Full Text Available 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. DOI: http://dx.doi.org/10.4314/bcse.v28i3.16

  5. [N-allyl-Dmt1]-endomorphins are micro-opioid receptor antagonists lacking inverse agonist properties.

    Science.gov (United States)

    Marczak, Ewa D; Jinsmaa, Yunden; Li, Tingyou; Bryant, Sharon D; Tsuda, Yuko; Okada, Yoshio; Lazarus, Lawrence H

    2007-10-01

    [N-allyl-Dmt1]-endomorphin-1 and -2 ([N-allyl-Dmt1]-EM-1 and -2) are new selective micro-opioid receptor antagonists obtained by N-alkylation with an allyl group on the amino terminus of 2',6'-dimethyl-L-tyrosine (Dmt) derivatives. To further characterize properties of these compounds, their intrinsic activities were assessed by functional guanosine 5'-O-(3-[35S]thiotriphosphate) binding assays and forskolin-stimulated cyclic AMP accumulation in cell membranes obtained from vehicle, morphine, and ethanol-treated SK-N-SH cells and brain membranes isolated from naive and morphine-dependent mice; their mode of action was compared with naloxone or naltrexone, which both are standard nonspecific opioid-receptor antagonists. [N-allyl-Dmt1]-EM-1 and -2 were neutral antagonists under all of the experimental conditions examined, in contrast to naloxone and naltrexone, which behave as neutral antagonists only in membranes from vehicle-treated cells and mice but act as inverse agonists in membranes from morphine- and ethanol-treated cells as well as morphine-treated mice. Both endomorphin analogs inhibited the naloxone- and naltrexone-elicited withdrawal syndromes from acute morphine dependence in mice. This suggests their potential therapeutic application in the treatment of drug addiction and alcohol abuse without the adverse effects observed with inverse agonist alkaloid-derived compounds that produce severe withdrawal symptoms.

  6. A Mechanistic Study of Direct Activation of Allylic Alcohols in Palladium Catalyzed Amination Reactions

    NARCIS (Netherlands)

    Gumrukcu, Y.; de Bruin, B.; Reek, J.N.H.

    2015-01-01

    We here report a computational approach on the mechanism of allylicamination reactions using allyl-alcohols and amines as the substrates and phosphoramidite palladium catalyst 1a, which operates in the presence of catalytic amount of 1,3-diethylurea as a co-catalyst. DFT calculations showed a cooper

  7. Cooperative catalysis by palladium and a chiral phosphoric acid: enantioselective amination of racemic allylic alcohols.

    Science.gov (United States)

    Banerjee, Debasis; Junge, Kathrin; Beller, Matthias

    2014-11-24

    Cooperative catalysis by [Pd(dba)2] and the chiral phosphoric acid BA1 in combination with the phosphoramidite ligand L8 enabled the efficient enantioselective amination of racemic allylic alcohols with a variety of functionalized amines. This catalytic protocol is highly regio- and stereoselective (up to e.r. 96:4) and furnishes valuable chiral amines in almost quantitative yield.

  8. Synthesis of allyl esters of fatty acids and their ovicidal effect on Cydia pomonella (L.).

    Science.gov (United States)

    Escribà, Marc; Barbut, Montserrat; Eras, Jordi; Canela, Ramon; Avilla, Jesús; Balcells, Mercè

    2009-06-10

    Eight allyl esters of fatty acids were synthesized in moderate to high yields with a novel two-step procedure using glycerol as a starting material. The two-step methodology avoids the use of allyl alcohol. The first step consisted of heating at 80 degrees C for 48 h a 2:1:5 mmol mixture of glycerol, a fatty acid, and chlorotrimethylsilane in a solvent-free medium. The crude compound was then dissolved in butanone and heated at 115 degrees C in the presence of NaI. A tandem Finkelstein rearrangement-elimination reaction occurs, producing the corresponding allyl ester. The activity of these esters against Cydia pomonella (L.) (Lepidoptera: Tortricidae) eggs was tested in the laboratory by topical application of one 0.1 microL drop. All of the compounds showed a concentration-mortality response and caused 100% mortality at the highest concentration tested (10 mg/mL). There was an inverse relationship between the alkyl chain length and the ovicidal activity of the allyl ester; the LC(50) and the LC(90) of the two compounds that have the longer alkyl chains were significantly higher than those of the rest of the compounds. The ovicidal and IGR activities of this kind of compound appear to be unprecedented.

  9. 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.

  10. Allylation of Functionalized Aldehydes by Potassium Allyltrifluoroborate Catalyzed by 18-Crown-6 in Aqueous Media

    Directory of Open Access Journals (Sweden)

    Roberta A. Oliveira

    2012-11-01

    Full Text Available An efficient method for the allylation of aldehydes containing a broad range of functional groups using potassium allyltrifluoroborate is described. The reaction utilizes a catalytic amount of 18-C-6 in biphasic media under open atmosphere and room temperature to provide the corresponding homoallylic alcohols in high yields and without the necessity of any subsequent purification.

  11. 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%.

  12. In(OTf)3 catalyzed allylation reaction of imines with tetraallyltin

    Institute of Scientific and Technical Information of China (English)

    Xiao Ning Wei; Ling Yan Liu; Bing Wang; Wei Xing Chang; Jing Li

    2009-01-01

    In the presence of catalytic amount of In(OTf)3 (10 mol%), a series of aldimines reacted with tetraallyltin in a 2:1 molar ratio to afford the corresponding homoallylic amines in good yields. The good atom efficiency was achieved under mild reaction conditions and a new protocol (allyl)4Sn/In(OTf)3 for simple imines was developed.

  13. Zirconium-allyl complexes as resting states in zirconocene-catalyzed α-olefin polymerization.

    Science.gov (United States)

    Panchenko, Valentina N; Babushkin, Dmitrii E; Brintzinger, Hans H

    2015-01-01

    UV-vis spectroscopic data indicate that zirconocene cations with Zr-bound allylic chain ends are generally formed during olefin polymerization with zirconocene catalysts. The rates and extent of their formation and of their re-conversion to the initial pre-catalyst cations depend on the types of zirconocene complexes and activators used.

  14. Electrochemical studies and self diffusion coefficients in cyclic ammonium based ionic liquids with allyl substituents

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Tzi-Yi [Department of Chemistry, National Cheng Kung University, Tainan 701, Taiwan (China); Department of Polymer Materials, Kun Shan University, Tainan 71003, Taiwan (China); Su, Shyh-Gang [Department of Chemistry, National Cheng Kung University, Tainan 701, Taiwan (China); Wang, H. Paul [Department of Environmental Engineering, National Cheng Kung University, Tainan, Taiwan (China); Lin, Yuan-Chung [Institute of Environmental Engineering, National Sun Yat-Sen University, Kaohsiung 804, Taiwan (China); Gung, Shr-Tusen; Lin, Ming-Wei [Department of Chemistry, National Cheng Kung University, Tainan 701, Taiwan (China); Sun, I.-Wen, E-mail: iwsun@mail.ncku.edu.t [Department of Chemistry, National Cheng Kung University, Tainan 701, Taiwan (China)

    2011-03-30

    Research highlights: Cyclic ammonium-based ionic liquids with allyl substituent have high conductivity. Ionic liquids with allyl substituent have wide electrochemical window. Electrochemical and self diffusion coefficients are available for comparison. The Stokes-Einstein plots of DT{sup -1} vs. {eta}{sup -1} for redox couples in ILs are evaluated. Stokes-Einstein product of ferrocene is larger than that of cobaltocenium in ILs. - Abstract: Several cyclic ammonium-based ionic liquids (ILs) with allyl substituent are synthesized, these allyl substituent ILs have high ionic conductivity (up to 4.72 mS cm{sup -1} at 30 {sup o}C) and wide electrochemical window of 5 V. The electrochemical behaviors of two organometallic redox couples Fc/Fc{sup +} (ferrocene/ferrocenium) and Cc/Cc{sup +} (cobaltocene/cobaltocenium) have been studied in these ILs, the calculated Stokes-Einstein product (D{eta} T{sup -1}) of ferrocene in ILs is larger than that of cobaltocenium in ILs. The self-diffusion coefficients of cation and anion in these ILs are studied using pulsed gradient spin-echo NMR technique. There are very few reports where electrochemically derived diffusion coefficients and self diffusion coefficients are available for comparison, so a new key concept in electrochemistry could be developed in this paper.

  15. Palladium-catalyzed cross-coupling reactions of allylic halides and acetates with indium organometallics.

    Science.gov (United States)

    Rodríguez, David; Pérez Sestelo, José; Sarandeses, Luis A

    2004-11-12

    The palladium(0)-catalyzed cross-coupling reaction of allylic halides and acetates with indium organometallics is reported. In this synthetic transformation, triorganoindium compounds and tetraorganoindates (aryl, alkenyl, and methyl) react with cinnamyl and geranyl halides and acetates to afford the S(N)2 product regioselectively and in good yield. The reaction proceeds with net inversion of the stereochemical configuration.

  16. Facile Formation of Ytterbium Diiodide and Its Use in the Synthesis of Allyl Selenides

    Institute of Scientific and Technical Information of China (English)

    SU,Wei-Ke(苏为科); ZHANG,Yong-Min(张永敏); ZHENG,Yun-Fa(郑云法); LI,Yong-Shu(李永曙)

    2002-01-01

    Ytterbium metal reacts with iodine to generate ytterbium diiodide directly, which can react with diselenides to form ytterbium selenolates (RSeYbI2). These species reacted smoothly with allyl bromide to give allylselenides in moderate to good yields under neutral conditions.

  17. 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 tolera...

  18. Polystyrene-supported Selenides and Selenoxide:Versatile Routes to Synthesize Allylic Alcohols

    Institute of Scientific and Technical Information of China (English)

    Wei Ming XU; You Chu ZHANG; Xian HUANG

    2003-01-01

    Several polystyrene-supported selenides and selenoxide have been prepared firstly. These novel reagents were treated with LDA to produce selenium stabilized carbanions, which reacted with aldehydes and alkyl halides, followed by selenoxide syn-elimination and [2,3] sigmatropic rearrangement respectively to give Z-allylic alcohols stereoselectively.

  19. 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.

    2008-01-01

    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 fo

  20. Synthesis, Characterization, and Some Properties of Cp*W(NO)(H)(η(3)-allyl) Complexes.

    Science.gov (United States)

    Baillie, Rhett A; Holmes, Aaron S; Lefèvre, Guillaume P; Patrick, Brian O; Shree, Monica V; Wakeham, Russell J; Legzdins, Peter; Rosenfeld, Devon C

    2015-06-15

    Sequential treatment at low temperatures of Cp*W(NO)Cl2 in THF with 1 equiv of a binary magnesium allyl reagent, followed by an excess of LiBH4, affords three new Cp*W(NO)(H)(η(3)-allyl) complexes, namely, Cp*W(NO)(H)(η(3)-CH2CHCMe2) (1), Cp*W(NO)(H)(η(3)-CH2CHCHPh) (2), and Cp*W(NO)(H)(η(3)-CH2CHCHMe) (3). Complexes 1-3 are isolable as air-stable, analytically pure yellow solids in good to moderate yields by chromatography or fractional crystallization. In solutions, complex 1 exists as two coordination isomers in an 83:17 ratio differing with respect to the endo/exo orientation of the allyl ligand. In contrast, complexes 2 and 3 each exist as four coordination isomers, all differing by the orientation of their allyl ligands which can have either an endo or an exo orientation with the phenyl or methyl groups being either proximal or distal to the nitrosyl ligand. A DFT computational analysis using the major isomer of Cp*W(NO)(H)(η(3)-CH2CHCHMe) (3a) as the model complex has revealed that its lowest-energy thermal-decomposition pathway involves the intramolecular isomerization of 3a to the 16e η(2)-alkene complex, Cp*W(NO)(η(2)-CH2═CHCH2Me). Such η(2)-alkene complexes are isolable as their 18e PMe3 adducts when compounds 1-3 are thermolyzed in neat PMe3, the other organometallic products formed during these thermolyses being Cp*W(NO)(PMe3)2 (5) and, occasionally, Cp*W(NO)(H)(η(1)-allyl)(PMe3). All new complexes have been characterized by conventional spectroscopic and analytical methods, and the solid-state molecular structures of most of them have been established by single-crystal X-ray crystallographic analyses.

  1. The Wacker oxidation of allyl alcohol along cyclic-intermediate routes: An ab initio molecular dynamics investigation

    Science.gov (United States)

    Imandi, Venkataramana; Nair, Nisanth N.

    2016-09-01

    The absence of isotope scrambling observed by Henry and coworkers in the Wacker oxidation of deuterated allylic alcohol was used by them as support for the inner-sphere mechanism hydroxypalladation mechanism. One of the assumptions used to interpret their experimental data was that allyl alcohol oxidation takes place through non-cyclic intermediate routes as in the case of ethene. Here we verify this assumption through ab initio metadynamics simulations of the Wacker oxidation of allyl alcohol in explicit solvent. Importance of our results in interpreting the isotope scrambling experiments is discussed.

  2. The magnesium-ene cyclization stereochemically directed by an allylic oxyanionic group and its application to a highly stereoselective synthesis of (+/-)-matatabiether. Allylmagnesium compounds by reductive magnesiation of allyl phenyl sulfides.

    Science.gov (United States)

    Cheng, D; Zhu, S; Yu, Z; Cohen, T

    2001-01-10

    The first example of a magnesium-ene cyclization stereochemically directed by an allylic oxyanionic group is demonstrated by a highly stereoselective synthesis of the bicyclic terpene matatabiether 10. The synthetic method is particularly valuable, not only because of the stereochemical control and the utility of the versatile hydroxyl group introduced into the product, but also because the precursor of the allylmagnesium is an allyl phenyl sulfide, which is more stable and more easily prepared in a connective fashion than the usual allyl halide precursor. Since the presence of lithium ions encourages undesirable proton transfer to the cyclized organometallic and is detrimental to the stereochemical control, the conversion of the allylic thioether to the allylmagnesium utilizes a lithium-free method involving direct reductive magnesiation in the presence of the magnesium-anthracene complex.

  3. From the tunneling dimer to the onset of microsolvation: Infrared spectroscopy of allyl radical water aggregates in helium nanodroplets

    Science.gov (United States)

    Leicht, Daniel; Kaufmann, Matin; Pal, Nitish; Schwaab, Gerhard; Havenith, Martina

    2017-03-01

    The infrared spectrum of allyl:water clusters embedded in helium nanodroplets was recorded. Allyl radicals were produced by flash vacuum pyrolysis and trapped in helium droplets. Deuterated water was added to the doped droplets, and the infrared spectrum of the radical water aggregates was recorded in the frequency range 2570-2820 cm-1. Several absorption bands are observed and assigned to 1:1 and 1:2 allyl:D2O clusters, based on pressure dependent measurements and accompanying quantum chemical calculations. The analysis of the 1:1 cluster spectrum revealed a tunneling splitting as well as a combination band. For the 1:2 cluster, we observe a water dimer-like motif that is bound by one π-hydrogen bond to the allyl radical.

  4. Chemoenzymatic one-pot synthesis in an aqueous medium: combination of metal-catalysed allylic alcohol isomerisation-asymmetric bioamination.

    Science.gov (United States)

    Ríos-Lombardía, Nicolás; Vidal, Cristian; Cocina, María; Morís, Francisco; García-Álvarez, Joaquín; González-Sabín, Javier

    2015-07-11

    The ruthenium-catalysed isomerisation of allylic alcohols was coupled, for the first time, with asymmetric bioamination in a one-pot process in an aqueous medium. In the cases involving prochiral ketones, the ω-TA exhibited excellent enantioselectivity, identical to that observed in the single step. As a result, amines were obtained from allylic alcohols with high overall yields and excellent enantiomeric excesses.

  5. Epoxidation of allyl alcohol to glycidol over the microporous TS-1 catalyst.

    Science.gov (United States)

    Wróblewska, Agnieszka; Fajdek, Anna

    2010-07-15

    The results of the epoxidation of allyl alcohol with 30% hydrogen peroxide over the TS-1 catalyst have been presented. The studies were carried out under the atmospheric pressure and at the presence of methanol as a solvent. The influence of the following technological parameters on the course of epoxidation was examined: the temperature of 20-60 degrees C, the molar ratio of AA/H(2)O(2) 1:1-5:1, the methanol concentration of 5-90 wt%, the catalyst content of 0.1-5.0 wt% and the reaction time 5-300 min. The main functions describing the process were the selectivity to glycidol in relation to allyl alcohol consumed, the conversion of substrates, and the selectivity of transformation to organic compounds in relation to hydrogen peroxide consumed. The parameters at which the functions describing the process reached the highest values were determined.

  6. [Surface modification of poly methyl methacrylate intraocular lens by alpha-allyl glucoside].

    Science.gov (United States)

    Qu, Chao; Yao, Ke; Kou, Ruiqiang; Xu, Zhikang

    2004-02-01

    A method for improving the biocompatibility of the intraocular lens (IOL) and reducing the cell attachment was adopted in this study. The alpha-Allyl glucoside was used for the surface modification of the poly methyl methacrylate (PMMA) IOL by way of plasma-induced in situ polymerization. The surfaces of the control and treatment IOLs were characterized by contact angle estimation and ESCA techniques. The resolution, diopter and anti-fatigue of loops were determined by physical and optical methods. Cell attachment on the surfaces was examined by light microscopy. The results indicated that all of the treatment groups had excellent physical and optical properties. The modification with the use of alpha-Allyl glucoside could improve the hydrophilicity of the anterior surface of the PMMA IOLs and reduce the cell attachment.

  7. Iron complexes of tetramine ligands catalyse allylic hydroxyamination via a nitroso-ene mechanism.

    Science.gov (United States)

    Porter, David; Poon, Belinda M-L; Rutledge, Peter J

    2015-01-01

    Iron(II) complexes of the tetradentate amines tris(2-pyridylmethyl)amine (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(hydroxy)carbamate) 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).

  8. Synthesis, characterization and evaluation of antioxidant and anticancer activities of novel benzisoxazole-substituted-allyl derivatives

    Energy Technology Data Exchange (ETDEWEB)

    Anand, Mohanam [Kingston Engineering College, Vellore (India); Selvaraj, Vaithialingam [University College of Engineering-Villupuram, Villupuram (India); Alagar, Muthukaruppan [Anna University, Chennai (India)

    2014-04-15

    A novel series of various 2-allylbenzo[d]isoxazol-3(2H)-ones were synthesized using benzo[d]isoxazol-3(2H)-one treated with different allyl bromides/chlorides in the presence of water-mediated cesium carbonate as a new catalyst 3(a-h). The structures of the newly synthesized Benzisoxazole-substituted-allyl derivatives were characterized by spectroscopic methods and mass spectrometry. These synthesized compounds were evaluated for their in vitro antioxidant and anticancer activity. Compounds 3b, d, f, h were identified as the best hit against HT-29 Human colon cancer cells. Similarly, compounds like 3b, d, f, h showed significant antioxidant activity compared to the standard drug butylated hydroxy toluene (BHT)

  9. Recent Advances in the Application of Chiral Phosphine Ligands in Pd-Catalysed Asymmetric Allylic Alkylation

    Directory of Open Access Journals (Sweden)

    Erika Martin

    2011-01-01

    Full Text Available One of the most powerful approaches for the formation of simple and complex chiral molecules is the metal-catalysed asymmetric allylic alkylation. This reaction has been broadly studied with a great variety of substrates and nucleophiles under different reaction conditions and it has promoted the synthesis of new chiral ligands to be evaluated as asymmetric inductors. Although the mechanism as well as the active species equilibria are known, the performance of the catalytic system depends on the fine tuning of factors such as type of substrate, nucleophile nature, reaction medium, catalytic precursor and type of ligand used. Particularly interesting are chiral phosphines which have proved to be effective asymmetric inductors in several such reactions. The present review covers the application of phosphine-donor ligands in Pd-catalysed asymmetric allylic alkylation in the last decade.

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

    DEFF Research Database (Denmark)

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

    2008-01-01

    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 ......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......-up of negative charge along with a small positive secondary kinetic isotope effect (k(H)/k(D) = 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...

  11. 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.

  12. Synthetic Studies on Tricyclic Diterpenoids: Direct Allylic Amination Reaction of Isopimaric Acid Derivatives.

    Science.gov (United States)

    Timoshenko, Mariya A; Kharitonov, Yurii V; Shakirov, Makhmut M; Bagryanskaya, Irina Yu; Shults, Elvira E

    2016-02-01

    A selective synthesis of 7- or 14-nitrogen containing tricyclic diterpenoids was completed according to a strategy in which the key step was the catalyzed direct allylic amination of methyl 14α-hydroxy-15,16-dihydroisopimarate with a wide variety of nitrogenated nucleophiles. It was revealed that the selectivity of the reaction depends on the nature of nucleophile. The catalyzed reaction of the mentioned diterpenoid allylic alcohol with 3-nitroaniline, 3-(trifluoromethyl)aniline, and 4-(trifluoromethyl)aniline yield the subsequent 7α-, 7β- and 14αnitrogen-containing diterpenoids. The reaction with 2-nitroaniline, 4-nitro-2-chloroaniline, 4-methoxy-2-nitroaniline, phenylsulfamide, or tert-butyl carbamate proceeds with the formation of 7α-nitrogen-substituted diterpenoids as the main products.

  13. 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.

  14. On the key role of water in the allylic activation catalysed by Pd (II) bisphosphinite complexes

    Indian Academy of Sciences (India)

    Rakesh Kumar Sharma; Ashoka G Samuelson

    2006-11-01

    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 of one equivalent of water. The near neutral conditions employed make the catalysts suitable for a wide variety of substrates.

  15. Highly Regioselective Palladium-Catalyzed Carboxylation of Allylic Alcohols with CO2.

    Science.gov (United States)

    Mita, Tsuyoshi; Higuchi, Yuki; Sato, Yoshihiro

    2015-11-01

    Various allylic alcohols were carboxylated in the presence of a catalytic amount of PdCl2 and PPh3 using ZnEt2 as a stoichiometric transmetalation agent under a CO2 atmosphere (1 atm). This carboxylation proceeded in a highly regioselective manner to afford branched carboxylic acids predominantly. The β,γ-unsaturated carboxylic acid thus obtained was successfully converted into an optically active γ-butyrolactone, a known intermediate of (R)-baclofen.

  16. 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.

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

    Science.gov (United States)

    Hemelaere, Rémy; Carreaux, François; Carboni, Bertrand

    2013-07-01

    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.

  18. 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)

  19. Direct Nucleophilic Substitution of Free Allylic Alcohols in Water Catalyzed by FeCl3⋅6 H2O: Which is the Real Catalyst?

    OpenAIRE

    Trillo Alarcón, María Paz; Baeza, Alejandro; Nájera Domingo, Carmen

    2013-01-01

    The allylic substitution reaction, and particularly the direct allylic amination reaction, of free allylic alcohols in water catalyzed by FeCl3⋅6 H2O is described. This novel environmentally-friendly methodology allows the use of a wide variety of nitrogenated nucleophiles such as sulfonamides, carbamates, benzamides, anilines, benzotriazoles, and azides, generally giving good yields of the corresponding substitution products. The synthetic applicability of the process is also demonstrated be...

  20. Lanthanide-surfactant-combined catalysts for the allylation of benzaldehyde with tetraallyltin in aqueous solutions

    Energy Technology Data Exchange (ETDEWEB)

    Deleersnyder, Karen; Shi Danzhao; Binnemans, Koen [Katholieke Universiteit Leuven, Department of Chemistry, Laboratory of Coordination Chemistry, Celestijnenlaan 200F, B-3001 Leuven (Belgium); Parac-Vogt, Tatjana N. [Katholieke Universiteit Leuven, Department of Chemistry, Laboratory of Coordination Chemistry, Celestijnenlaan 200F, B-3001 Leuven (Belgium)], E-mail: Tatjana.Vogt@chem.kuleuven.be

    2008-02-28

    Metal-surfactant-combined catalysts having the general formula M(DOS){sub x} (DOS = dodecylsulfate), x = 1-3, can be used for the efficient allylation of benzaldehyde with tetraallyltin in water. Due to the formation of micelles the reaction proceeds in the absence of organic solvents. Examination of a series of lanthanide(III) and divalent transition-metal dodecylsulfates as catalysts for the reaction between benzaldehyde and tetraallyltin revealed that the highest yields can be obtained when lanthanide(III) and copper(II) salts are used. Within 6 h at room temperature nearly quantitative conversion of benzaldehyde to 1-phenyl-3-buten-1-ol was achieved in the presence of 10 mol% of Cu(DOS){sub 2} or Yb(DOS){sub 3}. The influence of the amount of catalyst and tetraallyltin on the reaction yield was investigated. Different alkylsulfates, alkylsulfonates and arylsulfonates metal salts were prepared and tested as catalysts in the allylation reaction. The highest yields were obtained with ytterbium(III) alkylsulfates and ytterbium(III) arylsulfonates, while ytterbium(III) alkylsulfonates were found to be poor allylation catalysts. The results show that both the nature of the metal cation as well as the length and the nature of anionic surfactant chain are crucial for the activity of the metal-surfactant-combined catalysts in water.

  1. Impact of allyl disulfide on oxidative damage and liver regeneration in an experimental hepatectomy model.

    Science.gov (United States)

    Battal, M; Kartal, A; Citgez, B; Yilmaz, B; Akcakaya, A; Karatepe, O

    2015-01-01

    We investigated the effects of allyl disulfide (agarlic extract) on tissue damage, regeneration, proliferation and oxidative damage in an experimental liver resection model. In the study, 24 female Wistar albinorats weighing approximately 200-250 g were used. Group 1:The rats in the experimental group all received a 70%hepatectomy and were fed an Allyl disulfide (30 μg kg day,Allyl disulfide, Sigma-Aldrich, formula: C6H10S2, CASNumber: 2179-57-9, formula weight: 146.27 g mol) in supplement to a regular diet for 1 week both preoperatively and postoperatively. Group 2: The rats in the control group also underwent a 70% hepatectomy and were given regular food and water for 1 week both preop and postop. Group 3: In the sham group, all rats were sacrificed 7 days after surgery. Forbiochemical evaluation, SGOT, SGPT, bilirubin, CRP and MDA were studied. In a histopathological examination, the fattening of the liver tissue, existence of (macro-micro vesicular),fibrosis, pleomorphism at hepatocyte nuclei, portal inflammation, existence of intralobular inflammatory cells,dilation at sinusoids, congestion, congestion at the central vein, regeneration, existence of Kupffer cells in the sinu soidallumen and ki-67 proliferation index at hepatocytes were examined. A significant difference between group 1 and group2 was observed regarding the existence of regeneration,(p:0.06), the occurrence of nuclear pleomorphisms (p:0,001)and the fibroblast activity status (p:0.001). Significant differences were found between the experimental groups in regard to Kupffer cell increase and dilation and the hyperemiastatus in the sinusoid lumens (p:0.013 and p:0.001,respectively). In the Allyl disulfide group, the proliferation index was significantly higher than that of the other groups(p:0,001), while the average plasma MDA value was lower than that of the other groups (p: 0,042). No significant differences were found among the groups with respect to tissue MDA values (p:0,720). No

  2. Chemical Kinetics of Hydrogen Atom Abstraction from Allylic Sites by (3)O2; 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 O2 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

  3. Palladacyclic imidazoline-naphthalene complexes: synthesis and catalytic performance in Pd(II)-catalyzed enantioselective reactions of allylic trichloroacetimidates.

    Science.gov (United States)

    Cannon, Jeffrey S; Frederich, James H; Overman, Larry E

    2012-02-17

    A new family of air- and moisture-stable enantiopure C,N-palladacycles (PIN-acac complexes) were prepared in good overall yield in three steps from 2-iodo-1-naphthoic acid and enantiopure β-amino alcohols. Three of these PIN complexes were characterized by single-crystal X-ray analysis. As anticipated, the naphthalene and imidazoline rings of PIN-acac complexes 18a and 18b were canted significantly from planarity and projected the imidazoline substituents R(1) and R(2) on opposite faces of the palladium square plane. Fifteen PIN complexes were evaluated as catalysts for the rearrangement of prochiral (E)-allylic trichloroacetimidate 19 (eq 2) and the S(N)2' allylic substitution of acetic acid with prochiral (Z)-allylic trichloroacetimidate 23. Although these complexes were kinetically poor catalysts for the Overman rearrangement, they were good catalysts for the allylic substitution reaction, providing branched allylic esters in high yield. However, enantioselectivities were low to moderate and significantly less than that realized with palladacyclic complexes of the COP family. Computational studies support an anti-acetoxypalladation/syn-deoxypalladation mechanism analogous to that observed with COP catalysts. The computational study further suggests that optimizing steric influence in the vicinity of the carbon ligand of a chiral C,N-palladacycle, rather than near the nitrogen heterocycle, is the direction to pursue in future development of improved enantioselective catalysts of this motif.

  4. Genome wide association mapping in Arabidopsis thaliana identifies novel genes involved in linking allyl glucosinolate to altered biomass and defense

    Directory of Open Access Journals (Sweden)

    Marta Francisco

    2016-07-01

    Full Text Available A key limitation in modern biology is the ability to rapidly identify genes underlying newly identified complex phenotypes. Genome wide association studies (GWAS have become an increasingly important approach for dissecting natural variation by associating phenotypes with genotypes at a genome wide level. Recent work is showing that the Arabidopsis thaliana defense metabolite, allyl glucosinolate (GSL, may provide direct feedback regulation, linking defense metabolism outputs to the growth and defense responses of the plant. However, there is still a need to identify genes that underlie this process. To start developing a deeper understanding of the mechanism(s that modulate the ability of exogenous allyl GSL to alter growth and defense, we measured changes in plant biomass and defense metabolites in a collection of natural 96 A. thaliana accessions fed with 50 µM of allyl GSL. Exogenous allyl GSL was introduced exclusively to the roots and the compound transported to the leaf leading to a wide range of heritable effects upon plant biomass and endogenous GSL accumulation. Using natural variation we conducted GWAS to identify a number of new genes which potentially control allyl responses in various plant processes. This is one of the first instances in which this approach has been successfully utilized to begin dissecting a novel phenotype to the underlying molecular/polygenic basis.

  5. Resonance energies of the allyl cation and allyl anion: contribution by resonance and inductive effects toward the acidity and hydride abstraction enthalpy of propene.

    Science.gov (United States)

    Barbour, Josiah B; Karty, Joel M

    2004-02-06

    Density functional theory was employed to calculate the acidities and hydride abstraction enthalpies of propene (3) and propane (4), along with their vinylogues (5 and 6, respectively). The same reaction enthalpies were calculated for the propene vinylogues in which the terminal vinyl group was rotated perpendicular to the rest of the conjugated system (7). The contribution by resonance and inductive effects toward the acidity and hydride abstraction enthalpy of each vinylogue of 5 (n = 1-3) was computed and extrapolated to n = 0 (the parent propene system). The resonance energies of the allyl cation and anion were determined to be about 20-22 and 17-18 kcal/mol, respectively. Comparisons are made to resonance energies calculated using other methodologies.

  6. S-Allyl cysteine improves nonalcoholic fatty liver disease in type 2 diabetes Otsuka Long-Evans Tokushima Fatty rats via regulation of hepatic lipogenesis and glucose metabolism.

    Science.gov (United States)

    Takemura, Shigekazu; Minamiyama, Yukiko; Kodai, Shintaro; Shinkawa, Hiroji; Tsukioka, Takuma; Okada, Shigeru; Azuma, Hideki; Kubo, Shoji

    2013-09-01

    It is important to prevent and improve diabetes mellitus and its complications in a safe and low-cost manner. S-Allyl cysteine, an aged garlic extract with antioxidant activity, was investigated to determine whether S-allyl cysteine can improve type 2 diabetes in Otsuka Long-Evans Tokushima Fatty rats with nonalcoholic fatty liver disease. Male Otsuka Long-Evans Tokushima Fatty rats and age-matched Long-Evans Tokushima Otsuka rats were used and were divided into two groups at 29 weeks of age. S-Allyl cysteine (0.45% diet) was administered to rats for 13 weeks. Rats were killed at 43 weeks of age, and detailed analyses were performed. S-Allyl cysteine improved hemoglobinA1c, blood glucose, triglyceride, and low-density lipoprotein cholesterol levels. Furthermore, S-allyl cysteine normalized plasma insulin levels. S-Allyl cysteine activated the mRNA and protein expression of both peroxisome proliferator-activated receptor α and γ, as well as inhibiting pyruvate dehydrogenase kinase 4 in Otsuka Long-Evans Tokushima Fatty rat liver. Sterol regulatory element-binding protein 1c and forkhead box O1 proteins were normalized by S-allyl cysteine in Otsuka Long-Evans Tokushima Fatty rat liver. In conclusions, these findings support the hypothesis that S-allyl cysteine has diabetic and nonalcoholic fatty liver disease therapeutic potential as a potent regulating agent against lipogenesis and glucose metabolism.

  7. Thermosetting composite matrix materials based on allyl and/or propargyl substituted cyclopentadiene, indene and fluorene

    Science.gov (United States)

    Tregre, Gregory Jude

    A series of all-hydrocarbon thermoset composite matrix resins was synthesized via electrophilic substitution of cyclopentadiene, indene, and fluorene ring systems with allyl and/or propargyl halides under phase transfer conditions. Reaction of cyclopentadiene with allyl chloride (ACP resin), propargyl bromide (PCP resin) or various feed ratios of allyl chloride and propargyl bromide (APCP resins) yielded mixtures of products with 2-6 substituents per cyclopentadiene ring. Reaction of indene with allyl chloride (Al resins) or propargyl bromide (PI resins) yielded mixtures of products with 2-4 substituents per indene. In both sets of resins the allyl functionality obtained a greater average degree of substitution than the analogous propargyl species. Differential scanning calorimetric (DSC) analysis of the multifunctional resins showed broad, high-energy thermal cures in all cases. The enthalpies of cure for ACP and PCP were 750 J/g and 805 J/g, respectively, with peak cure energies occurring at 310 and 248sp°C. The enthalpy of cure for APCP resins ranged from 750 J/g to 800 J/g with higher propargyl-functional resins yielding higher enthalpies of cure. Physically mixed ACP/PCP resin systems gave peak cure temperatures and energy values comparable to APCP resins. The enthalpies of cure for Al and PI-resins were 480 J/g and 630 J/g, respectively. Peak cure temperature for Al resin was 320sp°C, while the peak cure for PI resin occurred at 282sp°C. Infrared spectroscopy (IR) and nuclear magnetic resonance spectroscopy (NMR) were used to evaluate mechanisms of cure in the experimental resins. The allyl functional resins cured through a combination of ene reactions and polyaddition reactions. The propargyl functional resins cured through ene reactions and polyadditions but also underwent some cyclotrimerization of the propargyl functionalities. A small amount of autoxidation was seen in all of the resins. Thermal stability and carbon yields of the cured resins were

  8. Study on the Preparation of Allyl-modified Starch in Isopropyl/Water Medium for Warp Sizing

    Institute of Scientific and Technical Information of China (English)

    LI Man-li; ZHU Zhi-feng; ZHANG Long-qiu

    2008-01-01

    A new method for the pretreatment of starch by etherification was developed to eliminate the problems of lower grafting efficiency associated with the preparation of starch graft copolymers as warp sizing agents.The etherification of starch with allyl chloride was investigated in order to effectively enhance the reaction efficiency.The technological variables of the reaction considered for evaluating the etherification included sodium hydroxide amount,water content in water-isopropyi alcohol medium,allyl cldoride concentration,reaction temperature and reaction time.The experimental result demonstrated that the variables considered showed evident effect on the reaction efficiency.For the etherification,a condition of 20% for the water content,1.5:1 for the molar ratio of sodium hydroxide to allyl chloride.and at 30℃ under 24h reaction is Sufficient to retain the reaction efficiency above 50%.Furthermore,a contrast test demonstrated that the graft efficiency can be increased with the etherification pretreatment.

  9. Chirality Transfer in Gold(I)-Catalysed Direct Allylic Etherifications of Unactivated Alcohols: Experimental and Computational Study.

    Science.gov (United States)

    Barker, Graeme; Johnson, David G; Young, Paul C; Macgregor, Stuart A; Lee, Ai-Lan

    2015-09-21

    Gold(I)-catalysed direct allylic etherifications have been successfully carried out with chirality transfer to yield enantioenriched, γ-substituted secondary allylic ethers. Our investigations include a full substrate-scope screen to ascertain substituent effects on the regioselectivity, stereoselectivity and efficiency of chirality transfer, as well as control experiments to elucidate the mechanistic subtleties of the chirality-transfer process. Crucially, addition of molecular sieves was found to be necessary to ensure efficient and general chirality transfer. Computational studies suggest that the efficiency of chirality transfer is linked to the aggregation of the alcohol nucleophile around the reactive π-bound Au-allylic ether complex. With a single alcohol nucleophile, a high degree of chirality transfer is predicted. However, if three alcohols are present, alternative proton transfer chain mechanisms that erode the efficiency of chirality transfer become competitive.

  10. [3,3]-sigmatropic rearrangements of fluorinated allyl (Thio)cyanates - a tool for the synthesis of fluorinated (Thio)ureas.

    Science.gov (United States)

    Ramb, Daniel C; Kost, Lisa; Haufe, Günter

    2014-01-01

    The first (thio)cyanate to iso(thio)cyanate rearrangements based on 2-fluoroallylic alcohols are presented. Long-chain 2-fluoroallylic alcohols were converted to corresponding N-unsubstituted carbamates by treatment with trichloroacetyl isocyanate. Dehydration using trifluoroacetic anhydride in the presence of triethylamine formed intermediate allylic cyanates, which immediately underwent sigmatropic rearrangement to fluorinated allyl isocyanates. Without isolation the latter delivered fluorinated ureas by addition of amines. The thiocyanate to isothiocyanate rearrangements started from the same fluorinated allylic alcohols, which were first converted to mesylates. Heating in THF with potassium thiocyanate led to fluorinated allyl isothiocyanates, via [3,3]-sigmatropic rearrangement of intermediate allyl thiocyanates. The formed products were further reacted with amines to fluorinated thioureas.

  11. 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.

  12. Synthesis of Aryl Allyl Ether in the Recyclable Ionic Liquid [bmim]PF6

    Institute of Scientific and Technical Information of China (English)

    Zhou Mei-Yun; Li Yi-Qun; Xu Xin-Ming

    2004-01-01

    Ionic liquids, especially imidazonium salts, have recently gained recognition as possible environmentally benign alternative chemical process solvents. This is mainly due to their nonvolatile nature, insolubility in some solvents as well as their ability to dissolve a wide range of organic and inorganic materials, allowing the ionic liquids easy recovery and recycling. Examples of their application in organic reactions have been summarized in a number of recent review articles.1Aryl allyl ether is very useful intermediate in organic synthesis. The Williamson reaction is a well knows method for the preparation ethers. However, the reaction of alkylating agents with the phenoxide ions was conventionally carried out in the organic solvents. The usual solvents for this type of reaction are DCM, 2 DMSO, 3 DMF, 4 CH3CN5 etc. With the current desire to avoid the use of organic molecular solvents in organic synthesis, we decide to investigate the use of the ionic liquid for the alternative solvent for the Williamson reaction to prepare the aryl allyl ethers. The ionic liquid employed here was the moisture stable 1-butyl-3-methylimidazolium hexafluorophosphate [bmim]PF6.6 The ionic liquid is non-volatile, thermally stable, and depending on the anion, can present low immiscible with water,alkanes and dialky ethers. We have now found that aryl allyl ethers can have been obtained from various phenols and allyl bromide in the presence of potassium hydroxide in [bmim]PF6 as a replacement for classical organic solvents in the ambient temperature. The results are shown in Scheme 1.The reaction were carried out by simple mixing the phenolwith the ally bromide and potassium hydroxide in [bmim]PF6 and stirred at room temperature for 4h. The results are summarized in Table 1.In conclusion, Williamson reaction can be successfully conducted in ionic liquid [bmim]PF6 with a number of advantages: the procedure is simple, the reaction condition is mild and the yields are excellent

  13. Stereodivergent Allylic Substitutions with Aryl Acetic Acid Esters by Synergistic Iridium and Lewis Base Catalysis.

    Science.gov (United States)

    Jiang, Xingyu; Beiger, Jason J; Hartwig, John F

    2017-01-11

    The preparation of all possible stereoisomers of a given chiral molecule bearing multiple stereocenters by a simple and unified method is a significant challenge in asymmetric catalysis. We report stereodivergent allylic substitutions with aryl acetic acid esters catalyzed synergistically by a metallacyclic iridium complex and benzotetramisole. Through permutations of the enantiomers of the two chiral catalysts, all four stereoisomers of the products bearing two adjacent stereocenters are accessible with high diastereoselectivity and enantioselectivity. The resulting chiral activated ester products can be converted readily to enantioenriched amides, unactivated esters, and carboxylic acids in a one-pot manner.

  14. 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.

  15. Synthesis of functionalized epoxides by copper-catalyzed alkylative epoxidation of allylic alcohols with alkyl nitriles.

    Science.gov (United States)

    Bunescu, Ala; Wang, Qian; Zhu, Jieping

    2015-04-17

    A copper-catalyzed oxyalkylation of allylic alcohols using nonactivated alkyl nitriles as reaction partners was developed. A sequence involving generation of an alkyl nitrile radical followed by its addition to a double bond and a copper-mediated formation of C(sp(3))-O bond was proposed to account for the reaction outcome. The protocol provided an efficient route to functionalized tri- and tetrasubstituted epoxides via formation of a C(sp(3))-C(sp(3)) and a C(sp(3))-O bond with moderate to excellent diastereoselectivity.

  16. 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.

  17. Catalytic enantioselective 1,6-conjugate additions of propargyl and allyl groups

    Science.gov (United States)

    Meng, Fanke; Li, Xiben; Torker, Sebastian; Shi, Ying; Shen, Xiao; Hoveyda, Amir H.

    2016-09-01

    Conjugate (or 1,4-) additions of carbanionic species to α,β-unsaturated carbonyl compounds are vital to research in organic and medicinal chemistry, and there are several chiral catalysts that facilitate the catalytic enantioselective additions of nucleophiles to enoates. Nonetheless, catalytic enantioselective 1,6-conjugate additions are uncommon, and ones that incorporate readily functionalizable moieties, such as propargyl or allyl groups, into acyclic α,β,γ,δ-doubly unsaturated acceptors are unknown. Chemical transformations that could generate a new bond at the C6 position of a dienoate are particularly desirable because the resulting products could then be subjected to further modifications. However, such reactions, especially when dienoates contain two equally substituted olefins, are scarce and are confined to reactions promoted by a phosphine-copper catalyst (with an alkyl Grignard reagent, dialkylzinc or trialkylaluminium compounds), a diene-iridium catalyst (with arylboroxines), or a bisphosphine-cobalt catalyst (with monosilyl-acetylenes). 1,6-Conjugate additions are otherwise limited to substrates where there is full substitution at the C4 position. It is unclear why certain catalysts favour bond formation at C6, and—although there are a small number of catalytic enantioselective conjugate allyl additions—related 1,6-additions and processes involving a propargyl unit are non-existent. Here we show that an easily accessible organocopper catalyst can promote 1,6-conjugate additions of propargyl and 2-boryl-substituted allyl groups to acyclic dienoates with high selectivity. A commercially available allenyl-boron compound or a monosubstituted allene may be used. Products can be obtained in up to 83 per cent yield, >98:2 diastereomeric ratio (for allyl additions) and 99:1 enantiomeric ratio. We elucidate the mechanistic details, including the origins of high site selectivity (1,6- versus 1,4-) and enantioselectivity as a function of the catalyst

  18. [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.

  19. Lanthanum triflate triggered synthesis of tetrahydroquinazolinone derivatives of N-allyl quinolone and their biological assessment

    Directory of Open Access Journals (Sweden)

    Jardosh Hardik H.

    2012-01-01

    Full Text Available A series of 24 derivatives of tetrahydroquinazolinone has been synthesized by one-pot cyclocondensation reaction of N-allyl quinolones, cyclic β-diketones and (thiourea/N-phenylthiourea in presence of lanthanum triflate catalyst. This methodology allowed us to achieve the products in excellent yield by stirring at room temperature. All the synthesized compounds were investigated against a representative panel of pathogenic strains using broth microdilution MIC (minimum inhibitory concentration method for their in vitro antimicrobial activity. Amongst these sets of heterocyclic compounds 5h, 6b, 6h, 5f, 5l, 5n and 6g found to have admirable activity.

  20. Synthesis of Aminophosphine Ligands with Binaphthyl Backbones for Silver(I)-catalyzed Enantioselective Allylation of Benzaldehyde

    Institute of Scientific and Technical Information of China (English)

    WANG,Yi(王以); JI,Bao-Ming(吉保明); DING,Kui-Ling(丁奎岭)

    2002-01-01

    A series of aminophosphine ligands was synthesized from 2amino-2′-hydroxy-1,1′-binaphthyl (NOBIN). Their asymmetric induction efficiency was examined for silver(I)catalyzed enantioselective allylation reaction of benzaldehyde with allyltributyltin.Under the optimized reaction conditions,quantitative yield as well as moderate ee value (54.5% ee)of product was achieved by the catalysis with silver(I)/3 complex. The effects of the binaphthyl backbone and the substituted situated at chelating N, Patoms on enantioselectivity of the reaction were also discussed.

  1. 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.

  2. 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.

  3. Nano-Aluminum Powder Mediated Allylation of Carbonyl Compounds in Aqueous Media

    Institute of Scientific and Technical Information of China (English)

    YUAN Shi-Zhen; LIU Jin

    2008-01-01

    A new and effective Barbier-Grignard allylation of aldehydes or ketones has been carried out with nano-aluminum powder in aqueous 0.1 mol·L-1 NH4Cl (aq.) under an atmosphere of nitrogen. Aromatic carbonyl compounds gave homoallylic alcohols in good yields. The effectiveness of reaction was strongly influenced by the steric environment surrounding the carbonyl group. Aliphatic carbonyl compounds proceeded in low yields. The dominant stereoisomer was an erythro-isomer when an ortho-hydroxyl carbonyl compound was reacted under such a reaction condition.

  4. Biphilic Organophosphorus Catalysis: Regioselective Reductive Transposition of Allylic Bromides via P(III)/P(V) Redox Cycling.

    Science.gov (United States)

    Reichl, Kyle D; Dunn, Nicole L; Fastuca, Nicholas J; Radosevich, Alexander T

    2015-04-29

    We report that a regioselective reductive transposition of primary allylic bromides is catalyzed by a biphilic organophosphorus (phosphetane) catalyst. Spectroscopic evidence supports the formation of a pentacoordinate (σ(5)-P) hydridophosphorane as a key reactive intermediate. Kinetics experiments and computational modeling are consistent with a unimolecular decomposition of the σ(5)-P hydridophosphorane via a concerted cyclic transition structure that delivers the observed allylic transposition and completes a novel P(III)/P(V) redox catalytic cycle. These results broaden the growing repertoire of reactions catalyzed within the P(III)/P(V) redox couple and suggest additional opportunities for organophosphorus catalysis in a biphilic mode.

  5. Mechanism of the cobalt oxazoline palladacycle (COP)-catalyzed asymmetric synthesis of allylic esters.

    Science.gov (United States)

    Cannon, Jeffrey S; Kirsch, Stefan F; Overman, Larry E; Sneddon, Helen F

    2010-11-03

    The catalytic enantioselective S(N)2' displacement of (Z)-allylic trichloroacetimidates catalyzed by the palladium(II) complex [COP-OAc](2) is a broadly useful method for the asymmetric synthesis of chiral branched allylic esters. A variety of experiments aimed at elucidating the nature of the catalytic mechanism and its rate- and enantiodetermining steps are reported. Key findings include the following: (a) the demonstration that a variety of bridged-dipalladium complexes are present and constitute resting states of the COP catalyst (however, monomeric palladium(II) complexes are likely involved in the catalytic cycle); (b) labeling experiments establishing that the reaction proceeds in an overall antarafacial fashion; (c) secondary deuterium kinetic isotope effects that suggest substantial rehybridization at both C1 and C3 in the rate-limiting step; and (d) DFT computational studies (B3-LYP/def2-TZVP) that provide evidence for bidentate substrate-bound intermediates and an anti-oxypalladation/syn-deoxypalladation pathway. These results are consistent with a novel mechanism in which chelation of the imidate nitrogen to form a cationic palladium(II) intermediate activates the alkene for attack by external carboxylate in the enantiodetermining step. Computational modeling of the transition-state structure for the acyloxy palladation step provides a model for enantioinduction.

  6. 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.

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

    Science.gov (United States)

    Shakoori, Alireza; Bremner, John B; Abdel-Hamid, Mohammed K; Willis, Anthony C; Haritakun, Rachada

    2015-01-01

    Summary 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. PMID:25977722

  8. Role of allyl group in the hydroxyl and peroxyl radical scavenging activity of S-allylcysteine.

    Science.gov (United States)

    Maldonado, Perla D; Alvarez-Idaboy, J Raúl; Aguilar-González, Adriana; Lira-Rocha, Alfonso; Jung-Cook, Helgi; Medina-Campos, Omar Noel; Pedraza-Chaverrí, José; Galano, Annia

    2011-11-17

    S-Allylcysteine (SAC) is the most abundant compound in aged garlic extracts, and its antioxidant properties have been demonstrated. It is known that SAC is able to scavenge different reactive species including hydroxyl radical (•OH), although its potential ability to scavenge peroxyl radical (ROO•) has not been explored. In this work the ability of SAC to scavenge ROO• was evaluated, as well as the role of the allyl group (-S-CH(2)-CH═CH(2)) in its free radical scavenging activity. Two derived compounds of SAC were prepared: S-benzylcysteine (SBC) and S-propylcysteine (SPC). Their abilities to scavenge •OH and ROO• were measured. A computational analysis was performed to elucidate the mechanism by which these compounds scavenge •OH and ROO•. SAC was able to scavenge •OH and ROO•, in a concentration-dependent way. Such activity was significantly ameliorated when the allyl group was replaced by benzyl or propyl groups. It was shown for the first time that SAC is able to scavenge ROO•.

  9. 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.

  10. Anti-Inflammatory and Antioxidant Effects of Repeated Exposure to Cruciferous Allyl Nitrile in Sensitizer-Induced Ear Edema in Mice.

    Science.gov (United States)

    Tanii, Hideji; Sugitani, Kayo; Saijoh, Kiyofumi

    2016-02-29

    Skin sensitizers induce allergic reactions through the induction of reactive oxygen species. Allyl nitrile from cruciferous vegetables has been reported to induce antioxidants and phase II detoxification enzymes in various tissues. We assessed the effects of repeated exposure to allyl nitrile on sensitizer-induced allergic reactions. Mice were dosed with allyl nitrile (0-200 µmol/kg), and then received a dermal application of 1 of 3 sensitizers on the left ear or 1 of 2 vehicles on the right ear. Quantitative assessment of edema was carried out by measuring the difference in weight between the portions taken from the right and left ears. We tested enzymes (superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), and thiobarbituric acid reactive substances (TBARS) in ears. Repeated exposure to allyl nitrile reduced edemas induced by glutaraldehyde and by 2, 4-dinitrochlorobenzene (DNCB), but not by formaldehyde. The repeated exposure decreased levels of TBARS, a marker of oxidative stress, induced by glutaraldehyde and by DNCB, but not by formaldehyde. Allyl nitrile elevated SOD levels for the 3 sensitizers, and CAT levels for formaldehyde and DNCB. Allyl nitrile also increased GPx levels for formaldehyde and DNCB, but not for glutaraldehyde. The reduced edemas were associated with changes in oxidative stress levels and antioxidant enzymes. Repeated exposure to allyl nitrile reduced allergic reactions induced by glutaraldehyde and by DNCB, but not by formaldehyde. This reduction was associated with changes in ROS levels and antioxidant enzyme activities.

  11. [(p-Cymene)RuCl2 ]2 : an efficient catalyst for highly regioselective allylic alkylations of chelated amino acid ester enolates.

    Science.gov (United States)

    Bayer, Anton; Kazmaier, Uli

    2014-08-11

    Chelated amino acid ester enolates are excellent nucleophiles for ruthenium-catalyzed allylic alkylations. Although [Cp*Ru(MeCN)3 ]PF6 was found to be the most reactive catalyst investigated, with the resulting allyl complexes reacting at temperatures as low as -78 °C, unfortunately the process took place with only moderate regio- and diastereoselectivity. In contrast, [(p-cymene)RuCl2 ]2 allowed allylations to be performed with a high degree of regioretention. Secondary allyl carboxylates with a terminal double bond were found to be the most reactive substrates, giving rise to the branched amino acids with perfect regioretention and chirality transfer. In this case, no isomerization of the Ru-allyl complex formed in situ was observed, in contrast to the analogues palladium complexes. This isomerization-free protocol can also be used for the synthesis of (Z)-configured γ,δ-unsaturated amino acid derivatives, starting from (Z)-allylic substrates. Here, the more reactive phosphates were found to be superior to the carboxylates, providing the required amino acids in almost quantitative yield with perfect regio- and stereoretention. Therefore, the Ru-catalyzed allylation reactions are well positioned to overcome the drawbacks of Pd-catalyzed processes. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. Regio- and Enantioselective Copper-Catalyzed Allylic Alkylation of Ortho-Substituted Cinnamyl Bromides with Grignard Reagents

    NARCIS (Netherlands)

    van der Molen, Nathalie C; Tiemersma-Wegman, Theodora D; Fañanás-Mastral, Martín; Feringa, Ben L

    2015-01-01

    A highly efficient method for the copper-catalyzed asymmetric allylic alkylation of ortho-substituted cinnamyl bromides with Grignard reagents is reported. The use of a catalytic system comprising CuBr center dot SMe2 and TaniaPhos as chiral ligands gives rise to a range of branched products with

  13. Efficient, regioselective palladium-catalyzed tandem Heck-isomerization reaction of aryl bromides and non-allylic benzyl alcohols.

    Science.gov (United States)

    Crawley, Matthew L; Phipps, Kristin M; Goljer, Igor; Mehlmann, John F; Lundquist, Joseph T; Ullrich, John W; Yang, Cuijian; Mahaney, Paige E

    2009-03-05

    An efficient and mild method to couple aryl bromides and activated non-allylic alcohols in a Heck reaction with tandem isomerization to selectively afford high yields of 1,5-diarylalkan-1-ones has been developed. Mechanistic insight was gained through NMR studies of products derived from deuterium-labeled intermediates.

  14. Antimicrobial activity of allyl isothiocyanate used to coat biodegradable composite films as affected by storage and handling conditions

    Science.gov (United States)

    We evaluated the effects of storage and handling conditions on the antimicrobial activity of biodegradable composite films (polylactic acid and sugar beet pulp) coated with allyl isothiocyanate (AIT). Polylactic acid (PLA) and chitosan were incorporated with AIT and coated on one side of the film. T...

  15. Synthesis of novel chiral phosphine-triazine ligand derived from α-phenylethylamine for Pd-catalyzed asymmetric allylic alkylation

    Institute of Scientific and Technical Information of China (English)

    Jia Di Huang; Xiang Ping Hu; Zhuo Zheng

    2008-01-01

    A novel chiral phosphine-triazine ligand was synthesized from chiral model reaction of Pd-catalyzed allylic alkylation of rac-l,3-diphenylprop-2-en-l-yl pivalate with dimethyl malonate, good enantioselectivity (90% e.e.) was obtained by using this ligand.

  16. Lewis base-promoted rearrangement of allylic cyanohydrins: construction of functionalized nitriles bearing 1,3-diketone moieties.

    Science.gov (United States)

    Zhang, Yan-Jing; Hou, Qi-Lan; Wang, Hai-Jing; Liao, Wei-Wei

    2014-11-21

    A novel Lewis base-promoted rearrangement of allylic cyanohydrins has been developed, in which the cyano group was rearranged, directly coupled with the generation of new functional groups. This protocol provides a unique and facile way to prepare highly functionalized nitriles bearing 1,3-diketone moieties under mild reaction conditions. Furthermore, the synthetic transformations of the functionalized products have also been demonstrated.

  17. 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 acces

  18. The NBS Reaction: A Simple Explanation for the Predominance of Allylic Substitution over Olefin Addition by Bromine at Low Concentrations.

    Science.gov (United States)

    Wamser, Carl C.; Scott, Lawrence T.

    1985-01-01

    Examines mechanisms related to use of N-bromosuccinimide (NBS) for bromination at an allylic position. Also presents derived rate laws for three possible reactions of molecular bromine with an alkene: (1) free radical substitution; (2) free radical addition; and (3) electrophilic addition. (JN)

  19. Enantioselective Construction of Acyclic Quaternary Carbon Stereocenters: Palladium-Catalyzed Decarboxylative Allylic Alkylation of Fully Substituted Amide Enolates.

    Science.gov (United States)

    Starkov, Pavel; Moore, Jared T; Duquette, Douglas C; Stoltz, Brian M; Marek, Ilan

    2017-07-19

    We report a divergent and modular protocol for the preparation of acyclic molecular frameworks containing newly created quaternary carbon stereocenters. Central to this approach is a sequence composed of a (1) regioselective and -retentive preparation of allyloxycarbonyl-trapped fully substituted stereodefined amide enolates and of a (2) enantioselective palladium-catalyzed decarboxylative allylic alkylation reaction using a novel bisphosphine ligand.

  20. Diastereoselective Allylation of "N"-"Tert"-Butanesulfinyl Imines: An Asymmetric Synthesis Experiment for the Undergraduate Organic Laboratory

    Science.gov (United States)

    Chen, Xiao-Yang; Sun, Li-Sen; Gao, Xiang; Sun, Xing-Wen

    2015-01-01

    An asymmetric synthetic experiment that encompasses both diastereoselectivity and enantioselectivity is described. In this experiment, Zn-mediated allylation of an ("R")-"N"-"tert"-butanesulfinyl imine is first performed to obtain either diastereomer using two different solvent systems, followed by oxidation of the…

  1. New chiral N, S-ligands with Thiophenyl at Benzylic Position. Palladium(Ⅱ)-catalyzed Enantioselective Allylic Alkylation

    Institute of Scientific and Technical Information of China (English)

    WU,Hao(吴昊); WU,Xun-Wei(巫循伟); HOU,Xue-Long(侯雪龙); DAI,Li-Xin(戴立信); WANG,Quan-Rui(王全瑞)

    2002-01-01

    New chiral N, S-ligands with oxazoline and thiphenyl substituents at benzene ring and benzylic position have been prepared and applied in palladium-catalyzed asymmetric allylic alkylation reaction to provide the product with high yield and entantioselectivity (82%-93% ee).

  2. 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.

  3. Phosphine-catalyzed [4 + 1] annulation between α,β-unsaturated imines and allylic carbonates: synthesis of 2-pyrrolines.

    Science.gov (United States)

    Tian, Junjun; Zhou, Rong; Sun, Haiyun; Song, Haibin; He, Zhengjie

    2011-04-01

    In this report, a phosphine-catalyzed [4 + 1] annulation between α,β-unsaturated imines and allylic carbonates is described. This reaction represents the first realization of catalytic [4 + 1] cyclization of 1,3-azadienes with in situ formed phosphorus ylides, which provides highly efficient and diastereoselective synthesis of 2-pyrrolines.

  4. Spectra of carbanions formed from allyl cyanide during isomerization in zeolite NaY-FAU with strong basic sites

    Science.gov (United States)

    Hannus, István; Förster, Horst; Tasi, Gyula; Kiricsi, Imre; Molnár, Árpád

    1995-03-01

    Double bond isomerization of allyl cyanide to crotononitrile over a basic zeolite catalyst was monitored by IR and UV-VIS spectroscopy in order to get information on the surface intermediates involved. Due to the spectral changes the occurence of a carbanionic intermediate seems to be highly probable characterized by an absorption at 400 nm.

  5. 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 subjected...... to the Pd-catalyzed cyclization conditions, and were found to form lactones via exo attack. DFT calculations using BP86/LACVP*+level of theory with a CH2Cl2 solvation correction reproduce the relative transition state energies. The preference for exo-cyclization of the nitrogen-containing starting material...... appears to result from the preference for near-planarity of the amide N. Both the oxygen- and nitrogen tethers are too short to allow efficient endo-cyclization, whereas the carbon-tether is long enough to allow favorable endo-cyclization. The carbon tether also disfavors the exo-cyclization transition...

  6. 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.

  7. An Efficient Amide-Aldehyde-Alkene Condensation: Synthesis for the N-Allyl Amides.

    Science.gov (United States)

    Quan, Zheng-Jun; Wang, Xi-Cun

    2016-02-01

    The allylamine skeleton represents a significant class of biologically active nitrogen compounds that are found in various natural products and drugs with well-recognized pharmacological properties. In this personal account, we will briefly discuss the synthesis of allylamine skeletons. We will focus on showing a general protocol for Lewis acid-catalyzed N-allylation of electron-poor N-heterocyclic amides and sulfonamide via an amide-aldehyde-alkene condensation reaction. The substrate scope with respect to N-heterocyclic amides, aldehydes, and alkenes will be discussed. This method is also capable of preparing the Naftifine motif from N-methyl-1-naphthamide or methyl (naphthalene-1-ylmethyl)carbamate, with paraformaldehyde and styrene in a one-pot manner.

  8. Low-temperature Electrodeposition of Aluminium from Lewis Acidic 1-Allyl-3-methylimidazolium Chloroaluminate Ionic Liquids

    Institute of Scientific and Technical Information of China (English)

    郑勇; 张锁江; 吕兴梅; 王倩; 左勇; 刘恋

    2012-01-01

    Lewis acidic 1-allyl-3-methylimidazolium chloroaluminate ionic liquids were used as promising electrolytes in the low-temperature electrodeposition of aluminium. Systematic studies on deposition process have been performed by cYClic voltammetry and chronoamperometry. The surface morphology and X-ray diffraction (XRD) patterns of deposits prepared at different experimental conditions were also investigated. It was shown that the nucleation density and growth rate of crystallites had a great effect on the structure of aluminium deposited. The crys- tallographic orientation of deposits was mainly influenced by temperature and current density. Smooth, dense and well adherent aluminium coatings were obtained on copper substrates at 10-25 mA.cm^-2 and 313.2-353.2 K. More- over, the current efficiency of deposition and purity of aluminium have been significantly improved, demonstrating that the ionic liquids tested have a prospectful potential in electroplating and electrorefining of aluminium.

  9. The Reaction of Allyl Isothiocyanate with Hydroxyl/Water and β-Cyclodextrin Using Ultraviolet Spectrometry

    Directory of Open Access Journals (Sweden)

    Zi-Tao Jiang

    2006-01-01

    Full Text Available The reaction of allyl isothiocyanate (AITC with hydroxyl/water and β-cyclodextrin (β-CD in different acidic-alkaline media has been investigated by ultraviolet spectrometry. The kinetic parameters of the reaction were measured. It was found that after AITC translating into thiourea, the absorption peak shifted from 240 to 226 nm and the molar absorptivity increased about 16 times. The reaction can be seen as a pseudo first order reaction because the concentration of hydroxyl was constant. β-CD can inhibit the reaction of AITC with hydroxyl/water, i.e. the hydrolysis of AITC. The formation constant (Ka and thermodynamic parameters of the complex reaction were calculated. Ka decreased with the increase of temperature. The experimental results indicated that the inclusive process was an exothermic and enthalpy-driven process accompanied with a negative entropic contribution.

  10. The allyl radical revisited: a theoretical study of the electronic spectrum

    Science.gov (United States)

    Aquilante, Francesco; Jensen, Kasper P.; Roos, Björn O.

    2003-10-01

    In this Letter, we report the electronic spectrum of the allyl radical, obtained with multiconfigurational perturbation theory (MS-CASPT2). The assignment of the spectrum is in accordance with experiment to within 0.2 eV. We have computed the complete first Rydberg series and the beginning of the second Rydberg series. A new valence-excited 2B 1 state has been found which has hitherto been hidden by Rydberg transitions. A rationalisation of the electronic spectrum is provided in terms of resonance forms in ground and excited states. This model shows that while a multiconfigurational wavefunction is necessary to qualitatively model the system, the large ionic character of the valence electronic states makes an accurate treatment of the dynamical correlation necessary for a quantitative description of the spectrum.

  11. 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.

  12. Dietary S-Allyl-L-cysteine Reduces Mortality with Decreased Incidence of Stroke and Behavioral Changes in Stroke-Prone Spontaneously Hypertensive Rats

    National Research Council Canada - National Science Library

    KIM, Ji-Myung; CHANG, Namsoo; KIM, Won-Ki; CHUN, Hyang Sook

    2006-01-01

    S-Allyl-L-cysteine (SAC), an active organosulfur compound derived from garlic, was found to reduce mortality with lesser incidence of stroke and also to lower the overall stroke-related behavioral score in stroke-prone...

  13. DFT mechanistic study of the selective terminal C–H activation of n-pentane with a tungsten allyl nitrosyl complex

    National Research Council Canada - National Science Library

    Lee, Richmond; Tan, Davin; Liu, Chaoli; Li, Huaifeng; Guo, Hao; Shyue, Jing-Jong; Huang, Kuo-Wei

    2017-01-01

    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...

  14. LiBF4-mediated C-glycosylation of glycals with allyltrimethylsilane: a facile synthesis of allyl C-glycosylic compounds.

    Science.gov (United States)

    Yadav, J S; Reddy, B V; Chandraiah, L; Reddy, K S

    2001-05-18

    The treatment of glycals with allyltrimethylsilane in the presence of lithium tetrafluoroborate in acetonitrile gave the corresponding allyl 2,3-unsaturated C-glycosylic compounds in excellent yields with high anomeric selectivity.

  15. Modular access to vicinally functionalized allylic (thio)morpholinonates and piperidinonates by substrate-controlled annulation of 1,3-azadienes with hexacyclic anhydrides.

    Science.gov (United States)

    Braunstein, Hannah; Langevin, Spencer; Khim, Monique; Adamson, Jonathan; Hovenkotter, Katie; Kotlarz, Lindsey; Mansker, Brandon; Beng, Timothy K

    2016-09-21

    A modular substrate-controlled hexannulation of inherently promiscuous 1,3-azadienes with hexacyclic anhydrides, which affords versatile vicinally functionalized allylic lactams, in high yields, regio- and stereoselectivities is described.

  16. 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.

  17. 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.

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

    Institute of Scientific and Technical Information of China (English)

    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.

  19. 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.

  20. Characterization of an allylic/benzyl alcohol dehydrogenase from Yokenella sp. strain WZY002, an organism potentially useful for the synthesis of α,β-unsaturated alcohols from allylic aldehydes and ketones.

    Science.gov (United States)

    Ying, Xiangxian; Wang, Yifang; Xiong, Bin; Wu, Tingting; Xie, Liping; Yu, Meilan; Wang, Zhao

    2014-04-01

    A novel whole-cell biocatalyst with high allylic alcohol-oxidizing activities was screened and identified as Yokenella sp. WZY002, which chemoselectively reduced the C=O bond of allylic aldehydes/ketones to the corresponding α,β-unsaturated alcohols at 30°C and pH 8.0. The strain also had the capacity of stereoselectively reducing aromatic ketones to (S)-enantioselective alcohols. The enzyme responsible for the predominant allylic/benzyl alcohol dehydrogenase activity was purified to homogeneity and designated YsADH (alcohol dehydrogenase from Yokenella sp.), which had a calculated subunit molecular mass of 36,411 Da. The gene encoding YsADH was subsequently expressed in Escherichia coli, and the purified recombinant YsADH protein was characterized. The enzyme strictly required NADP(H) as a coenzyme and was putatively zinc dependent. The optimal pH and temperature for crotonaldehyde reduction were pH 6.5 and 65°C, whereas those for crotyl alcohol oxidation were pH 8.0 and 55°C. The enzyme showed moderate thermostability, with a half-life of 6.2 h at 55°C. It was robust in the presence of organic solvents and retained 87.5% of the initial activity after 24 h of incubation with 20% (vol/vol) dimethyl sulfoxide. The enzyme preferentially catalyzed allylic/benzyl aldehydes as the substrate in the reduction of aldehydes/ketones and yielded the highest activity of 427 U mg(-1) for benzaldehyde reduction, while the alcohol oxidation reaction demonstrated the maximum activity of 79.9 U mg(-1) using crotyl alcohol as the substrate. Moreover, kinetic parameters of the enzyme showed lower Km values and higher catalytic efficiency for crotonaldehyde/benzaldehyde and NADPH than for crotyl alcohol/benzyl alcohol and NADP(+), suggesting the nature of being an aldehyde reductase.

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

    Science.gov (United States)

    Silveira-Dorta, Gastón; Álvarez-Méndez, Sergio J; Martín, Víctor S

    2016-01-01

    Summary 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-(dia)stereoselectivity was observed when compared to the previous one-pot method. The (dia)stereoselectivity 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. PMID:27340486

  2. Epoxidation of olefins and allylic alcohols with hydrogen peroxide catalyzed by heteropoly acids in the presence of cetylpyridinium chloride

    Energy Technology Data Exchange (ETDEWEB)

    Okabayashi, Takuji; Yamawaki, Kazumasa; Nishihara, Hideki; Yamada, Hiroshi; Ura, Toshikazu; Ishii, Yasutaka; Ogawa, Masaya

    1987-11-01

    The epoxidation of olefins and allylic alcohols with aqueous hydrogen peroxide could be achieved in good yield when 12-tungustophosphoric acid(WPA) was used with two phase condition using chloroform as the solvent. From the epoxidation result by 12-molybdophosphoric acid(MPA) and WPA catalysts, epoxidation activity of WPA catalyst was found to be remarkably higher than that of MPA. The rate of epoxidation by heteropoly acids catalyst depended markedly upon the activity of the reaction medium. Epoxidation of allylic alcohols with hydrogen peroxide proceeded under mild conditions, resulting good yield of epoxi-alcohols. Epoxidation of olefins by WPA/cetylpyridium chloride was confirmed to be promoted selectively with cheap and pure hydrogen peroxide, resulting good yield. (3 figs, 2 tabs, 18 refs)

  3. REDUCING NONSELECTIVE PROTEIN ADSORPTION AND CELL ADHESION ON POLYACRYLONITRILE FILMS BY COPOLYMERIZATION OF ACRYLONITRILE WITH α-ALLYL GLUCOSIDE

    Institute of Scientific and Technical Information of China (English)

    Rui-qiang Kou; Chao Qu; Zhi-kang Xu; You-yi Xu; Ke Yao

    2003-01-01

    In this work, the surface properties of novel sugar-containing polymers, α-allyl glucoside (AG)/acrylonitrile (AN)copolymers, were studied by contact angle, protein adsorption and cell adhesion measurements. It was found that the contact angle of the copolymer films decreased from 68° to 30° with the increase of AG content in the copolymer. The adsorption amount of bovine serum albumin (BSA) and the adhesive macrophage onto the film surface also decreased significantly with increasing α-allyl glucoside content from 0 to 42 wt% in the copolymer. These preliminary results reveal that both the hydrophilicity and the biocompatibility of polyacrylonitrile-based membranes could be improved by copolymerizing acrylonitrile with vinyl carbohydrates.

  4. 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.

  5. Platinum-catalyzed direct amination of allylic alcohols under mild conditions: ligand and microwave effects, substrate scope, and mechanistic study.

    Science.gov (United States)

    Ohshima, Takashi; Miyamoto, Yoshiki; Ipposhi, Junji; Nakahara, Yasuhito; Utsunomiya, Masaru; Mashima, Kazushi

    2009-10-14

    Transition metal-catalyzed amination of allylic compounds via a pi-allylmetal intermediate is a powerful and useful method for synthesizing allylamines. Direct catalytic substitution of allylic alcohols, which forms water as the sole coproduct, has recently attracted attention for its environmental and economical advantages. Here, we describe the development of a versatile direct catalytic amination of both aryl- and alkyl-substituted allylic alcohols with various amines using Pt-Xantphos and Pt-DPEphos catalyst systems, which allows for the selective synthesis of various monoallylamines, such as the biologically active compounds Naftifine and Flunarizine, in good to high yield without need for an activator. The choice of the ligand was crucial toward achieving high catalytic activity, and we demonstrated that not only the large bite-angle but also the linker oxygen atom of the Xantphos and DPEphos ligands was highly important. In addition, microwave heating dramatically affected the catalyst activity and considerably decreased the reaction time compared with conventional heating. Furthermore, several mechanistic investigations, including (1)H and (31)P{(1)H} NMR studies; isolation and characterization of several catalytic intermediates, Pt(xantphos)Cl(2), Pt(eta(2)-C(3)H(5)OH)(xantphos), etc; confirmation of the structure of [Pt(eta(3)-allyl)(xantphos)]OTf by X-ray crystallographic analysis; and crossover experiments, suggested that formation of the pi-allylplatinum complex through the elimination of water is an irreversible rate-determining step and that the other processes in the catalytic cycle are reversible, even at room temperature.

  6. Deconvoluting the memory effect in Pd-catalyzed allylic alkylation; effect of leaving group and added chloride

    DEFF Research Database (Denmark)

    Fristrup, Peter; Jensen, Thomas; Hoppe, Jakob

    2006-01-01

    An analysis of product distributions in the Tsuji-Trost reaction indicates that several instances of reported memory effects can be attributed to slow interconversion of the initially formed syn- and anti-[Pd(eta3-allyl)] complexes. Addition of chloride triggers a true memory effect, in which the...... that the position trans to the phosphine ligand is more reactive both in the initial ionization and in the subsequent nucleophilic attack....

  7. Allyl group as a protecting group for internucleotide phosphate and thiophosphate linkages in oligonucleotide synthesis: facile oxidation and deprotection conditions.

    Science.gov (United States)

    Manoharan, M; Lu, Y; Casper, M D; Just, G

    2000-02-10

    [reaction: see text] The allyl group, which serves as a protecting group for an internucleotide bond for both phosphates and phosphorothioates, can be easily removed by good nucleophiles under weakly basic or neutral conditions. For a practical synthesis on solid support, camphorsulfonyloxaziridine was used as the oxidizing agent for synthesizing DNA, while the Beaucage reagent was used for preparing phosphorothioate oligomers. Both types of oligonucleotides were easily deprotected by concentrated ammonium hydroxide containing 2% mercaptoethanol.

  8. Direct Conversion of Aldehydes and Ketones to Allylic Halides by a NbX(5-)[3,3] Rearrangement.

    Science.gov (United States)

    Fleming, Fraser F; Ravikumar, P C; Yao, Lihua

    2009-01-01

    Sequential addition of vinylmagnesium bromide and NbCl(5), or NbBr(5), to a series of aldehydes and ketones directly provides homologated, allylic halides. Transposition of the intermediate vinyl alkoxide is envisaged through a metalla-halo-[3,3] rearrangement with concomitant delivery of the halogen to the terminal carbon. The [3,3] rearrangement is equally effective for the conversion of a propargyllic alcohol to the corresponding allenyl bromide.

  9. Direct Conversion of Aldehydes and Ketones to Allylic Halides by a NbX5-[3,3] Rearrangement

    Science.gov (United States)

    Fleming, Fraser F.; Ravikumar, P. C.; Yao, Lihua

    2009-01-01

    Sequential addition of vinylmagnesium bromide and NbCl5, or NbBr5, to a series of aldehydes and ketones directly provides homologated, allylic halides. Transposition of the intermediate vinyl alkoxide is envisaged through a metalla-halo-[3,3] rearrangement with concomitant delivery of the halogen to the terminal carbon. The [3,3] rearrangement is equally effective for the conversion of a propargyllic alcohol to the corresponding allenyl bromide. PMID:20046989

  10. Synchrotron Photoionization Mass Spectrometry Measurements of Kinetics and Product Formation in the Allyl Radical (H2CCHCH2)Self Reaction

    Science.gov (United States)

    Selby, Talitha M.; Melini, giovanni; Goulay, Fabien; Leone, Stephen R.; Fahr, Askar; Taatjes, Craig A.; Osborn, David L.

    2008-01-01

    Product channels for the self-reaction of the resonance-stabilized allyl radical, C3H5 + C3H5, have been studied with isomeric specificity at temperatures from 300-600 K and pressures from 1-6 Torr using time-resolved multiplexed photoionization mass spectrometry. Under these conditions 1,5-hexadiene was the only C6H10 product isomer detected. The lack of isomerization of the C6H10 product is in marked contrast to the C6H6 product in the related C3H3 + C3H3 reaction, and is due to the more saturated electronic structure of the C6H10 system. The disproportionation product channel, yielding allene + propene, was also detected, with an upper limit on the branching fraction relative to recombination of 0.03. Analysis of the allyl radical decay at 298 K yielded a total rate coefficient of (2.7 +/- 0.8) x 10(exp -11) cu cm/molecule/s, in good agreement with pre.vious experimental measurements using ultraviolet kinetic absorption spectroscopy and a recent theoretical determination using variable reaction coordinate transition state theory. This result provides independent indirect support for the literature value of the allyl radical ultraviolet absorption cross-section near 223 nm.

  11. Synchrotron Photoionization Mass Spectrometry Measurements of Kinetics and Product Formation in the Allyl Radical (H2CCHCH2)Self Reaction

    Science.gov (United States)

    Selby, Talitha M.; Melini, giovanni; Goulay, Fabien; Leone, Stephen R.; Fahr, Askar; Taatjes, Craig A.; Osborn, David L.

    2008-01-01

    Product channels for the self-reaction of the resonance-stabilized allyl radical, C3H5 + C3H5, have been studied with isomeric specificity at temperatures from 300-600 K and pressures from 1-6 Torr using time-resolved multiplexed photoionization mass spectrometry. Under these conditions 1,5-hexadiene was the only C6H10 product isomer detected. The lack of isomerization of the C6H10 product is in marked contrast to the C6H6 product in the related C3H3 + C3H3 reaction, and is due to the more saturated electronic structure of the C6H10 system. The disproportionation product channel, yielding allene + propene, was also detected, with an upper limit on the branching fraction relative to recombination of 0.03. Analysis of the allyl radical decay at 298 K yielded a total rate coefficient of (2.7 +/- 0.8) x 10(exp -11) cu cm/molecule/s, in good agreement with pre.vious experimental measurements using ultraviolet kinetic absorption spectroscopy and a recent theoretical determination using variable reaction coordinate transition state theory. This result provides independent indirect support for the literature value of the allyl radical ultraviolet absorption cross-section near 223 nm.

  12. 烯丙基酚醛树脂的固化动力学%Curing Kinetics of Allyl Phenolic Resin

    Institute of Scientific and Technical Information of China (English)

    刘洋; 刘诗薇; 李志强; 于景坤

    2012-01-01

    The curing behavior of allyl phenolic resin was analyzed at different heating rates using differential scanning calorimetry.The obtained kinetic data were treated by Kissinger and KAS(Kissinger-Akahira-Sunose) methods to obtain the curing reaction kinetic parameters.A curing kinetics model was established for allyl phenolic resin.Compared with phenolic resin,the curing temperature of allyl phenolic resin is higher,the reaction order is closer to 1,and the average activation energy of the curing reaction is lower,111.45 kJ/mol.The activation energy of allyl phenolic resin is almost constant and changes little with temperature in the curing process.The curing kinetics model of allyl phenolic resin provides a theoretical basis for the study of curing process parameters.%利用差示扫描量热法分析了烯丙基酚醛树脂在不同升温速率下的固化行为,用Kissinger法和KAS(Kissinger-Akahira-Sunose)法对获得的动力学数据进行处理,得到了固化反应动力学参数,并建立了烯丙基酚醛树脂的固化动力学模型.结果表明:与纯酚醛树脂相比,烯丙基酚醛树脂固化温度较高,反应级数更接近于1,固化反应所需的平均表观活化能较低,为111.45kJ/mol;在整个固化过程中,烯丙基酚醛树脂的活化能较为恒定,随温度变化不大;烯丙基酚醛树脂固化动力学模型为研究该体系固化工艺参数提供了理论依据.

  13. Effects of Allyl Isothiocyanate, Acetaminophen, and Dipyrone in the Guinea-Pig Ileum.

    Science.gov (United States)

    Donnerer, Josef; Liebmann, Ingrid

    2017-01-01

    Allyl isothiocyanate (AITC, mustard oil, 50-200 µmol/l), depending on specific dosages, inhibited the cholinergic twitch response in the longitudinal muscle-myenteric plexus (LMMP) strip of the guinea-pig ileum. AITC also induced short-lasting contractile responses, and decreases of the basal tone of the LMMP strip at low concentrations and increases at high concentrations. Hexamethonium, a blocker of nicotinic ganglionic transmission, was able to prevent the AITC-evoked inhibitory effect, an effect that was also observed with the opioid antagonist naloxone. The P2 purinoceptor antagonist pyridoxalphosphate-6-azophenyl-2'-4'-disulphonic acid and guanethidine had no significant influence on the inhibitory effect of AITC. Since AITC also reduced the electrical stimulation-induced myogenic smooth muscle contractions in the LMMP preparation, its contractile and relaxant actions can be regarded as neurogenic and myogenic in nature. The analgesics, acetaminophen (paracetamol, 100-500 µmol/l) and dipyrone (metamizole, 100-500 µmol/l), reduced both the cholinergic twitch and the myogenic contractions in the LMMP strip to the same extent; therefore, their action in the intestinal smooth muscle can be regarded as myogenic spasmolytic in nature. © 2016 S. Karger AG, Basel.

  14. 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.

  15. 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.

  16. 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.

  17. Pharmacokinetics, Tissue Distribution, and Anti-Lipogenic/Adipogenic Effects of Allyl-Isothiocyanate Metabolites.

    Directory of Open Access Journals (Sweden)

    Yang-Ji Kim

    Full Text Available Allyl-isothiocyanate (AITC is an organosulfur phytochemical found in abundance in common cruciferous vegetables such as mustard, wasabi, and cabbage. Although AITC is metabolized primarily through the mercapturic acid pathway, its exact pharmacokinetics remains undefined and the biological function of AITC metabolites is still largely unknown. In this study, we evaluated the inhibitory effects of AITC metabolites on lipid accumulation in vitro and elucidated the pharmacokinetics and tissue distribution of AITC metabolites in rats. We found that AITC metabolites generally conjugate with glutathione (GSH or N-acetylcysteine (NAC and are distributed in most organs and tissues. Pharmacokinetic analysis showed a rapid uptake and complete metabolism of AITC following oral administration to rats. Although AITC has been reported to exhibit anti-tumor activity in bladder cancer, the potential bioactivity of its metabolites has not been explored. We found that GSH-AITC and NAC-AITC effectively inhibit adipogenic differentiation of 3T3-L1 preadipocytes and suppress expression of PPAR-γ, C/EBPα, and FAS, which are up-regulated during adipogenesis. GSH-AITC and NAC-AITC also suppressed oleic acid-induced lipid accumulation and lipogenesis in hepatocytes. Our findings suggest that AITC is almost completely metabolized in the liver and rapidly excreted in urine through the mercapturic acid pathway following administration in rats. AITC metabolites may exert anti-obesity effects through suppression of adipogenesis or lipogenesis.

  18. On the antioxidant, neuroprotective and anti-inflammatory properties of S-allyl cysteine: An update.

    Science.gov (United States)

    Colín-González, Ana Laura; Ali, Syed F; Túnez, Isaac; Santamaría, Abel

    2015-10-01

    Therapeutic approaches based on isolated compounds obtained from natural products to handle central and peripheral disorders involving oxidative stress and inflammation are more common nowadays. The validation of nutraceutics vs. pharmaceutics as tools to induce preventive and protective profiles in human health alterations is still far of complete acceptance, but the basis to start more solid experimental and clinical protocols with natural products has already begun. S-allyl cysteine (SAC) is a promising garlic-derived organosulfur compound exhibiting a considerable number of positive actions in cell models and living systems. An update, in the form of review, is needed from time to time to get access to the state-of-the-art on this topic. In this review we visited recent and refreshing evidence of new already proven and potential targets to explain the benefits of using SAC against toxic and pathological conditions. The broad spectrum of protective actions covered by this molecule comprises antioxidant, redox modulatory and anti-inflammatory activities, accompanied by anti-apoptotic, pro-energetic and signaling capacities. Herein, we detail the evidence on these aspects to provide the reader a more complete overview on the promising aspects of SAC in research.

  19. Study on the interaction of bioactive compound S-allyl cysteine from garlic with serum albumin

    Directory of Open Access Journals (Sweden)

    Yue-e Sun

    2017-04-01

    Full Text Available Multispectroscopic techniques were used to investigate the interaction of S-allyl cysteine (SAC from garlic with human serum albumin (HSA. UV–Vis absorption measurements prove the formation of the HSA–SAC complex. An analysis of fluorescence spectra revealed that in the presence of SAC, the quenching mechanism of HSA is considered static. The quenching rate constant Kq, KSV, and the binding constant KA were estimated. According to the Van’t Hoff equation, the thermodynamic parameters enthalpy change (ΔH and entropy change (ΔS were calculated to be −1.00×105 J/mol and −255 J/mol/K, respectively. These indicate that hydrogen bonds and van der Waals forces are the major forces between SAC and HSA. The changes in the secondary structure of HSA, which was induced by SAC, were determined by circular dichroism spectroscopy. Energy transfer was confirmed and the distance between donor and acceptor was calculated to be 2.83 nm.

  20. 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

    2014-06-01

    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, (1)H NMR binding studies provide experimental support for theoretical calculations.

  1. Synergistic effect of allyl isothiocyanate (AITC) on cisplatin efficacy in vitro and in vivo.

    Science.gov (United States)

    Ling, Xiang; Westover, David; Cao, Felicia; Cao, Shousong; He, Xiang; Kim, Hak-Ryul; Zhang, Yuesheng; Chan, Daniel Cf; Li, Fengzhi

    2015-01-01

    Although in vitro studies have shown that isothiocyanates (ITCs) can synergistically sensitize cancer cells to cisplatin treatment, the underlying mechanisms have not been well defined, and there are no in vivo demonstrations of this synergy. Here, we report the in vitro and in vivo data for the combination of allyl isothiocyanate (AITC), one of the most common naturally occurring ITCs, with cisplatin. Our study revealed that cisplatin and AITC combination synergistically inhibits cancer cell growth and colony formation, and enhances apoptosis in association with the downregulation of antiapoptotic proteins Bcl-2 and survivin. Importantly, the in vivo combination treatment suppresses human tumor growth in animal models without observable increases in toxicity (body weight loss) in comparison with single agent treatment. Furthermore, our data revealed that addition of AITC to cisplatin treatment changes the profile of G2/M arrest (e.g. increase in M phase cell number) and significantly extends the duration of G2/M arrest in comparison with cisplatin treatment alone. To explore the underlying mechanism, we found that AITC treatment rapidly depletes b-tubulin. Combination of AITC and cisplatin inhibits the expression of G2/M checkpoint-relevant proteins including CDC2, cyclin B1 and CDC25. Together, our findings reveal a novel mechanism for AITC enhancing cisplatin efficacy and provides the first in vivo evidence to support ITCs as potential candidates for developing new regimens to overcome platinum resistance.

  2. Release and antibacterial activity of allyl isothiocyanate/β-cyclodextrin complex encapsulated in electrospun nanofibers.

    Science.gov (United States)

    Aytac, Zeynep; Dogan, Sema Y; Tekinay, Turgay; Uyar, Tamer

    2014-08-01

    Allyl isothiocyanate (AITC) is known as an efficient antibacterial agent but it has a very high volatility. Herein, AITC and AITC/β-cyclodextrin (CD)-inclusion complex (IC) incorporated in polyvinyl alcohol (PVA) nanofibers were produced via electrospinning. SEM images elucidated that incorporation of AITC and AITC/β-CD-IC into polymer matrix did not affect the bead-free fiber morphology of PVA nanofibers. (1)H-NMR and headspace GC-MS analyses revealed that very low amount of AITC was remained in PVA/AITC-NF because of the rapid evaporation of AITC during the electrospinning process. Nevertheless, much higher amount of AITC was preserved in the PVA/AITC/β-CD-IC-NF due to the CD inclusion complexation. The sustained release of AITC from nanofibers was evaluated at 30°C, 50°C and 75°C via headspace GC-MS. When compared to PVA/AITC-NF, PVA/AITC/β-CD-IC-NF has shown higher antibacterial activity against Escherichia coli and Staphylococcus aureus due to the presence of higher amount of AITC in this sample which was preserved by CD-IC.

  3. Merging allylic carbon-hydrogen and selective carbon-carbon bond activation

    Science.gov (United States)

    Masarwa, Ahmad; Didier, Dorian; Zabrodski, Tamar; Schinkel, Marvin; Ackermann, Lutz; Marek, Ilan

    2014-01-01

    Since the nineteenth century, many synthetic organic chemists have focused on developing new strategies to regio-, diastereo- and enantioselectively build carbon-carbon and carbon-heteroatom bonds in a predictable and efficient manner. Ideal syntheses should use the least number of synthetic steps, with few or no functional group transformations and by-products, and maximum atom efficiency. One potentially attractive method for the synthesis of molecular skeletons that are difficult to prepare would be through the selective activation of C-H and C-C bonds, instead of the conventional construction of new C-C bonds. Here we present an approach that exploits the multifold reactivity of easily accessible substrates with a single organometallic species to furnish complex molecular scaffolds through the merging of otherwise difficult transformations: allylic C-H and selective C-C bond activations. The resulting bifunctional nucleophilic species, all of which have an all-carbon quaternary stereogenic centre, can then be selectively derivatized by the addition of two different electrophiles to obtain more complex molecular architecture from these easily available starting materials.

  4. Allyl functionalized phosphinite and phosphonite ligands: Synthesis, transition metal chemistry and orthopalladation reactions

    Indian Academy of Sciences (India)

    Singappagudem Govindaraju; Guddekoppa S Ananthnag; Susmita Naik; Shaikh M Mobin; Maravanji S Balakrishn

    2012-07-01

    Allyl functionalized phosphinite PPh2(OAr) [Ar=C6H4(-C3H5)] (1) and phosphonite PPh(OAr)2 (2) ligands were prepared by the reactions of 2-allylphenol with PPh2Cl and PPhCl2, respectively. The ruthenium(II) complexes, [Ru(6--cymene)(PPh2(OAr))Cl2] (3) and [Ru(6--cymene)(PPh(OAr)2Cl2)] (4) were obtained by reacting 1 or 2 with [Ru(6--cymene)Cl2]2 in 2:1 molar ratios, respectively. Reactions of 1 or 2 with AuCl(SMe2) gave [Au{PPh2(OAr)}Cl] (5) or [Au{PPh(OAr)2}Cl] (6) in good yield. The palladium complex, [Pd{PPh(OAr)2}2Cl2] (7) was prepared by reacting Pd(COD)Cl2 with 2 in 1:2 molar ratio. The reaction between Pd(COD)Cl2 and 1 yielded a mixture of orthopalladated cis- and trans-[Pd(Ph2P(OAr))Cl]2 (8a and 8b). The treatment of 8 with PPh3 and Ph2PCH2PPh2 resulted in the cleavage of chloro bridge to give respectively, [Ph2(OAr)PPd(PPh3)Cl] (9) and [Ph2(ArO)PPd(2-dppm)]OTf (10). Single crystal X-ray structure of the ruthenium complex 3 is described.

  5. Fluorinated alcohols as promoters for the metal-free direct substitution reaction of allylic alcohols with nitrogenated, silylated, and carbon nucleophiles.

    Science.gov (United States)

    Trillo, Paz; Baeza, Alejandro; Nájera, Carmen

    2012-09-01

    The direct allylic substitution reaction using allylic alcohols in 1,1,1,3,3,3-hexafluoroisopropanol (HFIP) and 2,2,2-trifluoroethanol (TFE) as reaction media is described. The developed procedure is simple, works under mild conditions (rt, 50 and 70 °C), and proves to be very general, since different nitrogenated nucleophiles and carbon nucleophiles can be used achieving high yields, especially when HFIP is employed as solvent and aromatic allylic alcohols are the substrates. Thus, sulfonamides, carbamates, carboxamides, and amines can be successfully employed as nitrogen-based nucleophiles. Likewise, silylated nucleophiles such as trimethylsilylazide, allyltrimethylsilane, trimethylsilane, and trimethylsilylphenylacetylene give the corresponding allylic substitution products in high yields. Good results for the Friedel-Crafts adducts are also achieved with aromatic compounds (phenol, anisole, indole, and anilines) as nucleophiles. Particularly interesting are the results obtained with electron-rich anilines, which can behave as nitrogenated or carbon nucleophiles depending on their electronic properties and the solvent employed. In addition, 1,3-dicarbonyl compounds (acetylacetone and Meldrum's acid) are also successfully employed as soft carbon nucleophiles. Studies for mechanism elucidation are also reported, pointing toward the existence of carbocationic intermediates and two working reaction pathways for the obtention of the allylic substitution product.

  6. Allyl/propenyl phenol synthases from the creosote bush and engineering production of specialty/commodity chemicals, eugenol/isoeugenol, in Escherichia coli.

    Science.gov (United States)

    Kim, Sung-Jin; Vassão, Daniel G; Moinuddin, Syed G A; Bedgar, Diana L; Davin, Laurence B; Lewis, Norman G

    2014-01-01

    The creosote bush (Larrea tridentata) harbors members of the monolignol acyltransferase, allylphenol synthase, and propenylphenol synthase gene families, whose products together are able to catalyze distinct regiospecific conversions of various monolignols into their corresponding allyl- and propenyl-phenols, respectively. In this study, co-expression of a monolignol acyltransferase with either substrate versatile allylphenol or propenylphenol synthases in Escherichia coli established that various monolignol substrates were efficiently converted into their corresponding allyl/propenyl phenols, as well as providing proof of concept for efficacious conversion in a bacterial platform. This capability thus potentially provides an alternate source to these important plant phytochemicals, whether for flavor/fragrance and fine chemicals, or ultimately as commodities, e.g., for renewable energy or other intermediate chemical purposes. Previous reports had indicated that specific and highly conserved amino acid residues 84 (Phe or Val) and 87 (Ile or Tyr) of two highly homologous allyl/propenyl phenol synthases (circa 96% identity) from a Clarkia species mainly dictate their distinct regiospecific catalyzed conversions to afford either allyl- or propenyl-phenols, respectively. However, several other allyl/propenyl phenol synthase homologs isolated by us have established that the two corresponding amino acid 84 and 87 residues are not, in fact, conserved.

  7. Facile coupling of propargylic, allylic and benzylic alcohols with allylsilane and alkynylsilane, and their deoxygenation with Et3SiH, catalyzed by Bi(OTf)3 in [BMIM][BF4] ionic liquid (IL), with recycling and reuse of the IL.

    Science.gov (United States)

    Kumar, G G K S Narayana; Laali, Kenneth K

    2012-09-28

    Allyltrimethylsilane (allyl-TMS) reacts with propargylic alcohols 1a-1d in the presence of 10% Bi(OTf)(3) in [BMIM][BF(4)] solvent to furnish the corresponding 1,5-enynes in respectable isolated yields (87-93%) at room temperature. The utility of Bi(OTf)(3) as a superior catalyst was demonstrated in a survey study on coupling of allyl-TMS with employing several metallic triflates (Bi, Ln, Al, Yb) as well as, B(C(6)F(5))(3), Zn(NTf(2))(2) and Bi(NO(3))(3)·5H(2)O. Coupling of cyclopropyl substituted propargylic alcohol with allyl-TMS gave the skeletally intact 1,5-enyne and a ring opened derivative as a mixture. Coupling of propargylic/allylic alcohol with allyl-TMS resulted in allylation at both benzylic (2 isomers) and propargylic positions, as major and minor products respectively. The scope of this methodology for allylation of a series of allylic and benzylic alcohols was explored. Chemoselective reduction of a host of propargylic, propagylic/allylic, bis-allylic, allylic, and benzylic alcohols with Et(3)SiH was achieved in high yields with short reaction times. The same approach was successfully applied to couple representative propargylic and allylic alcohols with 1-phenyl-2-trimethylsilylacetylene. The recovery and reuse of the ionic liquid (IL) was gauged in a case study with minimal decrease in isolated yields after six cycles.

  8. 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.

  9. New copolymer of acrylamide with allyl methacrylate and its capacity for the removal of azo dyes

    Directory of Open Access Journals (Sweden)

    Yeliz Yildirim

    2015-04-01

    Full Text Available The copolymerization reactions of Acrylamide (AA with the different mole ratios of allyl methacrylate (AMA such as 25/75, 50/50 and 75/25 were studied by radical polymerization under argon atmosphere using 2,2’-Azobis (isobutyronitri1e (AIBN as initiator. The copolymers were characterized with Fourier transform infrared spectroscopy (FTIR and thermogravimetric analysis (TG. FTIR spectra showed that the C=O, C-N and N-H groups in copolymers remained during the copolymerization. It is concluded from the thermograms that Poly(AA-co-AMA copolymers which contained different ratios of monomer and comonomer exhibit similar thermal behavior. Adsorption capacity, kinetic and isotherm studies of Direct Brown 2 onto the copolymers have been evaluated. Different factors such as the monomer ratio, pH, initial dye concentration, copolymer dosage and contact time affecting the removal process were studied. It was found that the adsorption process agreed with the Freundlich and Dubinin-Raduskevich model and the adsorption of Direct Brown 2 depended on the acrylamide content and pH of the solution. The standard Gibb’s free energy was determined as - 14.7 kJ/mol, which means that adsorption occurred spontaneously and the process is feasible. Increasing the acrylamide content led to increased adsorption of Direct Brown 2 on the copolymer. Moreover, adsorption kinetic studies showed that the adsorption followed a pseudo-second-order kinetic model, indicating that the chemical adsorption was the rate-limiting step. These results show that Poly(AA-co-AMA can be used as adsorbent for water pollutants such as Direct Brown 2 and has potential applications in related industrial and environmental areas.

  10. Stereoselective coordination: a six-membered P,N-chelate tailored for asymmetric allylic alkylation.

    Science.gov (United States)

    Császár, Z; Farkas, G; Bényei, A; Lendvay, G; Tóth, I; Bakos, J

    2015-10-01

    Six-membered chelate complexes [Pd(1a-b)Cl2], (2a-b) and [Pd(1a-b)(η(3)-PhCHCHCHPh)]BF4, (3a-b) of P,N-type ligands 1a, ((2S,4S)-2-diphenyl-phosphino-4-isopropylamino-pentane) and 1b, ((2S,4S)-2-diphenyl-phosphino-4-methylamino-pentane) have been prepared. The Pd-complexes have been characterized in solution by 1D and 2D NMR spectroscopy. The observed structures were confirmed by DFT calculations and in the case of 2a also by X-ray crystallography. Unexpectedly, the coordination of the all-carbon-backbone aminophosphine 1a resulted in not only a stereospecific locking of the donor nitrogen atom into one of the two possible configurations but also the conformation of the six-membered chelate rings containing three alkyl substituents was forced into the same single chair structure showing the axially placed isopropyl group on the coordinated N-atom. The stereodiscriminative complexation of 1a led to the formation of a palladium catalyst with a conformationally rigid chelate having a configurationally fixed nitrogen and electronically different coordination sites due to the presence of P and N donors. The stereochemically fixed catalyst provided excellent ee's (up to 96%) and activities in asymmetric allylic alkylation reactions. In contrast, the chelate rings formed by 1b exist in two different chair conformations, both containing axial methyl groups, but with the opposite configurations of the coordinated N-atom. Pd-complexes of 1b provided low enantioselectivities in similar alkylations, therefore emphasizing the importance of the stereoselective coordination of N-atoms in analogous P-N chelates. The factors determining the coordination of the ligands were also studied with respect to the chelate ring conformation and the nitrogen configuration.

  11. Mechanisms of transient receptor potential vanilloid 1 activation and sensitization by allyl isothiocyanate.

    Science.gov (United States)

    Gees, Maarten; Alpizar, Yeranddy A; Boonen, Brett; Sanchez, Alicia; Everaerts, Wouter; Segal, Andrei; Xue, Fenqin; Janssens, Annelies; Owsianik, Grzegorz; Nilius, Bernd; Voets, Thomas; Talavera, Karel

    2013-09-01

    Allyl isothiocyanate (AITC; aka, mustard oil) is a powerful irritant produced by Brassica plants as a defensive trait against herbivores and confers pungency to mustard and wasabi. AITC is widely used experimentally as an inducer of acute pain and neurogenic inflammation, which are largely mediated by the activation of nociceptive cation channels transient receptor potential ankyrin 1 and transient receptor potential vanilloid 1 (TRPV1). Although it is generally accepted that electrophilic agents activate these channels through covalent modification of cytosolic cysteine residues, the mechanism underlying TRPV1 activation by AITC remains unknown. Here we show that, surprisingly, AITC-induced activation of TRPV1 does not require interaction with cysteine residues, but is largely dependent on S513, a residue that is involved in capsaicin binding. Furthermore, AITC acts in a membrane-delimited manner and induces a shift of the voltage dependence of activation toward negative voltages, which is reminiscent of capsaicin effects. These data indicate that AITC acts through reversible interactions with the capsaicin binding site. In addition, we show that TRPV1 is a locus for cross-sensitization between AITC and acidosis in nociceptive neurons. Furthermore, we show that residue F660, which is known to determine the stimulation by low pH in human TRPV1, is also essential for the cross-sensitization of the effects of AITC and low pH. Taken together, these findings demonstrate that not all reactive electrophiles stimulate TRPV1 via cysteine modification and help understanding the molecular bases underlying the surprisingly large role of this channel as mediator of the algesic properties of AITC.

  12. S-Allyl-Cysteines Reduce Amelioration of Aluminum Induced Toxicity in Rats

    Directory of Open Access Journals (Sweden)

    Sadhana Shrivastava

    2011-01-01

    Full Text Available Problem statement: Aluminum (Al is a trivalent cation found in its ionic form in most kinds of animal tissues and in natural waters everywhere. Approach: It is a potent neurotoxin and has been associated in the pathogenesis of several clinical disorders including Alzheimer’s disease. Results: The aim of the study was to demonstrate the protective effect of S-Allyl-Cysteines (SAC against Al-induced toxicity in rat model on certain biochemical parameters, lipid peroxidation and oxidative stress enzymes of white albino rats. Six rats per group were divided into various treatment groups. Group one rats were given normal saline and served as control group. Group two animals received Al as aluminum nitrate 32.5 mg (i.p. for the induction of toxicity. Group three to five received different doses of SAC (25, 50 and 100 mg kg-1 for 3 days after 24 h of Al toxicity. Rats were orally administered their respective doses every day for 3 days. Evaluations were made in blood and tissues. The activity of Acetylcholinesterase (AchE was inhibited in all the parts of brain after Al intoxication. Significant rise were observed the Activities of Serum Transaminases (AST and ALT after toxicant exposure. The activity of â-Aminolevulinic acid Dehydratase (ALAD in blood and â-Aminolevulinic Acid Synthetase (ALAS in brain was decreased after Al exposure. Al significant increased cholesterol, triglyceride, creatinine and urea level in serum. TBARS level was significantly higher and GSH content were significantly lower during toxicity. Total and esterified cholesterol in liver, kidney and brain were increased after Al exposure. Histopathological changes in liver, kidney and brain were also recouped with the therapy. Conclusion/Recommendations: Our data proved that SAC which is a bioactive and bioavailable component of garlic has organosulfur compounds which regulates the thiol status of the cell and scavenges free radicals and work as an antioxidant. Thus SAC

  13. 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.

  14. Rheological and mechanical behavior of polyacrylamide hydrogels chemically crosslinked with allyl agarose for two-dimensional gel electrophoresis.

    Science.gov (United States)

    Suriano, R; Griffini, G; Chiari, M; Levi, M; Turri, S

    2014-02-01

    Two-dimensional (2-D) gel electrophoresis currently represents one of the most standard techniques for protein separation. In addition to the most commonly employed polyacrylamide crosslinked hydrogels, acrylamide-agarose copolymers have been proposed as promising systems for separation matrices in 2-D electrophoresis, because of the good resolution of both high and low molecular mass proteins made possible by careful control and optimization of the hydrogel pore structure. As a matter of fact, a thorough understanding of the nature of the hydrogel pore structure as well as of the parameters by which it is influenced is crucial for the design of hydrogel systems with optimal sieving properties. In this work, a series of acrylamide-based hydrogels covalently crosslinked with different concentrations of allyl agarose (0.2-1%) is prepared and characterized by creep-recovery measurements, dynamic rheology and tensile tests, in the attempt to gain a clearer understanding of structure-property relationships in crosslinked polyacrylamide-based hydrogels. The rheological and mechanical properties of crosslinked acrylamide-agarose hydrogels are found to be greatly affected by crosslinker concentration. Dynamic rheological tests show that hydrogels with a percentage of allyl agarose between 0.2% and 0.6% have a low density of elastically effective crosslinks, explaining the good separation of high molecular mass proteins in 2-D gel electrophoresis. Over the same range of crosslinker concentration, creep-recovery measurements reveal the presence of non-permanent crosslinks in the hydrogel network that justifies the good resolution of low molecular mass proteins as well. In tensile tests, the hydrogel crosslinked with 0.4% of allyl agarose exhibits the best results in terms of mechanical strength and toughness. Our results show how the control of the viscoelastic and the mechanical properties of these materials allow the design of mechanically stable hydrogels with improved

  15. The utilization of the mesoporous Ti-SBA-15 catalyst in the epoxidation of allyl alcohol to glycidol and diglycidyl ether in the water medium

    Directory of Open Access Journals (Sweden)

    Wróblewska Agnieszka

    2015-12-01

    Full Text Available This work presents the studies on the optimization the process of allyl alcohol epoxidation over the Ti-SBA-15 catalyst. The optimization was carried out in an aqueous medium, wherein water was introduced into the reaction medium with an oxidizing agent (30 wt% aqueous solution of hydrogen peroxide and it was formed in the reaction medium during the processes. The main investigated technological parameters were: the temperature, the molar ratio of allyl alcohol/hydrogen peroxide, the catalyst content and the reaction time. The main functions the process were: the selectivity of transformation to glycidol in relation to allyl alcohol consumed, the selectivity of transformation to diglycidyl ether in relation to allyl alcohol consumed, the conversion of allyl alcohol and the selectivity of transformation to organic compounds in relation to hydrogen peroxide consumed. The analysis of the layer drawings showed that in water solution it is best to conduct allyl alcohol epoxidation in direction of glycidol (selectivity of glycidol 54 mol% at: the temperature of 10–17°C, the molar ratio of reactants 0.5–1.9, the catalyst content 2.9–4.0 wt%, the reaction time 2.7–3.0 h and in direction of diglycidyl ether (selectivity of diglycidyl ether 16 mol% at: the temperature of 18–33°C, the molar ratio of reactants 0.9–1.65, the catalyst content 2.0–3.4 wt%, the reaction time 1.7–2.6 h. The presented method allows to obtain two very valuable intermediates for the organic industry.

  16. 烯丙基异硫氰酸酯的熏蒸毒力研究%FUMIGATION ACTIVITY OF THE ALLYL ISOTHIOCYANATE

    Institute of Scientific and Technical Information of China (English)

    陈春武; 谢令德; 陈雅群; 何君; 贺艳萍

    2012-01-01

    以玉米象和赤拟谷盗作为实验对象,采用熏蒸方式对烯丙基异硫氰酸酯的毒力进行测定.结果表明,烯丙基异硫氰酸酯对所研究的两种害虫有较好的快速致死作用,同时研究发现在相同熏蒸时间内烯丙基异硫氰酸酯对玉米象熏蒸的LC50和LC99均小于对赤拟谷盗的LC50和LC99,这说明烯丙基异硫氰酸酯对玉米象的熏蒸效果比对赤拟谷盗的好.%Chosing Si tophilus zesmais (Motschulsky) and Tribolium castaneun (Herbst) as experimental objects, the toxicity for the allyl isothiocyanate (AITC) is tested systematically by fumigation method. The result demonstrates that the allyl isothiocyanate presents rapid lethal effect against both of the two types of insects. The research also shows that both the LC50 and the LC99 of the fumigation of the allyl isothiocyanate to the Sitophilus zeamais are less than those of the allyl isothiocyanate to the Tribolium castaneum exposuring the same fumigating time, which indicates that the fumigating effect of the allyl isothiocyanate to the Sitophilus zeamais is more effective than that of the allyl isothiocyanate to the Tribolium castaneum.

  17. Antimicrobial activity of allyl isothiocyanate used to coat biodegradable composite films as affected by storage and handling conditions.

    Science.gov (United States)

    Li, Weili; Liu, Linshu; Jin, Tony Z

    2012-12-01

    We evaluated the effects of storage and handling conditions on the antimicrobial activity of biodegradable composite films (polylactic acid and sugar beet pulp) coated with allyl isothiocyanate (AIT). Polylactic acid and chitosan were incorporated with AIT and used to coat one side of the film. The films were subjected to different storage conditions (storage time, storage temperature, and packed or unpacked) and handling conditions (washing, abrasion, and air blowing), and the antimicrobial activity of the films against Salmonella Stanley in tryptic soy broth was determined. The films (8.16 μl of AIT per cm(2) of surface area) significantly (P packaging.

  18. 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.

  19. Tandem SN2' nucleophilic substitution/oxidative radical cyclization of aryl substituted allylic alcohols with 1,3-dicarbonyl compounds.

    Science.gov (United States)

    Zhang, Zhen; Li, Cheng; Wang, Shao-Hua; Zhang, Fu-Min; Han, Xue; Tu, Yong-Qiang; Zhang, Xiao-Ming

    2017-03-23

    A novel and efficient tandem SN2' nucleophilic substitution/oxidative radical cyclization reaction of aryl substituted allylic alcohols with 1,3-dicarbonyl compounds has been developed by using Mn(OAc)3 as an oxidant, which enables the expeditious synthesis of polysubstituted dihydrofuran (DHF) derivatives in moderate to high yields. The use of weakly acidic hexafluoroisopropanol (HFIP) as the solvent rather than AcOH has successfully improved the yields and expanded the substrate scope of this type of radical cyclization reactions. Mechanistic studies confirmed the cascade reaction process involving a final radical cyclization.

  20. SnCl2/Cu-Mediated Carbonyl Allylation Reaction in Water:Scope,Selectivity and Mechanism

    Institute of Scientific and Technical Information of China (English)

    TAN,Xiang-Hui(谭翔晖); HOU,Yong-Quan(侯永泉); LIU,Lei(刘磊); GUO,Qing-Xiang(郭庆祥)

    2004-01-01

    Copper was found to be able to promote the SnC12-mediated carbonyl allylation reactions in water,giving the corresponding homoallylic alcohol products in very high yields.Detailed studies showed that the reaction could be applied to a variety of carbonyl compounds including those with hydroxyl,amino and nitro groups.It was also found that this reaction showed good regioselectivities for some substrates.Furthermore,carefully controled experiments and in situ NMR measurements provided important insights into the mechanism of the newly developed reaction.

  1. 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.

  2. Green synthesis of allyl isobornyl ether%烯丙基异冰片基醚绿色合成研究

    Institute of Scientific and Technical Information of China (English)

    王士康; 徐徐; 兰蓝; 樊媛媛; 王石发

    2012-01-01

    以莰烯和烯丙醇为原料,研究了烯丙基异冰片基醚的绿色合成工艺,探讨了催化剂种类及用量、反应温度、反应时间,以及烯丙醇与莰烯物质的量之比对莰烯醚化反应选择性及烯丙基异冰片基醚产物得率的影响.采用正交试验方法确定了烯丙基异冰片基醚的最适工艺条件:A-15型阳离子树脂为催化剂,催化剂用量为烯丙醇和莰烯原料总质量的5%,烯丙醇与莰烯物质的量之比为1.5:1,反应温度75℃,反应时间7h.在此条件下工业莰烯转化率为85.5%,反应选择性为97.5%,烯丙基异冰片基醚得率为83.4%.最后采用GC-MS、IR等分析技术对合成所得产物的结构进行了分析测定.%Green synthetic method of allyl isobornyl ether was investigated by using camphene and allyl alcohol as the raw materials in this paper. Influence of catalysts and their usages, reaction temperature, reaction time, and the molar ratio of allyl alcohol to camphene on the selectivity of etherification and the yield of allyl isobornyl ether were examined, and the optimum synthesis conditions were determined based on the orthogonal test results as follows: A-15 resin was used as the catalyst for etherification, and the amount of A-15 cationic exchange resin was 5 % (based on the total weight of camphene and allyl alcohol) ; molar ratio of allyl alcohol to camphene was 1. 5-1; reaction temperature and reaction time were 75 ℃ and 7 h, respectively. The conversion ratio of camphene and the reaction selectivity reached 85. 5 % and 97. 5 % respectively, and the yield of allyl isobornyl ether also reached 83. 4 %. The structure of allyl isobornyl ether was identified by GC-MS and IR spectra.

  3. Rhodium-Catalyzed Regioselective Domino Azlactone-Alkyne Coupling/Aza-Cope Rearrangement: Facile Access to 2-Allyl-3-oxazolin-5-ones and Trisubstituted Pyridines.

    Science.gov (United States)

    Kuang, Jinqiang; Parveen, Shaista; Breit, Bernhard

    2017-07-10

    Rhodium-catalyzed regioselective addition of azlactones to internal alkynes combined with aza-Cope rearrangement provides efficient atom economic access to 2-allyl-3-oxazolin-5-one derivatives. Extension to a triple domino process, in which the above process is combined with in situ azlactone formation starting from amino acids renders this process even more attractive. Subsequent thermolysis of the 2-allyl-3-oxazolines enabled the de novo synthesis of trisubstituted pyridines. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. [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.

  5. Mg(OMe)2 promoted allylic isomerization of γ-hydroxy-α,β-alkenoic esters to synthesize γ-ketone esters.

    Science.gov (United States)

    Lai, Luhao; Li, A-Ni; Zhou, Jiawei; Guo, Yarong; Lin, Li; Chen, Wei; Wang, Rui

    2017-03-08

    This work concerns the Mg(OMe)2 promoted allylic isomerization of γ-hydroxy-α,β-alkenoic esters with TMEDA as an additive. The isomerization proceeded under mild conditions and afforded γ-keto esters in high yield (up to 96%) within 2 h. Both (Z)- and (E)-γ-hydroxy-α,β-alkenoic esters were tolerated under the reaction conditions. This transformation involves the in situ formation of a dienolate intermediate from the easily accessible γ-hydroxy-α,β-alkenoic ester. The in situ generated dienolate can react with benzaldehyde and undergo a practical, useful tandem allylic isomerization-Aldol reaction to afford more functionalized compounds.

  6. The - - and Submm-Wave Spectrum of Allyl Isocyanide and Radioastronomical Observations in Orion KL and the Primos Line Survey

    Science.gov (United States)

    Haykal, I.; Motiyenko, R. A.; Margules, L.; Huet, T. R.; Ecija, P.; Cocinero, E. J.; Basterretxea, F.; Fernandez, J. A.; Castano, F.; Tercero, B.; Cernicharo, J.; Lesarri, A.; Guillemin, J. C.

    2013-06-01

    Last year we presented the first rotational analysis of the ground state of the two conformers of allyl isocyanide from 4 GHz to 905 GHz. The analysis of the rotational spectrum of the cis conformer of allyl isocyanide was extended. We resolved Coriolis interactions of a and b types between the excited vibrational states ν_1=1 and ν_2=1, calculated to be at 156 cm^{-1} (A^{'}) and 167 cm^{-1} (A^{''}) respectively (MP2/aug-cc-pvtz), from 150 GHz to 600 GHz. Strong perturbations were observed in the 150-310 GHz range for low values of the quantum number K_a starting from K_a = 0, 1. The anharmonicities appeared as well at higher frequencies for larger quantum numbers. The two modes were fitted together with the SPFIT/SPCAT suite of programs and a set of Coriolis parameters was accurately determined. The fit contains more than 3000 lines up to J = 99 and K_a = 12 for both modes. We did not detect these species neither in the IRAM 30-m line survey of Orion KL nor in the PRIMOS survey towards SgrB2. Nevertheless, we provided upper limits to their column density in Orion KL. This work was supported by the CNES and the Action sur Projets de l'INSU, PCMI. I. Haykal et al. manuscript in preparation H. Pickett J. Mol. Spec.{148}, 371-377, 1991.

  7. Molecular detection and in vitro antioxidant activity of S-allyl-L-cysteine (SAC) extracted from Allium sativum.

    Science.gov (United States)

    Sun, Y-E; Wang, W-D

    2016-06-30

    It is well known that Allium sativum has potential applications to clinical treatment of various cancers due to its remarkable ability in eliminating free radicals and increasing metabolism. An allyl-substituted cysteine derivative - S-allyl-L-cysteine (SAC) was separated and identified from Allium sativum. The extracted SAC was reacted with 1-pyrenemethanol to obtain pyrene-labelled SAC (Py-SAC) to give SAC fluorescence properties. Molecular detection of Py-SAC was conducted by steady-state fluorescence spectroscopy and time-resolved fluorescence method to quantitatively measure concentrations of Py-SAC solutions. The ability of removing 1,1-diphenyl-2-picrylhydrazyl (DPPH) and hydroxyl radical using Py-SAC was determined through oxygen radical absorbance capacity (ORAC). Results showed the activity of Py-SAC and Vitamin C (VC) with ORAC as index, the concentrations of Py-SAC and VC were 58.43 mg/L and 5.72 mg/L respectively to scavenge DPPH, and 8.16 mg/L and 1.67 mg/L to scavenge •OH respectively. Compared with VC, the clearance rates of Py-SAC to scavenge DPPH were much higher, Py-SAC could inhibit hydroxyl radical. The ability of removing radical showed a dose-dependent relationship within the scope of the drug concentration.

  8. Allylic H-Abstraction Mechanism:  The Potential Energy Surface of the Reaction of Propene with OH Radical.

    Science.gov (United States)

    Szori, Milan; Fittschen, Christa; Csizmadia, Imre G; Viskolcz, Bela

    2006-11-01

    The allylic H-atom abstraction reaction plays a more dominant role, especially at lower temperature, than addition reactions in the case of the CH2 [Formula: see text] CH-CH3 + •OH system. Different computational methods including ab initio as well as density functional methods have been used to examine allylic H-abstraction. Both the energetically less favorable direct H-abstraction and the more favorable indirect H-abstractions have been investigated. Using first principles computations, for the indirect abstraction, a stable π- or reactantlike as well as a late productlike complex were found on the potential energy surface. Based on higher level single point calculations (QCISD(T)/6-311+G(3df,2p)), a new activation enthalpy value, Δ(⧧)H° = 0.3 ± 2 kJ/mol, is suggested for the title reaction. The computed reaction enthalpy ΔrH° = -124.7 ± 2 kJ/mol is in good agreement with the experimental value. The stability of the initial π-complex was found to be ΔH°π-complex = -7.1 kJ/mol. The product complex between the transition state and the product was found with the stability of -127.2 kJ/mol.

  9. 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

  10. 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 ...

  11. An Expeditious Synthesis of [1,2]Isoxazolidin-5-ones and [1,2]Oxazin-6-ones from Functional Allyl Bromide Derivatives

    Directory of Open Access Journals (Sweden)

    Imen Beltaïef

    2010-06-01

    Full Text Available Reaction of allyl bromide (Z-1 and (Z-2 with N-substituted hydroxylamine hydrochlorides in presence of tert-butoxide in tert-butanol at reflux provides a short and effective route to [1,2]isoxazolidin-5-ones 3 and [1,2]oxazin-6-ones 4.

  12. Nickel-catalyzed enantioselective hydrovinylation of silyl-protected allylic alcohols:An efficient access to homoallylic alcohols with a chiral quaternary center

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Asymmetric hydrovinylation of silyl-protected allylic alcohols catalyzed by nickel complexes of chiral spiro phosphoramidite ligands was developed.A series of homoallylic alcohols with a chiral quaternary center were produced in high yields(up to 97%) and high enantioselectivities(up to 95% ee).The reaction provides an efficient method for preparing bifunctional compounds with a chiral quaternary carbon center.

  13. Ruthenium(III)-catalysed phenylselenylation of allyl acetates by diphenyl diselenide and indium(I) bromide in neat: isolation and identification of intermediate.

    Science.gov (United States)

    Saha, Amit; Ranu, Brindaban C

    2011-03-21

    A fast and efficient phenylselenylation of allyl acetates by diphenyl diselenide and indium(I) bromide has been achieved in neat under the catalysis of Ru(acac)(3). The intermediate complex of diphenyl diselenide and indium has been isolated and identified as a polymeric pentacoordinated In(III) selenolate complex, [In(SePh)(3)](n).

  14. 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 cyclization reactions to take place in up to 94:6 enantiomeric ratio. A model Pd-allyl complex has been prepared and studied through NMR spectroscopic analysis, which provided insight into the processes responsible for the observed enantiomeric ratios. DFT studies were used to characterize the diastereomeric...

  15. 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...

  16. Highly enantio- and diastereoselective one-pot reactions in aqueous media : Combined asymmetric Rh-catalyzed conjugate addition/metal-mediated allylation

    NARCIS (Netherlands)

    Kallstrom, Sara; Jagt, Richard B. C.; Sillanpaa, Reijo; Feringa, Ben L.; Minnaard, Adriaan J.; Leino, Reko; Källström, Sara; Sillanpää, Reijo

    2006-01-01

    1,3-Disubstituted, enantiopure cyclohexanols have been prepared in very high diastereoselectivities and good yields by a concise one-pot method combining the enantioselective rhodium-catalyzed conjugate addition of arylboronic acids with indium-mediated allylation into a highly efficient one-pot rea

  17. Improved synthesis of cyclic tertiary allylic alcohols by asymmetric 1,2-addition of AlMe3 to enones.

    Science.gov (United States)

    Kolb, Andreas; Zuo, Wei; Siewert, Jürgen; Harms, Klaus; von Zezschwitz, Paultheo

    2013-11-25

    The development of an improved protocol for the enantioselective Rh(I) /binap-catalysed 1,2-addition of AlMe3 to cyclic enones is reported. (31)P NMR analysis of the reaction revealed that the catalyst in its resting state is a chloride-bridged dimer. This insight led to the use of AgBF4 as an additive for in situ activation of the dimeric precatalyst. Thus, the catalyst loading can now be reduced to only 1 mol% with respect to rhodium. Various 5-7-membered cyclic enones can be transformed into tertiary allylic alcohols with excellent levels of enantioselectivity and high yields. The obtained products are versatile synthetic building blocks, shown by a highly enantioselective formal total synthesis of the pheromone (-)-frontalin as well as formation of a bicyclic lactone that has the core structure of the natural flavour component "wine lactone".

  18. 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.

  19. Near-silence of isothiocyanate carbon in (13)C NMR spectra: a case study of allyl isothiocyanate.

    Science.gov (United States)

    Glaser, Rainer; Hillebrand, Roman; Wycoff, Wei; Camasta, Cory; Gates, Kent S

    2015-05-01

    (1)H and (13)C NMR spectra of allyl isothiocyanate (AITC) were measured, and the exchange dynamics were studied to explain the near-silence of the ITC carbon in (13)C NMR spectra. The dihedral angles α = ∠(C1-C2-C3-N4) and β = ∠(C2-C3-N4-C5) describe the conformational dynamics (conformation change), and the bond angles γ = ∠(C3-N4-C5) and ε = ∠(N4-C5-S6) dominate the molecular dynamics (conformer flexibility). The conformation space of AITC contains three minima, Cs-M1 and enantiomers M2 and M2'; the exchange between conformers is very fast, and conformational effects on (13)C chemical shifts are small (νM1 - νM2 silence of the ITC carbon in (13)C NMR spectra of organic isothiocyanates.

  20. Synthesis, spectroscopic characterization and solution behavior of new tin tetrachloride adducts with γ-keto allyl phosphonates

    Science.gov (United States)

    Elleuch, Haitham; Sanhoury, M. A. K.; Rezgui, F.

    2017-01-01

    Four new octahedral complexes of the type [SnCl4L2] (L = γ-keto allyl phosphonate) (1-4) were prepared and characterized by multinuclear (1H, 13C, 31P and 119Sn) NMR, IR spectroscopy and elemental analysis. The NMR data show, as expected, that these complexes exist in solution as mixtures of cis and trans isomers. More importantly, the solution structure was confirmed by 119Sn NMR spectra which show two triplets corresponding to the two isomers. In addition, the solution behavior of these complexes in the presence of excess ligand was studied by variable temperature NMR using the coalescence temperature method. The metal-ligand exchange activation energies were therefore determined and found to be in the range 57-60 kJ/mol. The effect of remote substituents on the metal-ligand interaction was studied and compared with closely related tin-phosphoryl complexes.

  1. 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.

  2. Practical and Broadly Applicable Catalytic Enantioselective Additions of Allyl-B(pin) Compounds to Ketones and α-Ketoesters.

    Science.gov (United States)

    Robbins, Daniel W; Lee, KyungA; Silverio, Daniel L; Volkov, Alexey; Torker, Sebastian; Hoveyda, Amir H

    2016-08-01

    A set of broadly applicable methods for efficient catalytic additions of easy-to-handle allyl-B(pin) (pin=pinacolato) compounds to ketones and acyclic α-ketoesters was developed. Accordingly, a large array of tertiary alcohols can be obtained in 60 to >98 % yield and up to 99:1 enantiomeric ratio. At the heart of this development is rational alteration of the structures of the small-molecule aminophenol-based catalysts. Notably, with ketones, increasing the size of a catalyst moiety (tBu to SiPh3 ) results in much higher enantioselectivity. With α-ketoesters, on the other hand, not only does the opposite hold true, since Me substitution leads to substantially higher enantioselectivity, but the sense of the selectivity is reversed as well.

  3. 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.

  4. 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.

  5. Modulation of the multidrug efflux pump EmrD-3 from Vibrio cholerae by Allium sativum extract and the bioactive agent allyl sulfide plus synergistic enhancement of antimicrobial susceptibility by A. sativum extract.

    Science.gov (United States)

    Bruns, Merissa M; Kakarla, Prathusha; Floyd, Jared T; Mukherjee, Mun Mun; Ponce, Robert C; Garcia, John A; Ranaweera, Indrika; Sanford, Leslie M; Hernandez, Alberto J; Willmon, T Mark; Tolson, Grace L; Varela, Manuel F

    2017-04-21

    The causative agent of cholera, Vibrio cholerae, is a public health concern. Multidrug-resistant V. cholerae variants may reduce chemotherapeutic efficacies of severe cholera. We previously reported that the multidrug efflux pump EmrD-3 from V. cholerae confers resistance to multiple structurally distinct antimicrobials. Medicinal plant compounds are potential candidates for EmrD-3 efflux pump modulation. The antibacterial activities of garlic Allium sativum, although poorly understood, predicts that a main bioactive component, allyl sulfide, modulates EmrD-3 efflux. Thus, we tested whether A. sativum extract acts in synergy with antimicrobials and that a main bioactive component allyl sulfide inhibits EmrD-3 efflux. We found that A. sativum extract and allyl sulfide inhibited ethidium bromide efflux in cells harboring EmrD-3 and that A. sativum lowered the MICs of multiple antibacterials. We conclude that A. sativum and allyl sulfide inhibit EmrD-3 and that A. sativum extract synergistically enhances antibacterial agents.

  6. Stereochemistry of Pd(II)-Catalyzed THF Ring Formation of ε-Hydroxy Allylic Alcohols and Synthesis of 2,3,5-Trisubstituted and 2,3,4,5-Tetrasubstituted Tetrahydrofurans.

    Science.gov (United States)

    Murata, Yuki; Uenishi, Jun'ichi

    2016-09-02

    Pd(II)-catalyzed ring formation of 2,3,5-trisubstituted and 2,3,4,5-tetrasubstituted tetrahydrofurans is described. Oxypalladation of a chiral ε-hydroxy allylic alcohol provides a 5-alkenyltetrahydrofuran ring in excellent yields via a 5-exo-trigonal process. Nine substrates including six secondary allylic alcohols and three primary allylic alcohols with or without an additional secondary hydroxy substituent at the γ-position have been examined. Their structures are restricted by a 2,2,4,4-tetraisopropyl-1,3,5,2,4-trioxadisilocane ring. The stereochemistry of the resulting tetrahydrofuran products was determined by chemical transformation. The reaction mechanism is discussed on the basis of the stereochemical results. The steps in the chiral allylic alcohol directed or the nucleophilic alcohol directed facial selection for the formation of the alkene-Pd(II)-π-complex, the cis-oxypalladation, and a syn-elimination mechanism account for the observed stereochemistry of the reaction.

  7. 超硬材料磨具用烯丙基化酚醛改性双马来酰亚胺树脂的研究%Bismaleimide Modified by Allyl Novolak for Superabrasives

    Institute of Scientific and Technical Information of China (English)

    郑红飞; 李志宏; 朱玉梅

    2007-01-01

    A novel thermosetting resin system for superabrasives based on novolak and bismaleimide (BMI) was developed.The novolak resin was allylated and then copolymerized with BMI.The structure of allyl novolak and reaction mechanism were analyzed by FTIR.Thermal and mechanical properties were characterized by using comprehensive thermal analyzer (DSC-TG) and strength tester,respectively.The results showed that high molecular weight of novolak was advantageous for heat-resistance,but was unfavorable for the bending strength.High allyl content improved the heat-resistance but lowered the bending strength.When the molecular weight of novolak was 450 and allyl content was 50%,the best resin system with good heat-resistance and bending strength was obtained.It was suitable for the manufacturing of superabrasive tools.

  8. A one-pot stereoselective synthesis of 1,4-dienyl selenides by hydrostannylation-Stille tandem reaction of acetylenic selenides with Bu3SnH and allylic bromides

    Institute of Scientific and Technical Information of China (English)

    La Mei Yu; Wen Yan Hao; Ming Zhong Cai

    2008-01-01

    1,4-Dienyl selenides can be stereoselectively synthesized in one pot under mild conditions in good yields by the palladium-catalyzed hydrostannylation of acetylenic selenides, followed by Stille coupling with allylic bromides.

  9. Role of cluster size and substrate in the gas phase CC bond coupling reactions of allyl halides mediated by Agn+ and Agn-1H+ cluster cations

    Science.gov (United States)

    Wang, Farrah Qiuyun; Khairallah, George N.; O'Hair, Richard A. J.

    2009-06-01

    Previous studies have demonstrated that the silver hydride cluster cation Ag4H+ promotes CC bond coupling of allylbromide [G.N. Khairallah, R.A.J. O'Hair, Angewandte Chemie International Edition 44 (2005) 728]. Here the influence of both the nature and the size of the silver cluster cation and the substrate on CC bond coupling are examined. Thus each of the cations Ag2H+, Ag4H+, Ag3+, and Ag5+ were allowed to react with three different halides: allyl chloride, allyl bromide and allyl iodide. No CC bond coupling is observed in the reactions of the cluster cations with allyl chloride. There are four main reaction sequences that result in CC bond coupling for allyl bromide and allyl iodide mediated by Agn+ and Agn-1H+ clusters: (i) A sequence involving the reactions of silver cluster cations with two molecules of C3H5X: Agn+ --> Agn(C3H5X)+ --> AgnX2+. This only occurs in the cases of: n = 3 and X = I; n = 5 and X = Br. (ii) A sequence involving the reactions of silver cluster cations with two molecules of C3H5X via an organometallic intermediate: Agn+ --> Agn-1(C3H5)+ --> Agn-1X+. This only occurs in the cases of: n = 5 and X = Br and I. (iii) A sequence involving the reactions of silver hydride cluster cations with three molecules of C3H5X: Agn-1H+ --> Agn-1X+ --> Agn-1X(C3H5X)+ --> Ag(C3H5)2+ and Agn-1X3+. This only occurs in the cases of: n = 5 and X = Br and I. (iv) A sequence involving the reactions of silver hydride cluster cations with three molecules of C3H5X via an organometallic intermediate: Agn-1H+ --> Agn-1X+ --> Agn-3(C3H5)+ --> Ag(C3H5)2+ and Agn-3X+. This only occurs in the cases of: n = 5 and X = I.

  10. A Review on Mutagenicity Testing for Hazard Classification of Chemicals at Work: Focusing on in vivo Micronucleus Test for Allyl Chloride.

    Science.gov (United States)

    Rim, Kyung-Taek; Kim, Soo-Jin

    2015-09-01

    Chemical mutagenicity is a major hazard that is important to workers' health. Despite the use of large amounts of allyl chloride, the available mutagenicity data for this chemical remains controversial. To clarify the mutagenicity of allyl chloride and because a micronucleus (MN) test had not yet been conducted, we screened for MN induction by using male ICR mice bone marrow cells. The test results indicated that this chemical is not mutagenic under the test conditions. In this paper, the regulatory test battery and several assay combinations used to determine the genotoxic potential of chemicals in the workplace have been described. Further application of these assays may prove useful in future development strategies of hazard evaluations of industrial chemicals. This study also should help to improve the testing of this chemical by commonly used mutagenicity testing methods and investigations on the underlying mechanisms and could be applicable for workers' health.

  11. A formal [3,3]-sigmatropic rearrangement route to quaternary alpha-vinyl amino acids: use of allylic N-PMP trifluoroacetimidates.

    Science.gov (United States)

    Berkowitz, David B; Wu, Bin; Li, Huijie

    2006-03-01

    Pd(II)-mediated rearrangement of allylic N-PMP (p-methoxyphenyl) trifluoroacetimidates provides the first formal sigmatropic route to quaternary, alpha-vinylic amino acids, potential suicide substrates for PLP enzymes. The amino acid side chains enter via transition-metal-mediated C-C bond constructions, including (i) Cu(I)-mediated conjugate addition (Ala); (ii) Pd(0)/AsPh3-mediated Stille coupling (allyl-Gly, Phe, DOPA, m-Tyr); and (iii) Pd(0)/Pt-Bu3-mediated Negishi coupling (Leu). In the synthesis of the DOPA decarboxylase inactivator, alpha-vinyl-m-tyrosine, the new N-PMP trifluoroacetimidate rearranges much more efficiently than the corresponding trichloroacetimidate.

  12. 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.

  13. Highly diastereo- and enantioselective allylboration of aldehydes using α-substituted allyl/crotyl pinacol boronic esters via in situ generated borinic esters.

    Science.gov (United States)

    Chen, Jack L-Y; Scott, Helen K; Hesse, Matthew J; Willis, Christine L; Aggarwal, Varinder K

    2013-04-10

    Readily available, α-substituted allyl/crotyl pinacol boronic esters often give low E/Z selectivity (with Z favored) in reactions with aldehydes. We found that addition of nBuLi to the pinacol boronic ester followed by trapping of the alkoxide with TFAA leads to an intermediate allyl borinic ester which undergoes allylboration with very high E selectivity. The substrate scope includes primary to tertiary alkyl α-substituents, crotyl substrates, and the previously unreported β-methallyl pinacol boronic esters. The latter give very high Z selectivity under standard conditions which is completely reversed to high E selectivity under the new conditions. Monitoring the reaction by (11)B NMR confirmed that the reaction proceeds through a borinic ester intermediate.

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

    Institute of Scientific and Technical Information of China (English)

    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 ℃ 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.

  15. Immobilization of Chiral Ferrocenyl Ligands on Silica Gel and their Testing in Pd-catalyzed Allylic Substitution and Rh-catalyzed Hydrogenation

    Directory of Open Access Journals (Sweden)

    Duncan J. Macquarrie

    2005-07-01

    Full Text Available Five different silica gels containing two chiral ferrocenyl ligands were prepared by various synthetic routes and tested in an enantioselective Pd(0-catalyzed allylic substitution and Rh-catalyzed hydrogenation. All the prepared anchored ligands were characterized by porosimetry data, DRIFTS spectra, thermal data and AAS. The aim of the work was to compare the influence of the carrier, surface properties and immobilization strategy on the performance of the catalyst.

  16. 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.

  17. Divergent synthetic routes for ring expansion or cyclization from 1,4-allylic diol derivatives via gold(I) catalysis or zinc(II) mediation.

    Science.gov (United States)

    Zhu, Li-Li; Li, Xiao-Xiao; Zhou, Wen; Li, Xin; Chen, Zili

    2011-11-04

    A new efficient method was developed to transform cyclic alkanols into one-carbon higher homologated ketones using various esters as the leaving groups through gold-catalyzed allylic cation-promoted pinacol-type rearrangement. This reaction, coupled with oxy-Cope rearrangement, provided a new strategy to synthesize five-carbon homologated ring ketones. In addition, using ZnBr(2), 2,5-dihydrofuran products were obtained in moderate to good yields via an intramolecular cyclization process.

  18. Palladium complexes with a tridentate PNO ligand. Synthesis of eta1-allyl complexes and cross-coupling reactions promoted by boron compounds.

    Science.gov (United States)

    Crociani, Bruno; Antonaroli, Simonetta; Burattini, Marcello; Paoli, Paola; Rossi, Patrizia

    2010-04-21

    The iminophosphine 2-(2-Ph(2)P)C(6)H(4)N=CHC(6)H(4)OH (P-N-OH) reacts with [Pd(mu-Cl)(eta(3)-C(3)H(5))](2) yielding [PdCl(P-N-O)] and propene. In the presence of NEt(3), the reaction of P-N-OH with [Pd(mu-Cl)(eta(3)-1-R(1),3-R(2)C(3)H(3))](2) (R(1) = R(2) = H, Ph; R(1) = H, R(2) = Ph) affords the eta(1)-allyl derivatives [Pd(eta(1)-1-R(1),3-R(2)C(3)H(3))](P-N-O)] (R(1) = R(2) = H: 1; R(1) = H, R(2) = Ph: 2; R(1) = R(2) = Ph: 3). In solution, the complexes 1 and 3 undergo a slow dynamic process which interconverts the bonding site of the allyl ligand. The X-ray structural analysis of 1 indicates a square-planar coordination geometry around the palladium centre with a P,N,O,-tridentate ligand and a sigma bonded allyl group. The complexes [PdR(P-N-O)] (R = C(6)H(4)Me-4, C[triple bond]CPh) react slowly with p-bromoanisole in the presence of p-tolylboronic acid to give [PdBr(P-N-O)] and the coupling product RC(6)H(4)OMe-4. The latter reactions also proceed at a low rate under catalytic conditions. The coupling of allyl bromide with p-tolylboronic acid is catalyzed by [PdCl(P-N-O)]/K(2)CO(3) to give 4-allyltoluene.

  19. 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.

  20. 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.

  1. 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.

  2. Effect of three 2-allyl-p-mentha-6,8-dien-2-ols on inhibition of mild steel corrosion in 1 M HCl

    Directory of Open Access Journals (Sweden)

    S. Kharchouf

    2014-11-01

    Full Text Available 2-Allyl-p-mentha-6,8-dien-2-ols P1−P3 synthesized from carvone P are tested as corrosion inhibitors of steel in 1 M HCl using weight loss measurements, potentiodynamic polarisation and impedance spectroscopy (EIS methods. The addition of 2-allyl-p-mentha-6,8-dien-2-ols reduced the corrosion rate. Potentiodynamic polarisation studies clearly reveal that the presence of inhibitors does not change the mechanism of hydrogen evolution and that they act essentially as cathodic inhibitors. 2-Allyl-p-mentha-6,8-dien-2-ols tested adsorb on the steel surface according to Langmuir isotherm. From the adsorption isotherm some thermodynamic data for the adsorption process are calculated and discussed. EIS measurements show the increase of the charge-transfer resistance with the inhibitor concentration. The highest inhibition efficiency (92% is obtained for P1 at 3 g/L. The corrosion rate decreases with the rise of temperature. The corresponding activation energies are determined.

  3. Epoxidation of allyl-glycidyl ether with hydrogen peroxide over Ti-SBA-15 catalyst and in methanol medium

    Directory of Open Access Journals (Sweden)

    Walasek Marika

    2016-12-01

    Full Text Available This work presents the studies on the epoxidation of allyl-glycidyl ether (AGE over the Ti-SBA-15 catalyst. In these studies an aqueous hydrogen peroxide was used as an oxidizing agent and as a solvent methanol was applied. The studies on the influence the following parameters: temperature (20–80°C, molar ratio of AGE/H2O2 (1:1.5–5:1, methanol concentration (10–90 wt%, catalyst content (1–9 wt% and reaction time (15–240 min. were carried out and the most favourable values of these parameters were chosen (temperature 80°C, molar ratio of AGE/H2O2 = 5:1, methanol concentration 30 wt%, catalyst content 3 wt% and the reaction time 240 min.. At these conditions the functions describing the process reached the following values: the selectivity of diglycidyl ether (DGE 9.2 mol%, the conversion of AGE 13.9 mol% and the efficiency of H2O2 conversion 89.9 mol%.

  4. Computational insight into complex structures of thorium coordination with N, N'- bis(3-allyl salicylidene)-o-phenylenediamine.

    Science.gov (United States)

    Lan, Wenbo; Gao, Sha; Lin, Ying-Wu; Liao, Lifu; Wang, Xiaofeng; Nie, Changming

    2016-09-01

    Theoretical calculations on the structure of Th(IV) complex containing N, N'- bis(3-allyl salicylidene)-o-phenylenediamine (BASPDA) were performed using density functional theory (DFT) at the B3LYP/6-311G** level. The geometrical structural parameters and infrared spectra results of the Th(BASPDA)2 from the calculation were compared with the parallel dislocated structure (PDS) obtained in laboratory. The calculated structural parameters were in good agreement with the experimental results. In addition, based on the calculations, a stereoisomer SFS (staggered finger " + " structure) of the Th(BASPDA)2 complex was forecasted by the analysis of a comprehensive method. The charge distribution, structural parameters, bond order indices, spectral properties and thermodynamic properties as well as the molecular orbitals of the two possible crystal structures of Th(BASPDA)2 were also systematically studied. It was expected that this work could provide insightful information for understanding the properties of Th (BASPDA)2 complex at the molecular level.

  5. 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.

  6. Allyl triphenyl phosphonium bromide based DES-functionalized carbon nanotubes for the removal of mercury from water.

    Science.gov (United States)

    AlOmar, Mohamed Khalid; Alsaadi, Mohammed Abdulhakim; Hayyan, Maan; Akib, Shatirah; Ibrahim, Muhammad; Hashim, Mohd Ali

    2017-01-01

    Recently, deep eutectic solvents (DESs) have shown their new and interesting ability for chemistry through their involvement in variety of applications. This study introduces carbon nanotubes (CNTs) functionalized with DES as a novel adsorbent for Hg(2+) from water. Allyl triphenyl phosphonium bromide (ATPB) was combined with glycerol as the hydrogen bond donor (HBD) to form DES, which can act as a novel CNTs functionalization agent. The novel adsorbent was characterized using Raman, FTIR, XRD, FESEM, EDX, BET surface area, TGA, TEM and Zeta potential. Response surface methodology was used to optimize the removal conditions for Hg(2+). The optimum removal conditions were found to be pH 5.5, contact time 28 min, and an adsorbent dosage of 5 mg. Freundlich isotherm model described the adsorption isotherm of the novel adsorbent, and the maximum adsorption capacity obtained from the experimental data was 186.97 mg g(-1). Pseudo-second order kinetics describes the adsorption rate order.

  7. Synthesis, structural characterization and biological activities of organotin(IV) complexes with 5-allyl-2-hydroxy-3-methoxybenzaldehyde-4-thiosemicarbazone

    Indian Academy of Sciences (India)

    Rosenani A Haque; M A Salam

    2015-09-01

    The organotin(IV) complexes [MeSnCl(L)] (2), [BuSnCl(L)] (3), [PhSnCl(L)] (4) and [Me2Sn(L)] (5) were synthesized by reacting organotin(IV) chloride(s) with 5-allyl-2-hydroxy-3-methoxybenzaldehyde- 4-thiosemicarbazone [H2L], (1)] in presence of KOH in 1:2:1 molar ratio (metal salt: base:ligand). All the complexes have been characterized by elemental analyses, UV-Vis, FT-IR, 1H, 13C and 119Sn NMR spectral studies. The molecular structure of complex 5 has been confirmed by single crystal X-ray diffraction analysis. The ligand, H2L coordinates to Sn(IV) in thiolate form through phenoxide-O, azomethine-N and thiolate-S atoms. The C-Sn-C angle measured from coupling constant 1 (119Sn, 13C) for dimethyltin(IV) complex 5 is 123.4°. The 2 (119Sn, 1H) coupling constant values for complex 2 and 5 are 72.4 and 76.3 Hz, respectively. Proposed geometry for five coordinated Sn(IV) atom is a strongly distorted trigonal bipyramid. Biological studies were preformed in vitro against four bacterial strains which have shown better activities and potential as antibacterial agents.

  8. Modification in surface properties of poly-allyl-diglycol-carbonate (CR-39 implanted by Au+ ions at different fluences

    Directory of Open Access Journals (Sweden)

    Sagheer Riffat

    2016-06-01

    Full Text Available Ion implantation has a potential to modify the surface properties and to produce thin conductive layers in insulating polymers. For this purpose, poly-allyl-diglycol-carbonate (CR-39 was implanted by 400 keV Au+ ions with ion fluences ranging from 5 × 1013 ions/cm2 to 5 × 1015 ions/cm2. The chemical, morphological and optical properties of implanted CR-39 were analyzed using Raman, Fourier transform infrared (FT-IR spectroscopy, atomic force microscopy (AFM and UV-Vis spectroscopy. The electrical conductivity of implanted samples was determined through four-point probe technique. Raman spectroscopy revealed the formation of carbonaceous structures in the implanted layer of CR-39. From FT-IR spectroscopy analysis, changes in functional groups of CR-39 after ion implantation were observed. AFM studies revealed that morphology and surface roughness of implanted samples depend on the fluence of Au ions. The optical band gap of implanted samples decreased from 3.15 eV (for pristine to 1.05 eV (for sample implanted at 5 × 1015 ions/cm2. The electrical conductivity was observed to increase with the ion fluence. It is suggested that due to an increase in ion fluence, the carbonaceous structures formed in the implanted region are responsible for the increase in electrical conductivity.

  9. Mesoporous sol-gel WO{sub 3} thin films via poly(styrene-co-allyl-alcohol) copolymer templates

    Energy Technology Data Exchange (ETDEWEB)

    Ozkan Zayim, Esra [Department of Physics, Faculty of Science and Letters, Istanbul Technical University, Maslak, Istanbul 80626 (Turkey); Liu, Ping; Lee, Se-Hee; Tracy, C. Edwin; Pitts, J. Roland; Deb, Satyen K. [National Renewable Energy Laboratory, Golden, CO 80401 (United States); Turner, John A.

    2003-12-01

    In this study a copolymer poly(styrene-co-allyl-alcohol), [-CH{sub 2}CH(C{sub 6}H{sub 5})-]{sub x}[-CH{sub 2}CH-(CH{sub 2}OH)-]{sub y} has been employed as a novel template in a sol-gel synthesis process to direct the formation of mesoporous tungsten oxide. The copolymer, due to its rigid hydrophobic block of polystyrene, is a more effective surfactant in an alcohol solution than polypropylene oxide-polyethylene oxide based compounds. The films have been prepared by a spin-coating technique from an ethanol solution of tungsten hexachloride. At room temperature, ultraviolet illumination method has been found to be very suitable for removing the polymer template, leading to the formation of a high-quality mesoporous structure. The electrochromic and optical properties of the mesoporous films are described and compared to standard sol-gel tungsten oxide films. Mesoporous materials exhibit superior high-rate ion-insertion performance when used as electrochromic layers.

  10. 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.

  11. 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.

  12. 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.

  13. Influence of the antimicrobial compound allyl isothiocyanate against the Aspergillus parasiticus growth and its aflatoxins production in pizza crust.

    Science.gov (United States)

    Quiles, Juan M; Manyes, Lara; Luciano, Fernando; Mañes, Jordi; Meca, Giuseppe

    2015-09-01

    Aflatoxins (AFs) are secondary metabolites produced by different species of Aspergillus, such as Aspergillus flavus and Aspergillus parasiticus, which possess mutagenic, teratogenic and carcinogenic activities in humans. In this study, active packaging devices containing allyl isothiocyanate (AITC) or oriental mustard flour (OMF) + water were tested to inhibit the growth of A. parasiticus and AFs production in fresh pizza crust after 30 d. The antimicrobial and anti-aflatoxin activities were compared to a control group (no antimicrobial treatment) and to a group added with commercial preservatives (sorbic acid + sodium propionate). A. parasiticus growth was only inhibited after 30 d by AITC in filter paper at 5 μL/L and 10 μL/L, AITC sachet at 5 μL/L and 10 μL/L and OMF sachet at 850 mg + 850 μL of water. However, AFs production was inhibited by all antimicrobial treatments in a dose-dependent manner. More importantly, AITC in a filter paper at 10 μL/L, AITC sachet at 10 μL/L, OMF sachet at 850 mg + 850 μL of water and sorbic acid + sodium propionate at 0.5-2.0 g/Kg completely inhibited AFs formation. The use of AITC in active packaging devices could be a natural alternative to avoid the growth of mycotoxinogenic fungi in refrigerated bakery products in substitution of common commercial preservatives. Copyright © 2015 Elsevier Ltd. All rights reserved.

  14. Enantiodivergent Fluorination of Allylic Alcohols: Data Set Design Reveals Structural Interplay between Achiral Directing Group and Chiral Anion.

    Science.gov (United States)

    Neel, Andrew J; Milo, Anat; Sigman, Matthew S; Toste, F Dean

    2016-03-23

    Enantioselectivity values represent relative rate measurements that are sensitive to the structural features of the substrates and catalysts interacting to produce them. Therefore, well-designed enantioselectivity data sets are information rich and can provide key insights regarding specific molecular interactions. However, if the mechanism for enantioselection varies throughout a data set, these values cannot be easily compared. This premise, which is the crux of free energy relationships, exposes a challenging issue of identifying mechanistic breaks within multivariate correlations. Herein, we describe an approach to addressing this problem in the context of a chiral phosphoric acid catalyzed fluorination of allylic alcohols using aryl boronic acids as transient directing groups. By designing a data set in which both the phosphoric and boronic acid structures were systematically varied, key enantioselectivity outliers were identified and analyzed. A mechanistic study was executed to reveal the structural origins of these outliers, which was consistent with the presence of several mechanistic regimes within the data set. While 2- and 4-substituted aryl boronic acids favored the (R)-enantiomer with most of the studied catalysts, meta-alkoxy substituted aryl boronic acids resulted in the (S)-enantiomer when used in combination with certain (R)-phosphoric acids. We propose that this selectivity reversal is the result of a lone pair-π interaction between the substrate ligated boronic acid and the phosphate. On the basis of this proposal, a catalyst system was identified, capable of producing either enantiomer in high enantioselectivity (77% (R)-2 to 92% (S)-2) using the same chiral catalyst by subtly changing the structure of the achiral boronic acid.

  15. Allyl isothiocyanate, a constituent of cruciferous vegetables, inhibits growth of PC-3 human prostate cancer xenografts in vivo.

    Science.gov (United States)

    Srivastava, Sanjay K; Xiao, Dong; Lew, Karen L; Hershberger, Pamela; Kokkinakis, Demetrius M; Johnson, Candace S; Trump, Donald L; Singh, Shivendra V

    2003-10-01

    We have shown previously that allyl isothiocyanate (AITC), a constituent of cruciferous vegetables, significantly inhibits survival of PC-3 and LNCaP human prostate cancer cells in culture, whereas proliferation of a normal prostate epithelial cell line is minimally affected by AITC even at concentrations that are highly cytotoxic to the prostate cancer cells. The present studies were designed to test the hypothesis that AITC administration may retard growth of human prostate cancer xenografts in vivo. Bolus i.p. injection of 10 micromol AITC, three times per week (Monday, Wednesday and Friday) beginning the day of tumor cell implantation, significantly inhibited the growth of PC-3 xenograft (P < 0.05 by two-way ANOVA). For example, 26 days after tumor cell implantation, the average tumor volume in control mice (1025 +/- 205 mm3) was approximately 1.7-fold higher compared with AITC-treated mice. Histological analysis of tumors excised at the termination of the experiment revealed a statistically significant increase in number of apoptotic bodies with a concomitant decrease in cells undergoing mitosis in the tumors of AITC-treated mice compared with that of control mice. Western blot analysis indicated an approximately 70% reduction in the levels of anti-apoptotic protein Bcl-2 in the tumor lysate of AITC-treated mice compared with that of control mice. Moreover, the tumors from AITC-treated mice, but not control mice, exhibited cleavage of BID, which is known to promote apoptosis. Statistically significant reduction in the expression of several proteins that regulate G2/M progression, including cyclin B1, cell division cycle (Cdc)25B and Cdc25C (44, 45 and 90% reduction, respectively, compared with control), was also observed in the tumors of AITC-treated mice relative to control tumors. In conclusion, the results of the present study indicate that AITC administration inhibits growth of PC-3 xenografts in vivo by inducing apoptosis and reducing mitotic activity.

  16. From a cycloheptatrienylzirconium allyl complex to a cycloheptatrienylzirconium imidazolin-2-iminato "pogo stick" complex with imido-type reactivity.

    Science.gov (United States)

    Glöckner, Andreas; Bannenberg, Thomas; Daniliuc, Constantin G; Jones, Peter G; Tamm, Matthias

    2012-04-02

    The reaction of the cycloheptatrienylzirconium half-sandwich complex [(η(7)-C(7)H(7))ZrCl(tmeda)] (1) (tmeda = N,N,N',N'-tetramethylethylenediamine) with Li(Im(Dipp)N), generated from bis(2,6-diisopropylphenyl)imidazolin-2-imine (Im(Dipp)NH) with methyllithium, yields the imidazolin-2-iminato complex [(η(7)-C(7)H(7))Zr(Im(Dipp)N)(tmeda)] (2). The corresponding tmeda-free complex [(η(7)-C(7)H(7))Zr(Im(Dipp)N)] (5) can be synthesized via the 1,3-bis(trimethylsilyl)allyl complex [(η(7)-C(7)H(7))Zr{η(3)-C(3)H(3)(TMS)(2)}(THF)] (3; TMS = SiMe(3)), which undergoes an acid-base reaction with Im(Dipp)NH to form 5 and 1,3-bis(trimethylsilyl)propene. 5 exhibits an unusual one-legged piano stool ("pogo stick") geometry with a particularly short Zr-N bond of 1.997(2) Å. Addition of 2,6-dimethylphenyl or tert-butyl isocyanide affords the complexes [(η(7)-C(7)H(7))Zr(Im(Dipp)N)(CNR)] (R = o-Xy, 6; R = t-Bu, 7), while the reaction with 2,6-dimethylphenyl isocyanate results in a [2 + 2] cycloaddition to form the ureato(1-) complex [(η(7)-C(7)H(7))Zr{Im(Dipp)N(C═O)N-o-Xy}] (8). 5 can also act as an initiator for the ring-opening polymerization of ε-caprolactone. These reactivity patterns together with density functional theory calculations reveal a marked similarity of the bonding in imidazolin-2-iminato and conventional imido transition-metal complexes.

  17. Adsorption of acrolein, propanal, and allyl alcohol on Pd(111): a combined infrared reflection-absorption spectroscopy and temperature programmed desorption study.

    Science.gov (United States)

    Dostert, Karl-Heinz; O'Brien, Casey P; Mirabella, Francesca; Ivars-Barceló, Francisco; Schauermann, Swetlana

    2016-05-18

    Atomistic-level understanding of the interaction of α,β-unsaturated aldehydes and their derivatives with late transition metals is of fundamental importance for the rational design of new catalytic materials with the desired selectivity towards C[double bond, length as m-dash]C vs. C[double bond, length as m-dash]O bond partial hydrogenation. In this study, we investigate the interaction of acrolein, and its partial hydrogenation products propanal and allyl alcohol, with Pd(111) as a prototypical system. A combination of infrared reflection-absorption spectroscopy (IRAS) and temperature programmed desorption (TPD) experiments was applied under well-defined ultrahigh vacuum (UHV) conditions to obtain detailed information on the adsorption geometries of acrolein, propanal, and allyl alcohol as a function of coverage. We compare the IR spectra obtained for multilayer coverages, reflecting the molecular structure of unperturbed molecules, with the spectra acquired for sub-monolayer coverages, at which the chemical bonds of the molecules are strongly distorted. Coverage-dependent IR spectra of acrolein on Pd(111) point to the strong changes in the adsorption geometry with increasing acrolein coverage. Acrolein adsorbs with the C[double bond, length as m-dash]C and C[double bond, length as m-dash]O bonds lying parallel to the surface in the low coverage regime and changes its geometry to a more upright orientation with increasing coverage. TPD studies indicate decomposition of the species adsorbed in the sub-monolayer regime upon heating. Similar strong coverage dependence of the IR spectra were found for propanal and allyl alcohol. For all investigated molecules a detailed assignment of vibrational bands is reported.

  18. 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

    with two phosphine ligands, the corresponding neutral complex with one phosphine and one chloride ligand, and a neutral eta(1)-allylPd complex with one chloride and two phosphine ligands. The eta(1)-complex is unreactive toward nucleophiles. The cationic eta(3)-complex is the intermediate most frequently...... invoked in the title reaction, but in the presence of halides, the neutral, unsymmetrically substituted eta(3)-CoMplex will be formed rapidly from anionic Pd(0) complexes in solution. Since the latter will prefer both leaving group ionization and reaction with nucleophiles in the position trans...

  19. Nucleophilic phosphine-catalyzed intramolecular Michael reactions of N-allylic substituted α-amino nitriles: construction of functionalized pyrrolidine rings via 5-endo-trig cyclizations.

    Science.gov (United States)

    En, Da; Zou, Gong-Feng; Guo, Yuan; Liao, Wei-Wei

    2014-05-16

    Pyrrolidine rings are common moieties for pharmaceutical candidates and natural compounds, and the construction of these skeletons has received much attention. α-Amino nitriles are versatile intermediates in synthetic chemistry and have been widely used in the generation of multiple polyfunctional structures. Herein, a novel nucleophilic phosphine-catalyzed intramolecular Michael reaction of N-allylic substituted α-amino nitriles has been developed for the efficient construction of functionalized 2,4-disubstituted pyrrolidines (N-heterocyclic α-amino nitriles) via 5-endo-trig cyclization. Furthermore, the one-pot sequence of the synthesis of pyrrolidine and the subsequent transformations of the functionalized products have also been demonstrated.

  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. (4R-4-(2-Allyl-2H-1,2,3-triazol-4-yl-1,2-O-isopropylidene-l-threose

    Directory of Open Access Journals (Sweden)

    David J. Watkin

    2008-12-01

    Full Text Available X-ray crystallography unequivocally confirmed the structure of the title compound, C12H17N3O4, as (4R-4-(2-allyl-2H-1,2,3-triazol-4-yl-1,2-O-isopropylidene-l-threose. The absolute configuration was determined by the use of d-glucorono-3,6-lactone as the starting material. The crystal structure consists of hydrogen-bonded chains of molecules running parallel to the a axis. There are no unusual packing features.

  2. A configurational switch based on iridium-catalyzed allylic cyclization: application in asymmetric total syntheses of prosopis, dendrobate, and spruce alkaloids.

    Science.gov (United States)

    Gnamm, Christian; Brödner, Kerstin; Krauter, Caroline M; Helmchen, Günter

    2009-10-12

    A method for the stereoselective synthesis of 2,6-disubstituted piperidines has been developed that is based on the use of an intramolecular iridium-catalyzed allylic substitution as a configurational switch. The procedure allows the preparation of 2-vinylpiperidines with enantiomeric excesses (ee) of greater than 99%. As applications, total syntheses of piperidine alkaloids have been elaborated, most often by using Ru-catalyzed cross-metatheses as a key step for introduction of a side chain. Asymmetric total syntheses of the prosopis alkaloids (+)-prosopinine, (+)-prosophylline, (+)-prosopine, and of the dendrobate alkaloid (+)-241D and its C6 epimer are described.

  3. Direct Substitution of the Hydroxy Group at the Allylic/propargylic Position with Carbon-and Heteroatomcentered Nucleophiles Catalyzed by Yb(OTf)3

    Institute of Scientific and Technical Information of China (English)

    HUANG Wen; SHEN Quan-Sheng; WANG Jia-Liang; ZHOU Xi-Geng

    2008-01-01

    An efficient and highly selective Yb(OTf)3-catalyzed direct substitution of the hydroxy group at the allylic and propargylic positions with a variety of heteroatom- and carbon-centered nucleophiles, such as alcohols, thiols,amines, amides and active methylene compounds has been developed. The advantages of the present catalytic system are wide availability of the starting materials, especially for tolerance to thiols, no need for dried solvents and additives, mild conditions, short time of reaction, simple manipulation and environmentally friendly catalyst that can be recovered and reused at least ten times without significant reduction of activity.

  4. Substituent Effects on Regioselectivity of the Diels-Alder Reactions: Reactions of 10-Allyl-1,8-dichloroanthracene with 2-Chloroacrylonitrile, 1-Cyanovinyl Acetate and Phenyl Vinyl Sulfone

    Directory of Open Access Journals (Sweden)

    Mujeeb A. Sultan

    2016-01-01

    Full Text Available Diels-Alder reaction of 10-allyl-1,8-dichloroanthracene (3 with 2-chloroacrylonitrile (4 and 1-cyanovinyl acetate (5 gives exclusively the ortho isomer while its reaction with phenyl vinyl sulfone (10 yields a mixture of two isomeric adducts with priority to ortho isomer. The reactions proceeded under microwave condition in xylene. Configurations of these isomers have been assigned with the help of NMR spectra. The results indicated that the steric effect is dominating toward the isomer regioselectivity in the Diels-Alder reaction of the present compounds.

  5. 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.

  6. On the regiochemistry of nucleophilic attack on 2-halo pi-allyl complexes. 4. The effect of silver acetate and nucleophile concentrations in competitive nucleophilic attack with malonate and phenoxide nucleophiles.

    Science.gov (United States)

    Organ, Michael G; Arvanitis, Elena A; Hynes, Stephen J

    2003-05-16

    2,3-Dibromo-1-propene or its allyl carbonate analogue are ionized under Pd catalysis to generate the 2-bromo Pd-pi-allyl complex (triphenylphosphine ligand), which alkylates with malonate nucleophile at the terminal position. The presence of acetate ion in the reaction mixture results in some malonate attack being redirected to the central carbon. The acetate ion can come from the ionization of 1-acetoxy-2-bromo-2-propene or by the addition of silver acetate to the reaction mixture. The addition of phenoxide ion to the reaction also causes the same regiochemical phenomena, although harder anions such as methoxide exert no such effect.

  7. Preservation of acidified cucumbers with a natural preservative combination of fumaric acid and allyl isothiocyanate that target lactic acid bacteria and yeasts.

    Science.gov (United States)

    Pérez-Díaz, I M; McFeeters, R F

    2010-05-01

    Without the addition of preservative compounds cucumbers acidified with 150 mM acetic acid with pH adjusted to 3.5 typically undergo fermentation by lactic acid bacteria. Fumaric acid (20 mM) inhibited growth of Lactobacillus plantarum and the lactic acid bacteria present on fresh cucumbers, but spoilage then occurred due to growth of fermentative yeasts, which produced ethanol in the cucumbers. Allyl isothiocyanate (2 mM) prevented growth of Zygosaccharomyces globiformis, which has been responsible for commercial pickle spoilage, as well as the yeasts that were present on fresh cucumbers. However, allyl isothiocyanate did not prevent growth of Lactobacillus plantarum. When these compounds were added in combination to acidified cucumbers, the cucumbers were successfully preserved as indicated by the fact that neither yeasts or lactic acid bacteria increased in numbers nor were lactic acid or ethanol produced by microorganisms when cucumbers were stored at 30 degrees C for at least 2 mo. This combination of 2 naturally occurring preservative compounds may serve as an alternative approach to the use of sodium benzoate or sodium metabisulfite for preservation of acidified vegetables without a thermal process.

  8. 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.

  9. Investigation of the O+allyl addition/elimination reaction pathways from the OCH(2)CHCH(2) radical intermediate.

    Science.gov (United States)

    Fitzpatrick, Benjamin L; Lau, Kai-Chung; Butler, Laurie J; Lee, Shih-Huang; Lin, Jim Jr-Min

    2008-08-28

    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 kcalmol. 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 me=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

  10. 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

  11. Ab initio heats of formation for chlorinated hydrocarbons: Allyl chloride, cis- and trans-1-chloropropene, and vinyl chloride

    Science.gov (United States)

    Colegrove, Brenda Thies; Thompson, Tyler B.

    1997-01-01

    Ab initio molecular energies at several levels of theory (MP4/6-311G**//MP2/6-31G*, MP4/6-311+G**//MP2/6-31G*,G1, and G2) are used to determine the heats of formation of several chlorinated hydrocarbons (allyl chloride, cis- and trans-1-chloropropene, and vinyl chloride) from atomization and isodesmic reactions. More than one isodesmic reaction was investigated for each molecule. Inconsistencies between the results from isodesmic reactions for a given molecule indicated possible errors in the experimental heats of formation for some of the chlorinated molecules used as references in the isodesmic reactions (in particular 1-chloropropane and 2-chloropropane). To further examine this possibility we did a multivariate regression for the G2 calculated reaction enthalpies for the 30 isodesmic reactions. In the regression, the heats of formation of the hydrocarbons and CH3Cl were fixed at the experimental values. The heats of formation of all the other chlorinated hydrocarbons were varied. The heats of formation determined using this method were: ΔHf298(CH2Cl2)=-22.6 kcal/mole, ΔHf298(CHCl=Cl2)=5.0 kcal/mole, ΔHf298(CCl2=CH2)=-0.2 kcal/mole, ΔHf298(CH2Cl-CH3)=-27.0 kcal/mole, ΔHf298(c-CHCl=CH-CH3)=-3.1 kcal/mole, ΔHf298(t-CHCl=CH-CH3)=-2.8 kcal/mole, ΔHf298(CH2=CClCH3)=-5.4 kcal/mole, ΔHf298(CH2=CH-CH2Cl)=-0.8 kcal/mole, ΔHf298(CH2Cl-CH2-CH3) =-32.2 kcal/mole, ΔHf298(CH3-CHCl-CH3 )=-35.9 kcal/mole. The calculated heats of formation were used to derive the following Benson group enthalpy values: C-(Cl)(H)2(Cd)=-15.6 kcal/mole, Cd-(Cl)(H)=-1.3 kcal/mole, and cis-halogen-alkyl =-0.3 kcal/mole.

  12. Allylic alcohol transposition by ortho ester-initiated carbonate extension. synthesis of the vasodilator 11(R),12(S),15(S)-trihydroxyeicosa- 5(Z),8(Z),13(E)-trienoic acid.

    Science.gov (United States)

    Conrow, Raymond E

    2006-05-25

    [reaction: see text] The title compound 1 was obtained via methyl ester 2, which was synthesized in four steps from an isomeric 11,14,15-triol ester 5. In the key step, Boc orthoformate 9 was treated with TMS triflate to initiate intramolecular nucleophilic substitution with allylic transposition, forming cyclic carbonates 10 and 11.

  13. Induction of apoptosis in human liver carcinoma HepG2 cell line by 5-allyl-7-gen-difluoromethylenechrysin

    Institute of Scientific and Technical Information of China (English)

    Xiang-Wen Tan; Hong Xia; Jin-Hua Xu; Jian-Guo Cao

    2009-01-01

    AIM: To investigate the effect of 5-allyl-7-gen-difluoromethylenechrysin (ADFMChR) on apoptosis of human liver carcinoma HepG2 cell line and the molecular mechanisms involved. METHODS: HepG2 cells and L-02 cells were cultured in vitro and the inhibitory effect of ADFMChR on their proliferation was measured by MTT assay. The apoptosis of HepG2 cells was determined by flow cytometry (FCM) using propidium iodide (PI) fluorescence staining.DNA ladder bands were observed by DNA agarose gel electrophoresis. The influence of ADFMChR on the proxisome proliferator-activated receptor γ (PPARγ), NF-κB, Bcl-2 and Bax protein expression of HepG2 cells were analyzed by Western blotting. RESULTS: MTT assay showed that ADFMChR significantly inhibited proliferation of HepG2 cells in a dosedependent manner, with little effect on growth of L-02 cells, and when IC50 was measured as 8.45 μmol/L and 191.55 μmol/L respectively, the potency of ADFMChR to HepG2 cells, was found to be similar to 5-fluorouracil (5-FU, IC50 was 9.27 μmol/L). The selective index of ADFMChR cytotoxicity to HepG2 cells was 22.67 (191.55/8.45), higher than 5-FU (SI was 7.05 (65.37/9.27). FCM with PI staining demonstrated that the apoptosis rates of HepG2 cells treated with 3.0, 10.0 and 30.0 μmol/L ADFMChR for 48 h were 5.79%, 9.29% and 37.8%, respectively, and were significantly higher when treated with 30.0 μmol/L ADFMChR than when treated with 30.0 μmol/L ChR (16.0%) ( P < 0.05) and were similar to those obtained with 30.0 μmol/L 5-FU (41.0%). DNA agarose gel electrophoresis showed that treatment of HepG2 cells with 10.0 μmol/L ADFMChR for 48 h and 72 h resulted in typical DNA ladders which could be reversed by 10.00 μmol/L GW9662, a blocker of PPARγ. Western blotting analysis revealed that after 24 h of treatment with 3.0, 10.0, 30.0 μmol/L ADFMChR, PPARγ and Bax protein expression in HepG2 cells increased but Bcl-2 and NF-κB expression decreased; however, pre-incubation with 10.0 μmol/L GW

  14. Reaction pathway and transition state of the Zn-promoted Barbier-type reactions of benzaldehyde and benzophenone with allylic iodides

    Energy Technology Data Exchange (ETDEWEB)

    Yamataka, Hiroshi; Nishikawa, Kazuyoshi; Hanafusa, Terukiyo (Osaka Univ., Ibaraki (Japan). Inst. of Scientific and Industrial Research)

    1994-01-01

    The carbonyl-[sup 14]C kinetic isotope effects and the substituent effects on the reactivity of the Zn-promoted Barbier-type reaction of allyl iodide (3-iodo-1-propene) with benzaldehyde and benzophenone were determined in THF at 25degC. The observed normal carbon isotope effects as well as positive Hammett [rho] values suggest that the reactions go through a direct nucleophilic addition mechanism. No indication of the occurrence of electron transfer was obtained by enone isomerization and dehalogenation probe experiments. Diastereoselectivity in the reaction of crotyl iodide (1-iodo-2-butene) with benzaldehyde was low and independent of the substituent on aldehyde, consistent with the six-membered cyclic transition state. (author).

  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. 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.

  17. Enhancement of the fungicidal activity of amphotericin B by allicin, an allyl-sulfur compound from garlic, against the yeast Saccharomyces cerevisiae as a model system.

    Science.gov (United States)

    Ogita, Akira; Fujita, Ken-ichi; Taniguchi, Makoto; Tanaka, Toshio

    2006-10-01

    Amphotericin B (AmB) is a representative antibiotic for the control of serious fungal infections, and its fungicidal activity was greatly enhanced by allicin, an allyl-sulfur compound from garlic. In addition to the plasma membrane permeability change, AmB induced vacuole membrane damage so that the organelles were visible as small discrete particles. Although allicin was ineffective in promoting AmB-induced plasma membrane disability, this compound enhanced AmB-induced structural damage to the vacuolar membrane even at a non-lethal dose of the antibiotic. Allicin could also enhance the antifungal activity of AmB against the pathogenic fungus Candida albicans and against Aspergillus fumigatus. In contrast, allicin did not enhance the cytotoxic activity of AmB against cells of human promyelocytic leukemia (HL-60), a vacuole-less organism.

  18. 1-Allyl-3-methyl-3′,5′-diphenylspiro[quinoxaline-2(1H,2′(3′H-[1,3,4]thiadiazole

    Directory of Open Access Journals (Sweden)

    Seik Weng Ng

    2010-12-01

    Full Text Available In the title spiro compound, C25H22N4S, the planar quinoxaline (r.m.s. deviation = 0.070 Å and planar thiadiazole (r.m.s. deviation = 0.060 Å ring systems share a common C atom; their mean planes are aligned at 89.7 (1°. The thiazole ring possesses two aromatic ring substituents and is nearly coplanar with these rings [the dihedral angles between the thiadiazole and phenyl rings are 5.7 (1 and 10.7 (1°]. The allyl unit is disordered over two positions in a 0.65 (1:0.35 (1 ratio.

  19. Preliminary investigation on the use of allyl isothiocyanate to increase the shelf-life of gilthead sea bream (Sparus aurata fillets

    Directory of Open Access Journals (Sweden)

    Filippo Giarratana

    2015-09-01

    Full Text Available The aim of this work is to evaluate the activity of allyl isothiocyanate (AITC against fish spoilage bacteria (specific spoilage organisms; SSOs as well as its possible use in gilthead sea bream (Sparus aurata fillets to extend their shelf-life. In this regard, in vitro tests are carried out in order to evaluate the inhibitory activity of AITC and its vapours on several strains of SSOs. The AITC effect on the shelflife of sea bream fillets was made by putting them in plastic trays hermetically closed with the addition AITC. Microbiological and sensorial evaluations were made on fish fillets during storage. Treated fillets maintained microbial populations at a significantly lower level compared with the control samples during storage, showing better sensorial characteristics. Therefore, the use of AITC’s vapours seems to be a new and interesting alternative way to increase fish product shelf-life.

  20. Structure-Activity Relationship Study on Isothiocyanates: Comparison of TRPA1-Activating Ability between Allyl Isothiocyanate and Specific Flavor Components of Wasabi, Horseradish, and White Mustard.

    Science.gov (United States)

    Terada, Yuko; Masuda, Hideki; Watanabe, Tatsuo

    2015-08-28

    Allyl isothiocyanate (ITC) (4) is the main pungent component in wasabi, and it generates an acrid sensation by activating TRPA1. The flavor and pungency of ITCs vary depending on the compound. However, the differences in activity to activate TRPA1 between ITCs are not known except for a few compounds. To investigate the effect of carbon chain length and substituents of ITCs, the TRPA1-activiting ability of 16 ITCs was measured. Since most of the ITCs showed nearly equal TRPA1-activiting potency, the ITC moiety is likely the predominant contributor to their TRPA1-activating abilities, and contributions of other functional groups to their activities to activate TRPA1 are comparatively small.

  1. Allylic ionic liquid electrolyte-assisted electrochemical surface passivation of LiCoO2 for advanced, safe lithium-ion batteries

    Science.gov (United States)

    Mun, Junyoung; Yim, Taeeun; Park, Jang Hoon; Ryu, Ji Heon; Lee, Sang Young; Kim, Young Gyu; Oh, Seung M.

    2014-01-01

    Room-temperature ionic liquid (RTIL) electrolytes have attracted much attention for use in advanced, safe lithium-ion batteries (LIB) owing to their nonvolatility, high conductivity, and great thermal stability. However, LIBs containing RTIL-electrolytes exhibit poor cyclability because electrochemical side reactions cause problematic surface failures of the cathode. Here, we demonstrate that a thin, homogeneous surface film, which is electrochemically generated on LiCoO2 from an RTIL-electrolyte containing an unsaturated substituent on the cation (1-allyl-1-methylpiperidinium bis(trifluoromethanesulfonyl)imide, AMPip-TFSI), can avert undesired side reactions. The derived surface film comprised of a high amount of organic species from the RTIL cations homogenously covered LiCoO2 with a <25 nm layer and helped suppress unfavorable thermal reactions as well as electrochemical side reactions. The superior performance of the cell containing the AMPip-TFSI electrolyte was further elucidated by surface, electrochemical, and thermal analyses. PMID:25168309

  2. 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.

  3. S-allyl cysteine activates the Nrf2-dependent antioxidant response and protects neurons against ischemic injury in vitro and in vivo.

    Science.gov (United States)

    Shi, Huanying; Jing, Xu; Wei, Xinbing; Perez, Ruth G; Ren, Manru; Zhang, Xiumei; Lou, Haiyan

    2015-04-01

    Stroke is a devastating clinical condition for which an effective neuroprotective treatment is currently unavailable. S-allyl cysteine (SAC), the most abundant organosulfur compound in aged garlic extract, has been reported to possess neuroprotective effects against stroke. However, the mechanisms underlying its beneficial effects remain poorly defined. The present study tests the hypothesis that SAC attenuates ischemic neuronal injury by activating the nuclear factor erythroid-2-related factor 2 (Nrf2)-dependent antioxidant response in both in vitro and in vivo models. Our findings demonstrate that SAC treatment resulted in an increase in Nrf2 protein levels and subsequent activation of antioxidant response element pathway genes in primary cultured neurons and mice. Exposure of primary neurons to SAC provided protection against oxygen and glucose deprivation-induced oxidative insults. In wild-type (Nrf2(+/+) ) mice, systemic administration of SAC attenuated middle cerebral artery occlusion-induced ischemic damage, a protective effect not observed in Nrf2 knockout (Nrf2(-/-) ) mice. Taken together, these findings provide the first evidence that activation of the Nrf2 antioxidant response by SAC is strongly associated with its neuroprotective effects against experimental stroke and suggest that targeting the Nrf2 pathway may provide therapeutic benefit for the treatment of stroke. The transcription factor Nrf2 is involved in cerebral ischemic disease and may be a promising target for the treatment of stroke. We provide novel evidence that SAC confers neuroprotection against ischemic stroke by activating the antioxidant Nrf2 signaling pathway. ARE, antioxidant response element; GCLC, glutathione cysteine ligase regulatory subunit; GCLM, glutathione cysteine ligase modulatory subunit; HO-1, heme oxygenase-1; JNK, c-Jun N-terminal kinase; Keap1, Kelch-like ECH-associated protein 1; Maf, musculoaponeurotic fibrosarcoma; Nrf2, nuclear factor erythroid-2-related factor 2

  4. Research on Industrial Catalytic Synthesis of Allyl Isothiocyanate%烯丙基异硫氰酸酯的工业催化合成研究

    Institute of Scientific and Technical Information of China (English)

    王咏梅

    2014-01-01

    Allyl isothiocyanate is an important Intermediate products in organic Production , it is widely used in va-rious fields such as pesticides , medicine and soil disinfection etc . This paper describes different methods from dif -ferent starting materials and routes of synthesis of isothiocyanates , and the temperature , pressure , ratio of raw materials was studied in detail . We also made the effect for the catalyst in this reaction , the influences of solvents on the reaction . Under catalytic conditions , to stage a way of industrial synthesis of allyl isothiocyanate , achieves better purification and reduce the cost of products of dual urpose .%烯丙基异硫氰酸酯是一种重要的有机合成中间体,在合成农药、医药等方面都有比较重要的用途,在土壤消毒方面也有应用。本文叙述了用不同起始原料,不同技术路线合成异硫氰酸酯的方法,并对温度、压力、配料比进行了细致的研究试验。特别研究了催化剂对反应的影响,探讨了溶剂对反应的影响。在催化条件下,以阶段升温的方式工业合成烯丙基异硫氰酯的方法,达到了纯化产品和降低成本的双重目的。

  5. Crystallization experiments with the dinuclear chelate ring complex di-μ-chlorido-bis[(η(2)-2-allyl-4-methoxy-5-{[(propan-2-yloxy)carbonyl]methoxy}phenyl-κC(1))platinum(II)].

    Science.gov (United States)

    Nguyen Thi Thanh, Chi; Pham Van, Thong; Le Thi Hong, Hai; Van Meervelt, Luc

    2016-10-01

    Crystallization experiments with the dinuclear chelate ring complex di-μ-chlorido-bis[(η(2)-2-allyl-4-methoxy-5-{[(propan-2-yloxy)carbonyl]methoxy}phenyl-κC(1))platinum(II)], [Pt2(C15H19O4)2Cl2], containing a derivative of the natural compound eugenol as ligand, have been performed. Using five different sets of crystallization conditions resulted in four different complexes which can be further used as starting compounds for the synthesis of Pt complexes with promising anticancer activities. In the case of vapour diffusion with the binary chloroform-diethyl ether or methylene chloride-diethyl ether systems, no change of the molecular structure was observed. Using evaporation from acetonitrile (at room temperature), dimethylformamide (DMF, at 313 K) or dimethyl sulfoxide (DMSO, at 313 K), however, resulted in the displacement of a chloride ligand by the solvent, giving, respectively, the mononuclear complexes (acetonitrile-κN)(η(2)-2-allyl-4-methoxy-5-{[(propan-2-yloxy)carbonyl]methoxy}phenyl-κC(1))chloridoplatinum(II) monohydrate, [Pt(C15H19O4)Cl(CH3CN)]·H2O, (η(2)-2-allyl-4-methoxy-5-{[(propan-2-yloxy)carbonyl]methoxy}phenyl-κC(1))chlorido(dimethylformamide-κO)platinum(II), [Pt(C15H19O4)Cl(C2H7NO)], and (η(2)-2-allyl-4-methoxy-5-{[(propan-2-yloxy)carbonyl]methoxy}phenyl-κC(1))chlorido(dimethyl sulfoxide-κS)platinum(II), determined as the analogue {η(2)-2-allyl-4-methoxy-5-[(ethoxycarbonyl)methoxy]phenyl-κC(1)}chlorido(dimethyl sulfoxide-κS)platinum(II), [Pt(C14H17O4)Cl(C2H6OS)]. The crystal structures confirm that acetonitrile interacts with the Pt(II) atom via its N atom, while for DMSO, the S atom is the coordinating atom. For the replacement, the longest of the two Pt-Cl bonds is cleaved, leading to a cis position of the solvent ligand with respect to the allyl group. The crystal packing of the complexes is characterized by dimer formation via C-H...O and C-H...π interactions, but no π-π interactions are observed despite the presence of

  6. Enantioselective allylation of imines catalyzed by newly developed (-)-β-pinene-based π-allylpalladium catalyst: an efficient synthesis of (R)-α-propylpiperonylamine and (R)-pipecolic acid.

    Science.gov (United States)

    Fernandes, Rodney A; Nallasivam, Jothi L

    2012-10-14

    A newly developed π-allylpalladium with a (-)-β-pinene framework and an isobutyl side chain catalyzed the enantioselective allylation of imines in good yields and enantioselectivities (20 examples, up to 98% ee). An efficient enantioselective synthesis of the (R)-α-propyl piperonylamine part of DMP 777, a human leukocyte elastase inhibitor and (R)-pipecolic acid have been achieved as a useful application of this methodology.

  7. 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.

  8. 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.

  9. Polymer-incarcerated gold-palladium nanoclusters with boron on carbon: a mild and efficient catalyst for the sequential aerobic oxidation-Michael addition of 1,3-dicarbonyl compounds to allylic alcohols.

    Science.gov (United States)

    Yoo, Woo-Jin; Miyamura, Hiroyuki; Kobayashi, Shuū

    2011-03-09

    We have developed a polymer-incarcerated bimetallic Au-Pd nanocluster and boron as a catalyst for the sequential oxidation-addition reaction of 1,3-dicarbonyl compounds with allylic alcohols. The desired tandem reaction products were obtained in good to excellent yields under mild conditions with broad substrate scope. In the course of our studies, we discovered that the excess reducing agent, sodium borohydride, reacts with the polymer backbone to generate an immobilized tetravalent boron catalyst for the Michael reaction. In addition, we found bimetallic Au-Pd nanoclusters to be particularly effective for the aerobic oxidation of allylic alcohols under base- and water-free conditions. The ability to conduct the reaction under relatively neutral and anhydrous conditions proved to be key in maintaining good catalyst activity during recovery and reuse of the catalyst. Structural characterization (STEM, EDS, SEM, and N(2) absorption/desorption isotherm) of the newly prepared PI/CB-Au/Pd/B was performed and compared to PI/CB-Au/Pd. We found that while boron was important for the Michael addition reaction, it was found to alter the structural profile of the polymer-carbon black composite material to negatively affect the allylic oxidation reaction.

  10. Highly efficient redox isomerisation of allylic alcohols catalysed by pyrazole-based ruthenium(IV) complexes in water: mechanisms of bifunctional catalysis in water.

    Science.gov (United States)

    Bellarosa, Luca; Díez, Josefina; Gimeno, José; Lledós, Agustí; Suárez, Francisco J; Ujaque, Gregori; Vicent, Cristian

    2012-06-18

    The catalytic activity of ruthenium(IV) ([Ru(η(3):η(3)-C(10)H(16))Cl(2)L]; C(10)H(16) = 2,7-dimethylocta-2,6-diene-1,8-diyl, L = pyrazole, 3-methylpyrazole, 3,5-dimethylpyrazole, 3-methyl-5-phenylpyrazole, 2-(1H-pyrazol-3-yl)phenol or indazole) and ruthenium(II) complexes ([Ru(η(6)-arene)Cl(2)(3,5-dimethylpyrazole)]; arene = C(6)H(6), p-cymene or C(6)Me(6)) in the redox isomerisation of allylic alcohols into carbonyl compounds in water is reported. The former show much higher catalytic activity than ruthenium(II) complexes. In particular, a variety of allylic alcohols have been quantitatively isomerised by using [Ru(η(3):η(3)-C(10)H(16))Cl(2)(pyrazole)] as a catalyst; the reactions proceeded faster in water than in THF, and in the absence of base. The isomerisations of monosubstituted alcohols take place rapidly (10-60 min, turn-over frequency = 750-3000 h(-1)) and, in some cases, at 35 °C in 60 min. The nature of the aqueous species formed in water by this complex has been analysed by ESI-MS. To analyse how an aqueous medium can influence the mechanism of the bifunctional catalytic process, DFT calculations (B3LYP) including one or two explicit water molecules and using the polarisable continuum model have been carried out and provide a valuable insight into the role of water on the activity of the bifunctional catalyst. Several mechanisms have been considered and imply the formation of aqua complexes and their deprotonated species generated from [Ru(η(3):η(3)-C(10)H(16))Cl(2)(pyrazole)]. Different competitive pathways based on outer-sphere mechanisms, which imply hydrogen-transfer processes, have been analysed. The overall isomerisation implies two hydrogen-transfer steps from the substrate to the catalyst and subsequent transfer back to the substrate. In addition to the conventional Noyori outer-sphere mechanism, which involves the pyrazolide ligand, a new mechanism with a hydroxopyrazole complex as the active species can be at work in water. The

  11. A new tetranuclear copper(I) complex based on allyl(5-phenyl-1,3,4-thiadiazol-2-yl)azanide ligand: Synthesis and structural characterization

    Science.gov (United States)

    Slyvka, Yu. I.; Goreshnik, E. A.; Ardan, B. R.; Veryasov, G.; Morozov, D.; Mys'kiv, M. G.

    2015-04-01

    By means of alternating current electrochemical technique a new tetranuclear crystalline copper(I) complex [CuI4(L-)4] (L- - allyl(5-phenyl-1,3,4-thiadiazol-2-yl)azanide ion) has been obtained and characterized by X-ray single crystal diffraction (Sp.gr. I41/a) and Raman spectroscopy. The metal center adopts linear arrangement, composed of one thiadiazole N atom from the one L- anion and one azanide N atom of the other L- ligand. A bridged Cu atoms stitch four L- ligands into the firstly observed tetranuclear copper(I) azanide complex with intramolecular Cu(I)⋯Cu(I) interactions at the distance of 2.7451(6) Å. Molecular structure and Raman spectrum of the compound have been computed using the DFT B3LYP methodology and the cc-pVDZ basis set. The results are compared with the experimental data obtained. Spectrum calculation followed by normalization to the most intensive peak allowed providing detailed vibrational band assignment.

  12. Direct catalytic asymmetric addition of allyl cyanide to ketones via soft Lewis acid/hard Brønsted base/hard Lewis base catalysis.

    Science.gov (United States)

    Yazaki, Ryo; Kumagai, Naoya; Shibasaki, Masakatsu

    2010-04-21

    We report that a hard Lewis base substantially affects the reaction efficiency of direct catalytic asymmetric gamma-addition of allyl cyanide (1a) to ketones promoted by a soft Lewis acid/hard Brønsted base catalyst. Mechanistic studies have revealed that Cu/(R,R)-Ph-BPE and Li(OC(6)H(4)-p-OMe) serve as a soft Lewis acid and a hard Brønsted base, respectively, allowing for deprotonative activation of 1a as the rate-determining step. A ternary catalytic system comprising a soft Lewis acid/hard Brønsted base and an additional hard Lewis base, in which the basicity of the hard Brønsted base Li(OC(6)H(4)-p-OMe) was enhanced by phosphine oxide (the hard Lewis base) through a hard-hard interaction, outperformed the previously developed binary soft Lewis acid/hard Brønsted base catalytic system, leading to higher yields and enantioselectivities while using one-tenth the catalyst loading and one-fifth the amount of 1a. This second-generation catalyst allows efficient access to highly enantioenriched tertiary alcohols under nearly ideal atom-economical conditions (0.5-1 mol % catalyst loading and a substrate molar ratio of 1:2).

  13. Micro-structure, Mechanical Properties and Dielectric Properties of Bisphenol A Allyl Compound-Bismaleimide Modified by Super-Critical Silica and Polyethersulfone Composite

    Science.gov (United States)

    Chen, Yufei; Wang, Botao; Li, Fangliang; Teng, Chengjun

    2017-07-01

    Bisphenol A allyl compound-bismaleimide (MBAE) composite modified by SCE-SiO2 and polyethersulfone (PES) resin has been prepared and researched. SCE-SiO2 was modified by super-critical ethanol and PES thermoplastic resin used as modifiers. The composite was prepared via the hot melting method. The FT-IR measurements indicated that ethanol molecular had adsorbed on the nano-SiO2 surface. SEM images showed that the composite had a multiphase structure, PES and SCE-SiO2 existed as a dispersed phase, and the interaction of the three phases affected each other, such that the bending fracture behavior transformed from brittle fracture to ductile fracture, and the modifiers of SCE-SiO2 and PES resin could improve the mechanical properties. The impact and the bending strength of the composite was 16.5 kJ/mm2 and 150.4 MPa, improved by 68.3% and 56.7% compared with those of the MBAE matrix, respectively, when the content of SCE-SiO2 was 2 wt.% and PES 5 wt.%. The dielectric constant ( ɛ) of the composites was less than 3.9 and decreased with increasing frequency, and the dielectric loss was less than 9 × 10-3 for frequencies between 102 Hz and 105 Hz. These properties could meet the requirement of insulating material.

  14. Decreased glycation and structural protection properties of γ-glutamyl-S-allyl-cysteine peptide isolated from fresh garlic scales (Allium sativum L.).

    Science.gov (United States)

    Tan, Dehong; Zhang, Yao; Chen, Lulu; Liu, Ling; Zhang, Xuan; Wu, Zhaoxia; Bai, Bing; Ji, Shujuan

    2015-01-01

    The antiglycative effect of γ-glutamyl-S-allyl-cysteine (GSAC) peptide isolated from fresh garlic scales was investigated in the bovine serum albumin (BSA)/glucose system. GSAC inhibited the increase of fluorescence intensity at about 440 nm in a concentration-dependent manner and reduced reacted free lysine side chains by 10.9%, 24.7% and 37.7%, as the GSAC concentrations increased from 0.1 to 2.5 mg mL(-1). Glycation-specific decline in BSA α-helix content (from 61.3% to 55.6%) and increase in β-sheet (from 2.1% to 5.4%) were prevented by GSAC (2.5 mg mL(-1)) in vitro, implying its stabilisation effect. GSAC treatment (2.5 mg mL(-1)) suppressed protein crosslinking to form polymers. Additionally, GSAC (10, 40, and 160 μg mL(-1)) showed radical-scavenging and metal-chelating capacities. In conclusion, GSAC has an antiglycative effect, which may involve its radical-scavenging and metal-chelating capacities.

  15. The antioxidative properties of S-allyl cysteine not only influence somatic cells but also improve early embryo cleavage in pigs

    Directory of Open Access Journals (Sweden)

    Markéta Dvořáková

    2016-08-01

    Full Text Available In vitro cultivation systems for oocytes and embryos are characterised by increased levels of reactive oxygen species (ROS, which can be balanced by the addition of suitable antioxidants. S-allyl cysteine (SAC is a sulfur compound naturally occurring in garlic (Allium sativum, which is responsible for its high antioxidant properties. In this study, we demonstrated the capacity of SAC (0.1, 0.5 and 1.0 mM to reduce levels of ROS in maturing oocytes significantly after 24 (reduced by 90.33, 82.87 and 91.62%, respectively and 48 h (reduced by 86.35, 94.42 and 99.05%, respectively cultivation, without leading to a disturbance of the standard course of meiotic maturation. Oocytes matured in the presence of SAC furthermore maintained reduced levels of ROS even 22 h after parthenogenic activation (reduced by 66.33, 61.64 and 57.80%, respectively. In these oocytes we also demonstrated a growth of early embryo cleavage rate (increased by 33.34, 35.00 and 35.00%, respectively. SAC may be a valuable supplement to cultivation media.

  16. 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).

  17. Isolation determination of garlic allyl sulfides and their antioxidant activity%大蒜烯丙基硫化物的分离鉴定及抗氧化性

    Institute of Scientific and Technical Information of China (English)

    刘玲; 陈琭璐; 张瑶; 白冰; 纪淑娟

    2015-01-01

    为了研究大蒜烯丙基硫化物的抗氧化活性,该文利用离子交换层析与制备液相技术从大蒜中分离得到 S-烯丙基-L-半胱氨酸(S-allyl-L-cysteine,SAC)、S-烯丙基-L-半胱氨酸亚砜(S-allyl-L-cysteine sulfoxide,ACSO)和γ-谷氨酰-S-烯丙基-L-半胱氨酸(γ-L-glutamyl-S-allyl-L-cysteine,GSAC)3种水溶性烯丙基硫化物。分离产物利用高效液相色谱-电喷雾离子化串联质谱联用(high performance liquid chromatography-electrospray ionization-mass/mass spectrometry, HPLC-ESI-MS/MS)、核磁共振氢谱(proton nuclear magnetic resonance,1H NMR)和核磁共振碳谱(carbon-13 nuclear magnetic resonance,13C NMR)技术及比旋光度检测方法鉴定,并与合成标准品比对分析确定。同时,该文以具有半胱氨酸结构的还原型谷胱甘肽(glutathione,GSH)为参照测定了 SAC、ACSO、GSAC 的1,1-二苯基-2-三硝基苯肼(1,1-diphenyl-2-picrylhydrazyl,DPPH)自由基清除能力及铁离子螯合能力。结果表明,SAC和GSAC对DPPH自由基的清除率较高(73.55%,72.68%)且与 GSH(71.14%)无显著性差异(P<0.05);SAC 和 ACSO 对铁离子的螯合率较高(81.21%,79.18%)且与GSH(78.13%)无显著性差异(P<0.05),尤其是GSAC对铁离子螯合率(92.76%)显著性高于GSH(P<0.05),证实了3种硫化物均具有很好的抗氧化性能。研究结果进一步解释和阐述大蒜硫化物的螯合能力,进而为大蒜硫化物以抗氧化为基础的其他功能活性研究提供参考。%The allyl-substituted cysteine derivatives were major components of sulfur compounds in garlic. This study separated and identified 3 allyl-substituted cysteine derivatives, i.e.S-allyl-L-cysteine (SAC),S-allyl-L-cysteine sulfoxide (ACSO) andγ-L-glutamyl-S-allyl-L-cysteine (GSAC). Furthermore, scavenging ability of 1,1-Diphenyl-2-picrylhydrazyl (DPPH) free radical and iron chelating ability were tested

  18. 烯丙基异丁基硫氨酯合成初探%Preliminary Study on Allyl Isobutyl Thiocarbamate Synthesis

    Institute of Scientific and Technical Information of China (English)

    王咏梅

    2015-01-01

    ,随着国内国际对环保的重视程度不断提高,环保高效型产品成为化工生产的热门课题。N -烯丙基-O -异丁基硫氨酯是一种环保新型酯类选矿捕收剂,它具有用量少、捕收力强、选择性好等优点,可提高铜精矿品位及铜、金的回收率,是铜锌等金属硫化矿分离的优良捕收促进剂。本文详细介绍了N -烯丙基-O -异丁基硫氨酯的工业合成工艺,其中重点介绍了第二步反应的各合成要素,分别从配料比,反应温度,催化剂,反应时间等几个方面入手,做了深入细致的研究工作,讨论了该反应诸要素的选择与制定,选择了最优的生产条件,产品品位最高可达到90%,达到国内先进水平。形成了一定的经济效益。经部分客户试用,反映良好,客户有进一步合作的意向。%In recent years , with the improving domestic and international attention to environmental protection , effi‐cient environmental protection type product has become a hot research topic in chemical production . N - allyl -O- isobutyl thionocarbamates collectors is a new environmental friendly esters flotation collector , it has advantages of less dosage , catching ability , good selectivity , it can improve the recovery of copper concentrate grade and cop‐per , gold rate , it is excellent collecting accelerator for copper and zinc sulfide ores . This paper introduces the in‐dustrial synthesis of N - allyl -O- isobutyl sulfur ammonia esterin in detail , in which focuses on the synthesis of element second step reaction , some intensive research work have done respectively from the mixture ratio , reac‐tion temperature , catalyst , reaction time and some other aspects , formulate selection factors have been discussed and formulated , the optimal production conditions have been chosen . Product quality can reach to a maximum of 90% , come up to internal advanced level , a certain economic

  19. Primary photodissociation pathways of epichlorohydrin and analysis of the C-C bond fission channels from an O((3)P)+allyl radical intermediate.

    Science.gov (United States)

    Fitzpatrick, Benjamin L; Alligood, Bridget W; Butler, Laurie J; Lee, Shih-Huang; Lin, Jim Jr-Min

    2010-09-01

    This study initially characterizes the primary photodissociation processes of epichlorohydrin, c-(H(2)COCH)CH(2)Cl. The three dominant photoproduct channels analyzed are c-(H(2)COCH)CH(2)+Cl, c-(H(2)COCH)+CH(2)Cl, and C(3)H(4)O+HCl. In the second channel, the c-(H(2)COCH) photofission product is a higher energy intermediate on C(2)H(3)O global potential energy surface and has a small isomerization barrier to vinoxy. The resulting highly vibrationally excited vinoxy radicals likely dissociate to give the observed signal at the mass corresponding to ketene, H(2)CCO. The final primary photodissociation pathway HCl+C(3)H(4)O evidences a recoil kinetic energy distribution similar to that of four-center HCl elimination in chlorinated alkenes, so is assigned to production of c-(H(2)COC)=CH(2); the epoxide product is formed with enough vibrational energy to isomerize to acrolein and dissociate. The paper then analyzes the dynamics of the C(3)H(5)O radical produced from C-Cl bond photofission. When the epoxide radical photoproduct undergoes facile ring opening, it is the radical intermediate formed in the O((3)P)+allyl bimolecular reaction when the O atom adds to an end C atom. We focus on the HCO+C(2)H(4) and H(2)CO+C(2)H(3) product channels from this radical intermediate in this report. Analysis of the velocity distribution of the momentum-matched signals from the HCO+C(2)H(4) products at m/e=29 and 28 shows that the dissociation of the radical intermediate imparts a high relative kinetic energy, peaking near 20 kcal/mol, between the products. Similarly, the energy imparted to relative kinetic energy in the H(2)CO+C(2)H(3) product channel of the O((3)P)+allyl radical intermediate also peaks at high-recoil kinetic energies, near 18 kcal/mol. The strongly forward-backward peaked angular distributions and the high kinetic energy release result from tangential recoil during the dissociation of highly rotationally excited nascent radicals formed photolytically in this

  20. Actinobacillus pleuropneumoniae is impaired by the garlic volatile allyl methyl sulfide (AMS) in vitro and in-feed garlic alleviates pleuropneumonia in a pig model.

    Science.gov (United States)

    Becker, Petra M; van Wikselaar, Piet G; Mul, Monique F; Pol, Arjan; Engel, Bas; Wijdenes, Jan W; van der Peet-Schwering, Carola M C; Wisselink, Henk J; Stockhofe-Zurwieden, Norbert

    2012-01-27

    Decomposition products of ingested garlic are to a certain extent excreted via the lungs. If the supposed health-supporting capacities associated with garlic extend to these exhaled sulfurous compounds, they could have an effect on the course of pneumonia. In this study, the garlic-derived volatile allyl methyl sulfide (AMS) as a lead compound of volatile garlic metabolites was shown to exhibit an antibacterial effect against the pig pathogen Actinobacillus pleuropneumoniae serotype 9. AMS caused a delay in the appearance of the optical density-monitored growth of A. pleuropneumoniae in medium when compared to unaffected growth curves, yet without lowering the stationary phase yield at the concentration range tested. At 1.1mM, AMS impaired the in vitro growth rate of A. pleuropneumoniae serotype 9 by 8% compared to unimpeded growth. In an animal trial, a garlic-fed group of 15 pigs that received a diet with 5% garlic feed component and a control group of 15 pigs that received a diet without garlic were infected with A. pleuropneumoniae serotype 2 via an aerosol and subsequently followed for 4 days. At the day of the challenge, blood AMS in the garlic-fed group amounted to 0.32 ± 0.13 μM. A beneficial, alleviating effect of garlic on the course and severity of an A. pleuropneumoniae infection in pigs was indicated by the reduced occurrence of characteristic pleuropneumonia lesions (27% of the lungs affected in the garlic-fed group vs. 47% in the control group) and a near to significant (p=0.06) lower relative lung weight post mortem in the garlic-fed group.

  1. SYNTHESIS, CHARACTERIZATION AND CATALYTIC ACTIVITY OF N,N'-BIS(3-ALLYL SALICYLIDENE)ETHYLENEDIAMINE COBALT(II) SCHIFF BASE COMPLEX ANCHORED ON A NEW POLYMER SUPPORT

    Institute of Scientific and Technical Information of China (English)

    K.C. Gupta; H.K. Abdulkadir; S. Chand

    2004-01-01

    A new chelating polymer support has been prepared by suspension copolymeriz a tion of synthesized N,N'-bis(3-allyl salicylidene)ethylenediamine monomer Schiff base (N,N'-BSEDA) with styrene (St) and divinylbenzene (DVB) using azobisisobutyronitrile (AIBN) as initiator in the presence of poly(vinyl alcohol). The content and complexation ability of monomer Schiff base (N,N'-BSEDA) for cobalt(II) ions in prepared crosslinked polymer beads have shown dependence on the amount of DVB used in reaction mixture. The amount of monomer Schiff base (N,N'-BSEDA) in crosslinked beads showed a substantial decreasing trend at high concentration of DVB in the reaction mixture (> 1.5 mol dm-3), hence the efficiency of complexation (EC%) and cobalt(II) ion loading (EL%) of polymer beads showed a decreasing trend. The structure of monomer Schiff base (N,N'-BSEDA) and its cobalt(II) complex on polymer support was elucidated by IR, UV and magnetic measurements. The catalytic activity of polymer bound cobalt(Ⅱ) Schiff base complex was evaluated by analyzing kinetic data of decomposition of hydrogen peroxide in the presence of either supported cobalt (II) complex or free cobalt(II) complex. The activation energy for the decomposition of hydrogen peroxide by polymer supported cobalt(II)complex was found to be low (33.37 kJ mol-l) in comparison with unsupported cobalt(II) complex (56.35 kJ mol-1). On the basis of experimental observations, reaction steps are proposed and a suitable rate expression derived.

  2. Ruthenium Catalyzed Diastereo- and Enantioselective Coupling of Propargyl Ethers with Alcohols: Siloxy-Crotylation via Hydride Shift Enabled Conversion of Alkynes to π-Allyls

    Science.gov (United States)

    Liang, Tao; Zhang, Wandi; Chen, Te-Yu; Nguyen, Khoa D.; Krische, Michael J.

    2015-01-01

    The first enantioselective carbonyl crotylations through direct use of alkynes as chiral allylmetal equivalents are described. Chiral ruthenium(II) complexes modified by Josiphos (SL-J009-1) catalyze the C-C coupling of TIPS-protected propargyl ether 1a with primary alcohols 2a-2o to form products of carbonyl siloxy-crotylation 3a-3o, which upon silyl deprotection-reduction deliver 1,4-diols 5a-5o with excellent control of regio-, anti-diastereo- and enantioselectivity. Structurally related propargyl ethers 1b and 1c bearing ethyl- and phenyl-substituents engage in diastereo- and enantioselective coupling, as illustrated in the formation of adducts 5p and 5q, respectively. Selective mono-tosylation of diols 5a, 5c, 5e, 5f, 5k and 5m is accompanied by spontaneous cyclization to deliver the trans-2,3-disubstituted furans 6a, 6c, 6e, 6f, 6k and 6m, respectively. Primary alcohols 2a, 2l and 2p were converted to the siloxy-crotylation products 3a, 3l and 3p, which upon silyl deprotection-lactol oxidation were transformed to the trans-4,5-disubstituted γ-butyrolactones 7a, 7l and 7p. The formation of 7p represents a total synthesis of (+)-trans-whisky lactone. Unlike closely related ruthenium catalyzed alkyne-alcohol C-C couplings, deuterium labeling studies provide clear evidence of a novel 1,2-hydride shift mechanism that converts metal-bound alkynes to π-allyls in the absence of intervening allenes. PMID:26418572

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

    Directory of Open Access Journals (Sweden)

    Vasilii GRAUR

    2015-12-01

    Full Text Available The paper presents the synthesis of the ligand 1-(2-hydroxyphenylethanone 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 cells and cervical cancer HeLa cells was determined. It was established that the substitution of hydrogen atom with methyl group in the azomethinic fragment leads to the growth of antitumor activity.SINTEZA ŞI ACTIVITATEA ANTITUMORALĂ A COMPUŞILOR COMPLECŞI AI CUPRULUI, NICHELULUI ŞI COBALTULUI CU N(4-ALIL-3-TIOSEMICARBAZONA 1-(2-HIDROXIFENILETANONEILucrarea conţine descrierea sintezei N(4-alil-3-tiosemicarbazonei 1-(2-hidroxifeniletanonei (H2L şi a şase compuşi coordinativi ai cuprului, nichelului şi cobaltului cu acest ligand. Structura tiosemicarbazonei H2L a fost stabilită în baza datelor spectroscopiei RMN 1H şi 13C. Compuşi coordinativi au fost studiaţi cu ajutorul analizei elementale, analizei gravimetrice a conţinutului de apă, conductivitaţii molare şi magnetochimiei. Pentru H2L a fost determinată activitatea antitumorală faţă de celulele leucemiei umane HL-60 şi ale cancerului cervical HeLa. S-a stabilit că înlocuirea atomului de hidrogen cu o grupare metil în fragmentul azomethinic conduce la creşterea activitaţii antitumorale.

  4. Allyl isothiocyanate, a constituent of cruciferous vegetables, inhibits proliferation of human prostate cancer cells by causing G2/M arrest and inducing apoptosis.

    Science.gov (United States)

    Xiao, Dong; Srivastava, Sanjay K; Lew, Karen L; Zeng, Yan; Hershberger, Pamela; Johnson, Candace S; Trump, Donald L; Singh, Shivendra V

    2003-05-01

    Dietary isothiocyanates (ITCs) are highly effective in affording protection against chemically induced cancers in laboratory animals. In the present study, we demonstrate that allyl isothiocyanate (AITC), a constituent of cruciferous vegetables, significantly inhibits proliferation of cultured PC-3 (androgen-independent) and LNCaP (androgen-dependent) human prostate cancer cells in a dose-dependent manner with an IC(50) of approximately 15-17 micro M. On the other hand, survival of a normal prostate epithelial cell line (PrEC) was minimally affected by AITC even at concentrations that were highly cytotoxic to the prostate cancer cells. Reduced proliferation of PC-3 as well as LNCaP cells in the presence of AITC correlated with accumulation of cells in G(2)/M phase and induction of apoptosis. In contrast, AITC treatment failed to induce apoptosis or cause G(2)/M phase arrest in PrEC cells. A 24 h treatment of PC-3 and LNCaP cells with 20 micro M AITC caused a significant decrease in the levels of proteins that regulate G(2)/M progression, including Cdk1 (32-50% reduction), Cdc25B (44-48% reduction) and Cdc25C (>90% reduction). A significant reduction in the expression of cyclin B1 protein (approximately 45%) was observed only in LNCaP cells. A 24 h exposure of PC-3 and LNCaP cells to an apoptosis-inducing concentration of AITC (20 micro M) resulted in a significant decrease (31-68%) in the levels of anti-apoptotic protein Bcl-2 in both cell lines, and approximately 58% reduction in Bcl-X(L) protein expression in LNCaP cells. In conclusion, it seems reasonable to hypothesize that AITC, and possibly other ITCs, may find use in the treatment of human prostate cancers.

  5. 烯丙基-联苯醚的合成及其共聚合%Synthesis of allyl biphenyl ether and its copolymerization

    Institute of Scientific and Technical Information of China (English)

    赵梦奇; 田玉川; 司马义·努尔拉

    2012-01-01

    采用相转移催化法合成了一种新型的非离子型疏水单体烯丙基-联苯醚(ABE),通过傅里叶变换红外光谱、核磁共振氢谱等表征了单体的结构,并分别用乳液法和溶液法合成了ABE-丙烯酰胺(AM)-丙烯酸(AA)三元共聚物.溶液法合成的共聚物为细小颗粒,平均粒径为900 nm左右,比表面积为14.93 m2/g,水溶性较差;而乳液法制备的共聚物水溶性较好,特性黏数大,达37.69 dL/g,耐热性能优良.%A novel non-ionic hydrophobic monomer, allyl biphenyl ether (ABE), was synthesized via phase-transfer catalysis. The monomer's structure was characterized by Fourier transform infrared spectroscopy (FTIR) and hydrogen nuclear magnetic resonance (1H-NMR). A terpolymer was prepared from ABE, acrylic acid and acrylamide through emulsion polymerization and solution polymerization, respectively. The terpolymer synthesized with solution polymerization process took the shape of tiny particles that possessed average size of about 900 nm and specific surface area of 14.93 m2/g. The terpolymer exhibited inferior solubility in water. In contrast, the terpolymer prepared with emulsion polymerization process had good solubility in water, high intrinsic viscosity of 37.69 Dl/g and superior thermal stability.

  6. Neurotoxicity induced by amyloid beta-peptide and ibotenic acid in organotypic hippocampal cultures: protection by S-allyl-L-cysteine, a garlic compound.

    Science.gov (United States)

    Ito, Yoshihisa; Ito, Moriyuki; Takagi, Noritaka; Saito, Hiroshi; Ishige, Kumiko

    2003-09-19

    We have assessed amyloid-beta (Abeta)-induced neurotoxicity, with and without added ibotenic acid (IBO), a potent N-methyl-D-aspartate (NMDA) agonist, in an organotypic hippocampal slice culture (OHC). In the OHC, there was little neurotoxicity after treatment with Abeta(25-35) (25 or 50 microM) alone for 48 h. However, with IBO alone neuronal death was observed in the pyramidal cell layer at low concentrations, and there was dramatic neuronal death at concentrations of 65 microM or more. When Abeta was combined with IBO (Abeta+IBO) there was more intense cell death than with IBO alone. S-Allyl-L-cysteine (SAC), one of the organosulfur compounds having a thioallyl group in aged garlic extract, was shown to protect the hippocampal neurons in the CA3 area and the dentate gyrus (DG) from the cell death induced by Abeta+IBO with no change in the CA1 area. Although L-glutamate (500 microM) potentiated the degree of IBO-induced neuronal death, it attenuated the Abeta+IBO-induced neuronal death in both the CA3 area and the DG with no obvious effect on the CA1 area. These results suggest that Abeta+IBO induces extensive neuronal death, and that SAC and L-glutamate protect cells from death in specific areas of the hippocampus. In addition, inhibition using a pan-caspase inhibitor, z-VAD-fmk, only provided partial protection from Abeta+IBO-induced toxicity for the neurons in the CA3 area. These results suggest that multiple mechanisms may be involved in Abeta+IBO-induced neuronal death in the OHC.

  7. Inactivation of Salmonella and Escherichia coli O157:H7 on sliced and whole tomatoes by allyl isothiocyanate, carvacrol, and cinnamaldehyde in vapor phase.

    Science.gov (United States)

    Obaidat, Mohammad M; Frank, Joseph F

    2009-02-01

    Little is known about the effectiveness of antimicrobials in the vapor phase for control of pathogens on the surface of fresh produce. We determined the activity of allyl isothiocyanate (AIT), cinnamaldehyde, and carvacrol against Salmonella and Escherichia coli O157:H7 on sliced and whole tomatoes. Samples were treated with various concentrations of antimicrobial in the vapor phase at 4, 10, and 25 degrees C in a closed container. AIT exhibited the highest antimicrobial activity followed by cinnamaldehyde. The lowest level of AIT (8.3 microl/liter of air) inactivated Salmonella on sliced tomatoes by 1.0 and 3.5 log at 4 and 10 degrees C, respectively, in 10 days and by 2.8 log at 25 degrees C in 10 h. This level of AIT inactivated Salmonella on whole tomatoes to the detection limit of tomato at 4 and 10 degrees C in 10 days and by 1.3 log CFU per tomato at 25 degrees C in 10 h. AIT also inactivated E. coli O157:H7 on sliced tomatoes by 3.0 log at 4 and 10 degrees C in 10 days, but there was no inactivation at 25 degrees C in 10 h. AIT reduced E. coli O157:H7 on whole tomatoes surface by 3.0 and 1.0 log CFU per tomato at 4 and 10 degrees C, respectively, in 10 days and by 2.0 log CFU per tomato at 25 degrees C in 10 h. Overall, greater inactivation occurred at 10 than at 4 degrees C and on the tomato surface than between slices. Antimicrobials in vapor phase may be useful for controlling pathogens on fresh tomatoes marketed in packages containing enclosed headspace.

  8. Control of Salmonella on fresh chicken breasts by κ-carrageenan/chitosan-based coatings containing allyl isothiocyanate or deodorized Oriental mustard extract plus EDTA.

    Science.gov (United States)

    Olaimat, Amin N; Holley, Richard A

    2015-06-01

    Control of Salmonella in poultry is a public health concern as salmonellosis is one of the most common foodborne diseases worldwide. This study aimed to screen the ability of 5 Salmonella serovars to degrade the mustard glucosinolate, sinigrin (by bacterial myrosinase) in Mueller-Hinton broth at 25 °C for 21 d and to reduce Salmonella on fresh chicken breasts by developing an edible 0.2% (w/v) κ-carrageenan/2% (w/v) chitosan-based coating containing Oriental mustard extract, allyl isothiocyanate (AITC), EDTA or their combinations. Individual Salmonella serovars degraded 50.2%-55.9% of the sinigrin present in 21 d. κ-Carrageenan/chitosan-based coatings containing 250 mg Oriental mustard extract/g or 50 μl AITC/g reduced the numbers of Salmonella on chicken breasts 2.3 log10 CFU/g at 21 d at 4 °C. However, when either mustard extract or AITC was combined with 15 mg/g EDTA in κ-carrageenan/chitosan-based coatings, Salmonella numbers were reduced 2.3 log10 CFU/g at 5 d and 3.0 log10 CFU/g at 21 d. Moreover, these treatments reduced numbers of lactic acid bacteria and aerobic bacteria by 2.5-3.3 log10 CFU/g at 21 d. κ-Carrageenan/chitosan coatings containing either 50 μl AITC/g or 250 mg Oriental mustard extract/g plus 15 mg EDTA/g have the potential to reduce Salmonella on raw chicken.

  9. An investigation of the Lewis acid mediated 1,3-dipolar cycloaddition between N-benzyl-C-(2-pyridyl)nitrone and allylic alcohol. Direct entry to isoxazolidinyl C-nucleosides.

    Science.gov (United States)

    Merino, Pedro; Tejero, Tomas; Laguna, Mariano; Cerrada, Elena; Moreno, Ana; Lopez, Jose A

    2003-07-07

    The cycloaddition reaction of N-benzyl C-(2-pyridyl) nitrone with allylic alcohol has been carried out to obtain the corresponding 2-benzyl-3-(2-pyridyl)-5-hydroxymethylisoxazolidine. The influence of Lewis acids in the reaction has been studied and a complete 3,5-regioselectivity and cis diastereoselectivity was observed when the reaction was carried out with 1.0 equiv of AgOTf, [Ag(OClO3)(PPh2Me)] or Zn(OTf)2. Insight into the mechanism of the reaction has been obtained by isolating and characterizing (X-ray) the intermediate complexes. Also, a model based on both experimental and theoretical results is proposed.

  10. Oxidation stability of biodiesel fuels and blends using the Rancimat and PetroOXY methods. Effect of 4-allyl-2,6-dimetoxiphenol and cathecol as biodiesel additives on oxidation stability

    Science.gov (United States)

    Botella, Lucía; Bimbela, Fernando; Martín, Lorena; Arauzo, Jesús; Sanchez, Jose Luis

    2014-07-01

    In the present work, several fatty acid methyl esters (FAME) have been synthesized from various fatty acid feedstocks: used frying olive oil, pork fat, soybean, rapeseed, sunflower and coconut. The oxidation stabilities of the biodiesel samples and of several blends have been measured simultaneously by both the Rancimat method, accepted by EN14112 standard, and the PetroOXY method, prEN16091 standard, with the aim of finding a correlation between both methodologies. Other biodiesel properties such as composition, cold filter plugging point (CFPP), flash point (FP) and kinematic viscosity have also been analyzed using standard methods in order to further characterize the biodiesel produced. In addition, the effect on the biodiesel properties of using 4-allyl-2,6-dimetoxiphenol and cathecol as additives in biodiesel blends with rapeseed and with soybean has also been analyzed. The use of both antioxidants results in a considerable improvement in the oxidation stability of both types of biodiesel, especially using cathecol. Adding cathecol loads as low as 0.05 % (m/m) in blends with soybean biodiesel and as low as 0.10 % (m/m) in blends with rapeseed biodiesel is sufficient for the oxidation stabilities to comply with the restrictions established by the European EN14214 standard.An empirical linear equation is proposed to correlate the oxidation stability by the two methods, PetroOXY and Rancimat. It has been found that the presence of either cathecol or 4-allyl-2,6-dimetoxiphenol as additives affects the correlation observed.

  11. Cyclization by intramolecular carbolithiation of alkyl- and vinyllithiums prepared by the action of aromatic radical anions on phenyl thioethers. High stereoselectivity in the cyclization accelerated by an allylic lithium oxyanion.

    Science.gov (United States)

    Deng, Kai; Bensari-Bouguerra, Ahlem; Whetstone, Joseph; Cohen, Theodore

    2006-03-17

    The reductive lithiation of alkyl and vinyl phenyl thioethers by aromatic radical anions is shown to be the most general method yet known for preparing organolithiums capable of intramolecular carbometalation of unactivated alkenes to produce five-membered rings and in one case a four-membered ring (in a far higher yield than known cases). The relative rates of cyclization for alkyllithiums are secondary > tertiary > primary, and the yields are very high. In the secondary case, the stereoselectivity is extremely high, producing a cyclopentylmethyllithium with a trans-2-alkyl substituent. A remarkable finding is that for all of the organolithiums a lithium oxyanionic group in the proximal allylic position to the alkene greatly accelerates the cyclization and leads almost exclusively to a trans relationship between the CH(2)Li group and the OLi group, the opposite relationship from that observed in intramolecular carbolithiations by allyllithiums. A mechanistic rationale for this divergence is discussed. One of the two types of proximal homoallylic lithium oxyanions exerts an analogous effect. An intriguing limitation, even occurring with the highly reactive secondary organolithium and in the presence of an allylic oxyanionic group, is the failure of intramolecular carbolithiation when a methyl group is at the terminus of the alkene.

  12. Oxidation stability of biodiesel fuels and blends using the Rancimat and PetroOXY methods. Effect of 4-allyl-2,6-dimethoxyphenol and catechol as biodiesel additives on oxidation stability.

    Science.gov (United States)

    Botella, Lucía; Bimbela, Fernando; Martín, Lorena; Arauzo, Jesús; Sánchez, José L

    2014-01-01

    IN THE PRESENT WORK, SEVERAL FATTY ACID METHYL ESTERS (FAME) HAVE BEEN SYNTHESIZED FROM VARIOUS FATTY ACID FEEDSTOCKS: used frying olive oil, pork fat, soybean, rapeseed, sunflower, and coconut. The oxidation stabilities of the biodiesel samples and of several blends have been measured simultaneously by both the Rancimat method, accepted by EN14112 standard, and the PetroOXY method, prEN16091 standard, with the aim of finding a correlation between both methodologies. Other biodiesel properties such as composition, cold filter plugging point (CFPP), flash point (FP), and kinematic viscosity have also been analyzed using standard methods in order to further characterize the biodiesel produced. In addition, the effect on the biodiesel properties of using 4-allyl-2,6-dimethoxyphenol and catechol as additives in biodiesel blends with rapeseed and with soybean has also been analyzed. The use of both antioxidants results in a considerable improvement in the oxidation stability of both types of biodiesel, especially using catechol. Adding catechol loads as low as 0.05% (m/m) in blends with soybean biodiesel and as low as 0.10% (m/m) in blends with rapeseed biodiesel is sufficient for the oxidation stabilities to comply with the restrictions established by the European EN14214 standard. An empirical linear equation is proposed to correlate the oxidation stability by the two methods, PetroOXY and Rancimat. It has been found that the presence of either catechol or 4-allyl-2,6-dimethoxyphenol as additives affects the correlation observed.

  13. 3-(alphaR)-alpha-((2S,5R)-4-allyl-2,5-dimethyl-1-piperazinyl)-3-hydroxybenzyl)-N-alkyl-N-arylbenzamides: potent, non-peptidic agonists of both the micro and delta opioid receptors.

    Science.gov (United States)

    Bishop, Michael J; Garrido, Dulce M; Boswell, G Evan; Collins, Mark A; Harris, Philip A; McNutt, Robert W; O'Neill, Scott J; Wei, Ke; Chang, Kwen-Jen

    2003-02-13

    Opioid analgesics with both micro and delta opioid receptor activation represent a new approach to the treatment of severe pain with an improved safety profile. Compounds with this profile may exhibit strong analgesic properties due to micro agonism, with a reduced side effect profile resulting from delta agonism. Replacing the p-diethylamide of the known potent delta opioid receptor selective agonist BW373U86 with a m-diethylamide resulted in a compound with agonist activity at both the micro and delta opioid receptors. Modifying the amide to an N-methyl-N-phenylamide increased agonist potency at both receptors. A series of 3-(alphaR)-alpha-((2S,5R)-4-allyl-2,5-dimethyl-1-piperazinyl)-3-hydroxybenzyl)-N-alkyl-N-arylbenzamides have been made to explore the structure-activity relationship (SAR) around the N-methyl-N-phenylamide. Several potent agonists of both the micro and delta opioid receptors have been identified, including (+)-3-((alphaR)-alpha-((2S,5R)-4-allyl-2,5-dimethyl-1-piperazinyl)-3-hydroxybenzyl)-N-(4-fluorophenyl)-N-methylbenzamide (23), which has EC50 values of 0.67 and 1.1 nM at the micro (guinea pig ileum assay) and delta (mouse vas deferens assay) opioid receptors, respectively.

  14. Effect of paclitaxel along with di allyl sulfide on immuno competent cells, immune complexes and immunoglobulins changes in 7,12 Di Methyl Benz(A Anthracene induced skin cancer in wistar rats.

    Directory of Open Access Journals (Sweden)

    Muninathan N, Ursula Sampson, Prashanth Talikoti, Uma Maheshwari, Archana, Kumar

    2014-03-01

    Full Text Available Our recent studies have shown that naturally occurring dietary organo sulfure compounds such as di allyl sulfide and paclitaxel are capable of inhibiting polycyclic aromatic hydrocarbon (PAH metabolism and subsequent PAH-DNA adduct formation in Wistar rats. In this study these plant phenols were tested for their effects against PAHs and 7,12 Di Methyl Benz (A Anthracene -induced skin tumorigenesis in rats. Each compounds was evaluated as a possible anticarcinogen in an initiation and promotion and a complete skin tumorigenesis protocol. In the two-stage tumor protocol in Wistar rats using 7,12-dimethylbenz(aanthracene as the initiating agent followed by twice weekly applications of acetone as tumor promoter each plant compounds afforded significant protection against skin tumorigenicity. The protective effects were verified both by prolongation of latency period and by subsequent tumor development. Our results suggest that these plants compounds have substantial though variable potential for modifying the risk of skin tumorigenicity induced by a wide variety of chemicals and of these combinations of Paclitaxel and Di allyl sulfide was shown to have maximal chemo protective effects.

  15. Application of a new phosphorus-free palladium heterogeneous nanocatalyst supported on modified MWCNT the highly selective and efficient cleavage of propargyl, allyl, and benzyl phenol ethers under mild conditions.

    Science.gov (United States)

    Sharghi, Hashem; Khoshnood, Abbas; Khalifeh, Reza; Doroodmand, Mohammad Mehdi

    2015-08-01

    A stable and efficient phosphorus-free, low Pd-loading heterogeneous nanocatalyst comprising palladium and a multi-walled carbon nanotube was prepared and characterized by various techniques such as SEM, TEM, AFM, FT-IR, and Raman spectrometry, N2 adsorption isotherm and thermogravimetric analysis. This catalyst was used for the deprotection of phenol ethers. The catalyst selectivity for deprotection of between propargyl, allyl, and benzyl, as a protecting group, was studied. Also, the presence of different functional groups was studied to establish the scope and limitations of this method. The catalytic activity of recycled catalyst was evaluated. The results indicated that the catalyst is heterogeneous, stable, and very active under the established conditions, and it could be reused up to five times without any significant leaching. In addition, according to ICP analysis, low leaves of leaching of palladium from the catalyst was observed, which indicates that anthraquinone has an excellent ability to coordinate with palladium.

  16. Fe(Ⅲ)催化的烯丙醇的Friedel-Crafts环化反应合成多取代茚%Synthesis of Multisubstituted Indenes by Fe(Ⅲ)-Catalyzed Friedel-Crafts Cyclization of Allylic Alcohols

    Institute of Scientific and Technical Information of China (English)

    张继坦; 张金花; 方旷; 束官莹; 谢美华

    2012-01-01

    在FeCl3·6H2O催化下,多取代的烯丙醇可以顺利进行分子内Friedel-Crafts环化反应,以中等到优良的产率得到一系列多取代茚化合物,该反应操作简单、反应条件温和.产物结构经IR,1H NMR,13C NMR,HR MS及X射线单晶衍射分析确证.%FeCl3·6H2O-catalyzed intramolecular Friedel-Crafts cyclization of multisubstituted allylic alcohols proceeded smoothly and a series of multisubstituted indenes were synthesized in moderate to high yields. The reaction has the advantages of simple manipulation and mild reaction conditions. The products were characterized by IR, 'H NMR, 13C NMR, HR MS and X-ray diffraction analysis.

  17. Photochemical Synthesis and Versatile Functionalization Method of a Robust Porous Poly(ethylene glycol methacrylate-co-allyl methacrylate Monolith Dedicated to Radiochemical Separation in a Centrifugal Microfluidic Platform

    Directory of Open Access Journals (Sweden)

    Marion Losno

    2016-03-01

    Full Text Available The use of a centrifugal microfluidic platform is an alternative to classical chromatographic procedures for radiochemistry. An ion-exchange support with respect to the in situ light-addressable process of elaboration is specifically designed to be incorporated as a radiochemical sample preparation module in centrifugal microsystem devices. This paper presents a systematic study of the synthesis of the polymeric porous monolith poly(ethylene glycol methacrylate-co-allyl methacrylate used as a solid-phase support and the versatile and robust photografting process of the monolith based on thiol-ene click chemistry. The polymerization reaction is investigated, varying the formulation of the polymerisable mixture. The robustness of the stationary phase was tested in concentrated nitric acid. Thanks to their unique “easy-to-use” features, centrifugal microfluidic platforms are potential successful candidates for the downscaling of chromatographic separation of radioactive samples (automation, multiplexing, easy integration in glove-boxes environment, and low cost of maintenance.

  18. Structures of complexes of benzyl and allyl esters of monensin A with Mg 2+, Ca 2+, Sr 2+, Ba 2+ cations studied by ESI-MS and PM5 methods

    Science.gov (United States)

    Huczyński, Adam; Brzezinski, Bogumil; Bartl, Franz

    2008-08-01

    Benzyl ester of monensin A (MON3) and allyl ester of monensin A (MON4) were synthesized and their ability of forming complexes with divalent cations was studied by ESI mass spectrometry and by PM5 semi empirical calculations. The ESI-MS spectra indicate that MON3 as well as MON4 form stable 1:1 complexes with the divalent cations used in this study. The complexes of MON3 are stable to cv = 50 V and after this cv value no m/ z signals are more observed in the spectra. In contrast, with increasing cone voltage values, a fragmentation process of the MON4 complexes is simultaneously observed, where dehydration processes are the main events. The structures of the complexes are discussed in detail on the basis of conformational analysis together with the PM5 semiempirical calculations.

  19. A broadly applicable NHC-Cu-catalyzed approach for efficient, site-, and enantioselective coupling of readily accessible (pinacolato)alkenylboron compounds to allylic phosphates and applications to natural product synthesis.

    Science.gov (United States)

    Gao, Fang; Carr, James L; Hoveyda, Amir H

    2014-02-05

    A set of protocols for catalytic enantioselective allylic substitution (EAS) reactions that allow for additions of alkenyl units to readily accessible allylic electrophiles is disclosed. Transformations afford 1,4-dienes that contain a tertiary carbon stereogenic site and are promoted by 1.0-5.0 mol % of a copper complex of an N-heterocyclic carbene (NHC). Aryl- as well as alkyl-substituted electrophiles bearing a di- or trisubstituted alkene may be employed. Reactions can involve a variety of robust alkenyl-(pinacolatoboron) [alkenyl-B(pin)] compounds that can be either purchased or prepared by various efficient, site-, and/or stereoselective catalytic reactions, such as cross-metathesis or proto-boryl additions to terminal alkynes. Vinyl-, E-, or Z-disubstituted alkenyl-, 1,1-disubstituted alkenyl-, acyclic, or heterocyclic trisubstituted alkenyl groups may be added in up to >98% yield, >98:2 SN2':SN2, and 99:1 enantiomeric ratio (er). NHC-Cu-catalyzed EAS with alkenyl-B(pin) reagents containing a conjugated carboxylic ester or aldehyde group proceed to provide the desired 1,4-diene products in good yield and with high enantioselectivity despite the presence of a sensitive stereogenic tertiary carbon center that could be considered prone to epimerization. In most instances, the alternative approach of utilizing an alkenylmetal reagent (e.g., an Al-based species) represents an incompatible option. The utility of the approach is illustrated through applications to enantioselective synthesis of natural products such as santolina alcohol, semburin, nyasol, heliespirone A, and heliannuol E.

  20. Oxidation stability of biodiesel fuels and blends using the Rancimat and PetroOXY methods. Effect of 4-allyl-2,6-dimetoxiphenol and cathecol as biodiesel additives on oxidation stability

    Directory of Open Access Journals (Sweden)

    Lucía eBotella

    2014-07-01

    Full Text Available In the present work, several fatty acid methyl esters (FAME have been synthesized from various fatty acid feedstocks: used frying olive oil, pork fat, soybean, rapeseed, sunflower and coconut. The oxidation stabilities of the biodiesel samples and of several blends have been measured simultaneously by both the Rancimat method, accepted by EN14112 standard, and the PetroOXY method, prEN16091 standard, with the aim of finding a correlation between both methodologies. Other biodiesel properties such as composition, cold filter plugging point (CFPP, flash point (FP and kinematic viscosity have also been analyzed using standard methods in order to further characterize the biodiesel produced. In addition, the effect on the biodiesel properties of using 4-allyl-2,6-dimetoxiphenol and cathecol as additives in biodiesel blends with rapeseed and with soybean has also been analyzed. The use of both antioxidants results in a considerable improvement in the oxidation stability of both types of biodiesel, especially using cathecol. Adding cathecol loads as low as 0.05 % (m/m in blends with soybean biodiesel and as low as 0.10 % (m/m in blends with rapeseed biodiesel is sufficient for the oxidation stabilities to comply with the restrictions established by the European EN14214 standard.An empirical linear equation is proposed to correlate the oxidation stability by the two methods, PetroOXY and Rancimat. It has been found that the presence of either cathecol or 4-allyl-2,6-dimetoxiphenol as additives affects the correlation observed.

  1. 含烯丙基侧基聚芳醚酮的制备及其表征%Preparation and Characterization of Poly ether ketone with Allyl Side Group

    Institute of Scientific and Technical Information of China (English)

    曹建伟; 王志鹏; 王红华; 周光远; 李存峰; 崔善子

    2012-01-01

    A novel type of poly(aryl ether ketone) bearing pendant allyl group (PEK-L-A) was prepared, first by SN2 nucleophilic polycondensation from phenolphthalin and 4,4'-difluorobenzophenone to prepare polyaryletherketone bearing pendant carboxyl group (PEK-L), followed by esterfication reaction with 2-hydroxyethyl acrylate (HEA). The ratio of allyl side group could be controlled by altering the amount of HEA. The structure and properties of PEK I. A were characterized and tested by FT-IR, 1H-NMR, DSC etc. Results showed that the heat resistant temperature of coating layer with PEK L-A as matrix resin after UV curing was up to 300 ℃, and impact strength higher than 100 kg · cm.%通过酚酞啉和二氟二苯酮的SN2亲核缩聚反应合成侧链含有羧基的聚芳醚酮(PEKL),再经与丙烯酸羟乙酯(HEA)的酯化反应得到了含有烯丙基侧基的聚芳醚酮树脂(PEK—L-A),通过改变反应物单体的加入量可调整烯丙基的接枝率。用FT—IR、^1H—NMR、DSC等手段表征和测试了聚合产物的结构与性能。结果表明:以该功能性聚芳醚酮为基体树脂配制的溶液涂层经紫外光固化后其涂层的耐热温度可达300℃,冲击强度高于100kg·cm。

  2. Synthesis and investigation of environment-friendly PF with allyl modified by naphthol%蔡酚改性烯丙基化环保型酚醛树脂的合成及研究

    Institute of Scientific and Technical Information of China (English)

    吴江涛; 齐暑华; 李春华; 李美玲

    2011-01-01

    With environment-friendly PF (phenolic resin) and PF-0 (environment-friendly PF modified by naphthol) as matrix materials respectively,so the PF with allyl and PF-1 (PF with allyl modified by naphthol) were successfully synthetized,then a PF-1/BMI(bismaleimide) copolymer resin was prepared. Finally a series of composites reinforced by glass fiber were prepared by above these resins as matrix resins respectively. The results showed that the toughening effect of PF-1 was lower than that of PF-1/BMI copolymer resin because the impact strength(321.6 kJ/m2)and flexural strength(524.1 MPa) of the composites with PF-1/BMI copolymer resin as matrix resin were 11.0% and 46.3% more than those with PF-1 as matrix resin,or were 42.8% and 258.2% more than those with unmodified environment-friendly PF with allyl as matrix resin. The heat resistance of the composites with PF-1/BMI copolymer resin as matrix resin was better than that with unmodified PF with ailyl as matrix resin because the residual carbon of the former (39.62%) was higher than that of the latter(10.92%) at 800 ℃.%分别以环保型PF(酚醛树脂)和萘酚改性环保型PF为母体,成功合成了烯丙基化PF和萘酚改性烯丙基化PF,并制备了萘酚改性烯丙基化PF/BMI(双马来酰亚胺)共聚树脂;然后分别以上述树脂作为基体树脂,制备了玻璃纤维增强型复合材料.结果表明:当基体树脂为萘酚改性烯丙基化PF/BMI共聚树脂时,相应复合材料的冲击强度(321.6 kJ/m2)和弯曲强度(524.1 MPa)比萘酚改性烯丙基化PF基复合材料提高了11.0%和46.3%,比未改性环保型烯丙基化PF基复合材料提高了42.8%和258.2%,说明萘酚改性烯丙基化PF/BMI共聚树脂的增韧效果优于萘酚改性烯丙基化PF;萘酚改性烯丙基化PF/BMI共聚树脂基复合材料的耐热性能优于未改性烯丙基化PF体系,这是因为前者800℃时的残炭率(39,62%)高于后者(10.92%)所致.

  3. Evaluation of the Effects of S-Allyl-L-cysteine, S-Methyl-L-cysteine, trans-S-1-Propenyl-L-cysteine, and Their N-Acetylated and S-Oxidized Metabolites on Human CYP Activities.

    Science.gov (United States)

    Amano, Hirotaka; Kazamori, Daichi; Itoh, Kenji

    2016-01-01

    Three major organosulfur compounds of aged garlic extract, S-allyl-L-cysteine (SAC), S-methyl-L-cysteine (SMC), and trans-S-1-propenyl-L-cysteine (S1PC), were examined for their effects on the activities of five major isoforms of human CYP enzymes: CYP1A2, 2C9, 2C19, 2D6, and 3A4. The metabolite formation from probe substrates for the CYP isoforms was examined in human liver microsomes in the presence of organosulfur compounds at 0.01-1 mM by using liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis. Allicin, a major component of garlic, inhibited CYP1A2 and CYP3A4 activity by 21-45% at 0.03 mM. In contrast, a CYP2C9-catalyzed reaction was enhanced by up to 1.9 times in the presence of allicin at 0.003-0.3 mM. SAC, SMC, and S1PC had no effect on the activities of the five isoforms, except that S1PC inhibited CYP3A4-catalyzed midazolam 1'-hydroxylation by 31% at 1 mM. The N-acetylated metabolites of the three compounds inhibited the activities of several isoforms to a varying degree at 1 mM. N-Acetyl-S-allyl-L-cysteine and N-acetyl-S-methyl-L-cysteine inhibited the reactions catalyzed by CYP2D6 and CYP1A2, by 19 and 26%, respectively, whereas trans-N-acetyl-S-1-propenyl-L-cysteine showed weak to moderate inhibition (19-49%) of CYP1A2, 2C19, 2D6, and 3A4 activities. On the other hand, both the N-acetylated and S-oxidized metabolites of SAC, SMC, and S1PC had little effect on the reactions catalyzed by the five isoforms. These results indicated that SAC, SMC, and S1PC have little potential to cause drug-drug interaction due to CYP inhibition or activation in vivo, as judged by their minimal effects (IC50>1 mM) on the activities of five major isoforms of human CYP in vitro.

  4. Crystal structure of cyclo-bis-(μ4-2,2-di-allyl-malonato-κ(6) O (1),O (3):O (3):O (1'),O (3'):O (1'))tetra-kis-(triphenyl-phosphane-κP)tetra-silver(I).

    Science.gov (United States)

    Frenzel, Peter; Jakob, Alexander; Schaarschmidt, Dieter; Rüffer, Tobias; Lang, Heinrich

    2014-10-01

    In the tetra-nuclear mol-ecule of the title compound, [Ag4(C9H10O4)2(C18H15P)4], the Ag(I) ion is coordinated by one P and three O atoms in a considerably distorted tetra-hedral environment. The two 2,2-di-allyl-malonate anions bridge four Ag(I) ions in a μ4-(κ(6) O (1),O (3):O (3):O (1'),O (3'):O (1')) mode, setting up an Ag4O8P4 core (point group symmetry -4..) of corner-sharing tetra-hedra. The shortest intra-molecular Ag⋯Ag distance of 3.9510 (3) Å reveals that no direct d (10)⋯d (10) inter-actions are present. Four weak intra-molecular C-H⋯O hydrogen bonds are observed in the crystal structure of the title compound, which most likely stabilize the tetra-nuclear silver core.

  5. A DFT study on PBu3-catalyzed intramolecular cyclizations of N-allylic substituted α-amino nitriles for the formation of functionalized pyrrolidines: mechanisms, selectivities, and the role of catalysts.

    Science.gov (United States)

    Zheng, Linjie; Tang, Mingsheng; Wang, Yang; Guo, Xiaokang; Wei, Donghui; Qiao, Yan

    2016-03-21

    The mechanisms and chemo- and stereo-selectivities of PBu3-catalyzed intramolecular cyclizations of N-allylic substituted α-amino nitriles leading to functionalized pyrrolidines (5-endo-trig cyclization, Mechanism A) and their competing reaction leading to another kind of pyrrolidine (5-exo-trig cyclization, Mechanism B) have been investigated using density functional theory (DFT). Multiple possible reaction pathways associated with four different isomers (RR, SR, RS, and SS) for Mechanism A, and two isomers (R and S) for Mechanism B have been studied. The calculated results indicate that the Gibbs free energy barriers of Mechanism A are remarkably lower than those of Mechanism B, and the reaction pathway leading to the RS-configured product has the lowest Gibbs free energy barrier, which is in agreement with the experiments. A C-H···π interaction has been identified to be responsible for the favorability of RS isomers by non-covalent interaction (NCI) analysis. Moreover, global reaction indexes (GRIs) and NBO analyses confirm that PBu3 acts as a Lewis base to strengthen the nucleophilicity of the reaction active site. The mechanistic insights gained in the present study should be valuable for the rational design of effective organocatalysts for this kind of reaction with high chemo- and stereo-selectivities.

  6. Enantiospecific total synthesis of (+)-tanikolide via a key [2,3]-Meisenheimer rearrangement with an allylic amine N-oxide-directed epoxidation and a one-pot trichloroisocyanuric acid N-debenzylation and N-chlorination.

    Science.gov (United States)

    Xie, Yangla; Sun, Moran; Zhou, Hang; Cao, Qiwei; Gao, Kaige; Niu, Changling; Yang, Hua

    2013-10-18

    The enantiospecific total synthesis of the δ-lactonic marine natural product (+)-tanikolide (1), isolated from Lyngbya majuscula , was achieved using a [2,3]-Meisenheimer rearrangement as the key reaction. During this rearrangement, we discovered that the allylic amine N-oxide could direct the m-CPBA double-bond epoxidation to the syn position. The resulting syn product 8 underwent epoxide ring opening under the m-CBA conditions to give the five- and six-membered cyclic ether amine N-oxides, which we further treated with Zn and conc. HCl to obtain the reduced bisbenzyl tertiary amines 23 and 22, respectively. When 23 and 22 were treated with trichloroisocyanuric acid (TCCA) in dichloromethane, oxidation at the benzyl position occurred, forming iminium ions. These intermediates were trapped by intramolecular reaction with the hydroxyls, and the resulting intermediates were then oxidized or shifted to afford 25 and 24, respectively. The entire one-pot process involves N-debenzylation, N-chlorination, and hemiacetal oxidation. The amine N-oxide-directed epoxidation complements Davies' ammonium-directed epoxidation. Thus, TCCA N-debenzylation is described for the first time and might be a useful N-debenzylation technique.

  7. 低温固化烯丙基酚氧树脂/双马来酰亚胺树脂的研究%Low temperature curable allyl phenol epoxy resin/bismaleimide resin

    Institute of Scientific and Technical Information of China (English)

    胡睿; 王汝敏; 王道翠; 强雪原

    2013-01-01

    In this paper,2-methylimidazole (2-MI) as the curing catalyst was added to the allyl phenol epoxy resin/bismaleimide resin system in order to reduce the curing temperature of modified bismaleimide resin.The gelation time,mechanical properties and thermal properties of the modified resin system were tested.It was found that when the content of the catalyst was 0.5 wt%, the impact toughness,flexible strength and heat distorsional temperature of the modified 2bismaleimide resin were 26.39 kJ/m ,144.85MPa and 202℃,respectively.That means the material has good toughness and heat resistance.%为降低双马来酰亚胺树脂的固化温度,用2-甲基咪唑(2-MI)为烯丙基酚氧树脂/双马来酰亚胺树脂体系的固化催化剂,测试了改性树脂体系的凝胶化时间、力学性能和热性能,并探讨了催化剂含量对树脂性能的影响。结果表明,当催化剂质量分数为0.5%时,体系性能最佳。冲击强2度为26.39 kJ/m ,弯曲强度为144.85 MPa,热变形温度为202℃,树脂具有良好的韧性,并保持了优异的耐热性。

  8. Preparation and characterization of allyl phenol epoxy resin/bismaleimide system%烯丙基酚氧树脂/双马来酰亚胺改性树脂的制备及表征

    Institute of Scientific and Technical Information of China (English)

    胡睿; 王汝敏; 王道翠; 袁利辉

    2013-01-01

    In this paper, a series of novel allyl phenol epoxy resins was successfully prepared with epoxy resins (EP) and 3,3’-diallyl-bisphenol A (DP) to modify the bismaletimide (BMI) resins.Mechanical property,viscosity characteristics and thermal property of the BMI resins modified with aforesaid phenol epoxy resins were tested.Then we discusssd the the impact of post-processing on the system.The impact toughness and heat distorsional temperature of the modified BMI resin were-222.31 kJ?m and 224℃,respectively.That shows the modified BMI resins have good toughness and heat resistance.The post processing obviously improved the heat resistance of the modified BMI resins and slightly reduced their toughness.%用环氧树脂和二烯丙基双酚A(DP)合成了3种新型烯丙基酚氧树脂,测试了该树脂改性双马来酰亚胺(BMI)树脂体系的力学性能和热性能及黏度特性,探讨了后处理对改性树脂性能的影响。结果表明,改性树脂具有良好的2韧性和耐热性,冲击强度达到了22.31 kJ/m ,HDT仍有224℃,后处理使得体系耐热性大大提高,韧性略有降低。

  9. Different regulation of human delta-opioid receptors by SNC-80 [(+)-4-[(alphaR)-alpha-((2S,5R)-4-allyl-2,5-dimethyl-1-piperazinyl)-3-methoxybenzyl]-N,N-diethylbenzamide] and endogenous enkephalins.

    Science.gov (United States)

    Lecoq, I; Marie, N; Jauzac, Ph; Allouche, S

    2004-08-01

    Among the different mechanisms underlying opioid tolerance, receptor desensitization would represent a major cellular adaptation process in which the role of receptor internalization is still a matter of debate. In the present study, we examined desensitization of the human delta-opioid receptor (hDOR) produced by endogenous opioid peptides Leu-enkephalin (Tyr-Gly-Gly-Phe-Leu) and Met-enkephalin (Tyr-Gly-Gly-Phe-Met), and the contribution of internalization in this process. Results obtained with natural peptides were compared with those produced by a synthetic opioid agonist, SNC-80 [(+)-4-[(alphaR)-alpha-((2S,5R)-4-allyl-2,5-dimethyl-1-piperazinyl)-3-methoxybenzyl]-N,N-diethylbenzamide). After a 30-min treatment, we observed a different regulation of hDOR between agonists. SNC-80 produced a stronger and faster desensitization and was associated with a loss of opioid binding sites by 50%. SNC-80 also caused a marked hDOR down-regulation by 30% as observed by Western blot. Immunocytochemistry revealed that SNC-80 induced a complete redistribution of hDOR from cell surface into intracellular compartments, whereas a partial internalization was visualized upon enkephalin exposure. In contrast, a stronger hDOR recycling and resensitization were measured after enkephalin treatment compared with SNC-80. These data strongly suggested a differential sorting of the internalized receptors caused by enkephalins and SNC-80 that was further confirmed by chloroquine as a lysosomal degradation blocker and monensin as a recycling endosome inhibitor. Finally, by preventing hDOR internalization with 0.5 M sucrose, we demonstrated that hDOR internalization contributes partially to desensitization. In conclusion, hDOR desensitization depends both on its internalization and its sorting either to the recycling pathway or to lysosomes.

  10. Well-defined mono(η3-allyl)nickel complex MONi(η3-C3H5) (M = Si or Al) grafted onto silica or alumina: A molecularly dispersed nickel precursor for syntheses of supported small size nickel nanoparticles

    KAUST Repository

    Li, Lidong

    2014-01-01

    Preparing evenly-dispersed small size nickel nanoparticles over inert oxides remains a challenge today. In this context, a versatile method to prepare supported small size nickel nanoparticles (ca. 1-3 nm) with narrow size distribution via a surface organometallic chemistry (SOMC) route is described. The grafted mono(η3-allyl)nickel complexes MONi(η 3-C3H5) (M = Si or Al) as precursors are synthesized and fully characterized by elemental analysis, FTIR spectroscopy and paramagnetic solid-state NMR. © 2014 the Partner Organisations.

  11. Study on the release behavior of allyl isothiocyanate in antimicrobial packaging%抗菌包装膜对异硫氰酸烯丙酯的释放规律研究

    Institute of Scientific and Technical Information of China (English)

    翟秀超; 王金鹏; 焦爱权; 金征宇

    2013-01-01

    缓释型抗菌包装是具有缓慢释放抗菌成分性能的一种活性包装.利用β~环糊精包埋异硫氰酸烯丙酯制备抗菌复合物,并将复合物与聚乳酸、聚乙二醇共混挤压吹塑制备了抗菌包装膜,研究了抗菌包装材料中异硫氰酸烯丙酯在不同环境条件下的释放规律和对常见食品微生物的抑制作用.结果表明,挥发性抗菌剂经过环糊精包埋,其耐热性得到明显提高,热加工损失率从98.77%降低到75.56%;抗菌包装控制抗菌剂释放的速率随着环境湿度和温度的升高而增大;同时,此抗菌包装对常见食品微生物具有较强的抑制作用,其中对酵母、霉菌的抑制作用强于细菌.%The sustained-release antimicrobial packaging is a kind of material that has the special property of releasing active antibacterial component slowly.In this study,antibacterial complex was firstly prepared by forming inculsions between allyl isothiocyanate(AITC)and β-CD.And then β-CD-AITC complex,was mixed together with PLA and PEG.These blenders were then extruded and blown for making the antimicrobial packaging.The release of AITC and its antibacterial effect were mainly investigated.The obtained data suggested that,firstly,the heatresistant ability of volatile antimicrobials had been improved markedly,as can be seen from the less loss rate of AITC about 75.56% when processing in extruder,compared with that of 98.77% before forming inclusions.Secondly,the release rate of AITC increased with the environmental temperature and humidity rising.Thirdly,the prepared antimicrobial packaging showed quite strong inhibitory effect on the main microorganism in food,especially on yeast and mould.

  12. Inhibition of lipopolysaccharide-inducible nitric oxide synthase and IL-1beta through suppression of NF-kappaB activation by 3-(1'-1'-dimethyl-allyl)-6-hydroxy-7-methoxy-coumarin isolated from Ruta graveolens L.

    Science.gov (United States)

    Raghav, Sunil Kumar; Gupta, Bhawna; Shrivastava, Anju; Das, Hasi Rani

    2007-03-29

    The Ruta graveolens L. plant is used in traditional medicine to treat a large number of diseases. The methanol (50%) extract of the whole plant was observed to inhibit the expression of inducible nitric oxide synthase (iNOS) and the cycloxygenase-2 (COX-2) gene in lipopolysaccharide (LPS)-induced macrophage cells (J774A.1, [Raghav, S.K., Gupta, B., Agrawal, C., Goswami, K., Das, H.R., 2006b. Anti-inflammatory effect of Ruta graveolens L. in murine macrophage cells. J. Ethnopharmacol. 104, 234-239]). The effect of whole plant extract on the expression of other pro-inflammatory genes such as tumor necrosis factor-alpha (TNF-alpha), interleukin-1beta (IL-1beta), IL-12, interferon-gamma (IFN-gamma) and the activation of nuclear factor-kB (NF-kappaB) were investigated in LPS stimulated macrophage cells. An active compound was isolated from this methanol extract by further solvent fractionation and reverse phase high performance liquid chromatography (RP-HPLC). The purified compound was identified as 3-(1'-1'-dimethyl-allyl)-6-hydroxy-7-methoxy-coumarin having IUPAC nomenclature of 6-hydroxy-7-methoxy-3-(2-methyl but-3-en-2yl)-2H-chromen-2-one by ESI-MS, MALDI, FT-IR and NMR. Effect of this purified compound was assessed on iNOS, COX-2 and various pro-inflammatory cytokine genes and was observed to inhibit both the protein and mRNA expression of iNOS and IL-1beta in LPS challenged macrophages. Electrophoretic mobility shift assay (EMSA) and Western blot analyses indicated that the plant extract and the isolated active compound blocked the LPS-induced activation of NF-kappaB through the prevention of inhibitor-kB (IkB) degradation. The purified compound also showed the anti-oxidant activity. The active compound at a dose of 40 mg/kg body weight was observed to inhibit the iNOS and IL-1beta gene expression significantly in endotoxin-induced inflammatory model of BALB/c mice. The low level of nitric oxide production was also observed in the sera of compound treated mice

  13. 壳聚糖席夫碱钴催化环己烯烯丙位氧化反应的研究%Allylic oxidation of cyclohexene catalyzed by chitosan Schiff base cobalt catalyst

    Institute of Scientific and Technical Information of China (English)

    刘丽君; 慈英倩; 刘翠娥; 高洪霞; 崔庆新

    2014-01-01

    制备了壳聚糖( CS)水杨醛席夫碱钴配合物,利用X射线粉末衍射( XRD)、红外( IR)等方法对其结构特征进行了分析,并以氧气为氧化剂,评价了该配合物的环己烯氧化催化性能,初步考察了催化剂用量、反应温度以及反应时间等因素对氧化反应的影响。实验结果表明:CS-席夫碱钴配合物具有良好的环己烯催化氧化活性和较高的烯丙位氧化选择性,在较优条件下,环己烯转化率和烯丙位氧化选择性分别达到85.3%和81.3%;催化剂具有较好的稳定性,易分离可多次重复使用。%A chitosan-schiff base cobalt comples( CS-Schiff base-Co) was prepared and characterized by X-ray diffraction,infrared spectroscopy and TG method,as well as the catalytic properties of this complex in oxidation of cyclohexene were studied in the pres-ence of oxygen. And the influences of the amount of catalyst,reaction temperature and reaction time on oxidation were also investiga-ted. These results indicated that CS-Schiff base-Co catalyst had excellent catalytic activity and selectivity for the allylic oxidation in cyclohexene. The conversion and selectivity were 85. 3%and 81. 3%under suitable conditons,respectively. The catalyst was perfect-ly leach-proof and could be resued at least four times.

  14. Return of the lysergamides. Part II: Analytical and behavioural characterization of N(6) -allyl-6-norlysergic acid diethylamide (AL-LAD) and (2'S,4'S)-lysergic acid 2,4-dimethylazetidide (LSZ).

    Science.gov (United States)

    Brandt, Simon D; Kavanagh, Pierce V; Westphal, Folker; Elliott, Simon P; Wallach, Jason; Colestock, Tristan; Burrow, Timothy E; Chapman, Stephen J; Stratford, Alexander; Nichols, David E; Halberstadt, Adam L

    2017-01-01

    Lysergic acid N,N-diethylamide (LSD) is perhaps one of the most intriguing psychoactive substances known and numerous analogs have been explored to varying extents in previous decades. In 2013, N(6) -allyl-6-norlysergic acid diethylamide (AL-LAD) and (2'S,4'S)-lysergic acid 2,4-dimethylazetidide (LSZ) appeared on the 'research chemicals'/new psychoactive substances (NPS) market in both powdered and blotter form. This study reports the analytical characterization of powdered AL-LAD and LSZ tartrate samples and their semi-quantitative determination on blotter paper. Included in this study was the use of nuclear magnetic resonance (NMR) spectroscopy, gas chromatography-mass spectrometry (GC-MS), low and high mass accuracy electrospray MS(/MS), high performance liquid chromatography diode array detection and GC solid-state infrared analysis. One feature shared by serotonergic psychedelics, such as LSD, is the ability to mediate behavioural responses via activation of 5-HT2A receptors. Both AL-LAD and LSZ displayed LSD-like responses in male C57BL/6 J mice when employing the head-twitch response (HTR) assay. AL-LAD and LSZ produced nearly identical inverted-U-shaped dose-dependent effects, with the maximal responses occurring at 200 µg/kg. Analysis of the dose responses by nonlinear regression confirmed that LSZ (ED50  = 114.2 nmol/kg) was equipotent to LSD (ED50  = 132.8 nmol/kg) in mice, whereas AL-LAD was slightly less potent (ED50  = 174.9 nmol/kg). The extent to which a comparison in potency can be translated directly to humans requires further investigation. Chemical and pharmacological data obtained from NPS may assist research communities that are interested in various aspects related to substance use and forensic identification. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

  15. Synthesis and Solution Properties of a Sulfonated Allyl Biphenyl Ether-Acrylamide-Acrylic Acid Terpolymer%新型磺化共聚物的合成及其溶液性能

    Institute of Scientific and Technical Information of China (English)

    赵梦奇; 陈德军; 吐尼沙古丽·阿吾提; 司马义·努尔拉

    2012-01-01

    A novel allyl biphenyl ether(ABE)-acrylamide(AM)-acrylic acid(AA) terpolymer was synthesized by emulsion polymerization with ABE as the hydrophobic monomer, lauryl sodium sulfate as the surfactant and azodiisobutyronitrile as the initiator. Water-soluble sulfonated terpolymers with different sulfonated degree were synthesized with concentrated sulfuric acid and oleum as the sulfonating agents. The terpolymer and sulfonated terpolymers were characterized by means of FTIR, 'H NMR and TG. The results show that the sulfonated terpolymers contain the units of ABE, AM and sulfonic groups. The influence of the sulfonic groups on the thermal stability of the sulfonated terpolymers is little. The solubility of both the terpolymer and the sulfonated terpolymers, and the properties of their solutions were studied. The results indicate that the sulfonated terpolymer with the sulphonated degree of 0.56 possesses a good tackability. The sulfonated terpolymer has obvious critical association feature and exhibits better temperature-tolerance and salt-resistance due to the introduction of ABE.%以烯丙基-联苯基醚(ABE)为疏水单体、十二烷基硫酸钠为表面活性剂、偶氮二异丁腈为引发剂,采用乳液自由基聚合法合成了ABE-丙烯酰胺(AM)-丙烯酸(AA)三元共聚物,并以浓硫酸和发烟硫酸为磺化剂对ABE-AM-AA三元共聚物进行磺化改性得到了新型磺化共聚物.采用FTIR和1H NMR方法对磺化共聚物进行了结构表征,并采用TG方法分析了它的热稳定性.表征结果显示,磺化共聚物中含有ABE、AM和磺酸基结构单元;磺酸基的引入对磺化共聚物的热稳定性影响较小.考察了磺化共聚物的溶解性及其溶液性能.实验结果表明,当磺化度为0.56时,磺化共聚物的增黏效果较好;ABE单体的引入使磺化共聚物的溶液具有明显的临界缔合特征和良好的耐温抗盐性能.

  16. Oxidative insults to neurons and synapse are prevented by aged garlic extract and S-allyl-L-cysteine treatment in the neuronal culture and APP-Tg mouse model.

    Science.gov (United States)

    Ray, Balmiki; Chauhan, Neelima B; Lahiri, Debomoy K

    2011-05-01

    Alzheimer's disease (AD) is one of the most common forms of dementia in the elderly. In AD patients, β-amyloid peptide (Aβ) plaques and neurofibrillary tangles are common features observed in the CNS. Aβ deposition results in the production of reactive oxygen species (ROS) leading to the hyperphosphorylation of tau that are associated with neuronal damage. Cholinesterase inhibitors and a partial NMDA receptor antagonist (memantine) have been identified as potential treatment options for AD. However, clinical studies have found that these drugs fail to prevent the disease progression. From ancient times, garlic (Allium sativum) has been used to treat several diseases. By 'aging' of garlic, some adverse reactions of garlic can be eliminated. Recent findings suggest that 'aged garlic extract' (AGE) may be a therapeutic agent for AD because of its antioxidant and Aβ lowering properties. To date, the molecular properties of AGE have been sparsely studied in vitro or in vivo. The present study tested specific biochemical and molecular effects of AGE in neuronal and AD rodent models. Furthermore, we identified S-allyl-L-cysteine (SAC) as one of the most active chemicals responsible for the AGE-mediated effect(s). We observed significant neuroprotective and neurorescue properties of AGE and one of its ingredients, SAC, from ROS (H(2)O(2))-mediated insults to neuronal cells. Treatment of AGE and SAC were found to protect neuronal cells when they were independently co-treated with ROS. Furthermore, a novel neuropreservation effect of AGE was detected in that pre-treatment with AGE alone protected ∼ 80% neuronal cells from ROS-mediated damage. AGE was also found to preserve pre-synaptic protein synaptosomal associated protein of 25 kDa (SNAP25) from ROS-mediated insult. For example, treatment with 2% AGE containing diet and SAC (20 mg/kg of diet) independently increased (∼70%) levels of SNAP25 and synaptophysin in Alzheimer's amyloid precursor protein-transgenic mice

  17. 全氟丁基磺酸锡催化醛烯丙基化和Mukaiyama-aldol反应%Bisperfluorobutylsulfonate Bisbutyltin Catalyzed Allylation and Mukaiyama-aldol Reaction of Aldehyde

    Institute of Scientific and Technical Information of China (English)

    刘毅; 王勰; 陈锦杨; 李宁波; 许新华

    2012-01-01

    二丁基二氯化锡与全氟丁基磺酸银在丙酮中室温反应,得到二丁基二全氟丁基磺酸锡.该配合物在空气中放置2d,1H NMR表明其结构未发生变化,TG-DSC表明在220℃是稳定的;配合物C4F9SO3)2SnBu2能溶解在乙酸乙酯、丙酮、乙腈、四氢呋喃、乙醚等极性有机溶剂中,但室温下,在非极性溶剂己烷、二氯甲烷、甲苯中不溶.以乙腈作溶剂,室温下,(C4F9SO3)2SnBu2的用量分别为1.0和5.0 mol%,醛的烯丙基化反应和Mukaiyama-aldol反应有效进行,高产率得到对应产物.%Bisperfluorobutylsulfonate bisbutyltin complex was successfully synthesized by treating C4F9SO3Ag with Bu2SnCl2 in acetone at room temperature. When the complex was exposed to air two days, 1H NMR spectra showed that its structure had no change. TG-DSC showed that the complex was stable below 220 ℃. The complex had a good solubility in polar solvents, such as ethyl acetate, acetone, acetonitrile, THF, ethyl ether. But it was poor soluble in hexane, CH2Cl2, toluene at room temperature. In the presence of 1.0 and 5.0 mol% of bisperfluorobutylsulfonate bisbutyltin respectively, allylation of aldehyde and Mukaiyama aldol reaction could efficiently occur in CH3CN at room temperature and give high yield of the corresponding products.

  18. Fault locator of an allyl chloride plant

    Directory of Open Access Journals (Sweden)

    Savković-Stevanović Jelenka B.

    2004-01-01

    Full Text Available Process safety analysis, which includes qualitative fault event identification, the relative frequency and event probability functions, as well as consequence analysis, was performed on an allye chloride plant. An event tree for fault diagnosis and cognitive reliability analysis, as well as a troubleshooting system, were developed. Fuzzy inductive reasoning illustrated the advantages compared to crisp inductive reasoning. A qualitative model forecast the future behavior of the system in the case of accident detection and then compared it with the actual measured data. A cognitive model including qualitative and quantitative information by fuzzy logic of the incident scenario was derived as a fault locator for an ally! chloride plant. The obtained results showed the successful application of cognitive dispersion modeling to process safety analysis. A fuzzy inductive reasoner illustrated good performance to discriminate between different types of malfunctions. This fault locator allowed risk analysis and the construction of a fault tolerant system. This study is the first report in the literature showing the cognitive reliability analysis method.

  19. 丙烯醇催化氨化合成3-甲基吡啶催化剂的制备及性能%Preparation and performance of Zn/H-ZSM-5 catalyst for catalytic amination of allyl alcohol to 3-picoline

    Institute of Scientific and Technical Information of China (English)

    马天奇; 魏天宇; 骈岩杰; 张月成; 赵继全

    2014-01-01

    采用浸渍法制备了一系列H-ZSM-5分子筛负载过渡金属锌催化剂,在固定床反应器上考察了这些催化剂对丙烯醇催化氨化合成3-甲基吡啶的催化性能。通过对 H-ZSM-5的硅铝比、锌负载量对催化剂催化性能影响的考察,发现硅铝比为80、锌负载量为12%时得到的催化剂Zn12/H-ZSM-5(80)的催化性能最佳。在常压、反应温度420℃、氨醇摩尔比3:1、空速300 h-1条件下,丙烯醇在该催化剂上的转化率和3-甲基吡啶的选择性分别达到97.8%和37.9%。利用X射线衍射(XRD)、X射线光电子能谱(XPS)以及吡啶吸附红外对催化剂进行了表征,结果表明,Zn12/H-ZSM-5(80)上负载的Zn2+为L酸;在丙烯醇生成3-甲基吡啶的反应过程中催化剂的脱氢活性物种为氧化锌,而加成和环合反应则主要是由催化剂中的L酸催化实现的。%H-ZSM-5 supported zinc catalysts were prepared by impregnation method, and their catalytic performances for amination of allyl alcohol to 3-picoline were evaluated in a fixed-bed reactor. It is found that the catalyst Zn12/H-ZSM-5(80) (H-ZSM-5 with 80 silicon/aluminum (Si/Al) ratio and zinc loading of 12%) shows the best performance among all the studied catalysts. 97.8%conversion of allyl alcohol and 37.9%selectivity toward 3-picoline are obtained on this catalyst using reaction conditions:atmospheric pressure, at 420℃, ammonia/allyl alcohol mole ratio 3:1 and gas hour space velocity 300 h-1. The characterization results, obtained by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and FT-IR of absorbed pyridine, indicate that zinc on Zn12/H-ZSM-5(80) is Zn2+, there is Lewis acid on HZSM-5. In 3-picoline formation, ZnO provides active sites of dehydrogenation reaction, and addition and cyclization reactions are mainly catalyzed by the Lewis acid.

  20. (2,4-二甲氧基苯基)烯丙基丙二酸二乙酯异构体的GC/MS研究%Study on Diethyl [3-(2,4-Dimethoxyphenyl) Allyl] Malonate Isomers by Gas Chromatography-Mass Spectrometry

    Institute of Scientific and Technical Information of China (English)

    王敏; 彭奇

    2012-01-01

    A method applying gas chromatography-ion trap mass spectrometry (GC/MS) for the simultaneous analysis of diethyl [3-(2,4-dimethoxyphenyl)allyl]malonate isomers is described. The diethyl [3-(2,4-dimethoxyph-enyl)allyl]malonate mixture of isomers was prepared by the decarboxylative Heck reaction of 2,4-dimethoxybenzoic acid with diethyl 2-al-lylmalonate firstly, and then was analyzed by GC/MS in Electron ionization (El) and Chemical ionization (CD full-scan mode. Two components were isolated by gas chromatography" and identified as isomers from the determination of the molecular ions. Next, the isomers were analyzed by tandem mass spectrometry (MS/MS) mode. Through the analysis of different cleavage fragments of the isomers in MS/MS mode, mass spectrometric fragmentation pathways of the isomers were discussed. The structures of two isomers were determined on the base of different mass characteristic fragmentation pathways. This new meth- od of identifying isomers is a time-saving, economical and effective method, which could provide reference for analysis and identification of this kind of compounds.%为了研究钯催化的2,4-二甲氧基苯甲酸与烯丙基丙二酸二乙酯的脱羧Heck反应的产物结构,建立了(2,4-二甲氧基苯基)烯丙基丙二酸二乙酯同分异构体的分离与鉴定的气相色谱-离子阱质谱方法.首先通过脱羧Heek反应制得(2,4-二甲氧基苯基)烯丙基丙二酸二乙酯异构体混合物,然后利用GC/MS联用技术对混合物进行分析,得到各组分的EI和CI全扫描模式质谱信息.通过对照各组分的分子离子峰确定互为异构体的组分,再对异构体组分采用MS/MS模式获取各自的裂解碎片.通过分析异构体的不同的裂解碎片,讨论质谱裂解方式,从而确定异构体的结构.该方法省时、经济、高效,可为此类化合物的分析与鉴别提供参考.

  1. Crystal structure of cyclo-bis­(μ4-2,2-di­allyl­malonato-κ6 O 1,O 3:O 3:O 1′,O 3′:O 1′)tetra­kis­(triphenyl­phosphane-κP)tetra­silver(I)

    Science.gov (United States)

    Frenzel, Peter; Jakob, Alexander; Schaarschmidt, Dieter; Rüffer, Tobias; Lang, Heinrich

    2014-01-01

    In the tetra­nuclear mol­ecule of the title compound, [Ag4(C9H10O4)2(C18H15P)4], the AgI ion is coordinated by one P and three O atoms in a considerably distorted tetra­hedral environment. The two 2,2-di­allyl­malonate anions bridge four AgI ions in a μ4-(κ6 O 1,O 3:O 3:O 1′,O 3′:O 1′) mode, setting up an Ag4O8P4 core (point group symmetry -4..) of corner-sharing tetra­hedra. The shortest intra­molecular Ag⋯Ag distance of 3.9510 (3) Å reveals that no direct d 10⋯d 10 inter­actions are present. Four weak intra­molecular C—H⋯O hydrogen bonds are observed in the crystal structure of the title compound, which most likely stabilize the tetra­nuclear silver core. PMID:25484645

  2. 1-O-烯丙基-4-羟基蒽醌与牛血清白蛋白相互作用的电化学研究%Electrochemical Study of the Interaction of 1-O-allyl-4-hydroxyanthraquinone with Albumin

    Institute of Scientific and Technical Information of China (English)

    钟桐生; 黄杉生; 刘国东; 杨欣

    2006-01-01

    The electrochemical behavior of 1-O-allyl-4-hydroxyanthraquinone (OAHAQ) in an aqueous medium was investigated. OAHAQ can form adducts with albumin (BSA). The apparent diffusion coefficients of OAHAQ and OAHAQ-BSA adduct and the stoichiometry of OAHAQ and BSA in OAHAQ-BSA adduct were measured. In the presence of BSA, the standard rate constant Ks of OAHAQ was not significantly changed. The reduction peak current of OAHAQ decreased with the addition of BSA in the solution. The proposed method can be operated to probe the interaction between these species and to determine BSA.%采用循环伏安法研究了1-O-烯丙基-4-羟基蒽醌(OAHAQ)的电化学行为.研究表明,OAHAQ 与BSA能形成了1:1的配合物,同时研究了OAHAQ及其与BSA配合物的表观扩散系数,在BSA存在下,OAHAQ的标准速率常数Ks没有显著的变化,其还原峰电流随着BSA的加入而减小,据此可用来测定BSA的浓度.

  3. 含烯丙基六苯氧基环三磷腈的合成及其在阻燃丙烯酸酯树脂中的应用%Synthesis of Hexaphenoxycyclotriphosphazene with Allyl Group and Application in Flame Retardant Acrylate Resin

    Institute of Scientific and Technical Information of China (English)

    元东海; 唐安斌; 黄杰; 马寒冰

    2012-01-01

    A novel cyclophosphazene flame retardant monomer with alyl group, 2-allyl phenoxy-pentaphenoxycyclotriphosphazene ( APPCP ) , was synthesized by using hexachlorocyclotriphosphazene ( HCCP) , 2-allylphenol and phenol as the starting materials. The structure of the product was characterized by FTIR, MS, 'H NMR and elemental analysis. The flame retardant acrylate resin was prepared through copolymerized with APPCP and aerylate resin monomers, and the effects of APPCP on the thermal and flame-retardant properties were investigated. With the addition of 20% APPCP, the flammability class of the copolymerized acrylate resin was attained to V-0, with the limiting oxygen index ( LOI) value increased to 31.2%, and the residual mass up to 23. 2% at 600 ℃.%以六氯环三磷腈(HCCP)、苯酚和2-烯丙基苯酚为原料,合成了新型含烯丙基的环磷腈阻燃单体(2-烯丙基苯氧基)五苯氧基环三磷腈(APPCP),用红外光谱、核磁氢谱、质谱和元素分析表征其组成和结构.将APPCP与丙烯酸酯单体共聚制备了阻燃丙烯酸酯树脂,测试了共聚丙烯酸酯树脂的热稳定性和阻燃性,当APPCP用量为20%时,共聚丙烯酸酯树脂燃烧等级(UL-94)可达Ⅴ-0级,极限氧指数(LOI)高达31.2%,在空气中600℃时残留质量提高至23.2%.

  4. S-烯丙基-L-半胱氨酸对抗离体大鼠心肌缺血/再灌损伤作用的研究%Effect of S-allyl-L-cysteine on isolate heart subject to ischemia/reperfusion

    Institute of Scientific and Technical Information of China (English)

    薛猛; 崔洁; 夏雯; 李英; 钱令波; 叶治国; 王会平; 夏强

    2011-01-01

    Objective: To investigate the effect of S-allyl-L-cysteine(SAC) on isolated rat heart subject to ischemia/reperfusion(I/R) injury and the mechanisms. Methods: The isolated perfused rat hearts on a langendorff apparatus were subjected to global ischemia for 30 min and followed by 120 min of reperfusion. Hemodynamic index, the production of formazan and the level of lactate dehydrogenase(LDH) in the coronary effluent were determined. Superoxide dismutase(SOD) and reactive oxygen species(ROS) in myocardial homogenates were rneasured.Results: Compared with I/R group, the hemodynamics were greatly improved, the production of formazan was increased, and LDH level in effluent was reduced in SAC group. SAC improved the SOD activity and significantly decreased the level of ROS. In addition, threonine(Thr ) attenuated the protective effect of SAC significantly. Conclusion: SAC has protective effect against myocardial ischemia/reperfusion injury on rats. The possible mechanism is that SAC be transported into the cell through alanine-serine-cysteine-transporterl (ASCT-1) improves SOD activity and reduces the level of ROS.%目的:探讨S-烯丙基-L-半胱氨酸(SAC)预处理对心肌缺血/再灌(I/R)损伤的保护作用及其机制.方法:采用离体大鼠心脏Langendorff灌流模型,全心停灌30 min,再灌120 min建立I/R模型.测定血流动力学指标和再灌各时间点冠脉流出液中乳酸脱氢酶(LDH)含量.实验结束测心肌组织中甲赞(formazan),超氧歧化酶(SOD)及活性氧(ROS)量的变化.结果:与对照组比,SAC明显改善左室血流动力学指标,提高心肌组织的formazan含量,降低再灌期间冠脉流出液中LDH含量,提高心肌组织中SOD的活性,降低心肌组织中ROS的水平.苏氨酸明显减弱SAC的保护作用.结论:SAC对离体大鼠I/R心肌损伤有保护作用,其机制可能与SAC通过心肌细胞膜上的氨基酸转运体ASCT-1进入心肌细胞,增加心肌SOD活性,减少活性氧的损伤有关.

  5. Origins of Regioselectivity in Iridium Catalyzed Allylic Substitution

    OpenAIRE

    Madrahimov, Sherzod T.; Li, Qian; Sharma, Ankit; Hartwig, John F.

    2015-01-01

    Detailed studies on the origin of the regioselectivity for formation of branched products over linear products have been conducted with complexes containing the achiral triphenylphosphite ligand. The combination of iridium and P(OPh)3 was the first catalytic system shown to give high regioselectivity for the branched product with iridium and among the most selective for forming branched products among any combination of metal and ligand. We have shown the active catalyst to be generated from ...

  6. Catalytic enantioselective reductions and allylations of prochiral ketones

    CERN Document Server

    Cunningham, A

    2002-01-01

    The use of LiGaH sub 4 in combination with the S,O-chelate 2-hydroxy-2'-mercapto-1,1'-binaphthyl (monothiobinaphthol, MTBH sub 2), forms an active catalyst (2 mol %) for the asymmetric reduction of prochiral ketones, when using catecholborane as the hydride source. This catalyst has successfully been applied to the enantioselective reduction of aryl/n-alkyl ketones, providing the chiral sec-alcohols in yields of 82 - 96% and with enantiomeric excess values of 59 - 93%. Alkyl/methyl ketones are reduced in yields of 72 - 93% and in 46 - 79% enantiomeric excess. Enantioface differentiation is on the basis of the steric requirements of the ketone substituents. The X-ray structure of the pre-catalyst, Li(THF) sub 3 Ga(MTB) sub 2 has been determined and in solution is in equilibrium with a dimeric species of constitution Li sub 2 Ga sub 2 (MTB) sub 4. An indium analogue whose X-ray structure was determined as Li sub 2 (THF) sub 5 lnCI(MTB) sub 2 has also been prepared. The indium- based catalyst does not form an en...

  7. Neutron response study using poly allyl diglycol carbonate

    Indian Academy of Sciences (India)

    Basma A El-Badry; M F Zaki; Tarek M Hegazy; A Ahmed Morsy

    2007-10-01

    The results of an experimental work aimed at improving the performance of the CR-39 nuclear track detector for neutron dosimetry applications are reported. A set of CR-39 plastic detectors was exposed to 252Cf neutron source, which has the emission rate of 0.68 × 108 s-1, and neutron dose equivalent rate 1 m apart from the source is equal to 3.8 mrem/h. The detection of fast neutrons performed with CR-39 detector foils, subsequent chemical etching and evaluation of the etched tracks by an automatic track counting system was studied. It is found that the track density increases with the increase of neutron dose and etching time. The track density in the detector is directly proportional to the neutron fluence producing the recoil tracks, provided the track density is in the countable range. This fact plays an important role in determining the equivalent dose in the field of neutron dosimetry. These results are compared with previous work. It is found that our results are in good agreement with their investigations.

  8. Screening of allyl alcohol resistant mutant of Rhizopus oryzae and ...

    African Journals Online (AJOL)

    STORAGESEVER

    2009-01-19

    Jan 19, 2009 ... acidulant, flavour and preservative in the food, pharma- ceutical, leather .... determining the ADH and LDH specific activities, and the others were dried to ... using HPLC by a reversed-phase C18 column as previously reported.

  9. 1-Allyl-3-phenylquinoxalin-2(1H-one

    Directory of Open Access Journals (Sweden)

    Hanane Benzeid

    2011-11-01

    Full Text Available The title compound, C17H14N2O, crystallizes with two molecules in the asymmetric unit. The dihedral angles between the mean planes of the quinoxaline ring system and the phenyl ring in the two molecules are 38.27 (10 and 37.14 (8°. In the crystal, π-stacking along the b axis contributes to the crystal cohesion with an average distance between quinoxaline units of 3.397 (3 Å. Weak C—H...O interactions also occur.

  10. Rearrangements of Allylic Sulfinates to Sulfones: A Mechanistic Study

    Science.gov (United States)

    Ball, David B.; Mollard, Paul; Voigtritter, Karl R.; Ball, Jenelle L.

    2010-01-01

    Most current organic chemistry textbooks are organized by functional groups and those of us who teach organic chemistry use functional-group organization in our courses but ask students to learn organic chemistry from a mechanistic approach. To enrich and extend the chemical understanding and knowledge of pericyclic-type reactions for chemistry…

  11. 3-Allyl-2-hydroxy-5,6,8-trimethoxynaphthalene-1,4-dione

    Directory of Open Access Journals (Sweden)

    Margaret A. Brimble

    2008-10-01

    Full Text Available In the crystal structure of the title compound, C16H16O6, a pair of naphthoquinone rings are linked via O—H...O—C hydrogen bonds in a nearly orthogonal arrangement. This dimeric unit is linked to a neighbouring dimer by π–π stacking interactions between the naphthoquinone rings, where the distance between the mean plane of the naphtoquinone backbones is 3.468 Å, and O—H...O—C hydrogen bonds.

  12. Chemically Modified Starch; Allyl- and Epoxy-Starch Derivatives: Their Synthesis and Characterization

    NARCIS (Netherlands)

    Franssen, M.C.R.; Boeriu, C.

    2014-01-01

    Both native and modified starches, such as starch that is pregelatinized, extruded, acid-converted, cross-linked, and substituted, are widely used in industry. This chapter describes a mild two-step process for the synthesis of novel, highly reactive granular epoxy-starch derivatives. Via this metho

  13. Pressure-Resistant Plane Disc Viewports from Allyl Diglycol Carbonate Plastic for Hyperbaric Chambers.

    Science.gov (United States)

    1985-09-01

    DISINFECTANT DEPTH OF CRAZING, in. STCP*, psi 6blu Vii-o-Ter 0.129 250 6b2u Lysol 0.159 220 6b3u methyl alcohol 0.184 120 6b4u Staphene 0.126 300 6b5u Amphyl...FOR 60 MIN SPECIMEN NO. DISINFECTANT DEPTH CRAZING, in. STCP*, psi 6alc Viro-Tec 0.117 270 6a2c Lysol failed after 18.5 min 6a3c methyl alcohol

  14. Electrochemical Oxidation of Fragrances 4-Allyl and 4-Propenylbenzenes on Platinum and Carbon Paste Electrodes

    Directory of Open Access Journals (Sweden)

    Lai-Hao Wang

    2015-03-01

    Full Text Available The electrochemical oxidation behaviors of 4-allylbenzenes (estragole, safrole and eugenol and 4-propenylbenzenes (anethole, asarone and isoeugenol on platinum and carbon paste electrodes were investigated in a Britton-Robinson buffer (pH = 2.93 and 10.93, acetate buffer, phosphate buffer solutions (pH = 2.19 and 6.67, and acetonitrile containing various supporting electrolytes examined lithium perchlorate. Their oxidation potential with Hammett (free-energy relationships and possible reaction mechanisms were discussed.

  15. Perfluoro Allyl Fluorosulfate (FAFS: A Versatile Building Block for New Fluoroallylic Compounds

    Directory of Open Access Journals (Sweden)

    Giuseppe Marchionni

    2011-08-01

    Full Text Available In this study we will present and discuss both the synthesis of CF2=CFCF2OSO2F (perfluoroallyl fluorosulfate, FAFS, focusing in particular on the important role of C3F6/SO3 ratio, reaction temperature and boron catalyst/SO3 ratio on FAFS’ yield and selectivity, as well as a wide variety of ionic and radical reactions possible with FAFS. We focused our attention on reactions of FAFS with aliphatic and aromatic alcohols, acyl halides, halides, H2O2, ketones and radicals whose synthesis and reaction mechanisms will be presented and discussed. Particular attention will be devoted to the novel diallyl-fluoroalkyl peroxide obtained. Factors such as pKa and Lowry and Pearson’s Hard/Soft Acid-Base Theory which determine the selectivity between Addition/Elimination vs. Nucleophilic Substitution reaction mechanisms on FAFS will also be presented and discussed.

  16. Mesoporous Metal Complex–Silica Aerogels for Environmentally Friendly Amination of Allylic Alcohols

    OpenAIRE

    Grau Atienza, Aida; Baeza, Alejandro; Serrano, Elena; Garcia-Martinez, Javier; Nájera Domingo, Carmen

    2015-01-01

    Two series of mesoporous hybrid iron(III) complex–silica aerogels were prepared in one-pot synthesis by using the sol–gel coordination chemistry approach. The use of the ligands 3-(2-aminoethylamino)propyltrimethoxysilane and 2-(diphenylphosphino)ethyltriethoxysilane, both with terminal triethoxysilyl groups, were used to incorporate metal complexes in situ into the framework of silica, through their co-condensation with a silicon alkoxide during the aerogel formation. This methodology yielde...

  17. Chemically Modified Starch; Allyl- and Epoxy-Starch Derivatives: Their Synthesis and Characterization

    NARCIS (Netherlands)

    Franssen, M.C.R.; Boeriu, C.

    2014-01-01

    Both native and modified starches, such as starch that is pregelatinized, extruded, acid-converted, cross-linked, and substituted, are widely used in industry. This chapter describes a mild two-step process for the synthesis of novel, highly reactive granular epoxy-starch derivatives. Via this metho

  18. 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

    reactions with carbon, nitrogen, and oxygen nucleophiles. In this latter step, the respective (E) and (Z) alkene substrate isomers were observed to react with opposite stereospecificity: the (E) alkene reacted with retention and the (Z) alkene with inversion of stereochemistry with respect to both...

  19. Multimetallic complexes and functionalized nanoparticles based on unsymmetrical dithiocarbamate ligands with allyl and propargyl functionality.

    Science.gov (United States)

    Hurtubise, Venesia L; McArdle, James M; Naeem, Saira; Toscani, Anita; White, Andrew J P; Long, Nicholas J; Wilton-Ely, James D E T

    2014-11-03

    The new, unsymmetrical dithiocarbamate ligands, KS2CN(CH2CH═CH2)Me and KS2CN(CH2C≡CH)Me, are formed from the respective amines on reaction with KOH and carbon disulfide. The homoleptic complexes [Ni{S2CN(CH2CH═CH2)Me}2] and [M{S2CN(CH2C≡CH)Me}2] (M = Ni, Pd, Pt) are formed on reaction with suitable metal precursors. Conversion between the two pendant functionalities was confirmed by hydrogenation of [Ni{S2CN(CH2C≡CH)Me}2] to yield [Ni{S2CN(CH2CH═CH2)Me}2]. The monodithiocarbamate compounds of group 8, 10, and 11 metals, [Ru{S2CN(CH2CH═CH2)Me}(dppm)2](+), [Ru(CH═CHC6H4Me-4){S2CN(CH2CH═CH2)Me}(CO)(PPh3)2], [Ni{S2CN(CH2CH═CH2)Me}(dppp)](+), and [Au{S2CN(CH2CH═CH2)Me}(PPh3)] were formed successfully. Using KS2CN(CH2C≡CH)Me, the complex [Ru{S2CN(CH2C≡CH)Me}(dppm)2](+) was obtained from cis-[RuCl2(dppm)2]. One palladium example, [Pd{S2CN(CH2C≡CH)Me}(PPh3)2](+), was also isolated in low yield. However, under the typical conditions employed, a rearrangement reaction prevented isolation of further group 10 propargyl-dithiocarbamate products. Over the extended reaction time required, Me(HC≡CCH2)NCS2(-) was found to undergo a remarkable, atom-efficient cyclization to form the thiazolidine-2-thione, H2C═CCH2N(Me)C(═S)S, in high yield, with MeC═CHN(Me)C(═S)S as the minor product. The reactivity of the pendant triple bonds in [Ni{S2CN(CH2C≡CH)Me}2] was probed in the reaction with [RuH(CO)(S2P(OEt)2)(PPh3)2] to form the trimetallic example [Ni{S2CN(Me)CH2CH═CHRu(CO)(S2P(OEt)2)(PPh3)2}2], while the copper(I) catalyzed reaction with benzylazide yielded the triazole product, [Ni{S2CN(Me)CH2(C2HN3)Bz}2]. KS2CN(CH2C≡CH)Me was also used to prepare the gold nanoparticles, Au@S2CN(CH2C≡CH)Me. Structural studies are reported for [Ru(CH═CHC6H4Me-4){S2CN(CH2CH═CH2)Me}(CO)(PPh3)2] and [Ru{S2CN(CH2C≡CH)Me}(dppm)2]PF6.

  20. HYDROCARBON RADICAL REACTIONS WITH O2: COMPARISON OF ALLYL, FORMYL AND VINYL TO ETHYL. (R824970)

    Science.gov (United States)

    The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

  1. The Isomerization of Allylrhodium Intermediates in the Rhodium-Catalyzed Nucleophilic Allylation of Cyclic Imines**

    Science.gov (United States)

    Hepburn, Hamish B; Lam, Hon Wai

    2014-01-01

    Allylrhodium species generated from potassium allyltrifluoroborates can undergo isomerization by 1,4-rhodium(I) migration to give more complex isomers, which then react with cyclic imines to provide products with up to three new stereochemical elements. High enantioselectivities are obtained using chiral diene–rhodium complexes. PMID:25205604

  2. Synthesis and Characterization of Novel Aliphatic Polycarbonates Bearing Pendant Allyl Ether Groups

    Institute of Scientific and Technical Information of China (English)

    Gang LIU; Feng HE; Yan Ping WANG; Jun FENG; Ren Xi ZHUO

    2006-01-01

    A new six-membered cyclic carbonate monomer, 5-allyloxytrimethylene carbonate (ATMC), was synthesized starting from glycerol, and the corresponding polycarbonates,poly(5-allyloxytrimethylene carbonate)(PATMC) were further synthesized by ring-opening polymerization in bulk at 150 ℃ using stannous octanoate as an initiator. The structures of the monomer and the polymers were confirmed by IR, 1H-NMR, 13C-NMR, and GPC analysis.

  3. Mild Cobalt(III)-Catalyzed Allylative C-F/C-H Functionalizations at Room Temperature.

    Science.gov (United States)

    Zell, Daniel; Müller, Valentin; Dhawa, Uttam; Bursch, Markus; Presa, Rubén Rubio; Grimme, Stefan; Ackermann, Lutz

    2017-09-07

    Sustainable, cobalt-catalyst enabled, synthetically significant C-F/C-H functionalizations were achieved with an ample substrate scope at an ambient temperature of 25 °C, thereby delivering perfluoroallylated heteroarenes. Detailed experimental and computational mechanistic studies on the C-F/C-H functionalizations provided strong support for a facile C-F cleavage. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. Radical heterosexuality: Straight teacher activism in schools : Does ally-led activism work?

    Directory of Open Access Journals (Sweden)

    Leigh Potvin

    2016-06-01

    Here, I explore the efficacy of straight teacher allies, the importance of understanding straight privilege, and the significance of radical heterosexuality for straight people doing LGBTQ activism. Relying on queer theory and decolonizing/Indigenous queer theory, I argue that it is necessary for straight teachers to acknowledge their straight privilege in order to challenge homophobia's companions: heterosexism and heteronormativity. In addressing the latter two covert forms of oppression in schools, teachers and students could shift into deeper, more effective resistance measures.

  5. Chemically Modified Starch; Allyl- and Epoxy-Starch Derivatives: Their Synthesis and Characterization

    NARCIS (Netherlands)

    Franssen, M.C.R.; Boeriu, C.

    2014-01-01

    Both native and modified starches, such as starch that is pregelatinized, extruded, acid-converted, cross-linked, and substituted, are widely used in industry. This chapter describes a mild two-step process for the synthesis of novel, highly reactive granular epoxy-starch derivatives. Via this

  6. Asymmetric Suzuki-Miyaura coupling of heterocycles via Rhodium-catalysed allylic arylation of racemates

    Science.gov (United States)

    Schäfer, Philipp; Palacin, Thomas; Sidera, Mireia; Fletcher, Stephen P.

    2017-06-01

    Using asymmetric catalysis to simultaneously form carbon-carbon bonds and generate single isomer products is strategically important. Suzuki-Miyaura cross-coupling is widely used in the academic and industrial sectors to synthesize drugs, agrochemicals and biologically active and advanced materials. However, widely applicable enantioselective Suzuki-Miyaura variations to provide 3D molecules remain elusive. Here we report a rhodium-catalysed asymmetric Suzuki-Miyaura reaction with important partners including aryls, vinyls, heteroaromatics and heterocycles. The method can be used to couple two heterocyclic species so the highly enantioenriched products have a wide array of cores. We show that pyridine boronic acids are unsuitable, but they can be halogen-modified at the 2-position to undergo reaction, and this halogen can then be removed or used to facilitate further reactions. The method is used to synthesize isoanabasine, preclamol, and niraparib--an anticancer agent in several clinical trials. We anticipate this method will be a useful tool in drug synthesis and discovery.

  7. 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

    groups and high end- group fi delity are obtained in a facile and robust synthetic scheme involving polycondensation, end-group transformation and di ff erent functionalisation reactions such as Cu( I )-mediated azide – alkyne cycloaddition. Pendant alkyl chloride, alkyl azide, bromoisobutyryl, 4...

  8. Radical graft polymerization of an allyl monomer onto hydrophilic polymers and their antibacterial nanofibrous membranes.

    Science.gov (United States)

    Wang, Dong; Xu, Weilin; Sun, Gang; Chiou, Bor-Sen

    2011-08-01

    Hydrophilic poly (vinyl alcohol-co-ethylene) (PVA-co-PE) copolymers with 27 mol %, 32 mol % and 44 mol % ethylene were functionalized by melt radical graft copolymerization with 2,4-diamino-6-diallylamino-1,3,5-triazine (NDAM) using reactive extrusion. This functionalization imparts antibacterial properties. The covalent attachments of the NDAM as side chains onto the PVA-co-PE polymer backbones were confirmed. The effects of initiator concentrations and ethylene contents in PVA-co-PE polymers on grafting of NDAM were studied. The chain scissions of PVA-co-PE polymers during reactive extrusion were investigated by monitoring changes in the melt torque and FTIR spectra. The NDAM grafted PVA-co-PE polymers were successfully fabricated into hydrophilic nanofibers and nanofibrous membranes with sufficient surface exposure of the grafted NDAM. The hydrophilicity of the PVA-co-PE polymers and the large specific surface area offered by the nanofiber membranes significantly facilitated the chlorine activation process, enhanced the active chlorine contents of the grafted PVA-co-PE nanofiber membranes, and therefore led to their superior antibacterial properties.

  9. InCl{sub 3}/NaClO: a reagent for allylic chlorination of terminal olefins

    Energy Technology Data Exchange (ETDEWEB)

    Pisoni, Diego S.; Gamba, Douglas; Fonseca, Carlos V.; Costa, Jesse S. da; Petzhold, Cesar L.; Oliveira, Eduardo R. de; Ceschi, Marco A. [Rio Grande do Sul Univ., Porto Alegre, RS (Brazil). Inst. de Quimica]. E-mail: mceschi@iq.ufrgs.br

    2006-03-15

    Indium trichloride promotes the chlorination of terminal olefins in the presence of sodium hypochlorite with good results. Carvone was chosen as a model compound to examine some of the general features of this reaction, such as stoichiometry, temperature, reaction time and product conversion. Treatment of {beta}-pinene with sodium hypochlorite in the presence of indium trichloride resulted in a facile rearrangement to selectively yield perillyl chloride, which is an important precursor for C-7 oxygenated limonenes. (author)

  10. Synthesis of allyl amine on glass by continuous plasma; Sintesis de alilamina sobre vidrio por plasma continuo

    Energy Technology Data Exchange (ETDEWEB)

    Morales, J.; Olayo, R. [UAM-I, 09340 Mexico D.F. (Mexico); Vasquez, M.; OLayo, M.G.; Cruz, G. [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico)

    2003-07-01

    In this work the synthesis by plasma of thin films of polyallyl amine under continuous plasma conditions for possible use in biomaterials is presented. It is shown that the thickness of the film depends so much of the time of synthesis like of the used power. The polymers were analyzed by X-ray photoelectron spectroscopy (XPS) and angle of contact before and after of being immersed in distilled water by 10 days. The allylamine shows lost of nitrogen and an increase in the content of oxygen with the immersion time due to the interaction among the water and the polymer. The angle of contact shows an increase of approximately 10 degrees, what indicates a change in the surface energy of the polymer. (Author)

  11. Carbocations generated under stable conditions by ionization of matrix-Isolated radicals: the allyl and benzyl cations

    OpenAIRE

    Mišić, Vladimir; Piech, Krzysztof; Bally, Thomas

    2013-01-01

    Carbocations are crucial intermediates in many chemical reactions; hence, considerable effort has gone into investigating their structures and properties, for example, in superacids, in salts, or in the gas phase. However, studies of the vibrational structure of carbocations are not abundant, because their infrared spectra are difficult to obtain in superacids or salts (where furthermore the cations may be perturbed by counterions), and the generation of gas-phase carbocations in discharges u...

  12. Bis{4-[(3-phenyl­allyl­idene)amino]cyclo­hexyl}methane trichloro­methane solvate

    OpenAIRE

    Wolfgang Imhof; Helmar Görls; Angela Göbel; Roberto Menzel

    2008-01-01

    The title compound, C31H38N2, was prepared from bis(4-aminocyclohexyl)methane and two equivalents of cinnamaldehyde. The cyclohexyl groups each show a chair conformation and the α,β-unsaturated imine side chains are all-trans configured. Two molecules of the title compound as well as two trichloromethane solvent molecules are present in the asymmetric unit. The solvent molecules interact with the diimines via weak C—H...N hydrogen bonds.

  13. Chiral Wide-Bite-Angle Diphosphine Ligands: Synthesis, Coordination Chemistry, and Application in Pd-Catalyzed Allylic Alkylation

    NARCIS (Netherlands)

    Czauderna, C.F.; Jarvis, A.G.; Heutz, F.J.L.; Cordes, D.B.; Slawin, A.M.Z.; van der Vlugt, J.I.; Kamer, P.C.J.

    2015-01-01

    A series of diphosphine ligands bearing ester- and ether-modified diphenylether backbones have been prepared. The introduction of carboxylic acid or ether auxiliaries in the ortho-positions relative to the diphenylphosphine groups was achieved via straightforward four-step synthetic protocols, prior

  14. Crystal structure of (E)-N-[(E)-3-(4-meth-oxy-phen-yl)allyl-idene]naphthalen-1-amine.

    Science.gov (United States)

    Lee, Jae Kyun; Cha, Joo Hwan; Cho, Yong Seo; Min, Sun-Joon; Lee, Joon Kyun

    2014-11-01

    In the title compound, C20H17NO, the dihedral angle between the mean planes of the 4-meth-oxy-phenyl ring and the naphthalene ring is 69.50 (7)°. The meth-oxy group is almost coplanar with the benzene ring to which it is connected [Cb-Cb-Om-Cm torsion angle of -7.9 (2)°; b = benzene and m = meth-oxy] and the imine group displays a C-C-N=C torsion angle is -57.2 (2)°. The imine (C=N) group has an E conformation. In the crystal, weak π-π inter-actions between the benzene rings [centroid-centroid distance = 3.7781 (10) Å] are observed.

  15. Degradation of Biofumigant Isothiocyanates and Allyl Glucosinolate in Soil and Their Effects on the Microbial Community Composition.

    Directory of Open Access Journals (Sweden)

    Franziska S Hanschen

    Full Text Available Brassicales species rich in glucosinolates are used for biofumigation, a process based on releasing enzymatically toxic isothiocyanates into the soil. These hydrolysis products are volatile and often reactive compounds. Moreover, glucosinolates can be degraded also without the presence of the hydrolytic enzyme myrosinase which might contribute to bioactive effects. Thus, in the present study the stability of Brassicaceae plant-derived and pure glucosinolates hydrolysis products was studied using three different soils (model biofumigation. In addition, the degradation of pure 2-propenyl glucosinolate was investigated with special regard to the formation of volatile breakdown products. Finally, the influence of pure glucosinolate degradation on the bacterial community composition was evaluated using denaturing gradient gel electrophoresis of 16S rRNA gene amplified from total community DNA. The model biofumigation study revealed that the structure of the hydrolysis products had a significant impact on their stability in the soil but not the soil type. Following the degradation of pure 2-propenyl glucosinolate in the soils, the nitrile as well as the isothiocyanate can be the main degradation products, depending on the soil type. Furthermore, the degradation was shown to be both chemically as well as biologically mediated as autoclaving reduced degradation. The nitrile was the major product of the chemical degradation and its formation increased with iron content of the soil. Additionally, the bacterial community composition was significantly affected by adding pure 2-propenyl glucosinolate, the effect being more pronounced than in treatments with myrosinase added to the glucosinolate. Therefore, glucosinolates can have a greater effect on soil bacterial community composition than their hydrolysis products.

  16. Neutral and cationic vanadium(III) alkyl and allyl complexes with a cyclopentadienyl-amine ancillary ligand

    NARCIS (Netherlands)

    Liu, GH; Beetstra, DJ; Meetsma, A; Hessen, B; Liu, Guohua; Beetstra, Dirk J.

    2004-01-01

    The (N,N-dimethylaminoethyl)cyclopentadienyI vanadium(III) complex [eta(5),eta(1)-C5H4(CH2)(2)-NMe2]VCl2(PMe3) (1), in which the pendant amine is coordinated to the metal center, was prepared by the reaction Of VCl3(PMe3)(2) with Li[C5H4(CH2)(2)NMe2] in THF. Reaction of 1 with 2 equiv of MeLi yields

  17. CCDC 929979: Experimental Crystal Structure Determination : (eta^3^-Allyl)-chloro-(1-cyclododecyl-3-mesitylimidazol-2-ylidene)-palladium

    KAUST Repository

    Queval, Pierre

    2014-01-01

    An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.

  18. Effect of 4-Allyl-1-hydroxy-2-methoxybenzene (Eugenol) on Inflammatory and Apoptosis Processes in Dental Pulp Fibroblasts

    Science.gov (United States)

    Martínez-Herrera, Andrea; Ruiz-Rodríguez, Socorro; Vértiz-Hernández, Antonio

    2016-01-01

    Eugenol (mixed with zinc oxide powder) is widely used as direct capping material during pulp therapy in primary teeth. The aim of the present study was to evaluate the effect of eugenol on diverse genes involved in inflammatory and cell apoptosis processes. The regulatory effect of eugenol on the expression of inflammation and apoptotic genes was evaluated in dental pulp fibroblasts from extracted third molars, cultured under concentration of eugenol of 13 μM. Eugenol allowed the expression of inflammatory and apoptotic genes when compared with positive and negative controls. Eugenol is a proinflammatory agent when it is in direct contact with healthy tissues and behaves as an anti-inflammatory agent in tissues undergoing inflammatory/apoptotic processes, as in cases of pulp inflammation in primary teeth. These findings are relevant for dentistry, when considering the application of safer pulp treatments to grossly carious children's teeth. PMID:28044068

  19. Hepatic progenitor cell lines from allyl alcohol-treated adult rats are derived from gamma-irradiated mouse STO cells.

    Science.gov (United States)

    Zhang, Mingjun; Sell, Stewart; Leffert, Hyam L

    2003-01-01

    In attempts to recharacterize several markers of putative rat liver progenitor cells, single-stage reverse transcription-polymerase chain reaction (RT-PCR) analyses failed to confirm the reported immunochemical detection of albumin, alpha(1)-fetoprotein, and cytochrome P450-1A2 in the clonal line, 3(8)#21, and the cloned derivative, 3(8)#21-EGFP (enhanced green fluorescent protein). Undetectable expression occurred whether or not both lines were cultured on or off feeder layers of gamma-irradiated mouse embryonic STO (SIM [Sandoz inbred Swiss mouse] thioguanine-resistant ouabain-resistant) cells. PCR amplification of liver progenitor cell chromosomal (rat and mouse Pigr, rat INS1, mouse INS2) and mitochondrial (rat and mouse COX1) genes revealed only mouse sequences. Further analyses of rat and mouse COX1 sequences in cells from untampered storage vials of all 11 reported liver progenitor cell lines and strains revealed only mouse sequences. In addition, uniquely similar metaphase spreads were observed in STO, 3(8)#21, and 3(8)#21-EGFP cells. The combined results suggest that the previously reported "rat" liver progenitor cell lines were most likely generated during early derivation in cell culture from gamma-radiation-resistant or ineffectively irradiated mouse STO cells used as the feeder layers. These findings reveal new types of artifacts encountered in cocultures of tissue progenitor cells and feeder layer cell lines, and they sound a cautionary note: phenotypic and genotypic properties of feeder layers should be well-characterized before and during coculture with newly derived stem cells and clonal derivatives.

  20. Chiral amino alcohol derived bis-phosphoramidite pincer palladium complexes and their applications in asymmetric allylation of aldimines

    NARCIS (Netherlands)

    Li, J.; Lutz, M.; Spek, A.L.; van Klink, G.P.M.; van Koten, G.; Klein Gebbink, R.J.M.

    2010-01-01

    Novel P-stereogenic bis-phosphoramidite pincer palladium complexes 1 and 2 derived from (S)-(-)-R,R-diphenyl-2-pyrrolidinemethanol and (S)-(þ)-indolinemethanol, respectively, were synthesized in reasonable yields (i.e., 55-62%) by using a flexible, modular synthetic approach and were characterized

  1. Multiphase enantioselective Kharasch-Sosnovsky allylic oxidation based on neoteric solvents and copper complexes of ditopic ligands.

    Science.gov (United States)

    Aldea, Luis; García, José I; Mayoral, José A

    2012-07-21

    Recoverable multiphase enantioselective catalytic systems for the Kharasch-Sosnovsky oxidation of cycloalkenes with tert-butyl peroxybenzoate are described, based on the use of [BMIM][PF(6)] and a new solvent derived from glycerol as the catalyst reservoir phases, and chiral copper complexes with different ligands from the bis(oxazoline) family. The best results are obtained with the glycerol-derived solvent and a recently described azabisoxazoline-based ditopic ligand, allowing up to four uses of the catalytic phase with good results.

  2. Direct asymmetric vinylogous aldol reaction of allyl ketones with isatins: Divergent synthesis of 3-hydroxy-2-oxindole derivatives

    KAUST Repository

    Zhu, Bo

    2013-05-03

    6 in 1: The highly enantioselective title reaction is mediated by a bifunctional catalyst and leads to E-configured vinylogous aldol products (see scheme). These products are used as common intermediates in the synthesis of six biologically active 3-hydroxy-2-oxindole derivatives (e.g., CPC-1). Computational studies indicated that the observed stereoselectivity is a result of favorable secondary π-π* and H-bonding interactions in the transition state. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. Removal of the 5-nitro-2-pyridine-sulfenyl protecting group from selenocysteine and cysteine by ascorbolysis.

    Science.gov (United States)

    Ste Marie, Emma J; Ruggles, Erik L; Hondal, Robert J

    2016-09-01

    We previously reported on a method for the facile removal of 4-methoxybenzyl and acetamidomethyl protecting groups from cysteine (Cys) and selenocysteine (Sec) using 2,2'-dithiobis-5-nitropyridine dissolved in trifluoroacetic acid, with or without thioanisole. The use of this reaction mixture removes the protecting group and replaces it with a 2-thio(5-nitropyridyl) (5-Npys) group. This results in either a mixed selenosulfide bond or disulfide bond (depending on the use of Sec or Cys), which can subsequently be reduced by thiolysis. A major disadvantage of thiolysis is that excess thiol must be used to drive the reaction to completion and then removed before using the Cys-containing or Sec-containing peptide in further applications. Here, we report a further advancement of this method as we have found that ascorbate at pH 4.5 and 25 °C will reduce the selenosulfide to the selenol. Ascorbolysis of the mixed disulfide between Cys and 5-Npys is much less efficient but can be accomplished at higher concentrations of ascorbate at pH 7 and 37 °C with extended reaction times. We envision that our improved method will allow for in situ reactions with alkylating agents and electrophiles without the need for further purification, as well as a number of other applications. Copyright © 2016 European Peptide Society and John Wiley & Sons, Ltd.

  4. Cobalt-catalyzed C-H olefination of aromatics with unactivated alkenes.

    Science.gov (United States)

    Manoharan, Ramasamy; Sivakumar, Ganesan; Jeganmohan, Masilamani

    2016-08-18

    A cobalt-catalyzed C-H olefination of aromatic and heteroaromatic amides with unactivated alkenes, allyl acetates and allyl alcohols is described. This method offers an efficient route for the synthesis of vinyl and allyl benzamides in a highly stereoselective manner. It is observed that the ortho substituent on the benzamide moiety is crucial for the observation of allylated products in unactivated alkenes.

  5. Computationally Designed Zirconium Organometallic Catalyst for Direct Epoxidation of Alkenes without Allylic H Atoms: Aromatic Linkage Eliminates Formation of Inert Octahedral Complexes

    CERN Document Server

    Yang, Bo

    2016-01-01

    We used density functional theory to computationally design a Zr organometallic catalyst for selectively oxidizing substrates using molecular oxygen as oxidant without coreductant. Each selective oxidation cycle involves four general steps: (a) a peroxo or weakly adsorbed O2 group releases an O atom to substrate to form substrate oxide and an oxo group, (b) an oxygen molecule adds to the oxo group to generate an eta2-ozone group, (c) the eta2-ozone group rearranges to form an eta3-ozone group, and (d) the eta3-ozone group releases an O atom to substrate to form substrate oxide and regenerate the peroxo or weakly adsorbed O2 group. This catalyst could potentially be synthesized via the condensation reaction Zr(N(R)R')4 + 2 C6H4-1,6-(N(C6H3-2',6'-(CH(CH3)2)2)OH)2 --> Zr(C6H4-1,6-(N(C6H3-2',6'-(CH(CH3)2)2)O)2)2 [aka Zr_Benzol catalyst] + 4 N(R)(R')H where R and R' are CH3, CH2CH3, or other alkyl groups. For direct ethylene epoxidation, the computed enthalpic energetic span (i.e., effective activation energy for ...

  6. Regioselective 5-exo-Trig Heterocyclization of 2-Allyl-1-naphthols under the Influence of N-Iodosuccinimide or Molecular Iodine in Aqueous Micelle

    Directory of Open Access Journals (Sweden)

    Pradipta Kumar Basu

    2012-01-01

    Full Text Available Regioselective iodocyclization of a series of allylhydroxy naphthalene precursors involving N-iodosuccinimide and environment friendly green approach associated with surfactant-promoted molecular-iodine-mediated 5-exo-trig cyclization strategies has been explored.

  7. Nanoscaled copper metal-organic framework (MOF) based on carboxylate ligands as an efficient heterogeneous catalyst for aerobic epoxidation of olefins and oxidation of benzylic and allylic alcohols.

    Science.gov (United States)

    Qi, Yue; Luan, Yi; Yu, Jie; Peng, Xiong; Wang, Ge

    2015-01-19

    Aerobic epoxidation of olefins at a mild reaction temperature has been carried out by using nanomorphology of [Cu3(BTC)2] (BTC = 1,3,5-benzenetricarboxylate) as a high-performance catalyst through a simple synthetic strategy. An aromatic carboxylate ligand was employed to furnish a heterogeneous copper catalyst and also serves as the ligand for enhanced catalytic activities in the catalytic reaction. The utilization of a copper metal-organic framework catalyst was further extended to the aerobic oxidation of aromatic alcohols. The shape and size selectivity of the catalyst in olefin epoxidation and alcohol oxidation was investigated. Furthermore, the as-synthesized copper catalyst can be easily recovered and reused several times without leaching of active species or significant loss of activity. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. DIASTEREOSELECTIVE INDIUM-PROMOTED ADDITION OF FUNCTIONALIZED ALLYL BROMIDES TO N-BENZYL-2,3-AZETIDINEDIONE UNDER AQUEOUS CONDITIONS. (R824725)

    Science.gov (United States)

    The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

  9. Synthesis of allyl-glycidyl ether by the epoxidation of diallyl ether with t-butyl hydroperoxide over the Ti-MWW catalyst

    Directory of Open Access Journals (Sweden)

    Agnieszka Wróblewska

    2017-01-01

    Full Text Available In this paper, modified hydrothermal method for Ti-MWW catalyst preparation has been shown. Instrumental analysis of the zeolite material Ti-MWW has been performed by means of UV-vis spectrometry, infrared spectrometry (IR, scanning electron microscope (SEM, X-ray diffraction (XRD, and X-ray microanalysis. Moreover, the results of the epoxidation of diallyl ether (DAE over the titanium silicate catalyst Ti-MWW and in the presence of methanol have been presented. t-Butyl hydroperoxide have been applied for the first time as an oxidant for this process. The influence of temperature (20-130°C, DAE/TBHP molar ratio (1:1-3:1, methanol concentration (10-80 wt%, amount of catalyst (1-7 wt% and reaction time (60-1440 min. was studied. The main functions describing the process were determined on the basis of the results obtained from the gas chromatography method.

  10. Thermal Rearrangement of Allyl Substituted Unsymmetric 4H-1,2,4-Triazoles to the Corresponding 1H-1,2,4-triazoles

    Directory of Open Access Journals (Sweden)

    Per H.J. Carlsen

    2001-04-01

    Full Text Available A series of neat 4-(2-alkenyl substituted 5-methyl-3-phenyl-4H-1,2,4-triazoles were thermolyzed at 320 oC producing a rearrangement products, of which the regioisomeric 1- and 2-substituted triazoles were the main products. The group migrations were rationalized in terms of consecutive SN2-type reactions. This mechanism was supported by a study of the alkylations of the triazoles which gave similar product mixtures. 4-(2-alkenyl substituted 3-phenyl-4H-1,2,4-triazoles, on the other hand, gave predominantly elimination products.

  11. CCDC 938918: Experimental Crystal Structure Determination : (eta^3^-Allyl)-chloro-(1-cyclododecyl-3-(2,6-di-isopropylphenyl)imidazol-2-ylidene)-palladium

    KAUST Repository

    Queval, Pierre

    2014-01-01

    An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.

  12. A dose-response study of topical allyl-isothiocyanate (mustard oil) as human surrogate model of pain, hyperalgesia, and neurogenic inflammation

    DEFF Research Database (Denmark)

    Andersen, Hjalte Holm; Lo Vecchio, Silvia; Gazerani, Parisa

    2017-01-01

    , sensitizing irritant remains to be elucidated in human skin. Three concentrations of AITC (10%, 50%, 90%) and vehicle (paraffin) were applied for 5 min to 3x3 cm areas on the volar forearms in 14 healthy volunteers, and evoked pain intensity (visual analog scale 0-100 mm) and pain quality were assessed...... AITC exposure. AITC induced significant dose-dependent, moderate-to-severe spontaneous burning pain, mechanical and heat hyperalgesia as well as dynamic mechanical allodynia (p

  13. The genotoxic potential in vitro and in vivo of the allyl benzene etheric oils estragole, basil oil and trans-anethole.

    Science.gov (United States)

    Müller, L; Kasper, P; Müller-Tegethoff, K; Petr, T

    1994-12-01

    Estragole, trans-anethole and basil oil were tested for their ability to induce DNA repair in rat hepatocytes in vitro and in rat liver in an ex vivo test. There was a marked induction of UDS by estragole and basil oil in vitro (LOEC about 10(-5) mol/l). The basil oil we used contained about 88.2% estragole. It is evident from our results that the induction of UDS with basil oil could be directly related to its main constituent estragole. trans-Anethole was only slightly effective in the in vitro UDS test. The ex vivo UDS test led to clearly elevated DNA repair for estragole and basil oil in rats treated orally with doses up to 2 g/kg body weight. Estragole was not positive in a chromosomal aberration test with V79 cells either via direct treatment, with rat liver S9 mix or with rat hepatocytes as source of metabolism.

  14. -FACIAL DIASTEREOSELECTION IN THE 1,2-ADDITION OF ALLYL METAL REAGENTS TO 2-METHOXYCYCLOHEXANONE AND TETRAHYDROFURANSPIRO-(2-CYCLOHEXANONE). (R824725)

    Science.gov (United States)

    The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

  15. A Novel Synthesis of 3-O-Allyl-4, 5, 6-tri-O-benzyl-1-O-(p-methoxybenzyl)-D-myo-inositol

    Institute of Scientific and Technical Information of China (English)

    Zhi Zhou YUE; Yuan Chao LI

    2005-01-01

    Highly efficient synthesis of the entitled compound was achieved from a readily available myo-inositol derivative. The key step involved a desymmetrization with (+)-camphor dimethyl ketal to give two diastereomers. The two diastereomers could be used to synthesize the same compound by changing the orders to introduce the protective groups.

  16. Synthesis of enantioenriched γ-quaternary cycloheptenones using a combined allylic alkylation/Stork–Danheiser approach: preparation of mono-, bi-, and tricyclic systems

    KAUST Repository

    Bennett, Nathan B.

    2012-01-01

    A general method for the synthesis of β-substituted and unsubstituted cycloheptenones bearing enantioenriched all-carbon γ-quaternary stereocenters is reported. Hydride or organometallic addition to a seven-membered ring vinylogous ester followed by finely tuned quenching parameters achieves elimination to the corresponding cycloheptenone. The resulting enones are elaborated to bi- and tricyclic compounds with potential for the preparation of non-natural analogs and whose structures are embedded in a number of cycloheptanoid natural products.

  17. N′-[(2Z-3-Allyl-4-oxo-1,3-thiazolidin-2-ylidene]-5-fluoro-3-phenyl-1H-indole-2-carbohydrazide

    Directory of Open Access Journals (Sweden)

    Orhan Büyükgüngör

    2009-05-01

    Full Text Available In the title compound, C21H17FN4O2S, the planar indole fused-ring [maximum deviation 0.009 (1 Å] makes dihedral angles of 54.75 (9 and 14.90 (9°, respectively, with the phenyl ring and the dihydrothiazolyl ring. The –CH2CH=CH2 substituent is disordered over two positions in a 0.51 (1:0.49 (1 ratio. An intramolecular N—H...S hydrogen bond generates an S(5 ring motif. The two independent molecules are linked into a dimer by two N—H...O hydrogen bonds, forming an R22(10 ring motif. The crystal structure features intermolecular C—H...π and π–π stacking [centroid–centroid distance = 3.679 (1 Å] interactions. C—H...O and C—H...F interactions are also present.

  18. Functionality of whey proteins covalently modified by allyl isothiocyanate. Part 1 physicochemical and antibacterial properties of native and modified whey proteins at pH 2 to 7

    NARCIS (Netherlands)

    Keppler, Julia Katharina; Martin, Dierk; Garamus, Vasil M.; Berton-Carabin, Claire; Nipoti, Elia; Coenye, Tom; Schwarz, Karin

    2017-01-01

    Whey protein isolate (WPI) (∼75% β-lactoglobulin (β-LG)) is frequently used in foods as a natural emulsifying agent. However, at an acidic pH value, its emulsification capacity is greatly reduced. The covalent attachment of natural electrophilic hydrophobic molecules to WPI proteins is a

  19. Functionality of whey proteins covalently modified by allyl isothiocyanate. Part 1 physicochemical and antibacterial properties of native and modified whey proteins at pH 2 to 7

    NARCIS (Netherlands)

    Keppler, Julia Katharina; Martin, Dierk; Garamus, Vasil M.; Berton-Carabin, Claire; Nipoti, Elia; Coenye, Tom; Schwarz, Karin

    2017-01-01

    Whey protein isolate (WPI) (∼75% β-lactoglobulin (β-LG)) is frequently used in foods as a natural emulsifying agent. However, at an acidic pH value, its emulsification capacity is greatly reduced. The covalent attachment of natural electrophilic hydrophobic molecules to WPI proteins is a promisin

  20. Preservation of acidified cucumbers with a natural preservative combination of fumaric acid and allyl isothiocyanate that target lactic acid bacteria and yeasts

    Science.gov (United States)

    Without the addition of preservative compounds cucumbers acidified with 150 mM acetic acid with pH adjusted to 3.5 typically undergo fermentation by lactic acid bacteria. Fumaric acid (20 mM) inhibited growth of Lactobacillus plantarum and the lactic acid bacteria present on fresh cucumbers, but sp...

  1. A Large Scale Formal Synthesis of CoQ{sub 10}: Highly Stereoselective Friedel-Crafts Allylation Reaction of Tetramethoxytoluene with (E)-4-Chloro-2-methyl-1-phenylsulfonyl-2-butene in the Presence of Montmorillonite K-10

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Sang Who; Lee, Hee Bong; Kim, Bong Chan; Sadaiah, Kadivendi; Lee, Kyuwoong; Shin, Hyunik [LG Life Sciences, Ltd., Daejeon (Korea, Republic of)

    2013-04-15

    We disclosed that MK-10 is a highly effective catalyst for the Friedel-Crafts reaction of 6 and 7 in terms of yield and of stereoselectivity. Although there are numerous applications of clays in Friedel-Crafts reaction, there is very limited example which demonstrated its effect on the stereoselectivity. In that context, our result is significant and further expansion in this direction is highly envisioned. Ubiquinone, as its name represents, exists ubiquitously in human body, particularly in the heart. It mediates the electron transfer process in mitochondria and also exerts strong antioxidant effect in its reduced form. In clinical trial, it showed beneficial effect on heart-related diseases such as myocardial infarction, angina, and other related symptoms to cause decreased mortality compared to the placebo group.

  2. Study on the kinetics of allyl alcohol epoxidition to glycidol over Ti-MWW catalyst%Ti-MWW催化烯丙醇环氧化制环氧丙醇的动力学研究

    Institute of Scientific and Technical Information of China (English)

    张文彬; 权霞; 墨玉欣; 陈晓晖; 魏可镁

    2006-01-01

    以水为溶剂,H2O2为氧化剂,Ti-MWW催化烯丙醇环氧化制备环氧丙醇的反应条件温和,产率高,对环境友好,并考察了反应温度、烯丙醇和H2O2的配比对环氧化反应的影响以及温度和pH值对副反应的影响.在此基础上提出了可能的反应机理,建立了主、副反应的动力学模型,确定了模型参数并对模型进行了检验.

  3. Epoxidation of Allyl Alcohol to Glycidol on Ti-MWW Molecular Sieves%Ti-MWW分子筛上烯丙醇环氧化制环氧丙醇

    Institute of Scientific and Technical Information of China (English)

    陈晓晖; 范志勇; 权霞; 魏可镁

    2006-01-01

    以哌啶为模板剂, 硼酸为结构承载助剂,采用动态水热法成功地合成了Ti-MWW层状前体,经酸处理和煅烧后,得到Ti-MWW分子筛. 紫外-可见光谱表明, Ti-MWW层状前体中含有四面体和八面体配位的钛物种. 酸处理可以很容易地将非骨架的八面体钛脱除,煅烧后分子筛不含锐钛矿相;未经酸处理直接煅烧,部分八面体钛会聚集形成锐钛矿相. Ti-MWW层状前体的红外光谱在960 cm-1 处没有骨架钛的特征吸收谱带出现,经酸处理后,该特征吸收峰出现. 以H2O2为氧化剂,考察了Ti-MWW分子筛上的烯丙醇环氧化性能,发现凝胶Si/Ti=20, 15%HNO3处理12~16 h的情况下,制得的Ti-MWW的催化性能最好,在温度为333 K和反应时间为30 min, 转化率为88.7%, 选择性为99%;但酸处理时间过长可使部分Ti-MWW中的钛生成锐钛矿相,从而导致催化剂活性下降.

  4. Facile Synthesis of Allyl-substituted Aza-heterocyclic Compounds%1-苄基-2-(2-氯代烯丙基)-3-哌啶酮的简便合成

    Institute of Scientific and Technical Information of China (English)

    张雅聪; 李成义; 张建

    2014-01-01

    以苄基哌啶酮为原料,采用2,3-二氯丙烯与NaI原位生成烯丙基碘代物的方法,通过Stevens重排反应高效合成了天然生物碱常山碱的重要中间体——1-苄基-2-(2-氯代烯丙基)-3-哌啶酮,其结构经1H NMR,13C NMR,IR和HR-ESI-MS确证.

  5. Crystal structure of 3-{1-[(1-allyl-1H-indazol-6-ylamino]ethylidene}-6-methyl-2H-pyran-2,4(3H-dione

    Directory of Open Access Journals (Sweden)

    Mohamed El Ghozlani

    2014-12-01

    Full Text Available In the title compound, C18H17N3O3, the dihedral angle between the planes of the indazole ring system [maximum deviation = 0.012 (1 Å] and the pyran-2,4-dione ring is 54.03 (6°. An intramolecular N—H...O hydrogen bond closes an S(6 ring. The same H atom also participates in an intermolecular N—H...O hydrogen bond, which generates an inversion dimer. The dimers are linked by weak C—H...O contacts, thereby forming a three-dimensional network.

  6. 二甲基烯丙基对甲基苄基氯化铵的合成与表征%Synthesis and Characterization of Dimethyl allyl p-methylbenzyl ammonium Chloride

    Institute of Scientific and Technical Information of China (English)

    赵文善; 于丽; 严军辉; 张曦霞

    2006-01-01

    以对甲基氯化苄与二甲基烯丙基胺为原料合成了二甲基烯丙基对甲基苄基氯化铵,考查了光照、氮气保护、避光、温度、原料配比、反应时间和不同溶剂等因素对反应的影响,通过四苯硼钠的定量分析确立了最佳反应条件,并对产物的结构进行了表征.

  7. SUBSTITUENT EFFECTS OF LIGANDS ON ASYMMETRIC INDUCTION IN A PROTOTYPICAL PALLADIUM-CATALYZED ALLYLATION REACTION: MAKING BOTH ENANTIOMERS OF A PRODUCT IN HIGH OPTICAL PURITY USING THE SAME SOURCE OF CHIRALITY. (R826120)

    Science.gov (United States)

    The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

  8. Spectral and structural analysis on 2-(4-Allyl-5-Mercapto-4H-1,2,4-Triazol-3-yl)Acetic acid: Experimental and theoretical (HF and DFT) studies

    Science.gov (United States)

    Şen, Fatih; Dinçer, Muharrem; Yilmaz, Ibrahim; Cukurovali, Alaaddin

    2017-06-01

    We examined the structural and spectral features of the title compound through with experimental and electronic structure methods. The crystal and molecular structure of compound has been brought out using single crystal X-ray diffraction. The spectroscopic investigations of the compound were studied by FT-IR and NMR techniques. The FT-IR spectra were recorded in solid phase on a Mattson 1000 in the region 4000-400 cm-1. 1H and 13C NMR spectra were recorded in deuterium oxide (D2O) chloroform solution on a Varian-Mercury-Plus 400 MHz spectrometer. To support experimental results, the structural and spectroscopic data of the molecular geometry which obtained from the X-ray molecular structure in the ground state were optimized by using Hartree-Fock (HF) and Density Functional Theory (DFT/B3LYP) methods with the 6-31+G(d, p) basis set. The calculated structural parameters (bond lengths, bond angles, torsion angles), vibrational assignments and chemical shifts compared with their experimental data. The frontier molecular orbitals (FMOs), molecular electrostatic potential maps (MEP), Mulliken charge analysis and thermodynamic properties of the compound were obtained by theoretical geometries.

  9. 烯丙式卤代烃在亲核取代反应中的活性%The Activity of Allyl Halogenated Hydrocarbon in Substitutes Reaction of Nucelophilic

    Institute of Scientific and Technical Information of China (English)

    沈柏川

    2001-01-01

    在亲核取代反应中;无论按SN1历程还是SN2历程,烯丙式卤代烃的反应速度都是最快的.一般教材对按SN1历程进行的反应机制介绍较多,而对SN2历程的反应机制则未说明原因.本文拟对烯丙式卤代烃按SN2历程反应的特点进行较深入的分析.

  10. Selenium as an electron acceptor during the catalytic mechanism of thioredoxin reductase.

    Science.gov (United States)

    Lothrop, Adam P; Snider, Gregg W; Ruggles, Erik L; Patel, Amar S; Lees, Watson J; Hondal, Robert J

    2014-02-04

    Mammalian thioredoxin reductase (TR) is a pyridine nucleotide disulfide oxidoreductase that uses the rare amino acid selenocysteine (Sec) in place of the more commonly used amino acid cysteine (Cys) in the redox-active tetrapeptide Gly-Cys-Sec-Gly motif to catalyze thiol/disulfide exchange reactions. Sec can accelerate the rate of these exchange reactions (i) by being a better nucleophile than Cys, (ii) by being a better electrophile than Cys, (iii) by being a better leaving group than Cys, or (iv) by using a combination of all three of these factors, being more chemically reactive than Cys. The role of the selenolate as a nucleophile in the reaction mechanism was recently demonstrated by creating a mutant of human thioredoxin reductase-1 in which the Cys497-Sec498 dyad of the C-terminal redox center was mutated to either a Ser497-Cys498 dyad or a Cys497-Ser498 dyad. Both mutant enzymes were incubated with human thioredoxin (Trx) to determine which mutant formed a mixed disulfide bond complex. Only the mutant containing the Ser497-Cys498 dyad formed a complex, and this structure has been determined by X-ray crystallography [Fritz-Wolf, K., Kehr, S., Stumpf, M., Rahlfs, S., and Becker, K. (2011) Crystal structure of the human thioredoxin reductase-thioredoxin complex. Nat. Commun. 2, 383]. This experimental observation most likely means that the selenolate is the nucleophile initially attacking the disulfide bond of Trx because a complex resulted only when Cys was present in the second position of the dyad. As a nucleophile, the selenolate of Sec helps to accelerate the rate of this exchange reaction relative to Cys in the Sec → Cys mutant enzyme. Another thiol/disulfide exchange reaction that occurs in the enzymatic cycle of the enzyme is the transfer of electrons from the thiolate of the interchange Cys residue of the N-terminal redox center to the eight-membered selenosulfide ring of the C-terminal redox center. The selenium atom of the selenosulfide could

  11. Oxidation of tertiary homoallylic alcohols by thallium trinitrate: fragmentation versus ring contraction

    Energy Technology Data Exchange (ETDEWEB)

    Silva Junior, Luiz F.; Quintiliano, Samir A.P.; Ferraz, Helena M.C. [Sao Paulo Univ., SP (Brazil). Inst. de Quimica. Dept. de Quimica Fundamental]. E-mail: luizfsjr@iq.usp.br; Santos, Leonardo S.; Eberlin, Marcos N. [Universidade Estadual de Campinas, SP (Brazil). Inst. de Quimica

    2006-09-15

    The oxidation of tertiary homoallylic alcohols with thallium trinitrate (TTN) was investigated. The alcohols bearing an allylic methyl group lose a molecule of acetone via a fragmentation reaction that leads to isomeric secondary allylic alcohols as major products, together with their corresponding acetylated derivatives. On the other hand, treating analogous tertiary alcohols without the allylic methyl group with TTN gives indans, through a ring contraction reaction. (author)

  12. Enantioselective, iridium-catalyzed monoallylation of ammonia.

    Science.gov (United States)

    Pouy, Mark J; Stanley, Levi M; Hartwig, John F

    2009-08-19

    Highly enantioselective, iridium-catalyzed monoallylations of ammonia are reported. These reactions occur with electron-neutral, -rich, and -poor cinnamyl carbonates, alkyl and trityloxy-substituted allylic carbonates, and dienyl carbonates in moderate to good yields and excellent enantioselectivities. This process is enabled by the use of an iridium catalyst that does not require a Lewis acid for activation and that is stable toward a large excess of ammonia. This selective formation of primary allylic amines allows for one-pot syntheses of heterodiallylamines and allylic amides that are not otherwise accessible via iridium-catalyzed allylic amination without the use of blocking groups and protective group manipulations.

  13. Pyridoxine-derived organoselenium compounds with glutathione peroxidase-like and chain-breaking antioxidant activity.

    Science.gov (United States)

    Singh, Vijay P; Poon, Jia-Fei; Butcher, Ray J; Engman, Lars

    2014-09-22

    One of the vitamin B6 vitamers, pyridoxine, was modified to incorporate selenium in various oxidation states in place of the methyl group in position 2. Such compounds were conveniently accessed by treatment of bis-4,5-(carboethoxy)-2-iodo-3-pyridinol with disodium diselenide and LiAlH4 -reduction. After work-up, selone 7 was isolated in good yield as an air-stable crystalline material. Hydrogen bonding to the neighboring hydroxyl group, as revealed by the short intramolecular Se⋅⋅⋅H distance in the crystal structure is likely to provide extra stabilization to the compound. Computational studies showed that selone 7 is more stable than the corresponding selenol tautomer by 12.2 kcal mol(-1) . Hydrogen peroxide oxidation of the selone 7 afforded diselenide 12, and, on further oxidation, seleninic acid 13. Treatment of the seleninic acid with thiophenol provided an isolable selenosulfide 14. The glutathione peroxidase-like properties of the pyridoxine-derived compounds were assessed by using the coupled reductase method. Seleninic acid 13 was found to be twofold more active than ebselen. The chain-breaking capacity of the pyridoxine compounds were studied in a water/chlorobenzene membrane model containing linoleic acid as an oxidizable substrate and N-acetylcysteine as a thiol reducing agent. Diselenide 15 could match α-tocopherol when it comes to reactivity towards peroxyl radicals and inhibition time.

  14. Zinc mediated domino elimination-alkylation of methyl 5-iodopentofuranosides

    DEFF Research Database (Denmark)

    Hyldtoft, Lene; Poulsen, Carina Storm; Madsen, Robert

    1999-01-01

    5-Iodopentofuranosides are converted with zinc and allyl/propargyl bromide into dienes/enynes which are further used in carbohydrate annulation reactions.......5-Iodopentofuranosides are converted with zinc and allyl/propargyl bromide into dienes/enynes which are further used in carbohydrate annulation reactions....

  15. Total synthesis of aeruginosin 98B.

    Science.gov (United States)

    Trost, Barry M; Kaneko, Toshiyuki; Andersen, Neil G; Tappertzhofen, Christoph; Fahr, Bruce

    2012-11-21

    The first total synthesis of aeruginosin 98B was accomplished. The key step is a highly diastereoselective Pd-catalyzed intramolecular asymmetric allylic alkylation reaction of a diastereomeric mixture of allylic carbonates that is enabled by the use of racemic phosphine ligand L1.

  16. Formation and Utility of Azasilacyclopentadienes Derived from Silacyclopropenes and Nitriles

    Science.gov (United States)

    Anderson, Laura L.; Woerpel, K. A.

    2009-01-01

    The copper-catalyzed insertions of nitriles into the Si–C bonds of silacyclopropenes provide azasilacyclopentadienes, which can be converted to allylic amines after reduction and protodesilylation. The enamine functionality of azasilacyclopentadienes also participates in 1,4-addition reactions and undergoes a hydroboration and oxidation sequence to form an allylic 1,2-amino alcohol. PMID:19072064

  17. Fabrication and bonding of thiol-ene-based microfluidic devices

    DEFF Research Database (Denmark)

    Sikanen, Tiina M; Lafleur, Josiane P.; Moilanen, Maria-Elisa

    2013-01-01

    In this work, the bonding strength of microchips fabricated by thiol-ene free-radical polymerization was characterized in detail by varying the monomeric thiol/allyl composition from the stoichiometric ratio (1:1) up to 100% excess of thiol (2:1) or allyl (1:2) functional groups. Four different t...

  18. Synthesis of Novel Carbosilane Dendrimers with Myo-inositol Cores

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    The preparation of carbosilane dendrimers with cores of myo-inositol and the outmost periphery groups of allyl groups has been reported.By using alternate hydrosilylation and alkenylation reactions, the dendrimer have been carried up to the third generation with 48 allyl groups on the periphery.

  19. Highly diastereoselective synthesis of quaternary α-trifluoromethyl α-amino acids from chiral imines of trifluoropyruvate.

    Science.gov (United States)

    Min, Qiao-Qiao; He, Chun-Yang; Zhou, Haibing; Zhang, Xingang

    2010-11-14

    An efficient method for highly diastereoselective synthesis of quaternary α-trifluoromethyl α-amino acids was developed via indium mediated allylation of (R)-phenylglycinol methyl ether based imines of trifluoropyruvate in good yields with high diastereoselectivities at room temperature; to illustrate the application of this method in organic synthesis, 2-allyl-2-(trifluoromethyl) aziridine was prepared in an efficient manner.

  20. Drug: D03976 [KEGG MEDICUS

    Lifescience Database Archive (English)

    Full Text Available Pyrazolones N02BB54 Propyphenazone, combinations excl. psycholeptics D03976 Isopropylantipyrine - allyl isop...ropyl acetyl urea - acetaminophen - anhydrous caffeine mixt N02BE Anilides N02BE51 Paracetamol, combinatio...ns excl. psycholeptics D03976 Isopropylantipyrine - allyl isopropyl acetyl urea - acetaminophen - anhydrous caffeine mixt PubChem: 17397993 ...

  1. A concise synthetic route to the conduritols from pentoses

    DEFF Research Database (Denmark)

    Keinicke, Lise Edelmann; Madsen, Robert

    2005-01-01

    A short synthetic strategy for preparation of the conduritols is described. The key step employs a zinc-mediated fragmentation of protected methyl 5-deoxy-5-iodo-D-pentofuranosides followed by an allylation of the intermediate aldehyde in the same pot. The allylation is performed with 3-bromoprop...

  2. Synthesis of allylamine in ethanol%乙醇中烯丙基胺的合成

    Institute of Scientific and Technical Information of China (English)

    唐炳涛; 张淑芬; 杨锦宗

    2005-01-01

    Allylamine was prepared from the ammonolysis of allyl chloride or the reaction of allyl chloride with hexamethylenetetramine in ethanol. The selectivity of allylamine was improved from 21.4% to 67.6% when the reaction was carried out in ethanol instead of liquid ammonia. At the same time, the selectivity of allylamine was increased from 13.3% to 67.6% when the molar ratio of NH3 to allyl chloride was increased from 4.5∶1 to 25∶1.However, the reaction of allyl chloride and hexamethylenetetramine in ethanol produced allylamine with high selectivity (100%) and high yield (87%).The synthesis of allylamine from the reaction of allyl chloride and hexamethylenetetramine in ethanol was more straightforward and convenient.

  3. Rotameric transformations in the photochemistry of TpM(CO)2(η(3)-C3H4R), where Tp = tris(pyrazolyl)borate, M = Mo or W, and R = H or Me.

    Science.gov (United States)

    Thornley, Wyatt A; Bitterwolf, Thomas E

    2015-05-01

    Low energy photolysis of TpM(CO)2(η(3)-C3H4R), where Tp = tris(pyrazolyl)borate, M = Mo or W, and R = 2-H or 2-Me in PVC matrices at 85 K results in exo/gauche isomerism of the allyl ligand. This transformation comes in contrast to the behaviour observed in cyclopentadienyl analogues which undergo exo/endo isomerism. DFT computations reveal an η(3) → η(1)* → η(3) mechanism for the allyl rotameric interconversion where the η(1)*-allyl intermediate is generated upon MLCT excitation.

  4. Tetranuclear organometallic complexes containing Mo2O4(2+) and allylmolybdenum(II) moieties.

    Science.gov (United States)

    Paredes, Paloma; López-Calzada, Angel; Miguel, Daniel; Villafañe, Fernando

    2010-11-14

    Refluxing toluene solutions of [Mo(η(3)-allyl)(O(2)CMe)(CO)(2)(pz*H)(2)] (pz*H = pzH, pyrazole, or dmpzH, 3,5-dimethylpyrazole) without exclusion of air, give the tetranuclear complexes [Mo(2)O(2)(O(2)CCH(3))(2){(μ(3)-O)(μ-pz*)Mo(η(3)-allyl)(CO)(2)(pz*H)}(2)], where two chelating acetato ligands and two "Mo(η(3)-allyl)(CO)(2)(pz*H)(μ-pz*)" fragments are bonded to a central Mo(2)O(4)(2+) moiety.

  5. 含硫Schiff碱型配体的合成研究--芳醛缩-4-烯丙基-3-硫代氨基脲的合成与表征%Synthetic study of Schiff base type ligands containing thiocar bamide group--synthesis and characterization of aro-matic-4-allyl-3-thiosemicarbazone

    Institute of Scientific and Technical Information of China (English)

    赵明根; 范建凤; 李志英; 刘成琪

    2003-01-01

    @@ 1合成方法 在100mL反应器中,加入1.31g(0.01mol)4-烯丙基-3-硫代氨基脲,20mL无水乙醇,加热搅拌溶解,然后加入0.01mol醛及1~2滴催化剂浓盐酸,电磁搅拌,回流反应2h,趁热将反应液转移到小烧杯中,冷却,溶剂自然挥发到一定量后有晶体析出.将所得粗品用醇-水重结晶即得纯品.

  6. 罗丹明B试法鉴定UO2+2用N-烯丙基-N′-(对苯磺钠)硫脲掩蔽Fe3+的干扰%Eliminating the interference of Fe3+ with the N-allyl-N′-(sodium-p-benzenesulfonate) thiourea in the indentification of UO2+2 using Rodamine B

    Institute of Scientific and Technical Information of China (English)

    马万山; 许春萱; 钟瑞琴; 张秀兰

    2002-01-01

    以实验为基础,提出了用罗丹明B试法鉴定UO2+2时,用N-烯丙基-N′-(对苯磺酸钠)硫脲掩蔽Fe3+离子的干扰.与传统的消除干扰的方法相比,具有条件容易控制,操作简便等优点.

  7. SYNTHESIS OF 1-ALLYL,3-METHYLIMIDAZOLIUM-BASED ROOM- TEMPERATURE IONIC LIQUID AND PRELIMINARY STUDY OF ITS DISSOLVING CELLULOSE%1-烯丙基,3-甲基咪唑室温离子液体的合成及其对纤维素溶解性能的初步研究

    Institute of Scientific and Technical Information of China (English)

    任强; 武进; 张军; 何嘉松; 过梅丽

    2003-01-01

    随着不可再生资源(如石油、天然气、煤矿和金属矿藏等)的急剧耗竭,天然高分子的开发与利用日益引起世人的关注.纤维素作为自然界中最丰富的天然高分子材料,其开发与利用一直备受关注[1].

  8. Cytokine Attenuation and Free Radical Scavenging Activity of a New Flavanone7,4'-Dihydroxy-3″,3″-Dimethyl -(5,6-Pyrano-2″-One)- 8- (3‴,3‴-Dimethyl Allyl)- Isolated from Mallotus philippensis: Possible Mechanism for Its Anti-Inflammatory Activity.

    Science.gov (United States)

    Rizvi, Waseeem; Fayazuddin, Mohd; Singh, Ompal; Naeem, Syed Shariq; Moin, Shagufta; Akhtar, Kafil; Kumar, Anil

    2016-01-01

    Mallotus philippensis L.(MP) commonly known as Kamala tree in Hindi,is a small to medium-sized monoecious tree.The objective of the study was to evaluate the anti-inflammatory activity of MPand a new flavanoneisolated from it by using in vivo models of inflammation.Albino wistar rats of either sex weighing 150-200g were used. Seven groups were made (n = 6), namely normal control group (normal saline, 1 ml/kg), standard control group (acetylsalicylic acid, 100 mg/kg), methanol crude extract (300 and 500 mg/kg), ethylacetate fraction (300 and 500 mg/kg) and active compound 4 (new flavanone, 50 mg/kg). The anti-inflammatory activity was studied using carrageenan induced paw edema method and cotton pellet granuloma method. Levels of cytokines (TNF-α, IL-1and IL-6) and activity of antioxidant enzymeslike catalase and glutathione peroxidase were estimated. It was found that the methanol extract, ethylacetate fraction and Flavanonedemonstrated significant reduction in paw edema in carrageenan induced paw edema method as compared to control. They also diminished the serum TNF-α, IL-6 and IL-1 levels. Significantly attenuated the malondialdehyde levels and increased the activities of catalase and glutathione peroxidase in paw tissue. Similarly there was asignificant decrease in granuloma formation in cotton pellet induced granuloma method. In conclusion, MP extracts and the newflavanonepossess anti-inflammatory activity and this might be due to the inhibition of various cytokines and increased free radical scavenging activity.

  9. Cytokine Attenuation and Free Radical Scavenging Activity of a New Flavanone7,4′-Dihydroxy-3″,3″-Dimethyl -(5,6-Pyrano-2″-One)- 8- (3‴,3‴-Dimethyl Allyl)- Isolated from Mallotus philippensis: Possible Mechanism for Its Anti-Inflammatory Activity

    OpenAIRE

    Rizvi, Waseeem; Fayazuddin, Mohd; Singh, Ompal; Naeem, Syed Shariq; Moin, Shagufta; Akhtar, Kafil; Kumar, Anil

    2016-01-01

    Mallotus philippensis L.(MP) commonly known as Kamala tree in Hindi,is a small to medium-sized monoecious tree.The objective of the study was to evaluate the anti-inflammatory activity of MPand a new flavanoneisolated from it by using in vivo models of inflammation.Albino wistar rats of either sex weighing 150-200g were used. Seven groups were made (n = 6), namely normal control group (normal saline, 1 ml/kg), standard control group (acetylsalicylic acid, 100 mg/kg), methanol crude extract (3...

  10. Cytokine Attenuation and Free Radical Scavenging Activity of a New Flavanone7,4′-Dihydroxy-3″,3″-Dimethyl -(5,6-Pyrano-2″-One)- 8- (3‴,3‴-Dimethyl Allyl)- Isolated from Mallotus philippensis: Possible Mechanism for Its Anti-Inflammatory Activity

    Science.gov (United States)

    Singh, Ompal; Moin, Shagufta; Akhtar, Kafil; Kumar, Anil

    2016-01-01

    Mallotus philippensis L.(MP) commonly known as Kamala tree in Hindi,is a small to medium-sized monoecious tree.The objective of the study was to evaluate the anti-inflammatory activity of MPand a new flavanoneisolated from it by using in vivo models of inflammation.Albino wistar rats of either sex weighing 150-200g were used. Seven groups were made (n = 6), namely normal control group (normal saline, 1 ml/kg), standard control group (acetylsalicylic acid, 100 mg/kg), methanol crude extract (300 and 500 mg/kg), ethylacetate fraction (300 and 500 mg/kg) and active compound 4 (new flavanone, 50 mg/kg). The anti-inflammatory activity was studied using carrageenan induced paw edema method and cotton pellet granuloma method. Levels of cytokines (TNF-α, IL-1and IL-6) and activity of antioxidant enzymeslike catalase and glutathione peroxidase were estimated. It was found that the methanol extract, ethylacetate fraction and Flavanonedemonstrated significant reduction in paw edema in carrageenan induced paw edema method as compared to control. They also diminished the serum TNF-α, IL-6 and IL-1 levels. Significantly attenuated the malondialdehyde levels and increased the activities of catalase and glutathione peroxidase in paw tissue. Similarly there was asignificant decrease in granuloma formation in cotton pellet induced granuloma method. In conclusion, MP extracts and the newflavanonepossess anti-inflammatory activity and this might be due to the inhibition of various cytokines and increased free radical scavenging activity. PMID:27941980

  11. Colour Reaction of N-Allyl-N′-(sodium-p-benzenesulfonate)thiourea with Palladium? and Its Application%N-烯丙基-N′-(对苯磺酸钠)硫脲与钯的显色反应及其应用

    Institute of Scientific and Technical Information of China (English)

    马万山; 许春萱; 张玉霞; 杨海申

    2001-01-01

    @@ 1 引言 N-烯丙基-N′-(对苯磺酸钠)硫脲(以下简写为NaNTU)是我们合成的一种新的硫脲类衍生物,性质稳定,易溶于水,无毒,具有很好的分析特性.从我们研究的36种离子与NaNTU 的反应情况看,在1.7~4.2 mol/L的HNO3溶液中,只有钯?能与NaNTU生成黄色络合物 .据此,我们成功地将其用于钯?的鉴定,取得了很好的效果.在此基础上,将该试剂首次应用于钯?的光度分析,从而建立了光度法测定微量钯?的新方法.研究表明,在1.7~4 .2 mol/L的HNO3溶液中,Pd2+和NaNTU形成一种稳定的摩尔比为1∶2的黄色水溶性络合物.络合物的最大吸收波长位于402 nm处;表观摩尔吸光系数ε402=3 .7×104L*mol-1*cm-1.钯?的浓度在0~4.8 mg/L范围内服从比尔定律,相关系数r=0.9996,灵敏度高于硫脲试剂法.该法试验条件容易控制,显色稳定 ,操作简便.研究了36种离子对钯?的干扰情况,在一定倍量的范围内均不干扰钯?的测定 .与有关文献报道的其它一些硫脲类衍生物作为显色剂分光光度测钯?的方法相比,该法具有线性范围宽,Cu2+不干扰等特点.因此,NaNTU是光度法测钯?的选择性很高的试剂.将其用于合成试样、催化剂中钯?的测定,均得到满意结果.

  12. 新显色剂N-烯丙基-N'-(对苯磺酸钠)硫脲与钌的显色反应及其应用%Colour Reaction of N-Allyl-N'-(Sodium-p-benzenesulfonate) thiourea with Ruthenium(Ⅲ) and Its Application

    Institute of Scientific and Technical Information of China (English)

    马万山; 甄西合; 马东兰

    2000-01-01

    研究了显色剂N-烯丙基-N'-(对苯磺酸钠)硫脲与钌(Ⅲ)的显色反应.在4.5~6.0 mol/L的HCl溶液中,钌(Ⅲ)与N-烯丙基-N'-(对苯磺酸钠)硫脲形成稳定的1:3蓝色水溶性络合物.最大吸收波长在630 nm,表观摩尔吸光系数为2.30×104L.mol-1.cm-1;钌(Ⅲ)的浓度在0.4~3.2 mg/L范围内服从比尔定律.此法具有显色稳定,选择性好,操作简便等优点.用于测定二次合金管理样和合成试样中钌,结果满意.

  13. Studies of the Formation of All-carbon Quaternary Centres, en route to Lyngbyatoxin A. A Comparison of Phenyl and 7-Substituted Indole Systems

    DEFF Research Database (Denmark)

    Tønder, Janne Ejrnæs; Hosseini, Masood; Ahrenst, Alex B.

    2004-01-01

    Copper mediated allylic substitutions and conjugate additions to geranyl, cinnamyl and allylic indole compounds have been investigated with the aim of finding a method for the creation of the all-carbon quaternary centre present in the natural product lyngbyatoxin A. Reaction conditions have been...... to the corresponding allylic compounds containing a 7-substituted indole moiety, the regioselectivity was reversed giving only the S(N)2 product. The allylic indole-containing substrates were also found to be unproductive in Pd- or Mo-catalysed S(N)2'-type substitution reactions. In related studies, copper catalysed...... conjugate addition of EtMgBr to the tricyclic lactam 6-methyl-pyrrolo[3,2,1-ij]quinolin-4-one gave a maximum of 20% of the 1,4-addition product....

  14. 1775-IJBCS-Article-Odin Monday

    African Journals Online (AJOL)

    hp

    Epoxidation of aminometradin (l-allyl-3-ethyl-6-amino uracil) using tetraoxochromate(VI) acid, trifloroperacetic acid and hydrogen peroxide as oxidants, catalyzed by ... is a diuretic drug which increases urine and solute excretion from the.

  15. Process for the synthesis of unsaturated alcohols

    Energy Technology Data Exchange (ETDEWEB)

    Maughon, Bob R.; Burdett, Kenneth A.; Lysenko, Zenon

    2007-02-13

    A process of preparing an unsaturated alcohol (olefin alcohol), such as, a homo-allylic mono-alcohol or homo-allylic polyol, involving protecting a hydroxy-substituted unsaturated fatty acid or fatty acid ester, such as methyl ricinoleate, derived from a seed oil, to form a hydroxy-protected unsaturated fatty acid or fatty acid ester; homo-metathesizing or cross-metathesizing the hydroxy-protected unsaturated fatty acid or fatty acid ester to produce a product mixture containing a hydroxy-protected unsaturated metathesis product; and deprotecting the hydroxy-protected unsaturated metathesis product under conditions sufficient to prepare the unsaturated alcohol. Preferably, methyl ricinoleate is converted by cross-metathesis or homo-metathesis into the homo-allylic mono-alcohol 1-decene-4-ol or the homo-allylic polyol 9-octadecene-7,12-diol, respectively.

  16. Catalytic asymmetric total synthesis of (S)-(-)-zearalenone, a novel lipoxygenase inhibitor.

    Science.gov (United States)

    Baggelaar, Marc P; Huang, Yange; Feringa, Ben L; Dekker, Frank J; Minnaard, Adriaan J

    2013-09-01

    A catalytic asymmetric synthesis of (S)-(-)-zearalenone is reported using asymmetric allylic alkylation for the introduction of the stereocenter. (S)-(-)-Zearalenone turned out to be a novel lipoxygenase inhibitor. Copyright © 2013 Elsevier Ltd. All rights reserved.

  17. Catalytic asymmetric total synthesis of (S)-(-)-zearalenone, a novel lipoxygenase inhibitor

    NARCIS (Netherlands)

    Baggelaar, Marc P.; Huang, Yange; Feringa, Ben L.; Dekker, Frank J.; Minnaard, Adriaan J.

    2013-01-01

    A catalytic asymmetric synthesis of (S)-(-)-zearalenone is reported using asymmetric allylic alkylation for the introduction of the stereocenter. (S)-(-)-Zearalenone turned out to be a novel lipoxygenase inhibitor. (C) 2013 Elsevier Ltd. All rights reserved.

  18. A concise total synthesis of (R)-fluoxetine, a potent and selective serotonin reuptake inhibitor

    Energy Technology Data Exchange (ETDEWEB)

    Fatima, Angelo de; Lapis, Alexandre Augusto M.; Pilli, Ronaldo A. [Universidade Estadual de Campinas, SP (Brazil). Inst. de Quimica]. E-mail: pilli@iqm.unicamp.br

    2005-05-15

    (R)-Fluoxetine, potent and selective serotonin reuptake inhibitor, has been synthesized in six steps, 50% overall yield and 99% ee from benzaldehyde via catalytic asymmetric allylation with Maruoka's catalyst. (author)

  19. Reverse-osmosis membranes by plasma polymerization

    Science.gov (United States)

    Hollahan, J. R.; Wydeven, T.

    1972-01-01

    Thin allyl amine polymer films were developed using plasma polymerization. Resulting dry composite membranes effectively reject sodium chloride during reverse osmosis. Films are 98% sodium chloride rejective, and 46% urea rejective.

  20. Synthesis of both enantiomers of isorobinal, a novel cyclic monoterpene isolated from the astigmatid mite, Rhizoglyphus sp.

    Science.gov (United States)

    Liang, Ting; Kuwahara, Shigefumi

    2002-11-01

    Both enantiomers of isorobinal, a cyclic monoterpene isolated from the astigmatid mite (Rhizoglyphus sp.), were synthesized from the enantiomers of perillaldehyde in four steps by using PCC-oxidation of a tertiary allylic alcohol intermediate as the key step.