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Sample records for stereoselective michael addition

  1. Hexafluorobenzene: A powerful solvent for a noncovalent stereoselective organocatalytic Michael addition reaction

    KAUST Repository

    Lattanzi, Alessandra

    2012-01-01

    A dramatic enhancement of the diastereo- and enantioselectivity in the nitro-Michael addition reaction organocatalysed by a commercially available α,α-l-diaryl prolinol was disclosed when performing the reaction in unconventional hexafluorobenzene as a medium. DFT calculations were performed to clarify the origin of stereoselectivity and the role of C 6F 6. © The Royal Society of Chemistry 2012.

  2. Hexafluorobenzene: A powerful solvent for a noncovalent stereoselective organocatalytic Michael addition reaction

    KAUST Repository

    Lattanzi, Alessandra; De Fusco, Claudia; Russo, Alessio; Poater, Albert; Cavallo, Luigi

    2012-01-01

    A dramatic enhancement of the diastereo- and enantioselectivity in the nitro-Michael addition reaction organocatalysed by a commercially available α,α-l-diaryl prolinol was disclosed when performing the reaction in unconventional hexafluorobenzene

  3. Michael additions of thiocompounds to {alpha}, {beta}-unsaturated carbonyl compounds in aqueous media: stereoselectivity with unambiguous characterization by NMR

    Energy Technology Data Exchange (ETDEWEB)

    Almeida, Queli Aparecida Rodrigues de; Pereira, Maria Luiza de Oliveira; Coelho, Ricardo Bezerra; Kaiser, Carlos Roland; Jones Junior, Joel; Silva, Flavia Martins da [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Inst. de Quimica. Dept. de Quimica Organica]. E-mail: soa@iq.ufrj.br; Carvalho, Erika Martins de [Instituto de Tecnologia em Farmacos (Far-Manguinhos), Rio de Janeiro, RJ (Brazil)

    2008-07-01

    The reactions of crotonaldehyde (8) with thiophenol (2) and benzalacetone (10) with ethane-1,2- dithiol (11) yield Michael addition products. The reactions of thiophenol (2) with (R)-carvone (13) and (S)-perillaldehyde (15) lead to (2S,3R,5S)-5-isopropenyl-2-methyl-3-(phenylthio)cyclohexanone (14) and (1R,2R,4S)-4-isopropenyl-2-(phenylthio)cyclohexanecarbaldehyde (16), respectively. An unambiguous elucidation of the stereochemistry of 14 and 16 by NMR is also presented. (author)

  4. Stereoselective synthesis of 5-alkoxycarbonyl-4 alkyl-2-anino-3-cyano-6-methyl-4H-pyranes 3 via asymmetric Michael addition to aceptors-gamma-stereogenics; Sintesis esteroselective de 5-alcoxicarbonil-4-alquil-2-amino-3-ciano-6-metil-4H-piranos via adicion Michael sobre aceptores-gama-esterogenicos

    Energy Technology Data Exchange (ETDEWEB)

    Martinez-Grau, A.; Jimenez, B.; Martin, N.; Seoane, C.; Marco, J.L. [Departamento de Quimica Organica, Facultad de Quimica, Universidad Complutense, Madrid (Spain)

    1994-12-31

    The stereoselective synthesis of 5-alkoxycarbonyl-4-alkyl-2-amino-3-cyano-6-methyl-4H-pyrans 3 via asymmetric Michael addition of malononitrile to gamma-stereogenic alpha-acetylacrylates 2 obtained by Knoevenagel reaction of acetylacetates to quiral alpha-hydroxyaldehydes 1 is described. The resulting 2-amino-4H-pyrans 3 have been obtained in moderate yield and good diastereoselectivity. 15 refs.

  5. Enantio- and Stereoselective Construction of Atisane Scaffold via Organocatalytic Intramolecular Michael Reaction and Diels-Alder Reaction.

    Science.gov (United States)

    Sekita, Hiroko; Adachi, Kyohei; Kobayashi, Ippei; Sato, Yusuke; Nakada, Masahisa

    2017-05-05

    An enantio- and stereoselective construction of the atisane scaffold via organocatalytic intramolecular Michael reaction and Diels-Alder reaction is described. The organocatalytic intramolecular Michael reaction has been found to stereoselectively generate a trans-stereodiad comprising an all-carbon quaternary and a tertiary stereogenic centers. Use of the chiral secondary amine bearing thiourea with benzoic acid as additive is the key to obtaining the desired product with excellent ee in synthetically acceptable yield. The prepared chiral building block has been successfully converted to the compound including the atisane scaffold via the highly stereoselective intramolecular Diels-Alder reaction.

  6. Stereoselective synthesis of diazaspiro[5.5]undecane derivatives via base promoted [5+1] double Michael addition of N,N-dimethylbarbituric acid to diaryliedene acetones

    Directory of Open Access Journals (Sweden)

    Mohammad Shahidul Islam

    2017-01-01

    Full Text Available The nitrogen containing spiro-heterocycle is one of the privileged synthetic motif that constitutes various naturally occurring molecules and displays a broad range of pharmaceutical and biological activities. A new methodology was developed for the synthesis of 2,4-diazaspiro[5.5]undecane-1,3,5,9-tetraones spiro-heterocyclic derivatives via cascade cyclization of [5+1] double Michael addition reaction of N,N-dimethylbarbituric acid with the derivatives of diaryldivinylketones in the presence of diethylamine at ambient temperature. The developed protocol is highly capable of furnishing diazaspiro[5.5]undecane derivatives 3a–m in excellent yields (up to 98%, from easily accessible symmetric and non-symmetric divinylketones 2a–m, containing aryl and heteroaryl substituents. The diazaspiro-heterocyclic structure was mainly elucidated by NMR and X-ray crystallographic techniques. The single-crystal X-ray studies revealed that, the cyclohexanone unit of spirocycles often prefers a chair conformation rather than twisted conformation. The intermolecular hydrogen bonding and CArH⋯π, π–π stacking interactions driving forces are mainly responsible for the crystal packing.

  7. Radiation curable Michael addition compounds

    International Nuclear Information System (INIS)

    Gruber, G.W.; Friedlander, C.B.; McDonald, W.H.; Dowbenko, R.

    1979-01-01

    Radiation polymerizable acrylyloxy-containing reaction products are provided from Michael addition reaction of an amide containing at least two acrylate groups with a primary or secondary amine. The resulting amine adducts of the amide, which contain at least one acrylate group per molecule, possesses high cure rates in air and are useful in compositions for forming coatings. (author)

  8. Organocatalytic asymmetric michael addition of aldehydes to beta-nitroacroleine dimethyl acetal.

    Science.gov (United States)

    Reyes, Efraim; Vicario, Jose L; Badía, Dolores; Carrillo, Luisa

    2006-12-21

    [Structure: see text] The organocatalytic asymmetric Michael addition of aldehydes to beta-nitroacroleine dimethyl acetal has been studied in detail. The reaction took place with excellent yields and high stereoselectivities when a chiral beta-amino alcohol such as L-prolinol was employed as the catalyst, leaving a formation of highly functionalized enantioenriched compounds containing two differentiated formyl groups together with a nitro moiety.

  9. Inverting the diastereoselectivity of the mukaiyama-michael addition with graphite-based catalysts

    KAUST Repository

    Acocella, Maria Rosaria

    2014-02-07

    Here, we show that graphite-based catalysts, mainly graphite oxide (GO) and exfoliated GO, are effective recyclable catalysts for a relevant stereoselective Mukaiyama-Michael addition, outperforming currently available catalysts. Moreover, the graphite-based catalysts described here invert the diastereoselectivity relative to that observed with known catalysts, with the unprecedented large prevalence of the anti diastereoisomer. This inverted diastereoselectivity is increased when the catalyst concentration is reduced and after catalyst recycling. Density functional theory calculations suggest that the selectivity is determined by two types of supramolecular interactions operating between the catalyst and the substrates at the diastereoselectivity- determining transition state, specifically, the π-stacking of b-nitrostyrene with graphite and the van der Waals interaction between the SiMe3 group of the silyl ether and the graphite. © 2013 American Chemical Society.

  10. Double Michael Addition Reaction of Bischalcone under Ultrasound

    Institute of Scientific and Technical Information of China (English)

    LI,Ji-Tai; XU,Wen-Zhi; CHEN,Guo-Feng; LI,Tong-Shuang

    2004-01-01

    @@ The Michael addition of 1,5-diaryl-1,4-pentadien-3-ones with active methylene compounds has been the subjects of many investigations. Ultrasound has increasingly been used in organic synthesis in the last three decades. Compared with traditional methods, this method is more convenient and easily controlled. A large number of organic reactions can be carried out in higher yield, shorter reaction time or milder conditions under ultrasonic irradiation. KF/Al2O3 as a useful solid supported catalyst has received considerable attention because of their high level of chemoselectivity and environmental compatibility as well as simplicity of operation and their ready availability at low cost. Herein we report the double Michael addition of dibenzalacetone with active methlene compounds such as dimethyl malonate, diethyl malonate,methyl cyanoacetate and ethyl cyanoacetate catalyzed by KF/Al2O3 under ultrasound irradiation.

  11. Asymmetric Michael Addition Mediated by Chiral Ionic Liquids

    Science.gov (United States)

    Suzuki, Yumiko

    2018-01-01

    Chiral ionic liquids with a focus on their applications in asymmetric Michael additions and related reactions were reviewed. The examples were classified on the basis of the mode of asymmetric induction (e.g., external induction/non-covalent interaction or internal induction/covalent bond formation), the roles in reactions (as a solvent or catalyst), and their structural features (e.g., imidazolium-based chiral cations, other chiral oniums; proline derivatives). Most of the reactions with high chiral induction are Michael addition of ketones or aldehydes to chalcones or nitrostyrenes where proline-derived chiral ionic liquids catalyze the reaction through enamine/ iminium formation. Many reports demonstrate the recyclability of ionic liquid-tagged pyrrolidines. PMID:29861702

  12. Asymmetric Michael Addition Mediated by Chiral Ionic Liquids.

    Science.gov (United States)

    Suzuki, Yumiko

    2018-06-01

    Chiral ionic liquids with a focus on their applications in asymmetric Michael additions and related reactions were reviewed. The examples were classified on the basis of the mode of asymmetric induction (e.g., external induction/non-covalent interaction or internal induction/covalent bond formation), the roles in reactions (as a solvent or catalyst), and their structural features (e.g., imidazolium-based chiral cations, other chiral oniums; proline derivatives). Most of the reactions with high chiral induction are Michael addition of ketones or aldehydes to chalcones or nitrostyrenes where proline-derived chiral ionic liquids catalyze the reaction through enamine/ iminium formation. Many reports demonstrate the recyclability of ionic liquid-tagged pyrrolidines.

  13. Stereoselective conjugate radical additions: application of a fluorous oxazolidinone chiral auxiliary for efficient tin removal.

    Science.gov (United States)

    Hein, Jason E; Zimmerman, Jake; Sibi, Mukund P; Hultin, Philip G

    2005-06-23

    [reaction: see text] A series of asymmetric free-radical-mediated intermolecular conjugate additions using a fluorous oxazolidinone chiral auxiliary has been completed. The fluorous auxiliary facilitated product isolation using fluorous solid phase extractions (FSPE), effectively removing excess organic and organometallic reagents. Parallel reactions carried out with a similar but nonfluorous norephedrine-derived oxazolidinone demonstrated the superior stereoselectivity and purification obtainable with the fluorous chiral auxiliary.

  14. Oxazolidine-2-thiones and thiazolidine-2-thiones as nucleophiles in intermolecular Michael additions.

    Science.gov (United States)

    Munive, Laura; Rivas, Veronica M; Ortiz, Aurelio; Olivo, Horacio F

    2012-07-06

    Conjugate addition of thiazolidinethiones and oxazolidinethiones to N-crotonylthiazolidinethiones and -oxazolidinethiones was observed in the presence of excess triethylamine in dichloromethane. The addition takes place by the nitrogen of the heterocycle with high diastereoselectivity. It was observed that the stereoselective addition occurs on the anti-s-cis conformation of the N-enoyl sulfur-containing heterocycle.

  15. Stereoselective synthesis of organosulfur compounds incorporating N-aromatic heterocyclic motifs and quaternary carbon centers via a sulfa-Michael triggered tandem reaction.

    Science.gov (United States)

    Qin, Tianyou; Cheng, Lu; Zhang, Sean Xiao-An; Liao, Weiwei

    2015-06-14

    A novel sulfa-Michael addition (SMA)-triggered tandem reaction was developed by combining a SMA reaction with a simultaneous rearomatization process utilizing a less reactive carbonyl group as an intramolecular electrophile partner, which provided a unique synthetic route to access various organosulfur compounds incorporating an N-aromatic heterocyclic motif and quaternary carbon centers.

  16. Arenethiolatecopper(I) complexes as homogeneous catalysts for Michael addition reactions

    NARCIS (Netherlands)

    Koten, G. van; Klaveren, M. van; Lambert, F.; Eijkelkamp, D.J.F.M.; Grove, D.M.

    1994-01-01

    Arenethiolatocopper(I) complexes are shown to be efficient homogeneous catalysts in Michael addition reactions of several Grignard reagents to acyclic enones; the addition products are formed with excellent chemoselectivity (>99%) and good enantioselectivity (76% e.e.).

  17. An unprecedented chemospecific and stereoselective tandem nucleophilic addition/cycloaddition reaction of nucleophilic carbenes with ketenimines.

    Science.gov (United States)

    Cheng, Ying; Ma, Yang-Guang; Wang, Xiao-Rong; Mo, Jun-Ming

    2009-01-16

    The first study of the reaction between nucleophilic carbenes and ketenimines is reported. The interaction of thiazole and benzothiazole carbenes with ketenimines proceeded in a chemospecific and stereoselective manner to produce thiazole- and benzothiazole-spiro-pyrrole derivatives generally in good yields. The reaction was proposed to proceed via a tandem nucleophilic addition of carbene to the C=N bond of ketenimine followed by a stepwise [3+2] cycloaddition of the 1,3-dipolar intermediate with the C=C bond of ketenimine. This reaction provides a powerful protocol for the construction of novel polyfunctional thiazole-spiro-pyrrole or benzothiazole-spiro-pyrrole compounds that are not readily accessible by other methods.

  18. Organocatalytic aza-Michael/retro-aza-Michael reaction: pronounced chirality amplification in aza-Michael reaction and racemization via retro-aza-Michael reaction.

    Science.gov (United States)

    Cai, Yong-Feng; Li, Li; Luo, Meng-Xian; Yang, Ke-Fang; Lai, Guo-Qiao; Jiang, Jian-Xiong; Xu, Li-Wen

    2011-05-01

    A detailed experimental investigation of an aza-Michael reaction of aniline and chalcone is presented. A series of Cinchona alkaloid-derived organocatalysts with different functional groups were prepared and used in the aza-Michael and retro-aza-Michael reaction. There was an interesting finding that a complete reversal of stereoselectivity when a benzoyl group was introduced to the cinchonine and cinchonidine. The chirality amplification vs. time proceeds in the quinine-derived organocatalyst containing silicon-based bulky group, QN-TBS, -catalyzed aza-Michael reaction under solvent-free conditions. In addition, we have demonstrated for the first time that racemization was occurred in suitable solvents under mild conditions due to retro-aza-Michael reaction of the Michael adduct of aniline with chalcone. These indicate the equilibrium of retro-aza-Michael reaction and aza-Michael reaction produce the happening of chirality amplification in aza-Michael reaction and racemization via retro-aza-Michael reaction under different conditions, which would be beneficial to the development of novel chiral catalysts for the aza-Michael reactions. Copyright © 2011 Wiley-Liss, Inc.

  19. Solvent-free microwave-mediated Michael addition reactions

    Indian Academy of Sciences (India)

    Unknown

    obviously difficult to scale up. In this context ... eco-friendly features such as, (i) no solvent is required to conduct the ... water soluble, addition of reaction mixture after com- ..... Yield: 855 mg (89%; viscous liquid). 3.4 Ethyl .... Jung M E 1993 Comprehensive organic synthesis ... Leshcheva I F and Bundel Y G 1997 Mendeleev.

  20. On the Michael addition of water to C = C bonds

    NARCIS (Netherlands)

    Chen, B.

    2015-01-01

    ?-Hydroxy carbonyl compounds are an important class of compounds often found as a common structural motif in natural products. Although the molecules themselves look rather simple, their synthesis can be challenging. Water addition to conjugated C = C bonds opens up a straightforward route for the

  1. SYNTHESIS OF SOME PROLINE DERIVATIVES BY MEANS OF MICHAEL ADDITIONS OF GLYCINE ESTERS

    NARCIS (Netherlands)

    VANDERWERF, A; KELLOGG, RM

    1991-01-01

    Addition of the Schiff bases derived from reaction of glycine alkyl esters with benzophenoneimine to alpha,beta-unsaturated ketones, followed by hydrogenation of the addition products, leads to 5- or 3,5-substituted prolines. Hydrolysis of the Michael adducts rather than hydrogenation allows

  2. A Greener, Efficient Approach to Michael Addition of Barbituric Acid to Nitroalkene in Aqueous Diethylamine Medium

    Directory of Open Access Journals (Sweden)

    Hany J. Al-Najjar

    2014-01-01

    Full Text Available An efficient method for the synthesis of a variety of pyrimidine derivatives 3a–t by reaction of barbituric acids 1a,b as Michael donor with nitroalkenes 2a–k as Michael acceptor using an aqueous medium and diethylamine is described. This 1,4-addition strategy offers several advantages, such as using an economic and environmentally benign reaction media, high yields, versatility, and shorter reaction times. The synthesized compounds were identified by 1H-NMR, 13C-NMR, CHN, IR, and MS. The structure of compound 3a was further confirmed by single crystal X-ray structure determination.

  3. Asymmetric organocatalytic Michael addition of Meldrum's acid to nitroalkenes: probing the mechanism of bifunctional thiourea organocatalysts

    OpenAIRE

    Kataja, Antti O.; Koskinen, Ari M.P.

    2010-01-01

    The asymmetric Michael addition of Meldrum’s acid to nitroalkenes was studied using a novel type of Cinchona alkaloid-based bifunctional thiourea organocatalyst. The functionality of the thiourea catalysts was also probed by preparing and testing thiourea-N-methylated analogues of the well-known bis-(3,5-trifluoromethyl)phenyl-substituted catalyst. Peer reviewed

  4. Highly Functionalized Cyclopentane Derivatives by Tandem Michael Addition/Radical Cyclization/Oxygenation Reactions

    Czech Academy of Sciences Publication Activity Database

    Holan, Martin; Pohl, Radek; Císařová, I.; Klepetářová, Blanka; Jones, P. G.; Jahn, Ullrich

    2015-01-01

    Roč. 21, č. 27 (2015), s. 9877-9888 ISSN 0947-6539 R&D Projects: GA ČR GA13-40188S Institutional support: RVO:61388963 Keywords : cyclization * domino reactions * electron transfer * Michael addition * radical reactions Subject RIV: CC - Organic Chemistry Impact factor: 5.771, year: 2015

  5. An efficient oxa-Michael addition to diethyl vinylphosphonate under mild reaction conditions

    Czech Academy of Sciences Publication Activity Database

    Baszczyňski, Ondřej; Jansa, Petr; Dračínský, Martin; Kaiser, Martin Maxmilian; Špaček, Petr; Janeba, Zlatko

    2012-01-01

    Roč. 2, č. 4 (2012), s. 1282-1284 ISSN 2046-2069 R&D Projects: GA MV VG20102015046 Institutional research plan: CEZ:AV0Z40550506 Keywords : oxa-Michael addition * secondary alcohols * diethyl vinylphosphonate Subject RIV: CC - Organic Chemistry Impact factor: 2.562, year: 2012

  6. DNA-based catalytic enantioselective intermolecular oxa-Michael addition reactions

    NARCIS (Netherlands)

    Megens, Rik P.; Roelfes, Gerard

    2012-01-01

    Using the DNA-based catalysis concept, a novel Cu(II) catalyzed enantioselective oxa-Michael addition of alcohols to enones is reported. Enantioselectivities of up to 86% were obtained. The presence of water is important for the reactivity, possibly by reverting unwanted side reactions such as

  7. Organocatalytic Asymmetric Michael Addition of 4-Hydroxycoumarin to β,γ-Unsaturated α-Keto Esters

    Energy Technology Data Exchange (ETDEWEB)

    Suh, Chang Won; Han, Tae Hyun; Kim, Dae Young [Soonchunhyang Univ., Asan (Korea, Republic of)

    2013-06-15

    In conclusion, we have developed organocatalytic enantioselective conjugate addition reaction of 4-hydroxycoumarin (1) to β,γ-unsaturated α-keto esters 2 to afford biologically valuable warfarin derivatives 3. The process is efficiently catalyzed by a binaphthyl-modified thiourea organocatalyst. The coumarin core is present as a characteristic structural motif in a large number of natural products and biologically active molecules.1 Particularly, many of these naturally occurring 4-hydroxycoumarin and their synthetic analogues are important precursors for the synthesis of natural products and pharmaceuticals. Enantioselective organocatalytic conjugate addition of 4-hydroxycoumarin to α,β-unsaturated ketones is a straightforward method to access warfarin which is an effective anticoagulants. Although a number of reactions of α,β-unsaturated ketones as Michael acceptors have been reported, the corresponding β,γ-unsaturated α-keto esters have received relatively little attention as Michael acceptors. Recently, several groups have reported the asymmetric Michael addition of 4-hydroxycoumarin to β,γ-unsaturated α-keto esters catalyzed by Cu(II)-bisoxazoline, N,N'-dioxide-Ni(II) complexes, thiourea catalysts. Although several efficient methods have been achieved by these systems, an effective method for the synthesis of warfarin analogues is still a challenge.

  8. Organocatalytic Asymmetric Michael Addition of 4-Hydroxycoumarin to β,γ-Unsaturated α-Keto Esters

    International Nuclear Information System (INIS)

    Suh, Chang Won; Han, Tae Hyun; Kim, Dae Young

    2013-01-01

    In conclusion, we have developed organocatalytic enantioselective conjugate addition reaction of 4-hydroxycoumarin (1) to β,γ-unsaturated α-keto esters 2 to afford biologically valuable warfarin derivatives 3. The process is efficiently catalyzed by a binaphthyl-modified thiourea organocatalyst. The coumarin core is present as a characteristic structural motif in a large number of natural products and biologically active molecules.1 Particularly, many of these naturally occurring 4-hydroxycoumarin and their synthetic analogues are important precursors for the synthesis of natural products and pharmaceuticals. Enantioselective organocatalytic conjugate addition of 4-hydroxycoumarin to α,β-unsaturated ketones is a straightforward method to access warfarin which is an effective anticoagulants. Although a number of reactions of α,β-unsaturated ketones as Michael acceptors have been reported, the corresponding β,γ-unsaturated α-keto esters have received relatively little attention as Michael acceptors. Recently, several groups have reported the asymmetric Michael addition of 4-hydroxycoumarin to β,γ-unsaturated α-keto esters catalyzed by Cu(II)-bisoxazoline, N,N'-dioxide-Ni(II) complexes, thiourea catalysts. Although several efficient methods have been achieved by these systems, an effective method for the synthesis of warfarin analogues is still a challenge

  9. Stereoselective synthesis of highly substituted bicyclic γ-lactones using homoaldol addition of 1-(1-cycloalkenyl)methyl carbamates

    DEFF Research Database (Denmark)

    Özlügedik, M.; Kristensen, Jesper Langgaard; Reuber, J.

    2004-01-01

    Stereoselective addition of aldehydes 4 to metallated 1-(1-cycloalkenyl) methyl N,N-diisopropylcarbamates 1 gave cyclic homoaldol adducts 6. By applying the (-)-sparteine method, enantiomerically enriched products were obtained. These were oxidatively cyclized to diastereomerically pure ¿-lactones...... 8 via the ¿-lactol ethers 7. After deprotonation of ¿-lactones 8 with lithium hexamethyldisilazide, a further substitution was achieved. By trapping the lactone enolates 11 with ß-naphthylmethyl bromide, single diastereomers of ¿-lactones 12 were produced....

  10. Production of Low-Freezing-Point Highly Branched Alkanes through Michael Addition.

    Science.gov (United States)

    Jing, Yaxuan; Xia, Qineng; Liu, Xiaohui; Wang, Yanqin

    2017-12-22

    A new approach for the production of low-freezing-point, high-quality fuels from lignocellulose-derived molecules was developed with Michael addition as the key step. Among the investigated catalysts, CoCl 2 ⋅6 H 2 O was found most active for the Michael addition of 2,4-pentanedione with FA (single aldol adduct of furfural and acetone, 4-(2-furanyl)-3-butene-2-one). Over CoCl 2 ⋅6 H 2 O, a high carbon yield of C 13 oxygenates (about 75 %) can be achieved under mild conditions (353 K, 20 h). After hydrodeoxygenation, low-freezing-point (hydrodeoxygenation, high density (0.8415 g mL -1 ) and low-freezing-point (<223 K) branched alkanes with 18, 23 carbons within lubricant range were also obtained over a Pd/NbOPO 4 catalyst. These highly branched alkanes can be directly used as transportation fuels or additives. This work opens a new strategy for the synthesis of highly branched alkanes with low freezing point from renewable biomass. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. Correction: Synthesis of pyrrolidine-3-carboxylic acid derivatives via asymmetric Michael addition reactions of carboxylate-substituted enones.

    Science.gov (United States)

    Yin, Feng; Garifullina, Ainash; Tanaka, Fujie

    2018-04-25

    Correction for 'Synthesis of pyrrolidine-3-carboxylic acid derivatives via asymmetric Michael addition reactions of carboxylate-substituted enones' by Feng Yin et al., Org. Biomol. Chem., 2017, 15, 6089-6092.

  12. Regio- and stereoselective 1,2-dihydropyridine alkylation/addition sequence for the synthesis of piperidines with quaternary centers.

    Science.gov (United States)

    Duttwyler, Simon; Chen, Shuming; Lu, Colin; Mercado, Brandon Q; Bergman, Robert G; Ellman, Jonathan A

    2014-04-07

    The first example of C alkylation of 1,2-dihydropyridines with alkyl triflates and Michael acceptors was developed to introduce quaternary carbon centers with high regio- and diastereoselectivity. Hydride or carbon nucleophile addition to the resultant iminium ion also proceeded with high diastereoselectivity. Carbon nucleophile addition results in an unprecedented level of substitution to provide piperidine rings with adjacent tetrasubstituted carbon atoms. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Ionic liquids as precatalysts in the highly stereoselective conjugate addition of α,β-unsaturated aldehydes to chalcones.

    Science.gov (United States)

    Ta, Linda; Axelsson, Anton; Bijl, Joachim; Haukka, Matti; Sundén, Henrik

    2014-10-20

    Imidazolium-based ionic liquids (ILs) serve both as recyclable reaction media and as precatalysts for the N-heterocyclic carbene-catalyzed conjugate addition of α,β-unsaturated aldehydes to chalcones. The reaction produces a broad scope of 1,6-ketoesters incorporating an anti-diphenyl moiety in high yields and with high stereoselectivity. In recycling experiments, the IL can be reused up to five times with retained reactivity and selectivity. Moreover, the 1,6-ketoesters form self-assembled organogels in aliphatic hydrocarbons. The reaction protocol is robust, easily operated, scalable and highly functionalized compounds can be obtained from inexpensive and readily accessible starting materials. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. N-Heterocyclic Carbene-Catalysed Diastereoselective Vinylogous Michael Addition Reaction of gamma-Substituted deconjugated Butenolides

    KAUST Repository

    Guo, Hao; Xing, Fen; Du, Guang-Fen; Huang, Kuo-Wei; Dai, Bin; He, Lin

    2015-01-01

    An efficient N-heterocyclic carbene (NHC)-catalysed vinylogous Michael addition of deconjugated butenolides was developed. In the presence of 5 mol% of the NHC catalyst, both γ-alkyl and aryl-substituted deconjugated butenolides undergo vinylogous Michael addition with various α, β-unsaturated ketones, esters, or nitriles to afford γ,γ-disubstituted butenolides containing adjacent quaternary and tertiary carbon centers in good to excellent yields with excellent diastereoselectivities. In this process, the free carbene is assumed to act as a strong Brønsted base to promote the conjugate addition.

  15. N-Heterocyclic Carbene-Catalysed Diastereoselective Vinylogous Michael Addition Reaction of gamma-Substituted deconjugated Butenolides

    KAUST Repository

    Guo, Hao

    2015-11-16

    An efficient N-heterocyclic carbene (NHC)-catalysed vinylogous Michael addition of deconjugated butenolides was developed. In the presence of 5 mol% of the NHC catalyst, both γ-alkyl and aryl-substituted deconjugated butenolides undergo vinylogous Michael addition with various α, β-unsaturated ketones, esters, or nitriles to afford γ,γ-disubstituted butenolides containing adjacent quaternary and tertiary carbon centers in good to excellent yields with excellent diastereoselectivities. In this process, the free carbene is assumed to act as a strong Brønsted base to promote the conjugate addition.

  16. Synthesis of some pyridine and pyrimidine derivatives via Michael-Addition

    International Nuclear Information System (INIS)

    El-Baih, Fatma E.M.; Al-Rasheed, Hessa H.; Al-Hazimi, Hassan M.

    2006-01-01

    Synthesis of pyridine and pyrimidine analogues 4 and 6-9 were achieved by Michael-addition of compounds containing either active methylene groups like, malononitrile , ethyl cyanoacetate and 1-tetralone or compounds containing active hydrogen atoms like, guanidine in the presence of an oxidizing agent and thiourea to 2-arylmethylidine-1-tetralone and 2-arylmethylidine-6-methoxy-1-tetralone (2) (enones). Addition of malononitrile in piperidine at room temperature to 2-amino-3-cyno-naphtho [1, 2-malonoitrile in sodium alkoxide or sodium hydroxide to 2 gave 4. Cyclization of 3a with acetic anhydride in the presence of conc. H2sO4 gave the naphtha-pyrano[2, 3-d]pyrimidin-8-one (5). Condensation of the pyrimidine thione derivatives 9 with chloroacetic acid gave the 3-oxobenzo[h]thiazoladino[2, 3-b]quinazoline derivatives (10), which were reacted through their active methylene groups with aromatic aldehydes to give the arylidine derivatives 11. These compounds were also prepared in one step by reacting 9 with chloroacetic acid and aromatic aldehydes. Condensation of 9 with 3-bromopropanoic acid gave 4-oxo-benzo[h]1, 3-thiazino[2, 3-b]quinazoline derivatives (12). The structures of the prepared compounds were mainly confirmed on the basis of spectroscopic methods. (author)

  17. Novel Interecting Blends Based on Amino Terminited Oligoimides by Using Michael Addition Reaction-II

    Directory of Open Access Journals (Sweden)

    Rita R. Patel

    2012-01-01

    Full Text Available New amino terminated oligoimides (AOIs were prepared by the Michael addition reaction of various bismaleimide (1, namely, 1-(4-((4-((2, 5-dioxocyclopent-3 enylamino methyl cyclohexyl methyl cyclohexyl-1, 6-dihydropyridine-2, 5-dione with excess of various diamines (2a-c. These AOIs were characterized by elemental analysis, FT-IR spectral studies and number average molecular weight estimated by non-aqueous conductometric titrations. AOIs were then treated with acrylol chloride and resultant acryl terminated oligoimides (AcOIs samples were also characterized thermogravimetrically. Each of these AcOI was then combined with the N-phenyl maleimide (PM in THF solvent. The resultant suspensions were then heated in the presence of azobisisobutyronitrile (AIBN as an initiator. The AcOI and PM polymerized through double bond simultaneously and form interacting blends, which were analyzed thermogravimetrically. The glass fiber reinforced composites were fabricated by using the suspensions of the AcOI and PM. The composites of Interacting blends were analyzed for their mechanical, chemical and electrical properties.

  18. Solvent-free, catalyst-free aza-Michael addition of cyclohexylamine to diethyl maleate: reaction mechanism and kinetics

    Czech Academy of Sciences Publication Activity Database

    Bláha, Michal; Trhlíková, Olga; Podešva, Jiří; Abbrent, Sabina; Steinhart, Miloš; Dybal, Jiří; Dušková-Smrčková, Miroslava

    2018-01-01

    Roč. 74, č. 1 (2018), s. 58-67 ISSN 0040-4020 Institutional support: RVO:61389013 Keywords : Aza-Michael addition * solvent-free * catalyst-free Subject RIV: CD - Macromolecular Chemistry OBOR OECD: Polymer science Impact factor: 2.651, year: 2016

  19. Aza-Michael Mono-addition Using Acidic Alumina under Solventless Conditions

    Directory of Open Access Journals (Sweden)

    Giovanna Bosica

    2016-06-01

    Full Text Available Aza-Michael reactions between primary aliphatic and aromatic amines and various Michael acceptors have been performed under environmentally-friendly solventless conditions using acidic alumina as a heterogeneous catalyst to selectively obtain the corresponding mono-adducts in high yields. Ethyl acrylate was the main acceptor used, although others such as acrylonitrile, methyl acrylate and acrylamide were also utilized successfully. Bi-functional amines also gave the mono-adducts in good to excellent yields. Such compounds can serve as intermediates for the synthesis of anti-cancer and antibiotic drugs.

  20. Tandem Michael addition/radical cyclizations for the construction of highly functionalized cyclopentanes

    Czech Academy of Sciences Publication Activity Database

    Holan, Martin; Pohl, Radek; Císarová, I.; Jahn, Ullrich

    2012-01-01

    Roč. 106, - (2012), s1298-s1298 ISSN 0009-2770. [EuCheMS Chemistry Congress /4./. 26.08.2012-30.08.2012, Prague] Institutional research plan: CEZ:AV0Z40550506 Keywords : cyclization * diastereoselectivity * Michael addiction * radical reactions * domino reactions Subject RIV: CC - Organic Chemistry

  1. Theoretical study on the reaction mechanisms of Michael chirality addition between propionaldehyde and nitroalkene catalyzed by an enantioselective catalyst.

    Science.gov (United States)

    Zhou, Xinming; Li, Ling; Sun, Xuejun; Wang, Yajun; Du, Dongmei; Fu, Hui

    2018-06-01

    The asymmetric Michael addition between propionaldehyde and nitroalkene catalyzed by 8-(ethoxycarbonyl)-1,2,3,3a,8,8a-hexahydropyrrolo[2,3-b]indole-2-carboxylic acid has obtained relatively high yields and excellent enantioselectivities at room temperature. In this study, the molecular structures and optical activity of the most stable conformation I are optimized at B3LYP/6-311++ G(d,p) level. We find that levorotatory conformation I catalyzing the same Michael addition can produce laevo-product A and dextrorotatory conformation I' can obtain the dextral-product A'. These results have guiding significance for further studying on the new chemzymes and the mechanism of the obtained different chiral products. © 2018 Wiley Periodicals, Inc.

  2. Stereoselective syntheses of (+- isoretronecanol and (+-5-epi-tashiromine via addition of chiral titanium (iv enolates to cyclic n-acyliminium ions

    Directory of Open Access Journals (Sweden)

    Elaine Pereira

    2008-01-01

    Full Text Available The stereoselective addition of the titanium (IV enolates derived from (S-4-isopropyl-N-4-chlorobutyryl-1,3-thiazolidine-2-thione (8 and from (S-4-isopropyl-N-4-chloropentanoyl-1,3-thiazolidine-2-thione (9 to N-Boc-2-methoxypyrrolidine (5b afforded the addition products (+-10 and (+-11 in 84% yield in both cases, as 8.6:1 and 10:1 diastereoisomeric mixtures, respectively. A three-step sequence allowed to convert these adducts to (+-isoretronecanol (1 and (+-5-epi-tashiromine (2 in 43% and 49% overall yield, respectively.

  3. Stereoselective syntheses of (+)- isoretronecanol and (+)-5-epi-tashiromine via addition of chiral titanium (IV) enolates to cyclic n-acyliminium ions

    Energy Technology Data Exchange (ETDEWEB)

    Pereira, Elaine; Alves, Conceicao de Fatima; Boeckelmann, Maria Alice; Pilli, Ronaldo A [Universidade Estadual de Campinas (UNICAMP), Campinas, SP (Brazil). Inst. de Quimica

    2008-07-01

    The stereoselective addition of the titanium (IV) enolates derived from (S)-4-isopropyl-N-4-chlorobutyryl-1,3-thiazolidine-2-thione (8) and from (S)-4-isopropyl-N-4-chloropentanoyl-1,3-thiazolidine-2-thione (9) to N-Boc-2-methoxypyrrolidine (5b) afforded the addition products (+)-10 and (+)-11 in 84% yield in both cases, as 8.6:1 and 10:1 diastereoisomeric mixtures, respectively. A three-step sequence allowed to convert these adducts to (+)-isoretronecanol (1) and (+)-5-epi-tashiromine (2) in 43% and 49% overall yield, respectively. (author)

  4. Stereoselective, nitro-Mannich/lactamisation cascades for the direct synthesis of heavily decorated 5-nitropiperidin-2-ones and related heterocycles

    Directory of Open Access Journals (Sweden)

    Pavol Jakubec

    2012-04-01

    Full Text Available A versatile nitro-Mannich/lactamisation cascade for the direct stereoselective synthesis of heavily decorated 5-nitropiperidin-2-ones and related heterocycles has been developed. A highly enantioenriched substituted 5-nitropiperidin-2-one was synthesised in a four component one-pot reaction combining an enantioselective organocatalytic Michael addition with the diastereoselective nitro-Mannich/lactamisation cascade. Protodenitration and chemoselective reductive manipulation of the heterocycles was used to install contiguous and fully substituted stereocentres in the synthesis of substituted piperidines.

  5. Synthesis of l-threitol-based crown ethers and their application as enantioselective phase transfer catalyst in Michael additions.

    Science.gov (United States)

    Rapi, Zsolt; Nemcsok, Tamás; Pálvölgyi, Ádám; Keglevich, György; Grün, Alajos; Bakó, Péter

    2017-06-01

    A few new l-threitol-based lariat ethers incorporating a monoaza-15-crown-5 unit were synthesized starting from diethyl l-tartrate. These macrocycles were used as phase transfer catalysts in asymmetric Michael addition reactions under mild conditions to afford the adducts in a few cases in good to excellent enantioselectivities. The addition of 2-nitropropane to trans-chalcone, and the reaction of diethyl acetamidomalonate with β-nitrostyrene resulted in the chiral Michael adducts in good enantioselectivities (90% and 95%, respectively). The substituents of chalcone had a significant impact on the yield and enantioselectivity in the reaction of diethyl acetoxymalonate. The highest enantiomeric excess (ee) values (99% ee) were measured in the case of 4-chloro- and 4-methoxychalcone. The phase transfer catalyzed cyclopropanation reaction of chalcone and benzylidene-malononitriles using diethyl bromomalonate as the nucleophile (MIRC reaction) was also developed. The corresponding chiral cyclopropane diesters were obtained in moderate to good (up to 99%) enantioselectivities in the presence of the threitol-based crown ethers. © 2017 Wiley Periodicals, Inc.

  6. Stereoselective synthesis of tricyclic compounds by intramolecular palladium-catalyzed addition of aryl iodides to carbonyl groups

    Directory of Open Access Journals (Sweden)

    Jakub Saadi

    2016-06-01

    Full Text Available Starting from γ-ketoesters with an o-iodobenzyl group we studied a palladium-catalyzed cyclization process that stereoselectively led to bi- and tricyclic compounds in moderate to excellent yields. Four X-ray crystal structure analyses unequivocally defined the structure of crucial cyclization products. The relative configuration of the precursor compounds is essentially transferred to that of the products and the formed hydroxy group in the newly generated cyclohexane ring is consistently in trans-arrangement with respect to the methoxycarbonyl group. A transition-state model is proposed to explain the observed stereochemical outcome. This palladium-catalyzed Barbier-type reaction requires a reduction of palladium(II back to palladium(0 which is apparently achieved by the present triethylamine.

  7. Aza‐Michael addition reaction: Post‐polymerization modification and preparation of PEI/PEG‐based polyester hydrogels from enzymatically synthesized reactive polymers

    DEFF Research Database (Denmark)

    Hoffmann, Christian; Stuparu, Mihaiela C.; Daugaard, Anders Egede

    2015-01-01

    The utility of aza‐Michael addition chemistry for post‐polymerization functionalization of enzymatically prepared polyesters is established. For this, itaconate ester and oligoethylene glycol are selected as monomers. A Candida Antarctica lipase B catalyzed polycondensation reaction between the two...... monomers provides the polyesters, which carry an activated carbon‐carbon double bond in the polymer backbone. These electron deficient alkenes represent suitable aza‐Michael acceptors and can be engaged in a nucleophilic addition reaction with small molecular mono‐amines (aza‐Michael donors) to yield...... functionalized linear polyesters. Employing a poly‐amine as the aza‐Michael donor, on the other hand, results in the formation of hydrophilic polymer networks....

  8. A simple protocol for the michael addition of indoles with electron ...

    Indian Academy of Sciences (India)

    Administrator

    attracted much attention in organic synthesis be- cause of their biological activities. 2,3. The conjugate addition ... mations, like selective oxidation of benzyl alcohols,. 17 have been ..... The colour change was assessed visually and the highest ...

  9. Synthesis of γ-Nitro Aliphatic Methyl Esters Via Michael Additions Promoted by Microwave Irradiation

    Directory of Open Access Journals (Sweden)

    Francisco D. Díaz-Coutiño

    2009-04-01

    Full Text Available A simple and efficient protocol has been developed for the direct synthesis of γ-nitrobutyric acid methyl esters under microwave irradiation. This methodology reduces reaction times from days to minutes, compared to conventional conditions. Additionally, these conditions increased yields and provided cleaner reactions.

  10. Synthesis of γ-Nitro Aliphatic Methyl Esters Via Michael Additions Promoted by Microwave Irradiation

    OpenAIRE

    Escalante, Jaime; Díaz-Coutiño, Francisco D.

    2009-01-01

    A simple and efficient protocol has been developed for the direct synthesis of γ-nitrobutyric acid methyl esters under microwave irradiation. This methodology reduces reaction times from days to minutes, compared to conventional conditions. Additionally, these conditions increased yields and provided cleaner reactions.

  11. Michael Thonet

    Index Scriptorium Estoniae

    2005-01-01

    Saksa päritolu austria mööblidisaineri ja mööblitöösturi Michael Thonet' (1796-1871) disainiloomingust. 1859. a. Michael Thonet' loodud tool nr. 14 on endiselt tootmises ja on tuntud ka Viini toolina. 2 ill

  12. Tetrabutylammonium Bromide Media Aza-Michael Addition of 1,2,3,6-Tetrahydrophthalimide to Symmetrical Fumaric Esters and Acrylic Esters under Solvent-Free Conditions

    Directory of Open Access Journals (Sweden)

    Mohammadreza Zamanloo

    2010-10-01

    Full Text Available The aza-Michael addition of 1,2,3,6-tetrahydrophthalimide with symmetrical fumaric esters has been performed efficiently in a solvent-free system at 100 °C and using 1,4-diazabicyclo[2.2.2]octane (DABCO as a base in the presence of tetrabutylammonium bromide (TBAB. The products were obtained in good to high yields within 2.5-7.0 h. This reaction worked well on linear alkyl fumarates and was not effective with nonlinear alkyl fumarates. Although the reaction was also applicable to acrylates such as n-butyl acrylate, methacrylates and crotonates were not suitable Michael acceptors for this reaction.

  13. Asymmetric synthesis of α-amino acids via homologation of Ni(II) complexes of glycine Schiff bases. Part 3: Michael addition reactions and miscellaneous transformations.

    Science.gov (United States)

    Aceña, José Luis; Sorochinsky, Alexander E; Soloshonok, Vadim

    2014-09-01

    The major goal of this review is a critical discussion of the literature data on asymmetric synthesis of α-amino acids via Michael addition reactions involving Ni(II)-complexes of amino acids. The material covered is divided into two conceptually different groups dealing with applications of: (a) Ni(II)-complexes of glycine as C-nucleophiles and (b) Ni(II)-complexes of dehydroalanine as Michael acceptors. The first group is significantly larger and consequently subdivided into four chapters based on the source of stereocontrolling element. Thus, a chiral auxiliary can be used as a part of nucleophilic glycine Ni(II) complex, Michael acceptor or both, leading to the conditions of matching vs. mismatching stereochemical preferences. The particular focus of the review is made on the practical aspects of the methodology under discussion and mechanistic considerations.

  14. Catalyst-free and solvent-free Michael addition of 1,3-dicarbonyl compounds to nitroalkenes by a grinding method

    Science.gov (United States)

    Xie, Zong-Bo; Wu, Ming-Yu; He, Ting; Le, Zhang-Gao

    2012-01-01

    Summary An environmentally benign, fast and convenient protocol has been developed for the Michael addition of 1,3-dicarbonyl compounds to β-nitroalkenes in good to excellent yields by a grinding method under catalyst- and solvent-free conditions. PMID:22563352

  15. Asymmetric Domino Aza-Michael Addition/[3+2] Cycloaddition Reactions as a Versatile Approach to alpha,beta,gamma,-Triamino Acid Derivatives

    Czech Academy of Sciences Publication Activity Database

    Kapras, Vojtěch; Pohl, Radek; Císařová, I.; Jahn, Ullrich

    2014-01-01

    Roč. 16, č. 4 (2014), s. 1088-1091 ISSN 1523-7060 Institutional support: RVO:61388963 Keywords : 1,3-dipolar cycloaddition * lithium amides * aza-Michael addition * amino acids * pyrazoles Subject RIV: CC - Organic Chemistry Impact factor: 6.364, year: 2014

  16. Polyfunctional beta-Dicarbonyl Compounds by Michael Addition Reactions of Ester Enolates to alpha-Benzylidene and alpha-Alkylidene-beta-dicarbonyl Compounds

    Czech Academy of Sciences Publication Activity Database

    Holan, Martin; Pohl, Radek; Císařová, I.; Jahn, Ullrich

    -, č. 18 (2012), s. 3459-3475 ISSN 1434-193X R&D Projects: GA ČR GA203/09/1936 Institutional research plan: CEZ:AV0Z40550506 Keywords : Michael addition * diastereoselectivity * regioselectivity * enols * dicarbonyl compounds Subject RIV: CC - Organic Chemistry Impact factor: 3.344, year: 2012

  17. Michael Scott

    Directory of Open Access Journals (Sweden)

    Ersin Hussein

    2015-04-01

    While Michael has contributed significantly to the field of classics and ancient history by publishing extensively, he has also enjoyed great success in engaging wider audiences with the ancient world. He regularly talks in schools around the country, writes books intended for the popular market as well as articles for national and international newspapers and magazines. Michael's experience in writing and presenting a range of programmes intended for TV and radio audiences has made him a household name. He has written and presented programmes for the National Geographic, History Channel, Nova, and the BBC including Delphi: bellybutton of the ancient world (BBC4; Guilty Pleasures: luxury in the ancient and medieval words (BBC4; Jesus: rise to power (Natural Geographic; Ancient Discoveries (History Channel; Who were the Greeks? (BBC2; The Mystery of the X Tombs (BBC2/Nova; The Greatest Show on Earth (BBC4, in conjunction with the Open University. He has also presented a radio series for BBC Radio 4, Spin the Globe. Michael's most recent programme, Roman Britain from the Air, was aired on ITV in December 2014. In this interview, I talk to him about his engagement with other disciplines within the humanities, his forthcoming book project, and his experiences writing and presenting TV and radio documentaries.

  18. Multicomponent Synthesis of Isoindolinone Frameworks via RhIII -Catalysed in situ Directing Group-Assisted Tandem Oxidative Olefination/Michael Addition.

    Science.gov (United States)

    Wang, Liang; Liu, Xi; Liu, Jian-Biao; Shen, Jun; Chen, Qun; He, Ming-Yang

    2018-04-04

    A Rh III -catalysed three-component synthesis of isoindolinone frameworks via direct assembly of benzoyl chlorides, o-aminophenols and activated alkenes has been developed. The process involves in situ generation of o-aminophenol (OAP)-based bidentate directing group (DG), Rh III -catalysed tandem ortho C-H olefination and subsequent cyclization via aza-Michael addition. This protocol exhibits good chemoselectivity and functional group tolerance. Computational studies showed that the presence of hydroxyl group on the N-aryl ring could enhance the chemoselectivity of the reaction. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. Nano-organocatalyst: magnetically retrievable ferrite-anchored glutathione for microwave-assisted Paal–Knorr reaction, aza-Michael addition, and pyrazole synthesis

    KAUST Repository

    Polshettiwar, Vivek; Varma, Rajender S.

    2010-01-01

    Postsynthetic Surface modification of magnetic nanoparticles by glutathione imparts desirable chemical functionality and enables the generation of catalytic sites on the surfaces of ensuing organocatalysts. In this article, we discuss the developments, unique activity, and high selectivity of nano-organocatalysts for microwave-assisted Paal-Knorr reaction, aza-Michael addition, and pyrazole synthesis. Their insoluble character Coupled with paramagnetic nature enables easy separation of these nano-catalysts from the reaction mixture using external magnet, which eliminates the requirement of catalyst filtration. Published by Elsevier Ltd.

  20. Spectroscopic Evidence for Covalent Binding of Sulfadiazine to Natural Soils via 1,4-nucleophilic addition (Michael Type Addition) studied by Spin Labeling ESR

    Science.gov (United States)

    Aleksandrova, Olga

    2015-04-01

    with different polarity. As shown by the spin labeling ESR experiment, molecules modeling SDZ were promptly bound to non-hydrolysable network of soil organic matter only via the aromatic amines that was accompanied by a prompt enlargement of humic particles binding aromatic amines, whereas binding of decomposition products of SDZ to humic acids of soil via the aliphatic amines was not observable. The ESR spectra obviously showed a single-phase process of covalent binding of the aromatic amines. Repeated washouts of labeled soil samples using distil water and ultrafiltration through the membrane of 5000 MWCO PES confirmed irreversible binding of the aromatic amines, and showed that via the aliphatic amines, binding of SDZ or decomposition products of SDZ to soil might also occur but reversibly and only to small soil molecules, which don't enter into the composition of non-hydrolysable part of soil organic matter. SL ESR experiments of different soils at the presence of Laccase highlighted that covalent binding of the aromatic amines to humic particles occurred in the specific hydrophobic areas of soil found as depleted in oxygen. All measured data evidenced that first, SDZ might be decomposed that allowed for measuring the same change of a paramagnetic signal of soil organic matter influenced by both aromatic and aliphatic amines as in the experiment of the interaction of soil with SDZ. Second, a decomposition product of SDZ with the aromatic amine might be bound to non-hydrolysable parts of soil organic matter under specific anaerobic conditions only via 1,4 - nucleophilic addition, Michael-type addition. Gulkowska, A., Thalmann, B., D., Hollender, J., & Krauss, M. (2014). Chemosphere, 107, 366 - 372. Müller, T., Rosendahl, I., Focks, A., Siemens, J., Klasmeier, J., & Matthies. (2013). Environmental Pollution, 172,180 - 185. Nowak, K.M., Miltner, A., Gehre, M., Schaeffer, A., & Kaestner, M. (2011). Environmental Science & Technology 45, 999 - 1006. Weber, E.J., Spidle

  1. A click chemistry approach to glycomimetics: Michael addition of 2,3,4,6-tetra-O-acetyl-1-thio-beta-D-glucopyranose to 4-deoxy-1,2-O-isopropylidene-L-glycero-pent-4-enopyranos-3-ulose--a convenient route to novel 4-deoxy-(1-->5)-5-C-thiodisaccharides.

    Science.gov (United States)

    Witczak, Zbigniew J; Lorchak, David; Nguyen, Nguyen

    2007-09-03

    The base catalyzed conjugate Michael addition of the 1-thiosugar, 2,3,4,6-tetra-O-acetyl-beta-D-glucopyranose, 1, to a new highly reactive enone 4-deoxy-1,2-O-isopropylidene-L-glycero-pent-4-enopyranos-3-ulose, 2, proceeds steroselectively with formation of adduct 3 in 94% yield. Convenient stereoselective reduction of the C-3 keto function of 3 with L-Selectride followed by in situ acetylation produces thiodisaccharide 4 in good 82% yield. Cleavage of the 1,2-O-isopropylidene protecting group with p-toluenesulfonic acid in methanol, followed by de-O-acetylation, produced an inseparable anomeric mixture of methyl 4-deoxy-5-C-(beta-D-glucopyranosyl)-thio-alpha/beta-L-ribo-pyranoside 5 in 72% overall yield. This approach constitutes a new general two-step click chemistry route to the previously unknown class of 4-deoxy-(1-->5)-5-C-thiodisaccharides as stable and biologically important glycomimetics.

  2. Metal-mediated aminocatalysis provides mild conditions: Enantioselective Michael addition mediated by primary amino catalysts and alkali-metal ions

    Directory of Open Access Journals (Sweden)

    Matthias Leven

    2013-01-01

    Full Text Available Four catalysts based on new amides of chiral 1,2-diamines and 2-sulfobenzoic acid have been developed. The alkali-metal salts of these betaine-like amides are able to form imines with enones, which are activated by Lewis acid interaction for nucleophilic attack by 4-hydroxycoumarin. The addition of 4-hydroxycoumarin to enones gives ee’s up to 83% and almost quantitative yields in many cases. This novel type of catalysis provides an effective alternative to conventional primary amino catalysis were strong acid additives are essential components.

  3. Minireview of Stereoselective Brain Imaging

    DEFF Research Database (Denmark)

    Smith, Donald F.; Jakobsen, Steen

    2014-01-01

    Stereoselectivity is a fundamental principle in living systems. Stereoselectivity reflects the dependence of molecular processes on the spatial orientation of constituent atoms. Stereoselective processes govern many aspects of brain function and direct the course of many psychotropic drugs. Today......, modern imaging techniques such as SPECT and PET provide a means for studying stereoselective processes in the living brain. Chemists have prepared numerous radiolabelled stereoisomers for use in SPECT and PET in order to explore various molecular processes in the living brain of anesthetized laboratory...... animals and awake humans. The studies have demonstrated how many aspects of neurotransmission consist of crucial stereoselective events that can affect brain function in health and disease. Here, we present a brief account of those findings in hope of stimulating further interest in the vital topic....

  4. Molecular Characterization of Thiols in Fossil Fuels by Michael Addition Reaction Derivatization and Electrospray Ionization Fourier Transform Ion Cyclotron Resonance Mass Spectrometry.

    Science.gov (United States)

    Wang, Meng; Zhao, Suoqi; Liu, Xuxia; Shi, Quan

    2016-10-04

    Thiols widely occur in sediments and fossil fuels. However, the molecular composition of these compounds is unclear due to the lack of appropriate analytical methods. In this work, a characterization method for thiols in fossil fuels was developed on the basis of Michael addition reaction derivatization followed by electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry (ESI FT-ICR MS). Model thiol compound studies showed that thiols were selectively reacted with phenylvinylsulfone and transformed to sulfones with greater than 98% conversions. This method was applied to a coker naphtha, light and heavy gas oils, and crude oils from various geological sources. The results showed that long alkyl chain thiols are readily present in petroleum, which have up to 30 carbon atoms. Large DBE dispersity of thiols indicates that naphthenic and aromatic thiols are also present in the petroleum. This method is capable of detecting thiol compounds in the part per million range by weight. This method allows characterization of thiols in a complex hydrocarbon matrix, which is complementary to the comprehensive analysis of sulfur compounds in fossil fuels.

  5. Michael Frayn visits CERN

    CERN Multimedia

    2007-01-01

    Award-winning playwright and novelist Michael Frayn gave a guest lecture in the main auditorium at CERN on Friday 15 March about his new book The Human Touch: Our Part in the Creation of the Universe. The lecture focused on cosmology and philosophy and the limitations that language places on our ability to understand the creation of a universe in which we seem to play such a small part. In addition to his novels and plays, which include Copenhagen, a play about the 1941 meeting between German physicist Werner Heisenberg and Danish physicist Niels Bohr, Frayn has translated several works from Russian, including plays by Chekhov and Tolstoy.

  6. Michael Griffin | NREL

    Science.gov (United States)

    Griffin Photo of Michael Griffin Michael Griffin Researcher III-Chemical Engineering production of high-value products Physical and chemical material characterization under reaction conditions Physical and chemical characterization of catalytic materials Surface science Design and operation of ultra

  7. Michael E. Himmel | NREL

    Science.gov (United States)

    E. Himmel Photo of Michael E. Himmel Michael Himmel Senior Research Fellow I-Molecular Biology biochemistry, recombinant technology, enzyme engineering, new micro-organism discovery, and physicochemistry of

  8. Facile Iodine-Catalyzed Michael Addition of Indoles to α,α′-Bis(arylmethylene)cyclopentanones: An Efficient Synthesis of E-2-(3-Indolylphenylmethyl)-5-phenylmethylenecyclopentanones

    Science.gov (United States)

    Pal, Rammohan; Das Gupta, Arpita; Mallik, Asok K.

    2012-01-01

    Iodine-catalyzed reaction of indoles with α,α′-bis(arylmethylene)cyclopentanones afforded one diastereomer of the corresponding Michael adducts, namely, E-2-(3-indolylphenylmethyl)-5-phenylmethylenecyclopentanones, in a good yield. The products form a new group of indole derivatives. PMID:24052849

  9. Jack Michael's Motivation

    OpenAIRE

    Miguel, Caio F.

    2013-01-01

    Among many of Jack Michael's contributions to the field of behavior analysis is his behavioral account of motivation. This paper focuses on the concept of motivating operation (MO) by outlining its development from Skinner's (1938) notion of drive. Conceptually, Michael's term helped us change our focus on how to study motivation by shifting its origins from the organism to the environment. Michael's account also served to stimulate applied research and to better understand behavioral functio...

  10. Significance and challenges of stereoselectivity assessing methods in drug metabolism

    Directory of Open Access Journals (Sweden)

    Zhuowei Shen

    2016-02-01

    Full Text Available Stereoselectivity in drug metabolism can not only influence the pharmacological activities, tolerability, safety, and bioavailability of drugs directly, but also cause different kinds of drug–drug interactions. Thus, assessing stereoselectivity in drug metabolism is of great significance for pharmaceutical research and development (R&D and rational use in clinic. Although there are various methods available for assessing stereoselectivity in drug metabolism, many of them have shortcomings. The indirect method of chromatographic methods can only be applicable to specific samples with functional groups to be derivatized or form complex with a chiral selector, while the direct method achieved by chiral stationary phases (CSPs is expensive. As a detector of chromatographic methods, mass spectrometry (MS is highly sensitive and specific, whereas the matrix interference is still a challenge to overcome. In addition, the use of nuclear magnetic resonance (NMR and immunoassay in chiral analysis are worth noting. This review presents several typical examples of drug stereoselective metabolism and provides a literature-based evaluation on current chiral analytical techniques to show the significance and challenges of stereoselectivity assessing methods in drug metabolism.

  11. Regio- and Stereoselective Conjugate Addition of Aldehydes to β-Tosyl Enones under the Catalysis of a Binaphthyl-Modified Chiral Amine.

    Science.gov (United States)

    Kano, Taichi; Sugimoto, Hisashi; Maruyama, Hiroki; Maruoka, Keiji

    2015-07-13

    A simple axially chiral amine catalyst promoted the regio-, diastereo-, and enantioselective conjugate addition of aldehydes to β-tosyl enones, which serve as ynone surrogates. The adducts were readily converted by treatment with L-selectride into less accessible enones with a γ stereogenic center. Such compounds cannot be prepared through the amine-catalyzed conjugate addition of aldehydes to ynones. The obtained enones underwent further conjugate addition of diorganozinc compounds in the presence of a copper catalyst. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. Conjugate additions of a simple monosilylcopper reagent with use of the CuI.DMS complex: stereoselectivities and a dramatic impact by DMS.

    Science.gov (United States)

    Dambacher, Jesse; Bergdahl, Mikael

    2005-01-21

    Conjugate additions utilizing the simple monosilylcuprate reagent Li[PhMe2SiCuI] to alpha,beta-unsaturated carbonyl compounds are described. The presence of dimethyl sulfide (DMS), either as a component originating from the (CuI)4(DMS)3 complex or as a solvent added, has an amazing influence on both chemical yield and the level of diastereomeric ratio (dr) of the products. Gilman-type silylcyanocuprates {Li(Ph2MeSi)2Cu/LiCN} have previously been used to guarantee good results in conjugate addition reactions. External additives such as HMPA, tributylphosphine, or dialkylzinc are not necessary in conjunction with the simple Li[PhMe2SiCuI] reagent. It is demonstrated that the monosilylcuprate reagent with DMS as the solvent is very useful with sterically hindered (beta,beta-disubstituted) enones, and provides very high yields of the beta-silylated 1,4-addition products. Since there is no oligomerization problem associated with the simple monosilylcuprate reagent, this reagent should be considered as a very useful 1,4-silyl donor to enals, enones, and enoates in conjugate addition reactions.

  13. Palladium-catalyzed regio- and stereoselective cross-addition of terminal alkynes to ynol ethers and synthesis of 1,4-enyn-3-ones.

    Science.gov (United States)

    Babu, Madala Hari; Dwivedi, Vikas; Kant, Ruchir; Reddy, Maddi Sridhar

    2015-03-16

    Conjugated enynes, enol ethers, and enynones are versatile building blocks that can be elaborated by a wide variety of synthetic transformations. The selective synthesis of such units is a prerequisite for their effective utilization. The synthesis of conjugated 2-phenoxyenynes through a palladium-catalyzed cross-addition of terminal alkynes to phenylethynyl ethers (hydroalkynylation) is now presented. The reaction is highly regio-, stereo-, and chemoselective, and shows excellent tolerance toward functional groups. The addition further features very mild reaction conditions (room temperature) and an inexpensive catalytic system (without a ligand and with a cheaply available Pd catalyst). The thus synthesized enynyl ethers with allylic hydroxy tethers, which survived the reaction, were shown to be ready precursors for valuable 1-en-4-yn-3-ones. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. Stereoselective Reduction of Imines with Trichlorosilane Using Solid-Supported Chiral Picolinamides

    Directory of Open Access Journals (Sweden)

    Sílvia D. Fernandes

    2016-09-01

    Full Text Available The stereoselective reduction of imines with trichlorosilane catalyzed by chiral Lewis bases is a well-established procedure for the synthesis of enantio-enriched amines. Five supported cinchona-based picolinamides have been prepared and their activity tested in a model reaction. The comparison of different supporting materials revealed that polystyrene gave better results than silica in terms of stereoselectivity. The applicability of the solid-supported catalyst of choice to the reduction of different imines was also demonstrated. Additionally, for the first time, a catalytic reactor containing a polymer-immobilized chiral picolinamide has been employed for the stereoselective reduction of imines with trichlorosilane under continuous flow conditions.

  15. Stereoselective Synthesis of Functionalized 1,3-Disubstituted Isoindolines via Rh(III)-Catalyzed Tandem Oxidative Olefination-Cyclization of 4-Aryl-cyclic Sulfamidate-5-Carboxylates.

    Science.gov (United States)

    Achary, Raghavendra; Jung, In-A; Son, Se-Mi; Lee, Hyeon-Kyu

    2017-07-21

    A new method for the direct, stereoselective synthesis of highly functionalized 1,3-disubstituted isoindolines 6 from enantiomerically enriched cyclic 4-aryl-sulfamidate-5-carboxylates (5) is described. The process involves sulfamidate directed, Rh(III)-catalyzed tandem ortho C-H olefination of the 4-aryl-sulfamidate-5-carboxylates and subsequent cyclization by aza-Michael addition. In the reaction, which generates trans-1,3-disubstituted isoindolines exclusively, the configurational integrity of the stereogenic center in the starting cyclic sulfamidate is completely retained in the product. Examples are provided which show that the cyclic sulfamidate moiety not only serves as a chiral directing group but also as a versatile handle for further functionalization of the generated isoindoline ring system.

  16. Michael Faraday's Bicentenary.

    Science.gov (United States)

    Williams, L. Pearce; And Others

    1991-01-01

    Six articles discuss the work of Michael Faraday, a chemist whose work revolutionized physics and led directly to both classical field and relativity theory. The scientist as a young man, the electromagnetic experiments of Faraday, his search for the gravelectric effect, his work on optical glass, his laboratory notebooks, and his creative use of…

  17. Following Michael Faraday's Footprints

    Science.gov (United States)

    Galeano, Javier

    2011-01-01

    Last fall I had the good fortune of receiving financial support to shoot a documentary about Michael Faraday. I took the opportunity to learn more about this great experimentalist and to visit the highlights of places in his life. In this paper, I would like to share a list and description of some of the most remarkable places in London suitable…

  18. Michael Faraday, media man.

    Science.gov (United States)

    Fara, Patricia

    2006-03-01

    Michael Faraday was an enthusiastic portrait collector, and he welcomed the invention of photography not only as a possible means of recording observations accurately, but also as a method for advertising science and its practitioners. This article (which is part of the Science in the Industrial Revolution series) shows that like many eminent scientists, Faraday took advantage of the burgeoning Victorian media industry by posing in various roles.

  19. Concepts for stereoselective acrylate insertion

    KAUST Repository

    Neuwald, Boris

    2013-01-23

    Various phosphinesulfonato ligands and the corresponding palladium complexes [{((PaO)PdMeCl)-μ-M}n] ([{( X1-Cl)-μ-M}n], (PaO) = κ2- P,O-Ar2PC6H4SO2O) with symmetric (Ar = 2-MeOC6H4, 2-CF3C6H4, 2,6-(MeO)2C6H3, 2,6-(iPrO)2C 6H3, 2-(2′,6′-(MeO)2C 6H3)C6H4) and asymmetric substituted phosphorus atoms (Ar1 = 2,6-(MeO)2C6H 3, Ar2 = 2′-(2,6-(MeO)2C 6H3)C6H4; Ar1 = 2,6-(MeO)2C6H3, Ar2 = 2-cHexOC 6H4) were synthesized. Analyses of molecular motions and dynamics by variable temperature NMR studies and line shape analysis were performed for the free ligands and the complexes. The highest barriers of ΔGa = 44-64 kJ/mol were assigned to an aryl rotation process, and the flexibility of the ligand framework was found to be a key obstacle to a more effective stereocontrol. An increase of steric bulk at the aryl substituents raises the motional barriers but diminishes insertion rates and regioselectivity. The stereoselectivity of the first and the second methyl acrylate (MA) insertion into the Pd-Me bond of in situ generated complexes X1 was investigated by NMR and DFT methods. The substitution pattern of the ligand clearly affects the first MA insertion, resulting in a stereoselectivity of up to 6:1 for complexes with an asymmetric substituted phosphorus. In the consecutive insertion, the stereoselectivity is diminished in all cases. DFT analysis of the corresponding insertion transition states revealed that a selectivity for the first insertion with asymmetric (P aO) complexes is diminished in the consecutive insertions due to uncooperatively working enantiomorphic and chain end stereocontrol. From these observations, further concepts are developed. © 2012 American Chemical Society.

  20. Green Michael addition of thiols to electron deficient alkenes using KF/alumina and recyclable solvent or solvent-free conditions

    Energy Technology Data Exchange (ETDEWEB)

    Lenardao, Eder J.; Trecha, Danusia O.; Ferreira, Patricia da C.; Jacob, Raquel G.; Perin, Gelson [Universidade Federal de Pelotas (UFPEL), Pelotas, RS (Brazil). Inst. de Quimica e Geociencias. Lab. de Sintese Organica Limpa (LASOL)]. E-mail: lenardao@ufpel.edu.br

    2009-07-01

    A general, clean and easy method for the conjugated addition of thiols to citral promoted by KF/Al{sub 2}O{sub 3} under solvent-free or using glycerin as recyclable solvent at room temperature is described. It was found that the solvent-free protocol is applicable to the direct reaction of thiophenol with the essential oil of lemon grass (Cymbopogon citratus) to afford directly 3,7-dimethyl-3-(phenylthio)oct-6-enal, a potential bactericide agent. The method was extended to other electron-poor alkenes with excellent results. For the solvent-free protocol, the use of microwave irradiation facilitated the procedure and accelerates the reaction. The catalytic system and glycerin can be reused up to three times without previous treatment with comparable activity. (author)

  1. Michael Jackson's Sound Stages

    OpenAIRE

    Morten Michelsen

    2012-01-01

    In order to discuss analytically spatial aspects of recorded sound William Moylan’s concept of ‘sound stage’ is developed within a musicological framework as part of a sound paradigm which includes timbre, texture and sound stage. Two Michael Jackson songs (‘The Lady in My Life’ from 1982 and ‘Scream’ from 1995) are used to: a) demonstrate the value of such a conceptualisation, and b) demonstrate that the model has its limits, as record producers in the 1990s began ignoring the conventions of...

  2. Enantioselective aminocatalysis: Michael addition of unactivated ...

    Indian Academy of Sciences (India)

    KHIANGTE VANLALDINPUIA

    2017-09-25

    Sep 25, 2017 ... the case of acetone) were stirred at room temperature for. 30 min. Nitroolefin (1 ..... Kaprzak A and Gawronski J 2001 Review on the use of cinchona ... 2006 Functionalized chiral ionic liquids as highly effi- cient asymmetric ...

  3. Professor Michael Levitt

    Directory of Open Access Journals (Sweden)

    Gemma-Louise Davies

    2015-10-01

    Full Text Available Professor Michael Levitt (Stanford University, USA won the 2013 Nobel Prize in Chemistry for the development of multiscale models for complex chemical systems—computational tools which can calculate the course of chemical reactions. Professor Levitt was born in Pretoria, South Africa; he came to the UK on a summer vacation aged 16, where he decided to stay and study for his A‑levels. His interest in the physics of living systems drove him to study biophysics at King’s College London, before securing a PhD position at the Laboratory of Molecular Biology in Cambridge. In the interim year between his degree and beginning his PhD, Professor Levitt worked at the Weizmann Institute of Science in Israel, where he met his future wife. They married later that year and moved to Cambridge, where their three children were born. After completing his PhD, he spent time working in Israel, Cambridge, the Salk Institute and Stanford (both California. Since 1986, he has split his time between Israel and California. Outside of science, he is a keen hiker and he is well-known to have attended the eclectic ‘Burning Man’ Festival in California.[1] Professor Levitt visited the University of Warwick to speak at the Computational Molecular Science Annual Conference in March 2015. In this interview, Dr Gemma-Louise Davies, an Institute of Advanced Study Global Research Fellow, spoke to Professor Levitt about the importance of Interdisciplinarity in his field, role models in Academia, and his plans for the future. Image: Professor Michael Levitt (left with Dr Scott Habershon (right, organiser of the 2015 Computational Molecular Science Annual Conference during his visit to the University of Warwick in March 2015. [1] ‘Burning Man’ is a unique annual festival dedicated to community, art, music, self-expression and self-reliance. Tens of thousands of people flock to this temporary metropolis built in the Californian desert.

  4. Synthesis of a stationary phase based on silica modified with branched octadecyl groups by Michael addition and photoinduced thiol-yne click chemistry for the separation of basic compounds.

    Science.gov (United States)

    Huang, Guang; Ou, Junjie; Wang, Hongwei; Ji, Yongsheng; Wan, Hao; Zhang, Zhang; Peng, Xiaojun; Zou, Hanfa

    2016-04-01

    A novel silica-based stationary phase with branched octadecyl groups was prepared by the sequential employment of the Michael addition reaction and photoinduced thiol-yne click chemistry with 3-aminopropyl-functionalized silica microspheres as the initial material. The resulting stationary phase denoted as SiO2 -N(C18)4 was characterized by elemental analysis, FTIR spectroscopy and Raman spectroscopy, demonstrating the existence of branched octadecyl groups in silica microspheres. The separations of benzene homologous compounds, acid compounds and amine analogues were conducted, demonstrating mixed-mode separation mechanism on SiO2 -N(C18)4 . Baseline separation of basic drugs mixture was acquired with the mobile phase of acetonitrile/H2 O (5%, v/v). SiO2 -N(C18)4 was further applied to separate Corydalis yanhusuo Wang water extracts, and more baseline separation peaks were obtained for SiO2 -N(C18)4 than those on Atlantis dC18 column. It can be expected that this new silica-based stationary phase will exhibit great potential in the analysis of basic compounds. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. Michael Levitt and Computational Biology

    Science.gov (United States)

    dropdown arrow Site Map A-Z Index Menu Synopsis Michael Levitt and Computational Biology Resources with Michael Levitt, PhD, professor of structural biology at the Stanford University School of Medicine, has function. ... Levitt's early work pioneered computational structural biology, which helped to predict

  6. Zinc mediated activation of terminal alkynes: stereoselective synthesis of alkynyl glycosides.

    Science.gov (United States)

    Tatina, Madhu Babu; Kusunuru, Anil Kumar; Yousuf, Syed Khalid; Mukherjee, Debaraj

    2014-10-28

    Zinc mediated alkynylation reaction was studied for the preparation of C-glycosides from unactivated alkynes. Different glycosyl donors such as glycals and anomeric acetates were tested towards an alkynyl zinc reagent obtained from alkynes using zinc dust and ethyl bromoacetate as an additive. The method provides simple, mild and stereoselective access to alkynyl glycosides both from aromatic and aliphatic acetylenes.

  7. Regio and stereoselectivity in ionic cycloadditions

    Indian Academy of Sciences (India)

    WINTEC

    Though the reactions have both electrostatic control and frontier orbital control the former dominates in the initial stages of the reaction. Keywords. Stereoselectivity; ionic cycloaddition; density functional theory; acridizinium ion; methyl vinyl ether; 2,3-dimethylisoquinolinium ion. 1. Introduction. In polar or ionic cycloadditions ...

  8. Regio- and stereoselective iodoacyloxylations of alkynes.

    Science.gov (United States)

    Priebbenow, Daniel L; Gable, Robert W; Baell, Jonathan

    2015-05-01

    A new method for the regioselective and stereoselective iodoacyloxylation of alkynes has been developed. This protocol utilizes a combination of an iodobenzene dicarboxylate and iodine to functionalize a series of activated and unactivated alkynes in an entirely selective and predictable fashion. The resultant iodo-enol esters were subsequently coupled with boronic acids to afford tetrasubstituted alkene derivatives, which could be further converted to the corresponding 1,1-disubstituted acetophenone.

  9. En bog om Michael Strunge

    DEFF Research Database (Denmark)

    Mai, Anne-Marie

    Antologi med bidrag om Michael Strunges forfatterskab. Bidrag af Anne-Marie Mai, Jørgen Aabenhus, Marianne Stidsen, Moritz Schramm, Tue Andersen Nexø, Lars Bukdahl, Jon Helt Haarder, Rune Kühl er optaget efter fagfællesbedømmelse. Antologien er redigeret af Anne-Marie Mai og Jørgen Aabenhus....

  10. Michael Beitz: Objects of Communication

    Science.gov (United States)

    Hoefferle, Mary

    2014-01-01

    For this Instructional Resource, the author interviewed contemporary sculptor Michael Beitz, who uses art to explore the role of designed objects in human communication and emotional experience. This column was written in response to calls for using Enduring Understandings/Big Ideas (National Coalition for Core Arts Standards, 2013; Stewart &…

  11. Michael J. Fox: Spurring Research on Parkinson's

    Science.gov (United States)

    ... turn JavaScript on. Feature: Parkinson's Disease Michael J. Fox: Spurring Research on Parkinson's Past Issues / Winter 2014 Table of Contents Michael J. Fox and his wife, actress Tracy Pollan, founded the ...

  12. Michael Faraday vs. the Spiritualists

    Science.gov (United States)

    Hirshfeld, Alan

    2006-12-01

    In the 1850s, renowned physicist Michael Faraday launched a public campaign against pseudoscience and spiritualism, which were rampant in England at the time. Faraday objected especially to claims that electrical or magnetic forces were responsible for paranormal phenomena, such as table-spinning and communication with the dead. Using scientific methods, Faraday unmasked the deceptions of spiritualists, clairvoyants and mediums and also laid bare the credulity of a public ill-educated in science. Despite his efforts, Victorian society's fascination with the paranormal swelled. Faraday's debacle anticipates current controversies about public science education and the interface between science and religion. This episode is one of many described in the new biography, The Electric Life of Michael Faraday (Walker & Co.), which chronicles Faraday's discoveries and his unlikely rise from poverty to the pinnacle of the English science establishment.

  13. Michael Niegl (1985-2009)

    CERN Multimedia

    2009-01-01

    Our friend and colleague Michael Niegl died in a tragic accident in the first hours of the new year. Michael was a Master’s student in Microsystems Engineering at the University of Applied Sciences Wiener Neustadt. He was responsible for the development of the ATLAS Beam Conditions Monitor (BCM) ROD FPGA firmware, which acquires the data from the BCM detector modules and provides online monitoring of the LHC beams within the ATLAS experiment. He spent several months at CERN to carry out beam tests on the BCM detectors and received his Bachelor of Science with first class honours for his thesis: Concept and Implementation of an FPGA-based Data Recorder and Processor for the ATLAS Beam Conditions Monitor. Michael spent six months at CERN last year to finish the development and commissioning of the ROD firmware for the first beam. He worked the entire night of 10 September to fine tune the system for the first beam. It was a joy to ...

  14. Michael De Sousa (1989 - 2012)

    CERN Multimedia

    2012-01-01

    We are deeply saddened to announce the death of Mr Michael De Sousa on 13 May 2012. Mr De Sousa, who was born on 02.09.1989, was working as an apprentice in the TE Department and had been at CERN since 24.08.2009. The Director-General has sent a message of condolence to his family on behalf of the CERN personnel. Social Affairs Human Resources Department     It is with great emotion and deep sadness that we learn of the tragic loss of our colleague and friend Michael De Sousa. Michael was a hard working colleague, cordial and considerate. Within a few months, he marked his presence by the implementation of the instrumentation benches for gas permeation measurement in polymers, and the calibration of high technology gas analyzers, necessary for vacuum technology. His last contribution will enable us to measure pressures in the extreme high vacuum range for the ELENA project.  With the continuation of this activity, his memory will remain. His accomplishments will remain...

  15. Visible-Light-Initiated Na2-Eosin Y Catalyzed Highly Regio- and Stereoselective Difunctionalization of Alkynes with Alkyl Bromides.

    Science.gov (United States)

    Wang, Kuai; Meng, Ling-Guo; Wang, Lei

    2016-08-19

    A highly regioselective and stereoselective addition of alkyl bromides (amino-brominated aromatic β,β-dicyanoalkenes) to arylacetylenes by photoredox catalysis was developed. This difunctionalization of arylacetylenes was accomplished under ambient and metal-free conditions to produce alkenyl bromides in high efficiency with a wide range of group tolerance.

  16. Photoredox-Catalyzed Stereoselective Conversion of Alkynes into Tetrasubstituted Trifluoromethylated Alkenes.

    Science.gov (United States)

    Tomita, Ren; Koike, Takashi; Akita, Munetaka

    2015-10-26

    A regio- and stereoselective synthesis of trifluoromethylated alkenes bearing four different substituents has been developed. Stereocontrolled sulfonyloxytrifluoromethylation of unsymmetric internal alkynes with an electrophilic CF3 reagent, namely the triflate salt of the Yagupol'skii-Umemoto reagent, in the presence of an Ir photoredox catalyst under visible-light irradiation afforded trifluoromethylalkenyl triflates with well-predictable stereochemistry resulting from anti addition of the trifluoromethyl and triflate groups. Subsequent palladium-catalyzed cross-couplings led to tetrasubstituted trifluoromethylated alkenes in a highly stereoselective manner. The present method is the first example of a facile one-pot synthesis of tetrasubstituted trifluoromethylated alkenes from simple alkynes. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. Michael Jackson antes del caos

    OpenAIRE

    Juan Luciano Nieves

    2015-01-01

    Michael Jackson es un buen ejemplo de cómo utilizar las relaciones públicas para realizar o manipular la imagen de un producto a través de los medios de comunicación. Este ensayo pretende analizar los eventos que tuvieron lugar antes de que el cantante fuera acusado de abuso sexual contra un menor. Dichos eventos formaron parte de un plan muy bien delineado para disminuir los efectos de la inminente crisis que se acercaba. Este trabajo combina la crítica retórica de temas de fantasía con teor...

  18. Video interview with Michael Dell

    CERN Multimedia

    CERN Bulletin

    2010-01-01

    Michael Dell, founder and presently Chairman of the Board of Directors and Chief Executive Office of the DELL computer company visited CERN on Tuesday 26th January 2010. The Bulletin and the Video productions team had the opportunity to meet him. The video interview is transcribed for your convenience.   Michael S. Dell with CERN Director-General Rolf Heuer. What motivated you to come and visit CERN? I obviously heard about the great science and research has going on here, and DELL is very pleased to be a partner and providing a lot of the computers to analyse the data and I really wanted to see for myself in person, some of the great science that is going on here. What is your view on fundamental research in IT, and in general? I think if you look at the field of science in the last hundred years, we have been able to solve a lot of problems, but there are still lots of unsolved problems and unsolved mysteries. And it is only through basic fundamental research that we will address these probl...

  19. SuchThatCast Episode 6: Michael Boylan

    NARCIS (Netherlands)

    Soraker, Johnny

    2012-01-01

    Michael Boylan is the John J. McDonnell jr chair in Ethics, and professor and chair of the philosophy department at Marymount University in Arlington, Virginia. In addition to being a poet and novelist, he has written more than 100 published articles and 25 books primarily in ethics, social and

  20. Aza-Michael Reaction for an Undergraduate Organic Chemistry Laboratory

    Science.gov (United States)

    Nigam, Manisha; Rush, Brittney; Patel, Jay; Castillo, Raul; Dhar, Preeti

    2016-01-01

    A green, aza-Michael reaction is described that can be used to teach undergraduate students conjugate addition of nitrogen nucleophile to an a,ß-unsaturated ester. Students analyze spectral data of the product obtained from the assigned reaction to determine product structure and propose the mechanism of its formation. The experiment requires…

  1. Stereoselective and nonstereoselective effects of ibuprofen enantiomers on mitochondrial beta-oxidation of fatty acids

    Energy Technology Data Exchange (ETDEWEB)

    Freneaux, E.; Fromenty, B.; Berson, A.; Labbe, G.; Degott, C.; Letteron, P.; Larrey, D.; Pessayre, D. (Unite de Recherches de Physiolopathologie Hepatique (INSERM U-24), Hopital Beaujon, Clichy (France))

    1990-11-01

    The effects of the R-(-) and S-(+)ibuprofen enantiomers were first studied in vitro with mouse liver mitochondria incubated in the presence of various concentrations of exogenous coenzyme A. In the presence of a low concentration of coenzyme A (2.5 microM), the R-(-)enantiomer (which forms an acylcoenzyme A) inhibited stereoselectively the beta oxidation of (1-{sup 14}C)palmitic acid but not that of (1-{sup 14}C)palmitoyl-L-carnitine (which can directly enter the mitochondria). In the presence, however, of a concentration of coenzyme A (50 microM) reproducing that present in liver cell cytosol, both enantiomers (2 mM) slightly inhibited the beta oxidation of (1-{sup 14}C)palmitic acid and markedly inhibited the beta oxidation of (1-{sup 14}C)octanoic acid and (1-{sup 14}C)butyric acid. In vivo, both enantiomers (1 mmol.kg-1) similarly inhibited the formation of ({sup 14}C)CO{sub 2} from (1-{sup 14}C)fatty acids. Both enantiomers similarly decreased plasma ketone bodies. Both similarly increased hepatic triglycerides, and both produced mild microvesicular steatosis of the liver. We conclude that both ibuprofen enantiomers inhibit beta oxidation of fatty acids in vitro and in vivo. In addition, the R-(-)enantiomer may stereoselectively sequester coenzyme A; at low concentrations of coenzyme A in vitro, this may stereoselectively inhibit the mitochondrial uptake and beta oxidation of long chain fatty acids.

  2. Stereoselective and nonstereoselective effects of ibuprofen enantiomers on mitochondrial beta-oxidation of fatty acids

    International Nuclear Information System (INIS)

    Freneaux, E.; Fromenty, B.; Berson, A.; Labbe, G.; Degott, C.; Letteron, P.; Larrey, D.; Pessayre, D.

    1990-01-01

    The effects of the R-(-) and S-(+)ibuprofen enantiomers were first studied in vitro with mouse liver mitochondria incubated in the presence of various concentrations of exogenous coenzyme A. In the presence of a low concentration of coenzyme A (2.5 microM), the R-(-)enantiomer (which forms an acylcoenzyme A) inhibited stereoselectively the beta oxidation of [1- 14 C]palmitic acid but not that of [1- 14 C]palmitoyl-L-carnitine (which can directly enter the mitochondria). In the presence, however, of a concentration of coenzyme A (50 microM) reproducing that present in liver cell cytosol, both enantiomers (2 mM) slightly inhibited the beta oxidation of [1- 14 C]palmitic acid and markedly inhibited the beta oxidation of [1- 14 C]octanoic acid and [1- 14 C]butyric acid. In vivo, both enantiomers (1 mmol.kg-1) similarly inhibited the formation of [ 14 C]CO 2 from [1- 14 C]fatty acids. Both enantiomers similarly decreased plasma ketone bodies. Both similarly increased hepatic triglycerides, and both produced mild microvesicular steatosis of the liver. We conclude that both ibuprofen enantiomers inhibit beta oxidation of fatty acids in vitro and in vivo. In addition, the R-(-)enantiomer may stereoselectively sequester coenzyme A; at low concentrations of coenzyme A in vitro, this may stereoselectively inhibit the mitochondrial uptake and beta oxidation of long chain fatty acids

  3. Michael Jackson antes del caos

    Directory of Open Access Journals (Sweden)

    Juan Luciano Nieves

    2015-01-01

    Full Text Available Michael Jackson es un buen ejemplo de cómo utilizar las relaciones públicas para realizar o manipular la imagen de un producto a través de los medios de comunicación. Este ensayo pretende analizar los eventos que tuvieron lugar antes de que el cantante fuera acusado de abuso sexual contra un menor. Dichos eventos formaron parte de un plan muy bien delineado para disminuir los efectos de la inminente crisis que se acercaba. Este trabajo combina la crítica retórica de temas de fantasía con teoría de comunicación.

  4. Enantiomeric metabolic interactions and stereoselective human methadone metabolism.

    Science.gov (United States)

    Totah, Rheem A; Allen, Kyle E; Sheffels, Pamela; Whittington, Dale; Kharasch, Evan D

    2007-04-01

    Methadone is administered as a racemate, although opioid activity resides in the R-enantiomer. Methadone disposition is stereoselective, with considerable unexplained variability in clearance and plasma R/S ratios. N-Demethylation of methadone in vitro is predominantly mediated by cytochrome P450 CYP3A4 and CYP2B6 and somewhat by CYP2C19. This investigation evaluated stereoselectivity, models, and kinetic parameters for methadone N-demethylation by recombinant CYP2B6, CYP3A4, and CYP2C19, and the potential for interactions between enantiomers during racemate metabolism. CYP2B6 metabolism was stereoselective. CYP2C19 was less active, and stereoselectivity was opposite that for CYP2B6. CYP3A4 was not stereoselective. With all three isoforms, enantiomer N-dealkylation rates in the racemate were lower than those of (R)-(6-dimethyamino-4,4-diphenyl-heptan-3-one) hydrochloride (R-methadone) or (S)-(6-dimethyamino-4,4-diphenyl-heptan-3-one) hydrochloride (S-methadone) alone, suggesting an enantiomeric interaction and mutual metabolic inhibition. For CYP2B6, the interaction between enantiomers was stereoselective, with S-methadone as a more potent inhibitor of R-methadone N-demethylation than R-of S-methadone. In contrast, enantiomer interactions were not stereoselective with CYP2C19 or CYP3A4. For all three cytochromes P450, methadone N-demethylation was best described by two-site enzyme models with competitive inhibition. There were minor model differences between cytochromes P450 to account for stereoselectivity of metabolism and enantiomeric interactions. Changes in plasma R/S methadone ratios observed after rifampin or troleandomycin pretreatment in humans in vivo were successfully predicted by CYP2B6- but not CYP3A4-catalyzed methadone N-demethylation. CYP2B6 is a predominant catalyst of stereoselective methadone metabolism in vitro. In vivo, CYP2B6 may be a major determinant of methadone metabolism and disposition, and CYP2B6 activity and stereoselective metabolic

  5. Jack Michael's Motivation

    Science.gov (United States)

    Miguel, Caio F.

    2013-01-01

    Among many of Jack Michael's contributions to the field of behavior analysis is his behavioral account of motivation. This paper focuses on the concept of "motivating operation" (MO) by outlining its development from Skinner's (1938) notion of "drive." Conceptually, Michael's term helped us change our focus on…

  6. Stereoselectivity of presynaptic autoreceptors modulating dopamine release

    International Nuclear Information System (INIS)

    Arbilla, S.; Langer, S.Z.

    1981-01-01

    The effects of the (R)- and (S)-enantiomers of sulpiride and butaclamol were studied on the spontaneous and field stimulation-evoked release of total radioactivity from slices of rabbit caudate nucleus prelabelled with [ 3 H]dopamine. (S)-Sulpiride in concentrations ranging from 0.01-1μM enhanced the electrically evoked release of [ 3 H]dopamine while (R)-sulpiride was 10 times less potent than (S)-sulpiride. Exposure to (S)-butaclamol (0.1-1 μM) but not to (R)-butaclamol (0.1-10μM) enhanced the field-stimulated release of [ 3 H]dopamine. The facilitatory effects of (S)- and (R)-sulpiride and (S)-butaclamol on the stimulated release of the labelled neurotransmitter were observed under conditions in which these drugs did not modify the spontaneous outflow of radioactivity. Only the active enantiomers of sulpiride and butaclamol antagonized the inhibition by apomorphine (1μM) of the stimulated release of [ 3 H]dopamine. Our results indicate that the presynaptic inhibitory dopamine autoreceptors modulating the stimulation-evoked release of [ 3 H]dopamine in the caudate nucleus are, like the classical postsynaptic dopamine receptors, chemically stereoselective. (Auth.)

  7. Stereoselectivity in the salt-cocrystal products formed by phenylglycinol or phenylglycine with their respective sodium or hydrochloride salts.

    Science.gov (United States)

    Brittain, Harry G

    2013-01-01

    The salt and stereoselective cocrystal phenomena associated with 2-phenylglycinol and 2-phenylglycine have been studied using X-ray powder diffraction and differential scanning calorimetry. The chiral identities of the free acids and their sodium salts, or the free bases and their chloride salts, were found to play a determining role as to whether a salt-cocrystal product could or could not be formed. In particular, when cocrystallization of an enantiomerically pure basic or zwitterionic substance with its enantiomerically pure acid addition salt was attempted, a salt-cocrystal was only obtained when the absolute configuration of the two reactants is opposite. On the other hand, it has been found that no stereoselectivity in salt-cocrystal formation existed in the cocrystallization of an enantiomerically pure acidic or zwitterionic substance with its enantiomerically pure base addition salt. Copyright © 2012 Wiley Periodicals, Inc.

  8. Regio- and stereoselective hydrosilylation of immobilized terminal alkynes

    DEFF Research Database (Denmark)

    Pedersen, Palle Jacob; Henriksen, Jonas; Gotfredsen, Charlotte Held

    2008-01-01

    Regio- and stereoselective hydrosilylation of terminal alkynes on solid support using diisopropyl hydrosilanes yielding b-(E)-vinyl silanes with excellent selectivity is reported. The hydrosilylation is catalyzed by Pt(DVDS)/P(iBuNCH2CH2)3N (DVDS = 1,3-divinyl-1,1,3,3-tetramethyl-disiloxane), in ...

  9. High stereoselectivity on low temperature Diels-Alder reactions

    Directory of Open Access Journals (Sweden)

    Invernize Paulo

    2005-12-01

    Full Text Available Abstract We have found that some of the usually poor dienophiles (2-cycloenones can undergo Diels-Alder reaction at -78°C with unusually high stereoselectivity in the presence of niobium pentachloride as a Lewis acid catalyst. A remarkable difference in reaction rates for unsubstituted and α- or β-methyl substituted 2-cycloenones was also observed.

  10. A sustainable process for gram-scale synthesis of stereoselective ...

    Indian Academy of Sciences (India)

    We have developed a new, simple and sustainable process for stereoselective synthesis of aryl substituted (E)-2-thiocyanatoacrylic acids by nucleophilic substitution and Knoevenagel condensation involving chloroacetic acid, ammonium thiocyanate and aromatic aldehydes at room temperature. The selectivity was ...

  11. Michael Wood’s Yangzhou Dream

    Institute of Scientific and Technical Information of China (English)

    Yuan; Dan

    2014-01-01

    <正>Mr.Michael Wood is a wellknown British historian and documentary maker who has produced more than a hundred documentaries on various national histories and cultures exemplified by The Story of India.They enjoy wide popularity in more than 150 countries.I met him in February when he took his fi lm crew to Yangzhou to shoot The Story of China documentary for the British Broadcasting Corporation(BBC).It was a snowy day,cold and wet,but Michael said happily that the

  12. Michael Tomasello: Award for Distinguished Scientific Contributions.

    Science.gov (United States)

    2015-11-01

    The APA Awards for Distinguished Scientific Contributions are presented to persons who, in the opinion of the Committee on Scientific Awards, have made distinguished theoretical or empirical contributions to basic research in psychology. One of the 2015 award winners is Michael Tomasello, who received this award for "outstanding empirical and theoretical contributions to understanding what makes the human mind unique. Michael Tomasello's pioneering research on the origins of social cognition has led to revolutionary insights in both developmental psychology and primate cognition." Tomasello's award citation, biography, and a selected bibliography are presented here. (c) 2015 APA, all rights reserved).

  13. Chiral Aminophosphines as Catalysts for Enantioselective Double-Michael Indoline Syntheses

    Directory of Open Access Journals (Sweden)

    Ohyun Kwon

    2012-05-01

    Full Text Available The bisphosphine-catalyzed double-Michael addition of dinucleophiles to electron-deficient acetylenes is an efficient process for the synthesis of many nitrogen-containing heterocycles. Because the resulting heterocycles contain at least one stereogenic center, this double-Michael reaction would be even more useful if an asymmetric variant of the reaction were to be developed. Aminophosphines can also facilitate the double-Michael reaction and chiral amines are more readily available in Nature and synthetically; therefore, in this study we prepared several new chiral aminophosphines. When employed in the asymmetric double-Michael reaction between ortho-tosylamidophenyl malonate and 3-butyn-2-one, the chiral aminophosphines produced indolines in excellent yields with moderate asymmetric induction.

  14. Interspecies In Vitro Evaluation of Stereoselective Protein Binding for 3,4-Methylenedioxymethamphetamine

    Directory of Open Access Journals (Sweden)

    Wan Raihana Wan Aasim

    2017-01-01

    Full Text Available Abuse of 3,4-methylenedioxymethamphetamine (MDMA is becoming more common worldwide. To date, there is no information available on stereoselectivity of MDMA protein binding in humans, rats, and mice. Since stereoselectivity plays an important role in MDMA’s pharmacokinetics and pharmacodynamics, in this study we investigated its stereoselectivity in protein binding. The stereoselective protein binding of rac-MDMA was investigated using two different concentrations (20 and 200 ng/mL in human plasma and mouse and rat sera using an ultrafiltration technique. No significant stereoselectivity in protein binding was observed in both human plasma and rat serum; however, a significant stereoselective binding (p<0.05 was observed in mouse serum. Since the protein binding of MDMA in mouse serum is considerably lower than in humans and rats, caution should be exercised when using mice for in vitro studies involving MDMA.

  15. Michael Heyrovsky, in memoriam (1932-2017)

    Czech Academy of Sciences Publication Activity Database

    Barek, J.; Černý, Slavoj; Herman, Zdeněk; Jindra, Jiří; Paleček, Emil

    2017-01-01

    Roč. 29, č. 8 (2017), s. 2001-2002 ISSN 1040-0397 Institutional support: RVO:68378114 ; RVO:61388955 ; RVO:68081707 Keywords : Michael Heyrovský Subject RIV: AB - History OBOR OECD: History (history of science and technology to be 6.3, history of specific sciences to be under the respective headings) Impact factor: 2.851, year: 2016

  16. Reframing Michael Scott: Exploring Inappropriate Workplace Communication

    Science.gov (United States)

    Schaefer, Zachary A.

    2010-01-01

    Individuals who work in professional settings interact with others who may exhibit a variety of cultural beliefs and decision-making approaches. Page (2007) argues that cognitive diversity (i.e., how people approach and attempt to solve problems) is a vital asset in effective organizations. Michael Scott, who portrays the inept main character on…

  17. Michael Hauskeller: Sex and the Posthuman Condition

    NARCIS (Netherlands)

    Miller, Lantz Eugene

    2016-01-01

    This new book from Michael Hauskeller explores the currently marketed or projected sex/love products that exhibit some trait of so-called “posthumanistic” theory or design. These products are so designated because of their intention to fuse high technologies, including robotics and computing, with

  18. Aza-Michael reaction: achievements and prospects

    International Nuclear Information System (INIS)

    Rulev, Alexander Yu

    2011-01-01

    Data published in the last 10 years on the use of the aza-Michael reaction in organic synthesis are described systematically. The attention is focused on environmentally friendly processes following green chemistry principles and on methods for the synthesis of compounds that are difficult to access by other routes.

  19. Endophytic fungi as models for the stereoselective biotransformation of thioridazine.

    Science.gov (United States)

    Borges, Keyller Bastos; Borges, Warley De Souza; Pupo, Mônica Tallarico; Bonato, Pierina Sueli

    2007-12-01

    The stereoselective kinetic biotransformation of thioridazine, a phenothiazine neuroleptic drug, by endophytic fungi was investigated. In general, the sulfur of lateral chain (position 2) or the sulfur of phenothiazinic ring (position 5) were oxidated yielding the major human metabolites thioridazine-2-sulfoxide and thioridazine-5-sulfoxide. The quantity of metabolites biosynthesized varied among the 12 endophytic fungi evaluated. However, mono-2-sulfoxidation occurred in higher ratio and frequency. Among the 12 fungi evaluated, 4 of them deserve prominence for presenting an evidenced stereoselective biotransformation: Phomopsis sp. (TD2), Glomerella cingulata (VA1), Diaporthe phaseolorum (VR4), and Aspergillus fumigatus (VR12). Both enantiomers of thioridazine were consumed by the fungi; however, the 2-sulfoxidation yielded preferentially the R configuration at the sulfur atom.

  20. Stereoselective synthesis of unsaturated α-amino acids.

    Science.gov (United States)

    Fanelli, Roberto; Jeanne-Julien, Louis; René, Adeline; Martinez, Jean; Cavelier, Florine

    2015-06-01

    Stereoselective synthesis of unsaturated α-amino acids was performed by asymmetric alkylation. Two methods were investigated and their enantiomeric excess measured and compared. The first route consisted of an enantioselective approach induced by the Corey-Lygo catalyst under chiral phase transfer conditions while the second one involved the hydroxypinanone chiral auxiliary, both implicating Schiff bases as substrate. In all cases, the use of a prochiral Schiff base gave higher enantiomeric excess and yield in the final desired amino acid.

  1. Stereoselective effects of MDMA on inhibition of monoamine uptake

    International Nuclear Information System (INIS)

    Steele, T.D.; Nichols, D.E.; Yim, G.K.W.

    1986-01-01

    The R(-)-isomers of hallucinogenic phenylisopropylamines are most active, whereas the S(+)-enantiomers of amphetamine (AMPH) and methylenedioxymethamphetamine (MDMA) are more potent centrally. To determine if MDMA exhibits stereoselective effects at the biochemical level that resemble either those of amphetamine or the potent hallucinogen 2,5-dimethoxy-4-methylamphetamine (DOM), the ability of the isomers of MDMA, AMPH and DOM to inhibit uptake of radiolabelled monoamines into synaptosomes was measured. AMPH was more potent than MDMA in inhibiting uptake of 3 H-norepinephrine (NE) into hypothalamic synaptosomes and 3 H-dopamine (DA) into striatal synaptosomes. The S(+)-isomer was more active in each case. MDMA was more potent than AMPH in inhibiting uptake of 3 H-serotonin (5-HT) into hippocampal synaptosomes and exhibited a high degree of stereoselectivity, in favor of the S(+)-isomer. DOM showed only minimal activity in inhibiting uptake of any monoamine (IC 50 > 10 -5 M). These results suggest that MDMA exhibits stereoselective effects similar to those of amphetamine on monoamine uptake inhibition, a parameter that is unrelated to the mechanism of action of the hallucinogen DOM

  2. Michael Haneke film Euroopa parim / M. T.

    Index Scriptorium Estoniae

    M. T.

    2005-01-01

    IX PÖFFil linastuv Michael Haneke film "Varjatud" ("Cache") võitis laupäeval mitu Euroopa Filmiakadeemia auhinda, selhulgas parima filmi, parima lavastaja, parima meesnäitleja (Daniel Auteuil) ja FIPRESCI auhinna. Parim naisnäitleja - Julia Jentsch ("Sophie Scholli viimased päevad"), operaator - Franz Lustig ("Don't Come Knocking"), stsenaarium - Hany Abu-Assad, Bero Beyer ("Kohe paradiisi")

  3. Obituary: Michael James Ledlow, 1964-2004

    Science.gov (United States)

    Puxley, Philip John; Grashuis, Randon M.

    2004-12-01

    Michael James Ledlow died on 5 June 2004 from a large, unsuspected brain tumor. Since 2000 he had been on the scientific staff of the Gemini Observatory in La Serena, Chile, initially as a Science Fellow and then as a tenure-track astronomer. Michael was born in Bartlesville, Oklahoma on 1 October 1964 to Jerry and Sharon Ledlow. He obtained his Bachelor Degree in astrophysics at the University of Oklahoma in 1987 and attended the University of New Mexico for his graduate work, obtaining his PhD while studying Galaxy Clusters under Frazer Owen in 1994. From 1995-1997 Michael held a postdoctoral position with Jack Burns at New Mexico State University where he used various astronomical facilities including the VLA and Apache Point Observatory to study distant galaxies. From 1998-2000 Michael rejoined the Physics and Astronomy Department at the University of New Mexico where he was a visiting professor until he moved on to Gemini. At the Gemini Observatory, Mike shared in the excitement, hard work and many long days and nights associated with bringing on-line a major new astronomical facility and its instrumentation. Following its commissioning he assisted visiting observers, supported and took data for many more remote users via the queue system, and for each he showed the same care and attention to detail evident in his own research to ensure that all got the best possible data. His research concentrated on the radio and optical properties of galaxy clusters, especially rich Abell clusters such as A2125, on luminous radio galaxies, including the detection of a powerful double radio source in the "wrong sort of galaxy," the spiral system 0313-192, and on EROs (extremely red objects), dusty galaxies barely detectable at optical wavelengths. Michael thoroughly enjoyed living in Chile and enthusiastically immersed himself in the culture of his surroundings. He and his family were actively involved with the International English Spanish Association in La Serena. He had a

  4. Stereoselective Hydrogenation and Ozonolysis of Iridoids. Conversion into Carbocyclic Nucleoside Analogues

    DEFF Research Database (Denmark)

    Franzyk, Henrik; Stermitz, Frank R.

    1999-01-01

    Stereoselective hydrogenation of the iridoids geniposide (9) and aucubin (19) was achieved by using the 1-methyl-1-methoxyethyl ether (MIP) as protecting group for the allylic alcohol, as it enhanced the stereoselectivity and prevented undesired hydrogenolysis. Ozonolysis of the hydrogenation...

  5. Highly Chemo- and Stereoselective Transfer Semihydrogenation of Alkynes Catalyzed by a Stable, Well-defined Manganese(II) Complex

    KAUST Repository

    Brzozowska, Aleksandra; Azofra, Luis Miguel; Zubar, Viktoriia; Atodiresei, Iuliana; Cavallo, Luigi; Rueping, Magnus; El-Sepelgy, Osama

    2018-01-01

    The first example of manganese catalyzed semihydrogenation of internal alkynes to (Z)-alkenes using ammonia borane as a hydrogen donor is reported. The reaction is catalyzed by a pincer complex of the earth abundant manganese(II) salt in the absence of any additives, base or super hydride. The ammonia borane smoothly reduces the manganese pre-catalyst [Mn(II)-PNP][Cl]2 to the catalytically active species [Mn(I)-PNP]-hydride in the triplet spin state. This manganese hydride is highly stabilized by complexation with the alkyne substrate. Computational DFT analysis studies of the reaction mechanism rationalizes the origin of stereoselectivity towards formation of (Z)-alkenes.

  6. Highly Chemo- and Stereoselective Transfer Semihydrogenation of Alkynes Catalyzed by a Stable, Well-defined Manganese(II) Complex

    KAUST Repository

    Brzozowska, Aleksandra

    2018-03-30

    The first example of manganese catalyzed semihydrogenation of internal alkynes to (Z)-alkenes using ammonia borane as a hydrogen donor is reported. The reaction is catalyzed by a pincer complex of the earth abundant manganese(II) salt in the absence of any additives, base or super hydride. The ammonia borane smoothly reduces the manganese pre-catalyst [Mn(II)-PNP][Cl]2 to the catalytically active species [Mn(I)-PNP]-hydride in the triplet spin state. This manganese hydride is highly stabilized by complexation with the alkyne substrate. Computational DFT analysis studies of the reaction mechanism rationalizes the origin of stereoselectivity towards formation of (Z)-alkenes.

  7. Stereoselective synthesis of L-[4-13C]carnitine

    International Nuclear Information System (INIS)

    Unkefer, C.J.; Ehler, D.S.

    1991-01-01

    The stereoselective synthesis of L-[4- 13 C]carnitine was achieved in 5 steps. The label was introduced from K 13 CN into an easily separated diastereomeric pair of 3-deoxy-D-[1- 13 C]aldohexoses. Reductive amination of the labeled aldohexose yielded the corresponding D-1-(dimethylamino)[1- 13 C]alditol which was oxidized in two steps and alkylated with iodomethane to yield L-[4- 13 C]carnitine. The stereochemical integrity at C-2 of the 3-deoxy-D-[1- 13 C]glucose precursor was maintained throughout the synthesis of L-[4- 13 C]carnitine. (author)

  8. Stereoselective synthesis of 1,3-disubstituted isoindolines via Rh(III)-catalyzed tandem oxidative olefination-cyclization of 4-aryl cyclic sulfamidates.

    Science.gov (United States)

    Son, Se-Mi; Seo, Yeon Ji; Lee, Hyeon-Kyu

    2016-03-21

    Rh(III)-catalyzed tandem ortho C-H olefination of cyclic 4-aryl sulfamidates (1) and subsequent intramolecular cyclization are described. This reaction serves as a method for the direct and stereoselective synthesis of 1,3-disubstituted isoindolines (3) starting with enantiomerically enriched 4-aryl cyclic sulfamidates. In this process, the configurational integrity of the stereogenic center in the starting cyclic sulfamidate is completely retained. In addition, the process generates trans-1,3-disubstituted isoindolines exclusively.

  9. Michael Roitmann : Kalandus ei ole Eestile ilmselt prioriteetne valdkond / Michael Roitmann ; interv. Marko Saaret

    Index Scriptorium Estoniae

    Roitmann, Michael

    2003-01-01

    Ilmunud ka: Delovõje Vedomosti 3. dets. lk. 9. Euroopa Komisjoni kalandusdirektoraadi koordinaator Euroopa Liidu laienemise küsimuses Michael Roitmann juhib tähelepanu Eesti kalanduse suurematele probleemidele ning prognoosib EL-iga liitumise mõju Eesti kalandussektori arengule

  10. Stereoselective interaction between piroxicam and acenocoumarol

    Science.gov (United States)

    BONNABRY, P.; DESMEULES, J.; RUDAZ, S.; LEEMANN, T.; VEUTHEY, J.-L.; DAYER, P.

    1996-01-01

    1An open-label study was performed to assess the effect of piroxicam on the pharmacokinetics of acenocoumarol enantiomers. 2Eight healthy male volunteers received an oral dose of 4 mg rac-acenocoumarol on days 1 and 8, plus 40 mg piroxicam orally 2 h before the anticoagulant on day 8. R- and S-acenocoumarol, piroxicam and their metabolites were measured in plasma over a 24 h interval. 3The pharmacokinetics of R-acenocoumarol were markedly modified by piroxicam: Cmax+28.0% (s.d.23.8), PPiroxicam plasma AUC(0, 24 h) correlated closely with R- and Sacenocoumarol AUCs on day 1 ( r=0.901, PPiroxicam markedly reduced acenocoumarol enantiomer clearance, with a greater effect on the more active R-isomer. This interaction, which occurs in addition to the well documented pharmacodynamic one (effect on platelets), is expected to result in increased anticoagulant effect. PMID:8799517

  11. Michael Maier--nine newly discovered letters.

    Science.gov (United States)

    Lenke, Nils; Roudet, Nicolas; Tilton, Hereward

    2014-02-01

    The authors provide a transcription, translation, and evaluation of nine newly discovered letters from the alchemist Michael Maier (1568-1622) to Gebhardt Johann von Alvensleben (1576-1631), a noble landholder in the vicinity of Magdeburg. Stemming from the final year of his life, this correspondence casts new light on Maier's biography, detailing his efforts to secure patronage amid the financial crisis of the early Thirty Years' War. While his ill-fated quest to perfect potable gold continued to form the central focus of his patronage suits, Maier also offered his services in several arts that he had condemned in his printed works, namely astrology and "supernatural" magic. Remarks concerning his previously unknown acquaintance with Heinrich Khunrath call for a re-evaluation of Maier's negotiation of the discursive boundaries between Lutheran orthodoxy and Paracelsianism. The letters also reveal Maier's substantial contribution to a work previously ascribed solely to the English alchemist Francis Anthony.

  12. Stereoselective synthesis of novel highly substituted isochromanone and isoquinolinone-containing exocyclic tetrasubstituted alkenes.

    Science.gov (United States)

    Arthuis, Martin; Pontikis, Renée; Florent, Jean-Claude

    2009-03-06

    An efficient synthetic route toward the synthesis of highly substituted arylethylidene-isoquinolinones/isochromanones is reported. The tandem carbopalladation/Suzuki-Miyaura coupling sequence stereoselectively provided various functionalized polycyclic compounds in moderate to excellent yields.

  13. Interview with Michael Apple: The Biography of a Public Intellectual

    Science.gov (United States)

    Peters, Michael A.

    2015-01-01

    Michael W. Apple is the John Bascom Professor of Curriculum and Instruction and Educational Policy Studies in the Departments of Curriculum and Instruction (CI) and Educational Policy Studies (EPS) at the University of Wisconsin-Madison School of Education where he has taught since 1970. Michael Apple is one of the foremost educational theorists…

  14. Book Review: Invitation to Topological Robotics by Michael Farber

    DEFF Research Database (Denmark)

    Raussen, Martin

    2009-01-01

    Book Review: Invitaton to Topological Robotics by Michael Farber. Zurich Lectures in Advanced Mathematics, European Mathematical Society (2008), ISBN 978-3-03719-054-8......Book Review: Invitaton to Topological Robotics by Michael Farber. Zurich Lectures in Advanced Mathematics, European Mathematical Society (2008), ISBN 978-3-03719-054-8...

  15. Stereoselective potencies and relative toxicities of coniine enantiomers.

    Science.gov (United States)

    Lee, Stephen T; Green, Benedict T; Welch, Kevin D; Pfister, James A; Panter, Kip E

    2008-10-01

    Coniine, one of the major toxic alkaloids present in poison hemlock ( Conium maculatum), occurs in two optically active forms. A comparison of the relative potencies of (+)- and (-)-coniine enantiomers has not been previously reported. In this study, we separated the enantiomers of coniine and determined the biological activity of each enantiomer in vitro and in vivo. The relative potencies of these enantiomers on TE-671 cells expressing human fetal nicotinic neuromuscular receptors had the rank order of (-)-coniine > (+/-)-coniine > (+)-coniine. A mouse bioassay was used to determine the relative lethalities of (-)-, (+/-)-, and (+)-coniine in vivo. The LD 50 values of the coniine enantiomers were 7.0, 7.7, and 12.1 mg/kg for the (-)-, (+/-)-, and (+)- forms of coniine, respectively. The results from this study demonstrate that there is a stereoselective difference in the in vitro potencies of the enantiomers of coniine that directly correlates with the relative toxicities of the enantiomers in vivo.

  16. An Expeditious Stereoselective Synthesis of (−)-Pinidinone from Ethyl Acetoacetate

    International Nuclear Information System (INIS)

    Damodar, Kongara; Jun, Jong-Gab

    2016-01-01

    An expeditious stereoselective synthesis of a naturally occurring 2,6-disubstituted piperidine alkaloid, (−)-pinidinone, has been accomplished with an overall yield of 31% in total eight steps. The synthesis involves ethyl acetoacetate as the starting material and the stereoselective α-aminoallylation of aldehyde with (S)-tert-butanesulfinamide, allyl bromide, and indium and Grubbs' olefin cross-metathesis as the pivotal steps.

  17. Stereoselective inhibition of the hERG1 potassium channel

    Directory of Open Access Journals (Sweden)

    Liliana eSintra Grilo

    2010-11-01

    Full Text Available A growing number of drugs have been shown to prolong cardiac repolarization, predisposing individuals to life-threatening ventricular arrhythmias known as Torsades de Pointes. Most of these drugs are known to interfere with the human ether à-gogo related gene 1 (hERG1 channel, whose current is one of the main determinants of action potential duration. Prolonged repolarization is reflected by lengthening of the QT interval of the electrocardiogram, as seen in the suitably named drug-induced long QT syndrome. Chirality (presence of an asymmetric atom is a common feature of marketed drugs, which can therefore exist in at least two enantiomers with distinct three-dimensional structures and possibly distinct biological fates. Both the pharmacokinetic and pharmacodynamic properties can differ between enantiomers, as well as also between individuals who take the drug due to metabolic polymorphisms. Despite the large number of reports about drugs reducing the hERG1 current, potential stereoselective contributions have only been scarcely investigated. In this review, we present a non-exhaustive list of clinically important molecules which display chiral toxicity that may be related to hERG1-blocking properties. We particularly focus on methadone cardiotoxicity, which illustrates the importance of the stereoselective effect of drug chirality as well as individual variations resulting from pharmacogenetics. Furthermore, it seems likely that, during drug development, consideration of chirality in lead optimization and systematic assessment of the hERG1 current block with all enantiomers could contribute to the reduction of the risk of drug-induced LQTS.

  18. Stereoselectivity of the distribution of labelled noradrenaline in rabbit aortic strips after inhibition of the noradrenaline-metabolizing enzymes

    Energy Technology Data Exchange (ETDEWEB)

    Eckert, E; Henseling, M; Gescher, A; Trendelenburg, U [Wuerzburg Univ. (Germany, F.R.). Inst. fuer Pharmakologie und Toxikologie

    1976-01-01

    Rabbit aortic strips (nerve-free, reserpinepretreated or normal) whose noradrenaline-metabolizing enzymes were inhibited (by in vitro treatment with 0.5 mM pargyline for 30 min and by the presence of 0.1 mM U-0521) were exposed to 1.18 ..mu..M labelled (-)- or (+)noradrenaline for 30 min. At the end of the incubation period some strips were used for analysis of radioactivity (i.e., of noradrenaline and its metabolites), while for others the efflux of radioactivity was determined during 250 min of washout with amine-free solution. An estimate of the original distribution of the amine into the various extraneuronal and neuronal compartments of the tissue was obtained by compartmental analysis of the efflux curves. The mechanisms responsible for the accumulation of radioactivity in extraneuronal and axoplasmic compartments lack stereoselectivity; the rate constants for the efflux of radioactivity from these compartments are the same for (-)- and (+)noradrenaline. Despite the use of enzyme inhibitors, the 'late neuronal efflux' of radioactivity (i.e., the efflux collected between the 200th and 250th min of wash out) contained a considerable proportion of metabolites of noradrenaline. The metabolism of noradrenaline was stereoselective: while dihydroxyphenylglycol (DOPEG) was the predominant metabolite in the efflux from strips incubated with (-)noradrenaline, a considerable part of the efflux from strips incubated with the (+)isomer consisted of dihydroxymandelic acid and 'O-methylated and deaminated' metabolites (in addition to DOPEG).

  19. Stereoselectivity of the distribution of labelled noradrenaline in rabbit aortic strips after inhibition of the noradrenaline-metabolizing enzymes

    International Nuclear Information System (INIS)

    Eckert, E.; Henseling, M.; Gescher, A.; Trendelenburg, U.

    1976-01-01

    Rabbit aortic strips (nerve-free, reserpinepretreated or normal) whose noradrenaline-metabolizing enzymes were inhibited (by in vitro treatment with 0.5 mM pargyline for 30 min and by the presence of 0.1 mM U-0521) were exposed to 1.18 μM labelled (-)- or (+)noradrenaline for 30 min. At the end of the incubation period some strips were used for analysis of radioactivity (i.e., of noradrenaline and its metabolites), while for others the efflux of radioactivity was determined during 250 min of washout with amine-free solution. An estimate of the original distribution of the amine into the various extraneuronal and neuronal compartments of the tissue was obtained by compartmental analysis of the efflux curves. The mechanisms responsible for the accumulation of radioactivity in extraneuronal and axoplasmic compartments lack stereoselectivity; the rate constants for the efflux of radioactivity from these compartments are the same for (-)- and (+)noradrenaline. Despite the use of enzyme inhibitors, the 'late neuronal efflux' of radioactivity (i.e., the efflux collected between the 200th and 250th min of wash out) contained a considerable proportion of metabolites of noradrenaline. The metabolism of noradrenaline was stereoselective: while dihydroxyphenylglycol (DOPEG) was the predominant metabolite in the efflux from strips incubated with (-)noradrenaline, a considerable part of the efflux from strips incubated with the (+)isomer consisted of dihydroxymandelic acid and 'O-methylated and deaminated' metabolites (in addition to DOPEG). (orig/GSE) [de

  20. Obituary: Michael John Klein, 1940-2005

    Science.gov (United States)

    Gulkis, Samuel

    2006-12-01

    Michael John Klein died on 14 May 2005 at home in South Pasadena, California. The cause of death was tongue cancer that metastasized to the lungs. He was a non-smoker. Mike was a passionate radio astronomer, a trusted astronomical observer, an educator and a family man. Mike was born on 19 January 1940 in Ames, Iowa, the son of Florence Marie (Graf) and Fred Michael Klein. His mother was a homemaker, and his father was a banker. Mike had two older sisters, Lois Jean (Klein) Flauher and Marilyn June (Klein) Griffin. In 1962, Mike married his high school sweetheart Barbara Dahlberg, who survives him along with their three children, Kristin Marie (Klein) Shields, Michael John Klein Jr., Timothy Joel Klein, and six grandchildren. Mike developed a love for astronomy early in his life, and credited an early morning, newspaper-delivery route that he had at age twelve, which took him outside well before sunrise. He told family members that as he walked along his route, he stared into the sky and wondered what everything was. He studied sky charts, located stars, and began to understand how the planets shifted their positions relative to the stars each day. Another big influence in Mike's life was his brother in-law, Jim Griffin. Jim helped Mike understand that his passion for science did not have to remain a hobby, but could and should become a career. Jim's encouragement led Mike to attend Iowa State University in Ames, where he earned a BS in electrical engineering in 1962. Mike then started graduate school in electrical engineering at Michigan State, but after one semester transferred to the University of Michigan, Ann Arbor, where he earned an MS (1966) and PhD (1968) in astronomy. His doctoral dissertation, under the direction of Professor Fred Haddock, was based on extensive observations of the planets and examined the physical and thermal properties of planetary atmospheres and surfaces. Mike was awarded a Resident Research Associate position at JPL by the National

  1. Race, punishment, and the Michael Vick experience.

    Science.gov (United States)

    Piquero, Alex R; Piquero, Nicole Leeper; Gertz, Marc; Baker, Thomas; Batton, Jason; Barnes, J C

    2011-01-01

    Objective. The relationship between race and crime has been contentious, focusing primarily on offending and incarceration patterns among minorities. There has been some limited work on public perceptions of criminal punishment, and findings show that while minorities believe in the role and rule of law, they simultaneously perceive the justice system as acting in a biased and/or unfair manner. Two limitations have stalled this literature. First, research has focused mainly on criminal punishments to the neglect of noncriminal punishments. Second, most studies have not examined whether race remains salient after considering other demographic variables or discrimination and legitimacy attitudes.Methods. Using data from 400 adults, we examine how race affects perceptions of criminal punishment and subsequent reinstatement into the National Football League in the case of Michael Vick, a star professional quarterback who pled guilty to charges of operating an illegal dog-fighting ring.Results. Findings show that whites are more likely to view Vick's punishment as too soft and that he should not be reinstated, while nonwhites had the opposite views. Race remained significant after controlling for other variables believed to be related to punishment perceptions.Conclusion. Attitudes toward both criminal punishment and NFL reinstatement vary across race such that there exists important divides in how individuals perceive the system meting out punishment and subsequently reintegrating offenders back into society. These results underscore that white and nonwhites perceive the law and its administration differently.

  2. One-pot cascade michael.cyclization reactions of ο-hydroxycinnamaldehydes: Synthesis of functionalized 2,3-dihydrobenzofuranes

    International Nuclear Information System (INIS)

    Gwon, Sung Hyuk; Kim, Sunggon

    2012-01-01

    We described the cascade Michael.cyclization reaction of o-hydroxycinnamaldehydes with diethyl α-bromomalonate promoted by potassium carbonate. The reactions provided functionalized 2,3-dihydrobenzofurans in good yields for a variety of o-hydroxyaromatic α,β-unsaturated aldehydes. Current work focuses on expanding the scope of this reaction to other substrates such as sulfur yields, and on developing an efficient catalytic asymmetric variant. 2,3-Dihydrobenzofurans are found in numerous biologically active natural products and synthetic compounds. These are an attractive type of oxygenated compound because their basic core skeleton is present in neolignans, pterocarpans, and synthetic drugs used in the treatment of pulmonary hypertension, atherosclerotic peripheral arterial disease, and central nervous system trauma and ischemia. Owing to the importance of their structures, numerous synthetic methods for 2,3-dihydrobenzofurans have been developed, primarily: radical cyclizations, Lewis acid promoted reactions, anionic cyclizations, and transition-metal catalyzed processes. However, these methods cannot be generalized as much as is desirable, and they yielded poor chemo- and/or stereoselectivities. Hence, the development of an efficient enantioselective synthetic method for obtaining 2,3-dihydrobenzofuran scaffolds attracted our attention

  3. One-pot cascade michael.cyclization reactions of ο-hydroxycinnamaldehydes: Synthesis of functionalized 2,3-dihydrobenzofuranes

    Energy Technology Data Exchange (ETDEWEB)

    Gwon, Sung Hyuk; Kim, Sunggon [Kyonggi Univ., Suwon (Korea, Republic of)

    2012-04-15

    We described the cascade Michael.cyclization reaction of o-hydroxycinnamaldehydes with diethyl α-bromomalonate promoted by potassium carbonate. The reactions provided functionalized 2,3-dihydrobenzofurans in good yields for a variety of o-hydroxyaromatic α,β-unsaturated aldehydes. Current work focuses on expanding the scope of this reaction to other substrates such as sulfur yields, and on developing an efficient catalytic asymmetric variant. 2,3-Dihydrobenzofurans are found in numerous biologically active natural products and synthetic compounds. These are an attractive type of oxygenated compound because their basic core skeleton is present in neolignans, pterocarpans, and synthetic drugs used in the treatment of pulmonary hypertension, atherosclerotic peripheral arterial disease, and central nervous system trauma and ischemia. Owing to the importance of their structures, numerous synthetic methods for 2,3-dihydrobenzofurans have been developed, primarily: radical cyclizations, Lewis acid promoted reactions, anionic cyclizations, and transition-metal catalyzed processes. However, these methods cannot be generalized as much as is desirable, and they yielded poor chemo- and/or stereoselectivities. Hence, the development of an efficient enantioselective synthetic method for obtaining 2,3-dihydrobenzofuran scaffolds attracted our attention.

  4. Michael Polanyi: Patriarch of Chemical Dynamics and Tacit Knowing.

    Science.gov (United States)

    Herschbach, Dudley R

    2017-03-20

    Connecting Science and the Humanities was the title of the symposium on Michael Polanyi that took place at the Technische Universität Berlin (Technical University of Berlin) in October 2016. This essay, which appraises the scientific and philosophical contributions of Michael Polanyi, is based on the presentation given by Dr. Herschbach on this occasion. In the photograph: Polanyi in 1931. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. Comparing Different Strategies in Directed Evolution of Enzyme Stereoselectivity: Single- versus Double-Code Saturation Mutagenesis.

    Science.gov (United States)

    Sun, Zhoutong; Lonsdale, Richard; Li, Guangyue; Reetz, Manfred T

    2016-10-04

    Saturation mutagenesis at sites lining the binding pockets of enzymes constitutes a viable protein engineering technique for enhancing or inverting stereoselectivity. Statistical analysis shows that oversampling in the screening step (the bottleneck) increases astronomically as the number of residues in the randomization site increases, which is the reason why reduced amino acid alphabets have been employed, in addition to splitting large sites into smaller ones. Limonene epoxide hydrolase (LEH) has previously served as the experimental platform in these methodological efforts, enabling comparisons between single-code saturation mutagenesis (SCSM) and triple-code saturation mutagenesis (TCSM); these employ either only one or three amino acids, respectively, as building blocks. In this study the comparative platform is extended by exploring the efficacy of double-code saturation mutagenesis (DCSM), in which the reduced amino acid alphabet consists of two members, chosen according to the principles of rational design on the basis of structural information. The hydrolytic desymmetrization of cyclohexene oxide is used as the model reaction, with formation of either (R,R)- or (S,S)-cyclohexane-1,2-diol. DCSM proves to be clearly superior to the likewise tested SCSM, affording both R,R- and S,S-selective mutants. These variants are also good catalysts in reactions of further substrates. Docking computations reveal the basis of enantioselectivity. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. Stereoselective in vitro metabolism of rhynchophylline and isorhynchophylline epimers of Uncaria rhynchophylla in rat liver microsomes.

    Science.gov (United States)

    Wang, Xin; Qiao, Zhou; Liu, Jia; Zheng, Mei; Liu, Wenyuan; Wu, Chunyong

    2017-11-10

    1. The objective was to investigate the underlying mechanism of the stereoselectivity in the metabolism of rhynchophylline (RIN) and isorhynchophylline (IRN) epimers in rat liver microsomes (RLM). 2. After incubation, eight metabolites of RIN (M1-5) and IRN (M6-8) reacted at A- and C-ring were identified using LC-Q-TOF/MS. Metabolic pathways included oxidation, hydroxylation, N-oxidation and dehydrogenation. In addition, hydroxylation at A-ring was the major metabolic pathway for RIN whereas the oxidation at C-ring was the major one for IRN. 3. Enzyme kinetics showed that the intrinsic clearance (CL int ) for IRN elimination was 1.9-fold higher than RIN and the degradation half-life (T 1/2 ) of RIN was 4.7-fold higher than that of IRN, indicating IRN was more favorable to be metabolized than RIN in RLM. 4. Data from chemical inhibition study demonstrated CYP3A was the predominant isoform involved in the metabolic elimination of both epimers, as well as the formation of M1-8. 5. In conclusion, data revealed that due to the spatial configurations at C-7 position, RIN and IRN epimers possessed different hepatic metabolic pathways and elimination rates which were mainly mediated by CYP3A.

  7. Stereoselectivity of Mucorales lipases toward triradylglycerols--a simple solution to a complex problem.

    Science.gov (United States)

    Scheib, H.; Pleiss, J.; Kovac, A.; Paltauf, F.; Schmid, R. D.

    1999-01-01

    The lipases from Rhizopus and Rhizomucor are members of the family of Mucorales lipases. Although they display high sequence homology, their stereoselectivity toward triradylglycerols (sn-2 substituted triacylglycerols) varies. Four different triradylglycerols were investigated, which were classified into two groups: flexible substrates with rotatable O'-C1' ether or ester bonds adjacent to C2 of glycerol and rigid substrates with a rigid N'-C1' amide bond or a phenyl ring in sn-2. Although Rhizopus lipase shows opposite stereopreference for flexible and rigid substrates (hydrolysis in sn-1 and sn-3, respectively), Rhizomucor lipase hydrolyzes both groups of triradylglycerols preferably in sn-1. To explain these experimental observations, computer-aided molecular modeling was applied to study the molecular basis of stereoselectivity. A generalized model for both lipases of the Mucorales family highlights the residues mediating stereoselectivity: (1) L258, the C-terminal neighbor of the catalytic histidine, and (2) G266, which is located in a loop contacting the glycerol backbone of a bound substrate. Interactions with triradylglycerol substrates are dominated by van der Waals contacts. Stereoselectivity can be predicted by analyzing the value of a single substrate torsion angle that discriminates between sn-1 and sn-3 stereopreference for all substrates and lipases investigated here. This simple model can be easily applied in enzyme and substrate engineering to predict Mucorales lipase variants and synthetic substrates with desired stereoselectivity. PMID:10210199

  8. Stereoselective Synthesis of Tetrasubstituted Furylalkenes via Gold-Catalyzed Cross-Coupling of Enynones with Diazo Compounds.

    Science.gov (United States)

    Liu, Pei; Sun, Jiangtao

    2017-07-07

    A stereoselective, gold-catalyzed, cross-coupling reaction of enynones with diazo compounds has been developed, affording 2-alkenylfurans in moderate to good yields with excellent E-stereoselectivity. Upon using diazo compounds as nucleophiles to trap the in situ formed gold furyl carbene, this protocol provides a novel path toward the formation of unsymmetrical tetrasubstituted alkenes.

  9. Principles of Chemistry (by Michael Munowitz)

    Science.gov (United States)

    Kovac, Reviewed By Jeffrey

    2000-05-01

    At a time when almost all general chemistry textbooks seem to have become commodities designed by marketing departments to offend no one, it is refreshing to find a book with a unique perspective. Michael Munowitz has written what I can only describe as a delightful chemistry book, full of conceptual insight, that uses a novel and interesting pedagogic strategy. This is a book that has much to recommend it. This is the best-written general chemistry book I have ever read. An editor with whom I have worked recently remarked that he felt his job was to help authors make their writing sing. Well, the writing in Principles of Chemistry sings with the full, rich harmonies and creative inventiveness of the King's Singers or Chanticleer. Here is the first sentence of the introduction: "Central to any understanding of the physical world is one discovery of paramount importance, a truth disarmingly simple yet profound in its implications: matter is not continuous." This is prose to be savored and celebrated. Principles of Chemistry has a distinct perspective on chemistry: the perspective of the physical chemist. The focus is on simplicity, what is common about molecules and reactions; begin with the microscopic and build bridges to the macroscopic. The author's perspective is clear from the organization of the book. After three rather broad introductory chapters, there are four chapters that develop the quantum mechanical theory of atoms and molecules, including a strong treatment of molecular orbital theory. Unlike many books, Principles of Chemistry presents the molecular orbital approach first and introduces valence bond theory later only as an approximation for dealing with more complicated molecules. The usual chapters on descriptive inorganic chemistry are absent (though there is an excellent chapter on organic and biological molecules and reactions as well as one on transition metal complexes). Instead, descriptive chemistry is integrated into the development of

  10. Highly Stereoselective Synthesis of Cyclopentanes bearing Four Stereocenters by a Rhodium Carbene–Initiated Domino Sequence

    Science.gov (United States)

    Parr, Brendan T.; Davies, Huw M. L.

    2014-01-01

    Stereoselective synthesis of a cyclopentane nucleus by convergent annulations constitutes a significant challenge for synthetic chemists. Though a number of biologically relevant cyclopentane natural products are known, more often than not, the cyclopentane core is assembled in a stepwise fashion due to lack of efficient annulation strategies. Herein, we report the rhodium-catalyzed reactions of vinyldiazoacetates with (E)-1,3-disubstituted 2-butenols generate cyclopentanes, containing four new stereogenic centers with very high levels of stereoselectivity (99% ee, >97 : 3 dr). The reaction proceeds by a carbene–initiated domino sequence consisting of five distinct steps: rhodium–bound oxonium ylide formation, [2,3]-sigmatropic rearrangement, oxy-Cope rearrangement, enol–keto tautomerization, and finally an intramolecular carbonyl ene reaction. A systematic study is presented detailing how to control chirality transfer in each of the four stereo-defining steps of the cascade, consummating in the development of a highly stereoselective process. PMID:25082301

  11. Guest Foreword from Michael Thomas CMG QC

    Directory of Open Access Journals (Sweden)

    Michael Thomas

    2012-04-01

    precedents and thought in a unique legal market in which ideas drawn from Islamic law, civil law and common law can intermingle and blend. It is not surprising therefore to see that this new publication will be dedicated to the subject of international law, both public and private. Its laudable aim is to promote legal discourse around the world, and to promote a wider international understanding of contemporary legal issues for the common benefit. As an open access, bilingual journal, addressing topics concerning any jurisdiction, I hope it will reach a wide audience, and fulfil its aim of promoting understanding between different cultures. I am sure that the journal will not only benefit Qatar’s legal community by advancing academic and practice-based legal discussion. I am also confident that it will stimulate thought in the global legal community at large. May I wish it every success and a long life. Michael Thomas CMG QC

  12. CuI/Pd0 cooperative dual catalysis: tunable stereoselective construction of tetra-substituted alkenes.

    Science.gov (United States)

    Vercruysse, Sébastien; Cornelissen, Loïc; Nahra, Fady; Collard, Laurent; Riant, Olivier

    2014-02-10

    This paper describes a tunable and stereoselective dual catalytic system that uses copper and palladium reagents. This cooperative silylcupration and palladium-catalyzed allylation readily affords trisubstituted alkenylsilanes. Fine-tuning the reaction conditions allows selective access to one stereoisomer over the other. This new methodology tolerates different substituents on both coupling partners with high levels of stereoselectivity. The one-pot reaction involving a Cu(I)/Pd(0) cooperative dual catalyst directly addresses the need to develop more time-efficient and less-wasteful synthetic pathways. Copyright © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Diversity-Oriented Syntheses by Combining CuAAC and Stereoselective INCIC Reactions with Peptides

    DEFF Research Database (Denmark)

    Wang, Yuanyuan; Madsen, Anders; Diness, Frederik

    2017-01-01

    Cascade reactions proceeding through peptide-derived N-carbamoyl iminium ions are reported. Two new reactions of N-carbamoyl iminium ions are described, including a stereoselective double cyclization generating N,N′-aminals and an acid-promoted auto-oxidation. Mechanistic investigations revealed...... that the N,N′-aminal formation is reversible under strongly acidic conditions. Both of these new reactions proved to be completely orthogonal to subsequent CuAAC chemistry. The reactions were performed in solution and on solid support. The robustness and high stereoselectivity of the methodology holds great...

  14. Stereoselective synthesis of hernandulcin, peroxylippidulcine A, lippidulcines A, B and C and taste evaluation

    Directory of Open Access Journals (Sweden)

    Marco G. Rigamonti

    2015-11-01

    Full Text Available The first stereoselective synthesis of lippidulcines A, B and C has been accomplished starting from (+-hernandulcin, which has been prepared on a multigram scale. The previously assigned absolute configurations have been confirmed. The key steps of this synthesis are based on a modified version of the Kornblum–DeLaMare rearrangement, and on a highly regioselective and stereoselective ketone reduction with the MeCBS reagent. The taste evaluations indicate that none of these sesquiterpenes are sweet, instead the lippidulcine A is a cooling agent with a mint after taste.

  15. Isoindolinones as Michael Donors under Phase Transfer Catalysis: Enantioselective Synthesis of Phthalimidines Containing a Tetrasubstituted Carbon Stereocenter

    Directory of Open Access Journals (Sweden)

    Francesco Scorzelli

    2015-05-01

    Full Text Available Readily available chiral ammonium salts derived from cinchona alkaloids have proven to be effective phase transfer catalysts in the asymmetric Michael reaction of 3-substituted isoindolinones. This protocol provides a convenient method for the construction of valuable asymmetric 3,3-disubstituted isoindolinones in high yields and  moderate to good enantioselectivity. Diastereoselectivity was also investigated in the construction of contiguous tertiary and quaternary stereocenters. The use of acrolein as Michael acceptor led to an interesting tricyclic derivative, a pyrroloisoindolinone analogue, via a tandem conjugated addition/cyclization reaction.

  16. Michael Novak's "Business as a Calling" as a Vehicle for Addressing Ethical and Policy Concerns in a Business Law Course

    Science.gov (United States)

    Murphy, Tonia Hap

    2008-01-01

    This article describes the author's experience of incorporating Michael Novak's "Business as a Calling: Work and the Examined Life" into a Business Law course. The author views it as a positive addition to the course, one that may be of interest to her colleagues at other institutions. Accordingly, after an overview of Novak's analysis in…

  17. Obituary: Michael John Seaton, 1923-2007

    Science.gov (United States)

    Pradhan, Anil; Nahar, Sultana

    2007-12-01

    Professor Michael John Seaton, hailed as the "Father of Atomic Astrophysics," passed away on May 29, 2007. He was one of the few Honorary Fellows of both the American Astronomical Society and the American Physical Society, so honored for his monumental contributions to both physics and astronomy. Mike Seaton was born on January 16, 1923 in Bristol, England. He attended Wallington County High School. But his leftist political activities, even at that stage, led to his expulsion, though he was eventually allowed to matriculate. He enlisted in the Royal Air Force as a navigator during the Second World War, and flew many dangerous missions. His legendary concentration and precision are reflected in the following anecdote. Once after a bombing mission his aircraft was lost in fog over the Alps. Seaton calculated the position and coordinates in flight to guide the aircraft. When the fog lifted, the crew found themselves flying perilously close to the mountains, but made it safely back. His associates often said, "A Seaton calculation is carried out as if his life depended on it." After the War he was admitted to University College London (UCL) as an undergraduate. Thereafter, he spent all of his professional career at UCL. Seaton received his Batchelor's degree in 1948, and his Ph.D. in 1951. His tenure at UCL coincided with the golden age of atomic astrophysics, for he was largely responsible for it. Seaton was elected Fellow of the Royal Society in 1967, and as President of the Royal Astronomical Society (RAS) in 1978. He was the recipient of an Honorary Doctorate from the Observatoire de Paris, an Honorary D.Sc. from the Queen's University of Belfast, the Gold Medal for Astronomy by the RAS, the Guthrie Medal by the Institute of Physics, the Royal Society Hughes award for lifetime work by the RAS, and several other prestigious awards. Nevertheless, as Alex Dalgarno recently remarked, Seaton was not part of the establishment because he chose not to be. Though rooted in

  18. Differences of first-pass effect in the liver and intestine contribute to the stereoselective pharmacokinetics of rhynchophylline and isorhynchophylline epimers in rats.

    Science.gov (United States)

    Wang, Xin; Zheng, Mei; Liu, Jia; Huang, Zhifeng; Bai, Yidan; Ren, Zhuoying; Wang, Ziwen; Tian, Yangli; Qiao, Zhou; Liu, Wenyuan; Feng, Feng

    2017-09-14

    Uncaria rhynchophylla (Miq.) Miq. ex Havil., is a plant species used in traditional Chinese medicine to treat cardiovascular and central nervous system diseases. Rhynchophylline (RIN) and isorhynchophylline (IRN), a pair of epimers, are major alkaloids isolated from U. rhynchophylla and exhibit diverse pharmacological effects. Our previous study demonstrated that the pharmacokinetics of these epimers existed stereoselectivity after oral administration; however, the specific mechanism remains unknown and merits investigation. In the present study, the aim was to elucidate the mechanism underlying stereoselective pharmacokinetic characteristics of RIN and IRN in rats. The total (F), hepatic (F h ) and intestinal (F a ·F g ) bioavailabilities of each epimer were measured using portal vein cannulated rats following different dosing routes (intravenous, intraportal and intraduodenal) to assess individual contributions of the liver and intestine in stereoselective pharmacokinetics. Then the differences of first-pass metabolism in the liver and intestine between two epimers were evaluated by in vitro incubation with rat liver microsomes, intestinal S9 and gastrointestinal (GI) content solutions, respectively. Meanwhile, the membrane permeability and efflux by P-glycoprotein (P-gp) were examined by in situ single-pass intestinal perfusion with and without P-gp inhibitor verapamil. The configurational interconversion at different pH values and the excretions via feces and urine were also examined. Pharmacokinetic data showed that the total bioavailability of RIN was 5.9 folds higher than that of IRN (23.4% vs. 4.0%). The hepatic availability of RIN was 4.6 folds higher than that of IRN (46.9% vs. 10.3%), whereas the intestinal availability of RIN (48.1%) was comparable to that of IRN (42.7%). In addition, intestinal perfusion showed that IRN possessed higher intestinal permeability than RIN and co-perfusion with verapamil could affect absorption process of RIN but not IRN

  19. Stereoselectivity in bioaccumulation and excretion of epoxiconazole by mealworm beetle (Tenebrio molitor) larvae.

    Science.gov (United States)

    Lv, Xiaotian; Liu, Chen; Li, Yaobin; Gao, Yongxin; Wang, Huili; Li, Jianzhong; Guo, Baoyuan

    2014-09-01

    Stereoselectivity in bioaccumulation and excretion of stereoisomers of epoxiconazole by mealworm beetle (Tenebrio molitor) larvae through dietary exposure was investigated. Liquid chromatography tandem mass spectrometry (HPLC-MS/MS) method that use a ChiralcelOD-3R[cellulosetris-Tris-(3, 5-dichlorophenyl-carbamate)] chromatography column was applied to carry out chiral separation of the stereoisomers. Wheat bran was spiked with racemic epoxiconazole at two dose levels of 20mg/kg and 2mg/kg (dry weight) to feed T. molitor larvae. The results showed that both the doses of epoxiconazole were taken up by Tenebrio molitor larvae rapidly at the initial stages. There was a significant trend of stereoselective bioaccumulation in the larvae with a preferential accumulation of (-)-epoxiconazole in the 20mg/kg dose. The stereoselectivity in bioaccumulation in the 2mg/kg dosage was not obvious compared to the 20mg/kg group. Results of excretion indicated an active excretion is an important pathway for the larvae to eliminate epoxiconazole which was a passive transport process with non stereoselectivity. The faster elimination might be the reason for the low accumulation of epoxiconazole, as measured by bioaccumulation factor (BAF). Copyright © 2014 Elsevier Inc. All rights reserved.

  20. Stereoselective synthesis of a-hydroxy-b-amino acids: the chiral pool approach

    Directory of Open Access Journals (Sweden)

    RADOMIR N. SAICIC

    2004-11-01

    Full Text Available A method for the stereoselective homologation of a-amino acids into syn-a-hydroxy-b-amino acids is described, based on the conversion of stereoisomeric cyanohydrins into trans-oxazolines. The synthetic potential of the method is illustrated in the enantioselective formal synthesis of Bestatin.

  1. DFT study of the mechanism and stereoselectivity of the 1,3-dipolar ...

    Indian Academy of Sciences (India)

    and methyl acrylate) using DFT method. An ana- lysis of ..... field (SCRF)30,46 model based on the polarizable con- tinuum model (PCM) of Tomasi's group47 have been applied. ... stereoselectivity relative to the gas-phase since the trends of ...

  2. Catalytic stereoselective synthesis of highly substituted indanones via tandem Nazarov cyclization and electrophilic fluorination trapping.

    Science.gov (United States)

    Nie, Jing; Zhu, Hong-Wei; Cui, Han-Feng; Hua, Ming-Qing; Ma, Jun-An

    2007-08-02

    A new catalytic stereoselective tandem transformation via Nazarov cyclization/electrophilic fluorination has been accomplished. This sequence is efficiently catalyzed by a Cu(II) complex to afford fluorine-containing 1-indanone derivatives with two new stereocenters with high diastereoselectivity (trans/cis up to 49/1). Three examples of catalytic enantioselective tandem transformation are presented.

  3. Stereoselectivity of sodium borohydride reduction of saturated steroidal ketones utilizing conditions of Luche reduction

    Czech Academy of Sciences Publication Activity Database

    Šťastná, Eva; Černý, Ivan; Pouzar, Vladimír; Chodounská, Hana

    2010-01-01

    Roč. 75, č. 10 (2010), s. 721-725 ISSN 0039-128X R&D Projects: GA ČR(CZ) GA203/08/1498; GA MŠk(CZ) LC06077 Institutional research plan: CEZ:AV0Z40550506 Keywords : steroid * synthesis * stereoselectivity Subject RIV: CC - Organic Chemistry Impact factor: 3.106, year: 2010

  4. Stereoselective total syntheses of three Lycopodium alkaloids, (-)-magellanine, (+)-magellaninone, and (+)-paniculatine, based on two Pauson-Khand reactions.

    Science.gov (United States)

    Kozaka, Takashi; Miyakoshi, Naoki; Mukai, Chisato

    2007-12-21

    The total syntheses of (-)-magellanine, (+)-magellaninone, and (+)-paniculatine were completed from diethyl l-tartrate via the common intermediate in a stereoselective manner. The crucial steps in these syntheses involved two intramolecular Pauson-Khand reactions of enynes: the first Pauson-Khand reaction constructed the bicyclo[4.3.0] carbon framework, the corresponding A and B rings of these alkaloids in a highly stereoselective manner, whereas the second Pauson-Khand reaction stereoselectively produced the bicyclo[3.3.0]skeleton, which could be converted into the C and D rings of the target natural products.

  5. Stereoselective and regiospecific hydroxylation of ketamine and norketamine.

    Science.gov (United States)

    Desta, Zeruesenay; Moaddel, Ruin; Ogburn, Evan T; Xu, Cong; Ramamoorthy, Anuradha; Venkata, Swarajya Lakshmi Vattem; Sanghvi, Mitesh; Goldberg, Michael E; Torjman, Marc C; Wainer, Irving W

    2012-11-01

    The objective was to determine the cytochrome P450s (CYPs) responsible for the stereoselective and regiospecific hydroxylation of ketamine [(R,S)-Ket] to diastereomeric hydroxyketamines, (2S,6S;2R,6R)-HK (5a) and (2S,6R;2R,6S)-HK (5b) and norketamine [(R,S)-norKet] to hydroxynorketamines, (2S,6S;2R,6R)-HNK (4a), (2S,6R;2R,6S)-HNK (4b), (2S,5S;2R,5R)-HNK (4c), (2S,4S;2R,4R)-HNK (4d), (2S,4R;2R,4S)-HNK (4e), (2S,5R;2R,5S)-HNK (4f). The enantiomers of Ket and norKet were incubated with characterized human liver microsomes (HLMs) and expressed CYPs. Metabolites were identified and quantified using LC/MS/MS and apparent kinetic constants estimated using single-site Michaelis-Menten, Hill or substrate inhibition equation. 5a was predominantly formed from (S)-Ket by CYP2A6 and N-demethylated to 4a by CYP2B6. 5b was formed from (R)- and (S)-Ket by CYP3A4/3A5 and N-demethylated to 4b by multiple enzymes. norKet incubation produced 4a, 4c and 4f and minor amounts of 4d and 4e. CYP2A6 and CYP2B6 were the major enzymes responsible for the formation of 4a, 4d and 4f, and CYP3A4/3A5 for the formation of 4e. The 4b metabolite was not detected in the norKet incubates. 5a and 4b were detected in plasma samples from patients receiving (R,S)-Ket, indicating that 5a and 5b are significant Ket metabolites. Large variations in HNK concentrations were observed suggesting that pharmacogenetics and/or metabolic drug interactions may play a role in therapeutic response.

  6. The stereoselective sulfate conjugation of 4'-methoxyfenoterol stereoisomers by sulfotransferase enzymes.

    Science.gov (United States)

    Iyer, Lalitha V; Ramamoorthy, Anuradha; Rutkowska, Ewelina; Furimsky, Anna M; Tang, Liang; Catz, Paul; Green, Carol E; Jozwiak, Krzysztof; Wainer, Irving W

    2012-10-01

    The presystemic sulfate conjugation of the stereoisomers of 4'-methoxyfenoterol, (R,R')-MF, (S,S')-MF, (R,S')-MF, and (S,R')-MF, was investigated using commercially available human intestinal S9 fractions, a mixture of sulfotransferase (SULT) enzymes. The results indicate that the sulfation was stereospecific and that an S-configuration at the β-OH carbon of the MF molecule enhanced the maximal formation rates with (S,R')-MF  (S,S')-MF  (R,S')-MF ≈ (R,R')-MF, and competition studies demonstrated that (S,R')-MF is an effective inhibitor of (R,R')-MF sulfation (IC(50) = 60 μM). In addition, the results from a cDNA-expressed human SULT isoform screen indicated that SULT1A1, SULT1A3, and SULT1E1 can mediate the sulfation of all four MF stereoisomers. Previously published molecular models of SULT1A3 and SULT1A1 were used in docking simulations of the MF stereoisomers using Molegro Virtual Docker. The models of the MF-SULT1A3 and MF-SULT1A1 complexes indicate that each of the two chiral centers of MF molecule plays a role in the observed relative stabilities. The observed stereoselectivity is the result of multiple hydrogen bonding interactions and induced conformational changes within the substrate-enzyme complex. In conclusion, the results suggest that a formulation developed from a mixture of (R,R')-MF and (S,R')-MF may increase the oral bioavailability of (R,R')-MF. Copyright © 2012 Wiley Periodicals, Inc.

  7. Cytochrome P-450 dependent ethanol oxidation. Kinetic isotope effects and absence of stereoselectivity

    International Nuclear Information System (INIS)

    Ekstroem, G.; Norsten, C.; Cronholm, T.; Ingelman-Sundberg, M.

    1987-01-01

    Deuterium isotope effects [/sup D/(V/K)] and stereoselectivity of ethanol oxidation in cytochrome P-450 containing systems and in the xanthine-xanthine oxidase system were compared with those of yeast alcohol dehydrogenase. The isotope effects were determined by using both a noncompetitive method, including incubation of unlabeled of [1,1- 2 H 2 ] ethanol at various concentrations, and a competitive method, where 1:1 mixtures of [1- 13 C]- and [ 2 H 6 ] ethanol or [2,2,2- 2 H 3 ]- and [1,1- 2 H 2 ] ethanol were incubated and the acetaldehyde formed was analyzed by gas chromatography/mass spectrometry. The /sup D/(V/K) isotope effects of the cytochrome P-450 dependent ethanol oxidation were about 4 with liver microsomes from imidazole-, phenobarbital- or acetone-treated rabbits or with microsomes from acetone- or ethanol-treated rats. Similar isotope effects were reached with reconstituted membranes containing the rabbit ethanol-inducible cytochrome P-450 (LMeb), whereas control rat microsomes and membranes containing rabbit phenobarbital-inducible P-450 LM 2 oxidized the alcohol with /sup D/(V/K) of about 2.8 and 1.8, respectively. Addition of Fe/sup III/EDTA either to microsomes from phenobarbital-treated rabbits or to membranes containing P-450 LMeb significantly lowered the isotope effect. Incubations of all cytochrome P-450 containing systems of the xanthine-xanthine oxidase systems with (1R)- and (1S)-[1- 2 H] ethanol, revealed, taking the isotope effects into account, that 44-66% of the ethanol oxidized had lost the 1-pro-R hydrogen. The data indicate that cytochrome P-450 dependent ethanol oxidation is not stereospecific and that cleavage of the C 1 -H bond appears to be a rate-determining step in the catalysis by the ethanol-inducible form of P-450. The contribution of hydroxyl radicals in ethanol oxidation by the various enzymic systems is discussed

  8. Tweeting Prayers and Communicating Grief over Michael Jackson Online

    Science.gov (United States)

    Sanderson, Jimmy; Cheong, Pauline Hope

    2010-01-01

    Death and bereavement are human experiences that new media helps facilitate alongside creating new social grief practices that occur online. This study investigated how people's postings and tweets facilitated the communication of grief after pop music icon Michael Jackson died. Drawing on past grief research, religion, and new media studies, a…

  9. Professor Porter ja tema viis konkurentsitegurit / Michael E Porter

    Index Scriptorium Estoniae

    Porter, Michael E

    2008-01-01

    Maailmas tuntud juhtimisguru Michael Porter viie konkurentsijõu teooriast ja selle rakendatavusest erinevates valdkondades. Lisad: Erinevused valdkondade kasumlikkuses; 5 määravat konkurentsijõudu; Investeeritud kapitali keskmine tasuvus; Mõnede USA tegevusvaldkondade kasumlikkus; Valdkonnaanalüüs praktikas; Valdkonna määratlemine; Valdkonnaanalüüsi sammud

  10. A Good Time: A Conversation with C. Michael Nelson

    Science.gov (United States)

    Zabel, Robert; Kaff, Marilyn; Teagarden, Jim

    2015-01-01

    C. Michael Nelson began his special education career as a teacher of adolescents with learning and behavior disorders. He has worked as a child psychologist and as a professor with the Department of Special Education and Rehabilitation Counseling at the University of Kentucky. He coordinated the graduate Personnel Preparation Program for Teachers…

  11. Eesti luksushotellide ristiisa / Michael Stenner ; interv. Malle Koido

    Index Scriptorium Estoniae

    Stenner, Michael

    2007-01-01

    Eesti tipphotelle 1997. aastast juhtinud sakslane, praegu hotellide Kolm Õde ja Telegraaf juht räägib Eesti ja Saksamaa erinevustest, Eesti hotelliärist, teeninduskultuurist ja personalist. Lisa: Kes on Michael Stenner ning kuidas ta Eestisse sattus? Ilmunud ka: Linnaleht : Pärnu, 23. veebr. 2007, lk. 5-6

  12. Michael Polanyi on the Education and Knowledge of Scientists.

    Science.gov (United States)

    Jacobs, Struan

    2000-01-01

    Explains why teachers addressing the nature of science should know the work of Michael Polanyi. Outlines Polanyi's intellectual career and examines his ideas on the education of scientists, research, and knowledge. Polanyi presaged Kuhn, Feyerabend, and the constructivists, yet insisted that science produces true knowledge about reality. (Contains…

  13. Michael Moore kaevati kohtusse pettuse eest / Mari Rebane

    Index Scriptorium Estoniae

    Rebane, Mari

    2006-01-01

    Dokumentaalfilm "9/11 Fahrenheiti" ("Fahrenheit 9/11") : režissöör Michael Moore : USA 2004. Iraagi sõja invaliidistunud veteran andis režissööri kohtusse teda kujutavate flmikaadrite loata ja tenentsliku kasutamise pärast

  14. Berliinis võidutses Michael Haneke / Jüri Laulik

    Index Scriptorium Estoniae

    Laulik, Jüri, 1959-

    2005-01-01

    IX PÖFFil linastuv Michael Haneke film "Varjatud" ("Cache") võitis laupäeval mitu Euroopa Filmiakadeemia auhinda, sealhulgas parima filmi, parima lavastaja ja parima meesnäitleja (Daniel Auteuil) auhinna. Parima naisnäitleja tiitli pälvis Julia Jentsch ("Sophie Scholli viimased päevad"). Elutööpreemia sai sir Sean Connery

  15. Educational Implications of Michael Fishbane's "Sacred Attunement: A Jewish Theology"

    Science.gov (United States)

    Marom, Daniel

    2008-01-01

    This article posits Michael Fishbane's Judaic scholarship as a prime resource for Jewish education. The link between the two fields can be made through a translation of the theological underpinnings of Fishbane's insights into Judaism to educational purposes and practices. Initial work with Jewish educators on establishing this link encouraged…

  16. Correspondence of Michael Faraday, v.5 1855-1860

    CERN Document Server

    Faraday, Michael

    2008-01-01

    This volume includes 70% of previously unpublished letters of Michael Farday spanning half of the 1850s and most of 1860. Topics include Faraday's work on regelation, the transmission of light through gold and his appointment by Emperor Napoleon III to be a Commander of the Legion of Honour.

  17. Michael Pärt ئ suure muusika taustajõud / Michael Pärt ; interv. Siim Nestor

    Index Scriptorium Estoniae

    Pärt, Michael

    2008-01-01

    Arvo Pärdi pojast Michael Pärdist. Tema tööst "music editor"-ina - helimonteerijana, tööst muusika produktsiooni, salvestamise ja muusika kirjutamise abijõuna. Koostööst maailmas tuntud muusikutega

  18. A stereoselective synthesis of (+)-physoperuvine using a tandem aza-Claisen rearrangement and ring closing metathesis reaction.

    Science.gov (United States)

    Zaed, Ahmed M; Swift, Michael D; Sutherland, Andrew

    2009-07-07

    A stereoselective synthesis of (+)-physoperuvine, a tropane alkaloid from Physalis peruviana Linne has been developed using a one-pot tandem aza-Claisen rearrangement and ring closing metathesis reaction to form the key amino-substituted cycloheptene ring.

  19. Stereo-selective hydrolytic reaction of toxic compounds by enzyme immobilized on porous ceramics; Takoshitsu ceramics kotaika koso ni yoru dokusei kagobutsu no rittai sentakuteki kasui bunkai hanno

    Energy Technology Data Exchange (ETDEWEB)

    Kato, K.; Saito, T. [National Industrial Research Institute of Nagoya, Nagoya (Japan)

    2000-08-25

    Experiment was made on stereo-selective hydrolytic reaction of trifluoroethyl ester of ketoprophene by various kinds of lipase. In addition, study was made on the stability of lipase simply immobilized on porous ceramics under the existence of organic solvent. In the experiment, the hydrolytic activity of 8 kinds of lipase was studied for ketoprophene monochloroethyl ester (1a) and trifluoroethyl ester (1b). The experiment result showed that lipase M originating in mold (Mucor Javanicus) shows a high reactivity and stereo-selectivity for the compound (1a). The lipase immobilized on porous ceramics was easily obtained by a very simple method composed of only throwing carriers into enzyme suspension, agitation and refrigerated drying. The lipase immobilized on porous ceramics 'Toyonite 200-A' synthesized from kaolinite retained the residual activity of nearly 50%, original selectivity and considerable stability after 5 times of repetitive uses. This study result is useful for bio- reactors and bio-sensors for synthesis or decomposition of compounds. (NEDO)

  20. Pengaruh Tipografi pada Era Massimo Vignelli terhadap Tipografi Michael Bierut

    Directory of Open Access Journals (Sweden)

    Irwan Harnoko

    2011-10-01

    Full Text Available Massimo Vignelli is a senior graphic designer lived in New York, as a vocal modernism against post-modernism. His statement firmly opposing post-modernism in several occasions: interview in Helvetica the movie, typeradio, talkshow, and some articles in Looking Closer or AIGA Journal. Graphic design works of Massimo Vignelli reflected his characteristic, which is firmly choosing typeface. Typefaces of Vignelly are around 5 typefaces: Bodoni, Helvetica, Times Roman, Century, and Futura. The article uses formal analysis method. The writers collected materials about Michael Bierut, Massimo VIgnelli and Tibor Kalman from books and websites. The writers compare the typeface opinion of Massimo Vignelli (modernism designer, Michael Bierut designer (transition era designer from modernism to post-modernism, and Tibor Kalman (a designer in A Century of Graphic Design, as the influencer of Bierut’s betrayal over Vignelli. 

  1. Tribute to Professor Anthony J. McMichael

    Directory of Open Access Journals (Sweden)

    Ashwin Swaminathan

    2014-11-01

    Full Text Available Emeritus Professor A. J. “Tony” McMichael (1942–2014 was an internationally renowned and pioneering Australian academic and advocate in epidemiology, who was passionate about understanding the influences of the environment on human health. In an illustrious career spanning more than four decades, he made significant contributions to the scientific community and policy discourse—including ground-breaking research related to the health of children. McMichael was a prolific academic writer with over 300 peer-reviewed papers; 160 book chapters and two sole-authored books. However, his outstanding talent was for integrating complex and seemingly unrelated strands from the environmental and health sciences into a cohesive narrative—and highlighting its relevance to lay persons, scientists and governments alike. He was instrumental in validating this nascent field of research and inspiring many others to follow his lead.

  2. A facile and efficient method of enzyme immobilization on silica particles via Michael acceptor film coatings: immobilized catalase in a plug flow reactor.

    Science.gov (United States)

    Bayramoglu, Gulay; Arica, M Yakup; Genc, Aysenur; Ozalp, V Cengiz; Ince, Ahmet; Bicak, Niyazi

    2016-06-01

    A novel method was developed for facile immobilization of enzymes on silica surfaces. Herein, we describe a single-step strategy for generating of reactive double bonds capable of Michael addition on the surfaces of silica particles. This method was based on reactive thin film generation on the surfaces by heating of impregnated self-curable polymer, alpha-morpholine substituted poly(vinyl methyl ketone) p(VMK). The generated double bonds were demonstrated to be an efficient way for rapid incorporation of enzymes via Michael addition. Catalase was used as model enzyme in order to test the effect of immobilization methodology by the reactive film surface through Michael addition reaction. Finally, a plug flow type immobilized enzyme reactor was employed to estimate decomposition rate of hydrogen peroxide. The highly stable enzyme reactor could operate continuously for 120 h at 30 °C with only a loss of about 36 % of its initial activity.

  3. Political Cinema and Culture industry: the work of Michael Moore

    OpenAIRE

    Cristiane Toledo Maria

    2015-01-01

    This article aims to reflect upon the production of the American filmmaker Michael Moore, proposing as a central question the relationship established between art and politics in a historical moment which, on one side, points to the crisis of capitalism and, on the other side, to the political fragmentation of the working class. Focusing on the analysis of the documentaries Roger & Me (1989) and Capitalism: a love story (2009), this article is an attempt to understand the method developed by ...

  4. Entretien avec Michael Quinn Patton | CRDI - Centre de recherches ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    9 févr. 2011 ... Michael Quinn Patton, évaluateur de renommée internationale, était récemment au CRDI .... C'est un mode de pensée analytique qui doit tout imprégner. ... des données solides et crédibles sur ce qui marche et ce qui ne marche pas. ... des emplois, des infrastructures et un accès à la nourriture et aux mar.

  5. Euroopa parimaks filmiks sai Michael Haneke "Valge lint" / Andres Laasik

    Index Scriptorium Estoniae

    Laasik, Andres, 1960-2016

    2009-01-01

    Euroopa Filmiakadeemia auhindadest: parima filmiauhinna sai Saksamaal Bochumis toimunud tseremoonial Michael Haneke "Valge lint", mille eest Haneke sai ka parima režissööri ja stsenaristi auhinna. Parimaks meesnäitlejaks pärjati Tahar Rahim ("Un Prophete"), parimaks naisnäitlejaks Kate Winslet ("The Reader"), publikupreemia sai Danny Boyle'i "Rentslimiljonär. Ka teistest võitjatest

  6. A multi-enzymatic cascade reaction for the stereoselective production of γ-oxyfunctionalyzed amino acids

    Directory of Open Access Journals (Sweden)

    Junichi eEnoki

    2016-04-01

    Full Text Available A stereoselective three-enzyme cascade for synthesis of diasteromerically pure γ-oxyfunctionalized α-amino acids was developed. By coupling a dynamic kinetic resolution using an N-acylamino acid racemase and an L-selective aminoacylase from Geobacillus thermoglucosidasius with a stereoselective isoleucine dioxygenase from Bacillus thuringiensis, diastereomerically pure oxidized amino acids were produced from racemic N-acetylamino acids. The three enzymes differ in their optimal temperature and pH-spectra. Their different metal cofactor dependencies lead to inhibitory effects. Under optimized conditions, racemic N-acetylmethionine was quantitatively converted into L-methionine-(S-sulfoxide with 97% conversion and 95% de. The combination of these three different biocatalysts allows the direct synthesis of diastereopure oxyfunctionalized amino acids from inexpensive racemic starting material.

  7. Marine Microorganisms as Source of Stereoselective Esterases and Ketoreductases: Kinetic Resolution of a Prostaglandin Intermediate

    KAUST Repository

    De Vitis, Valerio; Guidi, Benedetta; Contente, Martina Letizia; Granato, Tiziana Mariarita; Conti, Paola; Molinari, Francesco; Crotti, Elena; Mapelli, Francesca; Borin, Sara S.; Daffonchio, Daniele; Romano, Diego

    2014-01-01

    A screening among bacterial strains isolated from water-brine interface of the deep hypersaline anoxic basins (DHABs) of the Eastern Mediterranean was carried out for the biocatalytical resolution of racemic propyl ester of anti-2-oxotricyclo[2.2.1.0]heptan-7-carboxylic acid (R,S)-1, a key intermediate for the synthesis of d-cloprostenol. Bacillus horneckiae 15A gave highly stereoselective reduction of (R,S)-1, whereas Halomonas aquamarina 9B enantioselectively hydrolysed (R,S)-1; in both cases, enantiomerically pure unreacted (R)-1 could be easily recovered and purified at molar conversion below 57–58 %, showing the potential of DHAB extremophile microbiome and marine-derived enzymes in stereoselective biocatalysis.

  8. Stereoselective Carbonyl Olefination with Fluorosulfoximines: Facile Access to Z or E Terminal Monofluoroalkenes.

    Science.gov (United States)

    Liu, Qinghe; Shen, Xiao; Ni, Chuanfa; Hu, Jinbo

    2017-01-09

    Terminal monofluoroalkenes are important structural motifs in the design of bioactive compounds, such as homeostasis regulators and mechanism-based enzyme inhibitors. However, it is difficult to control the stereoselectivity of known carbonyl olefination reactions, and olefin metathesis is limited to disubstituted terminal monofluoroalkenes. Although sulfoximines have been used extensively in organic synthesis, reports on their use in carbonyl olefination reactions have not appeared to date. Herein, we report highly stereoselective carbonyl monofluoroolefination with a fluorosulfoximine reagent. The potential of this method is demonstrated by the synthesis of MDL 72161 and by the late-stage monofluoromethylenation of complex molecules, such as haloperidol and steroid derivatives. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. Exploiting Synergistic Effects in Organozinc Chemistry for Direct Stereoselective C-Glycosylation Reactions at Room Temperature.

    Science.gov (United States)

    Hernan-Gomez, Alberto; Orr, Samantha; Uzelac, Marina; Kennedy, Alan; Barroso, Santiago; Jusseau, Xavier; Lemaire, Sebastien; Farina, Vittorio; Hevia, Eva

    2018-06-01

    Pairing a range of bis(aryl) zinc reagents ZnAr2 with the stronger Lewis acidic [(ZnArF2)] (ArF = C6F5), enables highly stereoselective cross-coupling between glycosyl bromides and ZnAr2 without the use of a transition metal. Reactions occur at room temperature with excellent levels of stereoselectivity, where ZnArF2 acts as a non-coupling partner although its presence is crucial for the execution of the C(sp2)-C(sp3) bond formation process. Mechanistic studies have uncovered a unique synergistic partnership between the two zinc reagents, which circumvents the need for transition-metal catalysis or forcing reaction conditions. Key to the success of the coupling is the avoidance of solvents that act as Lewis bases vs. diarylzinc compounds (e.g. THF. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Marine Microorganisms as Source of Stereoselective Esterases and Ketoreductases: Kinetic Resolution of a Prostaglandin Intermediate

    KAUST Repository

    De Vitis, Valerio

    2014-09-30

    A screening among bacterial strains isolated from water-brine interface of the deep hypersaline anoxic basins (DHABs) of the Eastern Mediterranean was carried out for the biocatalytical resolution of racemic propyl ester of anti-2-oxotricyclo[2.2.1.0]heptan-7-carboxylic acid (R,S)-1, a key intermediate for the synthesis of d-cloprostenol. Bacillus horneckiae 15A gave highly stereoselective reduction of (R,S)-1, whereas Halomonas aquamarina 9B enantioselectively hydrolysed (R,S)-1; in both cases, enantiomerically pure unreacted (R)-1 could be easily recovered and purified at molar conversion below 57–58 %, showing the potential of DHAB extremophile microbiome and marine-derived enzymes in stereoselective biocatalysis.

  11. Stereoselective Phytotoxicity of HCH Mediated by Photosynthetic and Antioxidant Defense Systems in Arabidopsis thaliana

    OpenAIRE

    Zhang, Qiong; Zhou, Cong; Zhang, Quan; Qian, Haifeng; Liu, Weiping; Zhao, Meirong

    2013-01-01

    BACKGROUND: Hexachlorocyclohexane (HCH) has been used for plant protection and sanitation world-widely, and its isomers have been detected in water, soil, and air as well as in vegetation. As a sink for lipophilic pollutants, vegetation is very important for the degradation and fate of organic contamination; however, little was known about their phytotoxicity and mechanisms of toxic effect. In this study, the stereoselective phototoxicity of four isomers (α, β, γ, and δ) of HCHs mediated by i...

  12. Stereoselective total synthesis of the potent anti-asthmatic compound CMI-977 (LDP-977)

    Energy Technology Data Exchange (ETDEWEB)

    Dias, Luiz Carlos; Farina, Lui Strambi; Ferreira, Marco Antonio Barbosa, E-mail: ldias@iqm.unicamp.br [Universidade de Campinas (UNICAMP), SP (Brazil). Instituto de Quimica

    2013-02-15

    A short and efficient stereoselective total synthesis of CMI-977 (LDP-977), a potent and orally active anti-asthmatic compound, was developed. The key steps involve a highly diastereoselective Mukaiyama oxidative cyclization, which provides the trans-THF (tetrahydrofuran) unit and a Seyferth-Gilbert homologation to construct the triple bond in the target molecule. The synthesis of the key chiral building block was performed using Jacobsen hydrolytic kinetic resolution. (author)

  13. Stereoselective hydrogenation of H-alkynes on boron-nickel catalysts

    International Nuclear Information System (INIS)

    Petrova, S.S.; Sijmer, Eh.Kh.; Amitan, I.I.

    1992-01-01

    It is ascertained that in the course of stereoselective hydrogenation of H-alkynes on boron-nickel catalysts the contact modified by 2-phenyl-1,5 dimethylpyrasol-2-anom in the ratio Ni(2+):BH 4 -=1:5 is the most active and selective one. Moreover, cis-alkane was prepared with the yield of 94.5% and selective of 79%

  14. Biological stereoselective reduction of 3,3,5-trimethylcyclohexanone by Glomerella cingulata.

    Science.gov (United States)

    Okamura, S; Kameoka, H; Miyazawa, M

    2001-01-01

    The microbial transformation of 3,3,5-trimethylcyclohexanone was investigated using the plant pathogenic fungus, Glomerella cingulata. With this organism 3,3,5-trimethylcyclohexanone gave the corresponding cis- and trans-3,3,5-trimethylcyclohexanols with the ratio of 20:1 forming the cis-isomer highly stereoselectively, upon 5 days incubation together with 3,3,5-trimethyl-2-cyclohexen-1-one (isophrone) as a minor product.

  15. Stereoselective sulfate conjugation of racemic 4-hydroxypropranolol by human and rat liver cytosol

    Energy Technology Data Exchange (ETDEWEB)

    Walle, T.; Walle, U.K. (Department of Cell and Molecular Pharmacology and Experimental Therapeutics, Medical University of South Carolina, Charleston (USA))

    1991-03-01

    The objective of this study was to determine the stereochemistry of sulfoconjugation of a chiral phenolic amine drug, 4-hydroxypropranolol (HOP), by the human liver. The reaction was catalyzed by the 100,000 g cytosol as the phenolsulfotransferase (PST) enzyme source with PAP35S as the co-substrate. The enantiomers of the intact sulfate conjugate formed, (+)-HOP35S and (-)-HOP35S, were separated by HPLC and measured by liquid scintillation spectrometry. Complex velocity vs. substrate concentration curves were obtained with two peaks of activity, one at 3 microM (high affinity) and one at 500 microM (low affinity). The high-affinity reaction demonstrated a high degree of stereoselectivity. Whereas the affinity of the enantiomers for this reaction was identical, with a very low apparent KM value of 0.59 microM, the apparent Vmax value for (+)-HOPS formation was 4.6-fold higher than for (-)-HOPS. In sharp contrast, the low-affinity reaction, with an apparent KM of 65 microM, was not stereoselective. Inhibition of the high-affinity reaction by elevated temperature, but not by dichloronitrophenol, indicated that this activity was due to a monoamine form of PST. Inhibition of the low-affinity reaction by dichloronitrophenol, but not by elevated temperature, indicated that this activity was due to a phenol form of PST. As a comparison, experiments with the rat liver cytosol demonstrated only one activity, with apparent KM values of 50 microM for both enantiomers and opposite stereoselectivity in maximum velocity compared to humans, {plus minus}-HOPS ratio 0.72. The results of this study demonstrate stereoselectivity in human hepatic sulfation of a chiral phenolic amine, with clear differences between PST isoenzymes.

  16. Studies in the stereoselective synthesis of 1,1-disubstituted 1,2,3,4-tetrahydroisoquinolines

    OpenAIRE

    Berg, Michael Arthur George

    1992-01-01

    Isoquinoline alkaloids and analogs play an important role in today's pharmaceutical industry. The need to synthesize single stereoisomers of these alkaloids is important. Many times only a single stereoisomer exhibits the desired activity, while other stereoisomers of the alkaloid exhibit undesired side effects. The stereoselective synthesis of 1, 1-disubstituted 1,2,3,4- tetrahydroisoquinolines using Reissert compound chemistry containing chiral acyl auxiliaries was studied with the ultimate...

  17. Stereoselective handling of perhexiline: implications regarding accumulation within the human myocardium.

    Science.gov (United States)

    Chong, Cher-Rin; Drury, Nigel E; Licari, Giovanni; Frenneaux, Michael P; Horowitz, John D; Pagano, Domenico; Sallustio, Benedetta C

    2015-12-01

    Perhexiline is a prophylactic anti-ischaemic agent with weak calcium antagonist effect which has been increasingly utilised in the management of refractory angina. The metabolic clearance of perhexiline is modulated by CYP2D6 metaboliser status and stereoselectivity. The current study sought to (1) determine whether the acute accumulation of perhexiline in the myocardium is stereoselective and (2) investigate the relationship between duration of short-term therapy and the potential stereoselective effects of perhexiline within myocardium. Patients (n = 129) from the active arm of a randomised controlled trial of preoperative perhexiline in cardiac surgery were treated with oral perhexiline for a median of 9 days. Correlates of atrial and ventricular concentrations of enantiomers were sought via univariate followed by multivariate analyses. Myocardial uptake of both (+) and (-) perhexiline was greater in ventricles than in atria, and there was more rapid clearance of (-) than (+) perhexiline. The main determinants of atrial uptake of both (+) and (-) perhexiline were the plasma concentrations [(+) perhexiline: β = -0.256, p = 0.015; (-) perhexiline: β = -0.347, p = 0.001] and patients' age [(+) perhexiline: β = 0.300, p = 0.004; (-) perhexiline: β = 0.288, p = 0.005]. Atrial uptake of (+) enantiomer also varied directly with duration of therapy (β = 0.228, p = 0.025), while atrial uptake of (-) perhexiline varied inversely with simultaneous heart rate (β = -0.240, p = 0.015). (1) Uptake of both perhexiline enantiomers into atrium is greater with advanced age and displays evidence of both saturability and minor stereoselectivity. (2) Atrial uptake of (-) perhexiline may selectively modulate heart rate reduction.

  18. Easy Access to Evans’ Oxazolidinones. Stereoselective Synthesis and Antibacterial Activity of a New 2-Oxazolidinone Derivative

    Directory of Open Access Journals (Sweden)

    Gaspar Diaz

    2014-06-01

    Full Text Available An interesting new approach was developed for the synthesis of Evans’ chiral auxiliaries with excellent yields. In turn, another new stereoselective and efficient strategy has also allowed for the preparation of a 2-oxazolidinone derivative in 34% overall yield from the Morita-Baylis-Hillman adduct. The antibacterial activity of this oxazolidinone was tested against Staphylococcus aureus strains isolated from animals with mastitis infections.

  19. Stereoselective separation of β-adrenergic blocking agents containing two chiral centers by countercurrent chromatography.

    Science.gov (United States)

    Lv, Liqiong; Bu, Zhisi; Lu, Mengxia; Wang, Xiaoping; Yan, Jizhong; Tong, Shengqiang

    2017-09-01

    Four β-adrenergic blocking agents, including 1-[(1-methylethyl)amino]-3-phenoxy-2-propanol (1), 1-[(1-methylethyl)amino]-3-(3-methylphenoxy)-2-propanol (2), 1,1'-[1,4-phenylenebis(oxy)]bis[3-[(1-methylethyl)amino]-2-propanol (3) and 1,1'-[(4-methyl-1,2-phenylene)bis(oxy)]bis[3-[(1-methylethyl)amino]-2-propanol (4), were stereoselectively separated by countercurrent chromatography using di-n-hexyl l-tartrate and boric acid as chiral selector. The compounds (3) and (4) have four optical isomers since they contained two chiral centers. A two-phase solvent system composed of chloroform-0.05molL -1 of acetate buffer containing 0.10molL -1 of boric acid (1:1, v/v) was selected, in which 0.10molL -1 of di-n-hexyl l-tartrate was added in the organic phase as chiral selector. 20-42mg of each racemate was stereoselectively separated by countercurrent chromatography in a single run with high purity of 96-98%, and the recovery of each separated compound reached around 87-93%. This is the first time report on successful stereoselective separation of optical isomeric compounds containing two chiral centers by countercurrent chromatography. At the same time, a chiral stationary phase was screened for analytical stereoselective separation of compounds (3) and (4) by high performance liquid chromatography. Copyright © 2017 Elsevier B.V. All rights reserved.

  20. Stereoselective total synthesis of the potent anti-asthmatic compound CMI-977 (LDP-977)

    International Nuclear Information System (INIS)

    Dias, Luiz Carlos; Farina, Lui Strambi; Ferreira, Marco Antonio Barbosa

    2013-01-01

    A short and efficient stereoselective total synthesis of CMI-977 (LDP-977), a potent and orally active anti-asthmatic compound, was developed. The key steps involve a highly diastereoselective Mukaiyama oxidative cyclization, which provides the trans-THF (tetrahydrofuran) unit and a Seyferth-Gilbert homologation to construct the triple bond in the target molecule. The synthesis of the key chiral building block was performed using Jacobsen hydrolytic kinetic resolution. (author)

  1. Electronic forces as descriptors of nucleophilic and electrophilic regioselectivity and stereoselectivity.

    Science.gov (United States)

    Liu, Shubin; Rong, Chunying; Lu, Tian

    2017-01-04

    One of the main tasks of theoretical chemistry is to rationalize computational results with chemical insights. Key concepts of such nature include nucleophilicity, electrophilicity, regioselectivity, and stereoselectivity. While computational tools are available to predict barrier heights and other reactivity properties with acceptable accuracy, a conceptual framework to appreciate above quantities is still lacking. In this work, we introduce the electronic force as the fundamental driving force of chemical processes to understand and predict molecular reactivity. It has three components but only two are independent. These forces, electrostatic and steric, can be employed as reliable descriptors for nucleophilic and electrophilic regioselectivity and stereoselectivity. The advantages of using these forces to evaluate molecular reactivity are that electrophilic and nucleophilic attacks are featured by distinct characteristics in the electrostatic force and no knowledge of quantum effects included in the kinetic and exchange-correlation energies is required. Examples are provided to highlight the validity and general applicability of these reactivity descriptors. Possible applications in ambident reactivity, σ and π holes, frustrated Lewis pairs, and stereoselective reactions are also included in this work.

  2. One-Pot Synthesis of 2-Acylindole-3-acetylketones via Domino Aza-alkylation/Michael Reaction Using o-Aminophenyl α,β-Unsaturated Ketones Followed by Desulfonative Dehydrogenation

    Energy Technology Data Exchange (ETDEWEB)

    Kim, A Reum; Yu, Mi Rim; Sim, Jong Tack; Kim, Sung Gon [Kyonggi Univ., Suwon (Korea, Republic of)

    2016-09-15

    The development of novel and practical synthetic methods with a minimum number of operations for the construction of bioactive structurally complex compounds is a major challenge in synthetic organic chemistry. Recently, we reported an efficient method for the stereoselective synthesis of 2,3-disubstituted indoline derivatives; cis-2,3-disubstituted indolines were obtained by the aza-alkylation/Michael cascade reaction of 2-(tosylamino)phenyl α,β-unsaturated ketones with α-bromoacetophenones in good yields and with excellent diastereoselectivities (Scheme 2, Eq. (1)). Among the available synthetic strategies, domino or cascade reactions have received wide acceptance as highly efficient and powerful methods for the synthesis of molecules with a high structural complexity. An efficient synthesis of 2,3-disubstituted indoles was developed by the domino aza-alkylation/intramolecular Michael reaction of 2-(tosylamino)phenyl α,β-unsaturated ketones with α-bromoacetophenones, followed by desulfonative dehydrogenation with DBU. The reaction afforded structurally diverse and highly functionalized 2,3-disubstituted indoles in moderate to excellent yields (up to 99%). The synthesis of 2,3-disubstituted indoles without desulfonation through DDQ-induced oxidative dehydrogenation was also achieved.

  3. Stereoselectivity in ene reactions with 1O2: matrix effects in polymer supports, photo-oxygenation of organic salts and asymmetric synthesis.

    Science.gov (United States)

    Griesbeck, Axel G; Bartoschek, Anna; Neudörfl, Jörg; Miara, Claus

    2006-01-01

    The ene reaction of chiral allylic alcohols is applied as a tool for the investigation of intrapolymer effects by means of the stereoselectivity of the singlet-oxygen addition. The diastereo selectivity strongly depends on the structure of the polymer, the substrate loading degree and also on the degree of conversion demonstrating additional supramolecular effects evolving during the reaction. The efficiency and the stability of polymer-bound sensitizers were evaluated by the ene reaction of singlet oxygen with citronellol. The ene reaction with chiral ammonium salts of tiglic acid was conducted under solution phase conditions or in polystyrene beads under chiral contact ion-pair conditions. The products thus obtained precipitate during the photoreaction as ammonium salts. Moderate asymmetric induction was observed for this procedure for the first time.

  4. NAA-modified DNA oligonucleotides with zwitterionic backbones: stereoselective synthesis of A-T phosphoramidite building blocks.

    Science.gov (United States)

    Schmidtgall, Boris; Höbartner, Claudia; Ducho, Christian

    2015-01-01

    Modifications of the nucleic acid backbone are essential for the development of oligonucleotide-derived bioactive agents. The NAA-modification represents a novel artificial internucleotide linkage which enables the site-specific introduction of positive charges into the otherwise polyanionic backbone of DNA oligonucleotides. Following initial studies with the introduction of the NAA-linkage at T-T sites, it is now envisioned to prepare NAA-modified oligonucleotides bearing the modification at X-T motifs (X = A, C, G). We have therefore developed the efficient and stereoselective synthesis of NAA-linked 'dimeric' A-T phosphoramidite building blocks for automated DNA synthesis. Both the (S)- and the (R)-configured NAA-motifs were constructed with high diastereoselectivities to furnish two different phosphoramidite reagents, which were employed for the solid phase-supported automated synthesis of two NAA-modified DNA oligonucleotides. This represents a significant step to further establish the NAA-linkage as a useful addition to the existing 'toolbox' of backbone modifications for the design of bioactive oligonucleotide analogues.

  5. Studies on the Total Synthesis of Amphidinolide O (II): A Stereoselective Synthesis of C1-C11 Fragment

    Energy Technology Data Exchange (ETDEWEB)

    Jang, Mi Yeon; Kim, Jong Woo; Lee, Duck Hyung [Sogang University, Seoul (Korea, Republic of)

    2005-10-15

    Two ketones and, the C1-C11 fragment of Amphidinolide O, were prepared stereoselectively via 14 and 16 step sequences in 8.7% and 2.0% overall yield, respectively. The amphidinolides were isolated from the marine dinoflagellate Amphidinium sp., which produces a host of secondary metabolites endowed with potent cytotoxicity against various cancer cell lines. Amphidinolide O displayed potent in vitro cytotoxicity against L1210 marine leukemia cells and human epidermoid carcinoma KB cells with 1.7 and 3.6 μg/mL of IC50s, respectively. In addition to our recent reports regarding to the synthesis of C12-C17 and C3-C11 fragments of amphidinolide O, we describe herein a new route to diastereoselective synthesis of C1-C11 fragment of. The retrosynthetic analysis of led to the C1-C11 fragment and C12-C17 fragment. The hemiketal was expected from acyclic precursor 4 which, in turn, would be derived by diastereoselective aldol reaction between ketone and aldehyde.

  6. Complete Chiral Resolution Using Additive-Induced Crystal Size Bifurcation During Grinding

    NARCIS (Netherlands)

    Noorduin, Wim L.; Asdonk, Pim van der; Meekes, Hugo; Enckevort, Willem J.P. van; Kaptein, Bernard; Leeman, Michel; Kellogg, Richard M.; Vlieg, Elias

    2009-01-01

    Grinding them down: By using a tailor-made additive, even in the absence of racemization in solution, abrasive grinding can yield an enantiopure solid state. This novel chiral resolution technique is based on an asymmetric bifurcation in the crystal size distribution as a result of stereoselective

  7. Michael Kohlhaas or the Germans and Their Law

    Directory of Open Access Journals (Sweden)

    Heike Jung

    2014-12-01

    Full Text Available Asked to pick a single representative ‘German’ piece for a discourse on ‘Law and Literature’ one almost inevitably ends up with Kleist’s tale Michael Kohlhaas. It seems to be the literary incarnation of the German stance vis-à-vis the law. It is all about horses; it could just as well be about dogs. Kohlhaas fights a devastating battle, using legal means and outright violence, even warfare, for their recovery in good shape. Victorious eventually with his legal actions, he is happy to trade in his own life for this victory, thus giving an extreme example for the nice line between being in the right and pursuing this position with disproportionate rigour. Of course, the interpretations of Michael Kohlhaas (which, in its complete version, dates of 1810 have varied from epoch to epoch as well as from reader to reader. It is not possible to rehearse the bulk of ‘Kohlhaas literature’. In comparing legal cultures, it might be of interest to look into the question why such a somber story on the law forms part and will continue to form part of the German cultural heritage. Si se tiene que elegir un único representante “alemán” para una ponencia sobre “derecho y literatura”, es inevitable optar por la obra de Kleist, Michael Kohlhaas. Parece la encarnación literaria de la posición alemana hacia el derecho. El libro trata de caballos; también podría tratar sobre perros. Kohlhaas libra una batalla devastadora usando medios legales y la violencia pura y dura, incluso la guerra, para que se recuperen en buena forma. Finalmente resulta ganador mediante acciones legales, está contento de dedicar su propia vida para conseguir esta victoria, dando así un ejemplo extremo de la línea que existe entre tener la razón y seguir esta posición con un rigor desproporcionado. Por supuesto, las interpretaciones de Michael Kohlhaas (publicado en 1810 han variado de una época a otra, y de un lector a otro. No es posible revisar el grueso de

  8. The Correspondence of Michael Faraday Pt 6 1860-1867

    CERN Document Server

    Frank, James

    2012-01-01

    Michael Faraday (1791-1867) was one of the most important men of science in nineteenth century Britain. His discoveries of electro-magnetic rotations (1821) and electro-magnetic induction (1831) laid the foundations of the modern electrical industry. His discovery of the magneto-optical effect and diamagnetism (1845) led him to formulate the field theory of electro-magnetism, which forms one of the cornerstones of modern physics.These and a whole host of other fundamental discoveries in physics and chemistry, together with his lecturing at the Royal Institution, his work for the state (includi

  9. Michael Marinov memorial volume multiple facets of quantization and supersymmetry

    CERN Document Server

    Vainshtein, A I

    2002-01-01

    This book is dedicated to the memory of Michael Marinov, the theorist who, together with Felix Berezin, introduced the classical description of spin by anticommuting Grassmann variables. It contains original papers and reviews by physicists and mathematicians written specifically for the book. These articles reflect the current status and recent developments in the areas of Marinov's research: quantum tunneling, quantization of constrained systems, supersymmetry, and others. The personal recollections included portray the human face of M Marinov, a person of great knowledge and integrity.

  10. Enantioselective desymmetrization of prochiral cyclohexanones by organocatalytic intramolecular Michael additions to α,β-unsaturated esters.

    Science.gov (United States)

    Gammack Yamagata, Adam D; Datta, Swarup; Jackson, Kelvin E; Stegbauer, Linus; Paton, Robert S; Dixon, Darren J

    2015-04-13

    A new catalytic asymmetric desymmetrization reaction for the synthesis of enantioenriched derivatives of 2-azabicyclo[3.3.1]nonane, a key motif common to many alkaloids, has been developed. Employing a cyclohexanediamine-derived primary amine organocatalyst, a range of prochiral cyclohexanone derivatives possessing an α,β-unsaturated ester moiety linked to the 4-position afforded the bicyclic products, which possess three stereogenic centers, as single diastereoisomers in high enantioselectivity (83-99% ee) and in good yields (60-90%). Calculations revealed that stepwise C-C bond formation and proton transfer via a chair-shaped transition state dictate the exclusive endo selectivity and enabled the development of a highly enantioselective primary amine catalyst. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. Studies on NaI/DMSO induced retro-Michael addition (RMA ...

    Indian Academy of Sciences (India)

    Unknown

    e-mail: hspr@yahoo.com. MS received 5 August .... evaluate the electronic influence of substituents on the aromatic ..... SJ thanks Council of Scientific and Industrial Res- earch, New Delhi ... thesis 1037; (c) Nelson J H, Howells P N, DeLullo G.

  12. Inverting the diastereoselectivity of the mukaiyama-michael addition with graphite-based catalysts

    KAUST Repository

    Acocella, Maria Rosaria; Mauro, Marco; Falivene, Laura; Cavallo, Luigi; Guerra, Gaetano

    2014-01-01

    , the graphite-based catalysts described here invert the diastereoselectivity relative to that observed with known catalysts, with the unprecedented large prevalence of the anti diastereoisomer. This inverted diastereoselectivity is increased when the catalyst

  13. Novel in situ forming, degradable dextran hydrogels by michael addition chemistry: synthesis, rheology, and degradation

    NARCIS (Netherlands)

    Hiemstra, C.; van der Aa, L.J.; Zhong, Zhiyuan; Dijkstra, Pieter J.; Feijen, Jan

    2007-01-01

    Various vinyl sulfone functionalized dextrans (dex-VS) (Mn,dextran = 14K or 31K) with degrees of substitution (DS) ranging from 2 to 22 were conveniently prepared by a one-pot synthesis procedure at room temperature. This procedure involved reaction of a mercaptoalkanoic acid with an excess amount

  14. Well-defined single-chain polymer nanoparticles via thiol-Michael addition

    NARCIS (Netherlands)

    Kröger, A. Pia P.; Boonen, Roy J.E.A.; Paulusse, Jos M.J.

    2017-01-01

    A synthetic strategy has been developed giving facile access to well-defined single-chain polymer nanoparticles (SCNPs) from styrene-, acrylate- and methacrylate-based polymers. Random copolymers (polydispersity indices 1.10–1.15) of methyl (meth)acrylate, benzyl methacrylate or styrene containing

  15. Rhodium-catalyzed [(3+2)+2] carbocyclization of alkynylidenecyclopropanes with substituted allenes: stereoselective construction of tri- and tetrasubstituted exocyclic olefins.

    Science.gov (United States)

    Evans, P Andrew; Negru, Daniela E; Shang, Deju

    2015-04-13

    The development of the stereoselective rhodium-catalyzed [(3+2)+2] carbocyclization of alkynylidenecyclopropanes (ACPs) with substituted allenes is described. This work demonstrates that activated and unactivated allenes preferentially undergo carbometalation at the distal terminus to generate tri- and tetrasubstituted exocyclic olefins with a neutral rhodium catalyst. In addition, this method provides a strategy for the total synthesis of the guaiane family of sesquiterpenes, which are not directly accessible using alkynes as exogenous π-components. Finally, the preparation of the bicyclo[5.4.0]undecane ring system using a homologated ACP tether serves to further illustrate the versatility of this approach. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. A sustainable process for gram-scale synthesis of stereoselective ...

    Indian Academy of Sciences (India)

    RAJAN ABRAHAM

    2018-02-07

    Feb 7, 2018 ... for the additional structure modification.17–20. Acrylic acid derivatives ... mild conditions, and application in synthesizing bio- logically ... cal process for the gram-scale synthesis of streoselective ... ate yield of desired product 2 (58%, Table 1, entry. 2). .... Cross-Coupling and Atom-Economic Addition Reac-.

  17. Synergistic Diazo-OH Insertion/Conia-Ene Cascade Catalysis for the Stereoselective Synthesis of γ-Butyrolactones and Tetrahydrofurans.

    Science.gov (United States)

    Hunter, Arianne C; Schlitzer, Steven C; Sharma, Indrajeet

    2016-11-02

    A novel and highly efficient diazo-OH insertion/Conia-ene cascade reaction of readily available homopropargylic acids and alcohols with diazo carbonyl compounds is described. The cascade reaction involves a synergistic Rh/Ag/Au catalyst cocktail and proceeds instantly with a variety of substituted diazo compounds and acids/alcohols to provide functionalized γ-butyrolactones and tetrahydrofurans with complete regio- and stereoselectivity. The unprecedented rate-enhancement, complete stereoselectivity, and the enabling of new Conia-ene cyclizations suggest a concerted [4+1]-cycloaddition reaction pathway under synergistic (Rh/Ag/Au)-catalysis conditions. © 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. A Stereoselective [3+1] Ring Expansion for the Synthesis of Highly Substituted Methylene Azetidines.

    Science.gov (United States)

    Schmid, Steven C; Guzei, Ilia A; Schomaker, Jennifer M

    2017-09-25

    The reaction of rhodium-bound carbenes with strained bicyclic methylene aziridines results in a formal [3+1] ring expansion to yield highly substituted methylene azetidines with excellent regio- and stereoselectivity. The reaction appears to proceed through an ylide-type mechanism, where the unique strain and structure of the methylene aziridine promotes a ring-opening/ring-closing cascade that efficiently transfers chirality from substrate to product. The resultant products can be elaborated into new azetidine scaffolds containing vicinal tertiary-quaternary and even quaternary-quaternary stereocenters. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. Regio- and stereoselective carbometallation reactions of N-alkynylamides and sulfonamides

    Directory of Open Access Journals (Sweden)

    Yury Minko

    2013-03-01

    Full Text Available The carbocupration reactions of heterosubstituted alkynes allow the regio- and stereoselective formation of vinyl organometallic species. N-Alkynylamides (ynamides are particularly useful substrates for the highly regioselective carbocupration reaction, as they lead to the stereodefined formation of vinylcopper species geminated to the amide moiety. The latter species are involved in numerous synthetically useful transformations leading to valuable building blocks in organic synthesis. Here we describe in full the results of our studies related to the carbometallation reactions of N-alkynylamides.

  20. Palladium-catalyzed arylation of enoates with iodobenzene: stereoselective synthesis of trisubstituted olefins

    Energy Technology Data Exchange (ETDEWEB)

    Fernandes, Talita de A. [Universidade Federal do Rio de Janeiro (UFRJ/LQB), RJ (Brazil). Nucleo de Pesquisas de Produtos Naturais. Laboratorio de Quimica Bioorganica; Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Instituto de Quimica. Interlab; Silva, Alcides J.M. da; Costa, Paulo R.R., E-mail: prrcosta2011@gmail.com [Universidade Federal do Rio de Janeiro (UFRJ/LQB), RJ (Brazil). Nucleo de Pesquisas de Produtos Naturais. Laboratorio de Quimica Bioorganica; Esteves, Pierre M. [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Instituto de Quimica. Interlab; Eberlin, Marcos N., E-mail: eberlin@iqm.unicamp.br [Universidade Estadual de Campinas (UNICAMP), SP (Brazil). Instituto de Quimica. Laboratorio ThoMSon de Espectrometria de Massas; Vaz, Boniek G. [Universidade Estadual de Campinas (UNICAMP), SP (Brazil). Instituto de Quimica. Laboratorio ThoMSon de Espectrometria de Massas; Universidade Federal de Goias (UFGO), Goiania, GO (Brazil). Instituto de QuImica

    2013-03-15

    The Heck reaction between E- and Z-enoates and iodobenzene was studied in the presence of Pd(OAc){sub 2}. The stereochemistry in resulting adducts was dependent on the enoate geometry (stereospecific reaction). Best yields were obtained from Z-isomers in acetone using Ag{sub 2} CO{sub 3} as base. The main cationic palladium intermediates possibly involved in the catalytic cycle could be intercepted and characterized by electrospray ionization mass spectrometry (ESI-MS). The stereoselectivity observed was rationalized through the classic mechanism of the Heck reaction. (author)

  1. Stereoselective 1,3-Insertions of Rhodium(II) Azavinyl Carbenes

    Science.gov (United States)

    Chuprakov, Stepan; Worrell, Brady T.; Selander, Nicklas; Sit, Rakesh K.; Fokin, Valery V.

    2014-01-01

    Rhodium(II) azavinyl carbenes, conveniently generated from 1-sulfonyl-1,2,3-triazoles, undergo a facile, mild and convergent formal 1,3-insertion into N–H and O–H bonds of primary and secondary amides, various alcohols, and carboxylic acids to afford a wide range of vicinally bis-functionalized Z-olefins with perfect regio- and stereoselectively. Utilizing the distinctive functionality installed through these reactions, a number of subsequent rearrangements and cyclizations expand the repertoire of valuable organic building blocks constructed by reactions of transition metal carbene complexes, including α-allenyl ketones and amino-substituted heterocycles. PMID:24295389

  2. Palladium-catalyzed arylation of enoates with iodobenzene: stereoselective synthesis of trisubstituted olefins

    International Nuclear Information System (INIS)

    Fernandes, Talita de A.; Universidade Federal do Rio de Janeiro; Silva, Alcides J.M. da; Costa, Paulo R.R.; Esteves, Pierre M.; Eberlin, Marcos N.; Vaz, Boniek G.; Universidade Federal de Goias

    2013-01-01

    The Heck reaction between E- and Z-enoates and iodobenzene was studied in the presence of Pd(OAc) 2 . The stereochemistry in resulting adducts was dependent on the enoate geometry (stereospecific reaction). Best yields were obtained from Z-isomers in acetone using Ag 2 CO 3 as base. The main cationic palladium intermediates possibly involved in the catalytic cycle could be intercepted and characterized by electrospray ionization mass spectrometry (ESI-MS). The stereoselectivity observed was rationalized through the classic mechanism of the Heck reaction. (author)

  3. Wittig Reaction: Domino Olefination and Stereoselectivity DFT Study. Synthesis of the Miharamycins' Bicyclic Sugar Moiety.

    Science.gov (United States)

    Cachatra, Vasco; Almeida, Andreia; Sardinha, João; Lucas, Susana D; Gomes, Ana; Vaz, Pedro D; Florêncio, M Helena; Nunes, Rafael; Vila-Viçosa, Diogo; Calhorda, Maria José; Rauter, Amélia P

    2015-11-20

    2-O-Acyl protected-d-ribo-3-uloses reacted with [(ethoxycarbonyl)methylene]triphenylphosphorane in acetonitrile to afford regio- and stereoselectively 2-(Z)-alkenes in 10-60 min under microwave irradiation. This domino reaction is proposed to proceed via tautomerization of 3-ulose to enol, acyl migration, tautomerization to the 3-O-acyl-2-ulose, and Wittig reaction. Alternatively, in chloroform, regioselective 3-olefination of 2-O-pivaloyl-3-uloses gave (E)-alkenes, key precursors for the miharamycins' bicyclic sugar moiety.

  4. Stereoselective synthesis of hydroxy stilbenoids and styrenes by atom-efficient olefination with thiophthalides.

    Science.gov (United States)

    Mitra, Prithiba; Shome, Brateen; De, Saroj Ranjan; Sarkar, Anindya; Mal, Dipakranjan

    2012-04-14

    The synthesis of stilbenoids and styryl carboxylic acids is accomplished with high E-stereoselectivity by olefination of aldehydes with thiophthalides under basic conditions. The olefination is highly atom-efficient as it only loses elemental sulfur during the reaction. This olefination, in conjunction with retro Kolbe-Schmitt reaction, allows facile synthesis of E-hydroxystilbenoids with minimal employment of protecting groups. This study also discloses two important findings: formation of i) 4-methylsulfanyl isocoumarins and ii) an 2-arylindenone. This journal is © The Royal Society of Chemistry 2012

  5. A Study of Postmodern Narrative in Michael Cunningham's The Hours

    Directory of Open Access Journals (Sweden)

    Hajar Abbasi Narinabad

    2012-09-01

    Full Text Available This project aims at providing a detailed analysis of the major features of the theory of postmodern narrative and at going through the novel The Hours by the American writer Michael Cunningham concentrating on some postmodern narrative techniques. To do so, the researcher goes through the theories set forth by some postmodern theoreticians like Roland Barthes, Jacque Derrida, Jean-François Lyotard and Julia Kristeva to investigate the postmodern narrative techniques and elements used in the novel. The researcher first examines the theories and then critically applies them on the novel. The article goes through the most eminent elements of postmodern narrative including intertextuality, stream of consciousness style, fragmentation and representation respectively which are delicately utilized in The Hours. The article concludes by recommending a few directions for the further research.

  6. Michael Longley’s Father: Memory, Mourning and History

    Directory of Open Access Journals (Sweden)

    Barry Sloan

    2012-03-01

    Full Text Available Michael Longley’s father has been a recurring presence in the poet’s work from his earliest to his most recent collection. This paper examines the exceptional strength of that bond reflected in the varied and changing ways in which the poet has responded to it – memorizing and mourning his loss; discovering through his father’s First World War stories a means of memorialising loss of life in contemporary conflicts and a way of facing the history of the twentieth century; confronting his own ageing and sense of mortality; and marking the specific, but also representative, generational history of his family. Close readings of key poems are offered to highlight Longley’s skills in meeting his own exacting standards of aesthetic propriety and moral and social responsibility for writers of elegy in order to avoid either exploitation of tragedy and loss, or facile gestures of consolation.

  7. Estratégia competitiva: Michael Porter 30 anos depois

    Directory of Open Access Journals (Sweden)

    Manuel Portugal Ferreira

    2009-12-01

    Full Text Available Os estudos de estratégia têm sido muito influenciados pelos trabalhos de Michael Porter, em todas as suas fases, como as cinco forças, as estratégias genéricas, a cadeia de valor e as vantagens competitivas das nações. Neste artigo, analisou-se a influência de Porter nos trabalhos brasileiros em estratégia, a partir dos trabalhos selecionados e apresentados no EnANPAD. No levantamento para a análise dos artigos, considerando 10 anos de EnANPAD (1997-2006, foram selecionados 46 artigos. A identificação e seleção dos artigos envolveram os seguintes critérios: busca complementar por palavra-chave Porter na base de dados do EnANPAD; avaliação dos títulos e resumos dos artigos apresentados na área de estratégia entre 1997 e 2006, bem como na íntegra quando necessário. Procedeu-se também à análise das referências utilizadas nos artigos e o posicionamento dos autores em relação às tipologias de Porter. Como resultado, verificou-se que Michael Porter é um autor com grande influência nas pesquisas acadêmicas de estratégia. Seus estudos mais utilizados são os da análise da indústria e das estratégias genéricas, e também se verificou que a maioria dos estudos analisados é favorável aos seus conceitos, mesmo existindo pesquisas contrárias.

  8. Stereoselective phytotoxicity of HCH mediated by photosynthetic and antioxidant defense systems in Arabidopsis thaliana.

    Science.gov (United States)

    Zhang, Qiong; Zhou, Cong; Zhang, Quan; Qian, Haifeng; Liu, Weiping; Zhao, Meirong

    2013-01-01

    Hexachlorocyclohexane (HCH) has been used for plant protection and sanitation world-widely, and its isomers have been detected in water, soil, and air as well as in vegetation. As a sink for lipophilic pollutants, vegetation is very important for the degradation and fate of organic contamination; however, little was known about their phytotoxicity and mechanisms of toxic effect. In this study, the stereoselective phototoxicity of four isomers (α, β, γ, and δ) of HCHs mediated by independent as well as interconnecting systems of photosynthesis and enzymatic antioxidant defense system in Arabidopsis thaliana were assessed. Our results revealed that all the HCHs not only stimulated the activities of catalase (CAT) and peroxidase (POD), but also inhibited the activity of superoxide dismutase (SOD). In photosynthesis system, the photosynthetic efficiency of PSI and PSII were all down regulated. Meanwhile, results from both systems showed that δ-HCH was the most toxic one, while α-HCH the least in Arabidopsis thaliana. For the first time, stereoselective effects of different isomers of HCH in plant were demonstrated. And the results suggest that it requires further research to fully elucidate the environmental toxicity and their mechanisms.

  9. Stereoselective phytotoxicity of HCH mediated by photosynthetic and antioxidant defense systems in Arabidopsis thaliana.

    Directory of Open Access Journals (Sweden)

    Qiong Zhang

    Full Text Available BACKGROUND: Hexachlorocyclohexane (HCH has been used for plant protection and sanitation world-widely, and its isomers have been detected in water, soil, and air as well as in vegetation. As a sink for lipophilic pollutants, vegetation is very important for the degradation and fate of organic contamination; however, little was known about their phytotoxicity and mechanisms of toxic effect. In this study, the stereoselective phototoxicity of four isomers (α, β, γ, and δ of HCHs mediated by independent as well as interconnecting systems of photosynthesis and enzymatic antioxidant defense system in Arabidopsis thaliana were assessed. PRINCIPAL FINDINGS: Our results revealed that all the HCHs not only stimulated the activities of catalase (CAT and peroxidase (POD, but also inhibited the activity of superoxide dismutase (SOD. In photosynthesis system, the photosynthetic efficiency of PSI and PSII were all down regulated. Meanwhile, results from both systems showed that δ-HCH was the most toxic one, while α-HCH the least in Arabidopsis thaliana. CONCLUSIONS: For the first time, stereoselective effects of different isomers of HCH in plant were demonstrated. And the results suggest that it requires further research to fully elucidate the environmental toxicity and their mechanisms.

  10. Probing the stereoselective interaction of ofloxacin enantiomers with corresponding monoclonal antibodies by multiple spectrometry

    Science.gov (United States)

    Mu, Hongtao; Xu, Zhenlin; Liu, Yingju; Sun, Yuanming; Wang, Baoling; Sun, Xiulan; Wang, Zhanhui; Eremin, Sergei; Zherdev, Anatoly V.; Dzantiev, Boris B.; Lei, Hongtao

    2018-04-01

    Although stereoselective antibody has immense potential in chiral compounds detection and separation, the interaction traits between stereoselective antibody and the corresponding antigenic enantiomers are not yet fully exploited. In this study, the stereospecific interactions between ofloxacin isomers and corresponding monoclonal antibodies (McAb-WR1 and McAb-MS1) were investigated using time-resolved fluorescence, steady-state fluorescence, and circular dichroism (CD) spectroscopic methods. The chiral recognition discrepancies of antibodies with ofloxacin isomers were reflected through binding constant, number of binding sites, driving forces and conformational changes. The major interacting forces of McAb-WR1 and McAb-MS1 chiral interaction systems were hydrophobic force and van der Waals forces joined up with hydrogen bonds, respectively. Synchronous fluorescence spectra and CD spectra results showed that the disturbing of tyrosine and tryptophan micro-environments were so slightly that no obvious secondary structure changes were found during the chiral hapten binding. Clarification of stereospecific interaction of antibody will facilitate the application of immunoassay to analyze chiral contaminants in food and other areas.

  11. Microbial Stereoselective One-Step Conversion of Diols to Chiral Lactones in Yeast Cultures

    Directory of Open Access Journals (Sweden)

    Filip Boratyński

    2015-12-01

    Full Text Available It has been shown that whole cells of different strains of yeast catalyze stereoselective oxidation of meso diols to the corresponding chiral lactones. Among screening-scale experiments, Candida pelliculosa ZP22 was selected as the most effective biocatalyst for the oxidation of monocyclic diols 3a–b with respect to the ratio of high conversion to stereoselectivity. This strain was used in the preparative oxidation, affording enantiomerically-enriched isomers of lactones: (+-(3aR,7aS-cis-hexahydro-1(3H -isobenzofuranone (2a and (+-(3aS,4,7,7aR-cis-tetrahydro-1(3H-isobenzofuranone (2b. Scaling up the culture growth, as well as biotransformation conditions has been successfully accomplished. Among more bulky substrates, bicyclic diol 3d was totally converted into enantiomerically-pure exo-bridged (+-(3aR,4S,7R,7aS-cis-tetrahydro-4,7-methanoisobenzofuran -1(3H-one (2d by Yarrovia lipolytica AR71. Microbial oxidation of diol 3f by Candida sake AM908 and Rhodotorula rubra AM4 afforded optically-pure cis-3-butylhexahydro-1(3H -isobenzofuranone (2f, however with low conversion.

  12. Stereoselective bioaccumulation of chiral PCB 91 in earthworm and its metabolomic and lipidomic responses.

    Science.gov (United States)

    He, Zeying; Wang, Yuehua; Zhang, Yanwei; Cheng, Haiyan; Liu, Xiaowei

    2018-07-01

    Stereoselective bioaccumulation, elimination, metabolomic and lipidomic responses of earthworm Eisenia fetida exposed to chiral polychlorinated biphenyl (PCB) 91 in an earthworm-soil system were investigated. Preferential bioaccumulation of (-)-PCB 91 and elimination of (+)-PCB 91 were observed following 50 and 500 μg/kg dwt exposures. Enantiomer fraction (EF) values decreased over time during the uptake and elimination periods. Metabolomics and lipidomics techniques based on ultra-performance liquid chromatography/quadrupole time-of-flight mass spectrometry (UPLC-QTOF-MS) revealed significant changes in 108 metabolites after earthworms exposure to (+)-, (-)-, and (±)-PCB 91, compared to control groups. Forty two of these metabolites were identified as amino acids, nucleosides, fatty acids, dicarboxylic acids, vitamins or others. Lysophospholipids including six lysophosphatidylcholines (LPC), six lysophosphatidylethanolamine (LPE), eight lysophosphatidylinositol (LPI) and five lysophosphatidylserine (LPS) were also differentially expressed between exposure and control groups. Alterations in the levels of metabolites and lipids indicated stereoselective effects of chiral PCB 91 on earthworm amino acid, energy, and nucleotide metabolism, neurodevelopment and gene expression. Overall, the effects of (+)-PCB 91 were more pronounced than that of (-)- and (±)-PCB 91. Copyright © 2018 Elsevier Ltd. All rights reserved.

  13. Stereoselective formation of a cholesterol ester conjugate from fenvalerate by mouse microsomal carboxyesterase(s).

    Science.gov (United States)

    Miyamoto, J; Kaneko, H; Takamatsu, Y

    1986-06-01

    In accordance with in vivo findings, of the four chiral isomers of fenvalerate (S-5602 Sumicidin, Pydrin, [RS]-alpha-cyano-3-phenoxybenzyl [RS]-2-(4-chlorophenyl)isovalerate), only the [2R, alpha S]-isomer (B-isomer) yielded cholesteryl [2R]-2-(4-chlorophenyl)isovalerate (CPIA-cholesterol ester) in the in vitro study using several tissue homogenates of mice, rats, dogs, and monkeys. There were species differences in the extent of CPIA-cholesterol-ester formation, with mouse tissues showing relatively higher activity than those of other animals. The kidney, brain, and spleen of mice showed relatively higher capacities to form this ester compared to other tissues, and the enzyme activity was mainly localized in microsomal fractions. The CPIA-cholesterol ester did not seem to be produced by three known biosynthetic pathways of endogenous cholesterol esters--acyl-CoA:cholesterol O-acyltransferase (ACAT), lecithin:cholesterol O-acyltransferase (LCAT), and cholesterol esterase. Carboxyesterase(s) of mouse kidney microsomes solubilized by digitonin hydrolyzed only the B alpha-isomer of fenvalerate, yielding CPIA, whereas they yielded the corresponding cholesterol ester in the presence of artificial liposomes containing cholesterol. Thus, it appears that the stereoselective formation of the CPIA-cholesterol ester results from the stereoselective formation of the CPIA-carboxyesterase complex only from the B alpha-isomer, which subsequently undergoes cleavage by cholesterol to yield the CPIA-cholesterol ester.

  14. Stereoselective inhibition of thromboxane-induced coronary vasoconstriction by 1,4-dihydropyridine calcium channel antagonists

    International Nuclear Information System (INIS)

    Eltze, M.; Boer, R.; Sanders, K.H.; Boss, H.; Ulrich, W.R.; Flockerzi, D.

    1990-01-01

    The biological activity of the (+)-S- and (-)-R-enantiomers of niguldipine, of the (-)-S- and (+)-R-enantiomers of felodipine and nitrendipine, and of rac-nisoldipine and rac-nimodipine was investigated in vitro and in vivo. Inhibition of coronary vasoconstriction due to the thromboxane A2 (TxA2)-mimetic U-46619 in guinea pig Langendorff hearts, displacement of (+)-[ 3 H]isradipine from calcium channel binding sites of guinea pig skeletal muscle T-tubule membranes, and blood pressure reduction in spontaneously hypertensive rats were determined. The enantiomers were obtained by stereoselective synthesis. Cross-contamination was less than 0.5% for both S- and R-enantiomers of niguldipine and nitrendipine and less than 1% for those of felodipine. From the doses necessary for a 50% inhibition of coronary vasoconstriction, stereoselectivity ratios for (+)-(S)-/(-)-(R)-niguldipine, (-)-(S)-/(+)-(R)-felodipine, and (-)-(S)-/(+)-(R)-nitrendipine of 28, 13, and 7, respectively, were calculated. The potency ratio rac-nisoldipine/rac-nimodipine was 3.5. Ratios obtained from binding experiments and antihypertensive activity were (+)-(S)-/(-)-(R)-niguldipine = 45 and 35, (-)-(S)-/(+)-(R)-felodipine = 12 and 13, (-)-(S)-/(+)-(R)-nitrendipine = 8 and 8, and rac-nisoldipine/rac-nimodipine = 8 and 7, respectively. Highly significant correlations were found between the in vitro potency of the substances to prevent U-46619-induced coronary vasoconstriction and their affinity for calcium channel binding sites as well as their antihypertensive activity

  15. Metabolic stereoselectivity of cytochrome P450 3A4 towards deoxypodophyllotoxin : In silico predictions and experimental validation

    NARCIS (Netherlands)

    Julsing, Mattijs K.; Vasilev, Nikolay P.; Schneidman-Duhovny, Dina; Muntendarn, Remco; Woerdenbag, Herman J.; Quax, Wim J.; Wolfson, Haim J.; Ionkova, Iliana; Kayser, Oliver

    Deoxypodophyllotoxin is stereoselectively converted into epipodophyllotoxin by recombinant human cytochrome P450 3A4 (CY-P3A4). Further kinetic analysis revealed that the Michaelis-Menten K(m) and V(max) for hydroxylation of deoxypodophyllotoxin by CYP3A4 at C7 position were 1.93 mu M and 1.48

  16. Stereoselective Preparation of N-Alkyl Dipeptide Analogues via Dynamic Kinetic Resolution of α-Halo Acyl Amino Esters

    International Nuclear Information System (INIS)

    Shin, Eun Kyoung; Chang, Ji Yeon; Kim, Hyun Jung; Kim, Yong Tae; Park, Yong Sun

    2006-01-01

    We have shown that dynamic kinetic resolution of α-bromo and α-chloro amides in nucleophilic substitution reaction can be successfully applied towards the preparation of various N-terminal functionalized dipeptide analogues. The stereochemical aspects of the results showed that stereoselectivity depends critically on the structures of amine nucleophiles. This mild and practical method can be run on a multi-gram scale without any special precautions and should be applicable to stereoselective syntheses of various peptidomimetics. Extension of this synthetic methodology to dynamic resolution of N-(α-haloacetyl) peptides in the stereospecific nucleophilic substitution (S N 2) could be an attractive synthetic strategy for asymmetric syntheses of peptide analogues. Recently it has been shown from our group that the chiral information of adjacent amino acid residue is efficiently transferred to the new C-N bond formation at α-halo carbon center for asymmetric syntheses of di-, tri- and tetrapeptide analogues. The α-halo stereogenic center of undergoes rapid epimerization in the presence of diisopropylethylamine (DIEA) and tetrabutylammonium iodide (TBAI), and (αS) reacts with the nucleophile preferentially to provide the dipeptide analogue (αR). The mechanistic investigation showed that this is a case of dynamic kinetic resolution, in which the stereoselectivity is determined by the difference in the diastereomeric transition state energies for the reaction with the nucleophiles. Herein we describe our recent progress to extend the scope of the methodology to stereoselective preparation of N-terminal functionalized dipeptide analogues with various amine nucleophiles

  17. Studying Teachers and Schools: Michael Pressley's Legacy and Directions for Future Research

    Science.gov (United States)

    Mohan, Lindsey; Lundeberg, Mary A.; Reffitt, Kelly

    2008-01-01

    Much of Michael Pressley's work during the past decade focused on the nature of highly effective, engaging literacy instruction. Michael Pressley believed that studying effective teachers and schools had the potential to influence more engaging and effective teaching, especially in underresourced schools. First, we describe the grounded…

  18. Markets, Marx, Modernity and Mathematics Education: A Response to Michael Apple.

    Science.gov (United States)

    Gates, Peter

    This paper is a response to Michael Apple's paper, "What Postmodernists Forget: Cultural Capital and Official Knowledge." The paper advocates Michael's identification of the current dangers and processes of the growth of new right ideologies in the development of subjectivity, society, and education. The differences in success in the education…

  19. Reflections on Michael Hardt and Antonio Negri’s Book “Assembly”

    Directory of Open Access Journals (Sweden)

    Christian Fuchs

    2017-10-01

    Full Text Available This contribution presents reflections on Michael Hardt and Antonio Negri’s book “Assembly” (2017, Oxford: Oxford University Press, ISBN 978-0190677961. Keywords: assembly, Michael Hardt, Antonio Negri, multitude, common, entrepreneurship of the multitude, the new Prince, digital capitalism, digital assemblage, neoliberalism, finance

  20. Stereoselective synthesis of stable-isotope-labeled amino acids

    Energy Technology Data Exchange (ETDEWEB)

    Unkefer, C.J.; Martinez, R.A.; Silks, L.A. III [Los Alamos National Laboratory, NM (United States); Lodwig, S.N. [Centralia College, WA (United States)

    1994-12-01

    For magnetic resonance and vibrational spectroscopies to reach their full potential, they must be used in combination with sophisticated site-specific stable isotope labeling of biological macromolecules. Labeled amino acids are required for the study of the structure and function of enzymes and proteins. Because there are 20 common amino acids, each with its own distinguishing chemistry, they remain a synthetic challenge. The Oppolzer chiral auxiliary provides a general tool with which to approach the synthesis of labeled amino acids. By using the Oppolzer auxiliary, amino acids can be constructed from several small molecules, which is ideal for stable isotope labeling. In addition to directing the stereochemistry at the {alpha}-carbon, the camphorsultam can be used for stereo-specific isotope labeling at prochiral centers in amino acids. By using the camphorsultam auxiliary we have the potential to synthesize virtually any isotopomer of all of the common amino acids.

  1. Stereoselective synthesis of stable-isotope-labeled amino acids

    International Nuclear Information System (INIS)

    Unkefer, C.J.; Martinez, R.A.; Silks, L.A. III; Lodwig, S.N.

    1994-01-01

    For magnetic resonance and vibrational spectroscopies to reach their full potential, they must be used in combination with sophisticated site-specific stable isotope labeling of biological macromolecules. Labeled amino acids are required for the study of the structure and function of enzymes and proteins. Because there are 20 common amino acids, each with its own distinguishing chemistry, they remain a synthetic challenge. The Oppolzer chiral auxiliary provides a general tool with which to approach the synthesis of labeled amino acids. By using the Oppolzer auxiliary, amino acids can be constructed from several small molecules, which is ideal for stable isotope labeling. In addition to directing the stereochemistry at the α-carbon, the camphorsultam can be used for stereo-specific isotope labeling at prochiral centers in amino acids. By using the camphorsultam auxiliary we have the potential to synthesize virtually any isotopomer of all of the common amino acids

  2. Stereoselective virtual screening of the ZINC database using atom pair 3D-fingerprints.

    Science.gov (United States)

    Awale, Mahendra; Jin, Xian; Reymond, Jean-Louis

    2015-01-01

    Tools to explore large compound databases in search for analogs of query molecules provide a strategically important support in drug discovery to help identify available analogs of any given reference or hit compound by ligand based virtual screening (LBVS). We recently showed that large databases can be formatted for very fast searching with various 2D-fingerprints using the city-block distance as similarity measure, in particular a 2D-atom pair fingerprint (APfp) and the related category extended atom pair fingerprint (Xfp) which efficiently encode molecular shape and pharmacophores, but do not perceive stereochemistry. Here we investigated related 3D-atom pair fingerprints to enable rapid stereoselective searches in the ZINC database (23.2 million 3D structures). Molecular fingerprints counting atom pairs at increasing through-space distance intervals were designed using either all atoms (16-bit 3DAPfp) or different atom categories (80-bit 3DXfp). These 3D-fingerprints retrieved molecular shape and pharmacophore analogs (defined by OpenEye ROCS scoring functions) of 110,000 compounds from the Cambridge Structural Database with equal or better accuracy than the 2D-fingerprints APfp and Xfp, and showed comparable performance in recovering actives from decoys in the DUD database. LBVS by 3DXfp or 3DAPfp similarity was stereoselective and gave very different analogs when starting from different diastereomers of the same chiral drug. Results were also different from LBVS with the parent 2D-fingerprints Xfp or APfp. 3D- and 2D-fingerprints also gave very different results in LBVS of folded molecules where through-space distances between atom pairs are much shorter than topological distances. 3DAPfp and 3DXfp are suitable for stereoselective searches for shape and pharmacophore analogs of query molecules in large databases. Web-browsers for searching ZINC by 3DAPfp and 3DXfp similarity are accessible at www.gdb.unibe.ch and should provide useful assistance to drug

  3. Hexamethoxylated Monocarbonyl Analogues of Curcumin Cause G2/M Cell Cycle Arrest in NCI-H460 Cells via Michael Acceptor-Dependent Redox Intervention.

    Science.gov (United States)

    Li, Yan; Zhang, Li-Ping; Dai, Fang; Yan, Wen-Jing; Wang, Hai-Bo; Tu, Zhi-Shan; Zhou, Bo

    2015-09-09

    Curcumin, derived from the dietary spice turmeric, holds promise for cancer prevention. This prompts much interest in investigating the action mechanisms of curcumin and its analogues. Two symmetrical hexamethoxy-diarylpentadienones (1 and 2) as cucumin analogues were reported to possess significantly enhanced cytotoxicity compared with the parent molecule. However, the detailed mechanisms remain unclear. In this study, compounds 1 and 2 were identified as the G2/M cell cycle arrest agents to mediate the cytotoxicity toward NCI-H460 cells via Michael acceptor-dependent redox intervention. Compared with curcumin, they could more easily induce a burst of reactive oxygen species (ROS) and collapse of the redox buffering system. One possible reason is that they could more effectively target intracellular TrxR to convert this antioxidant enzyme into a ROS promoter. Additionally, they caused up-regulation of p53 and p21 and down-regulation of redox-sensitive Cdc25C along with cyclin B1/Cdk1 in a Michael acceptor- and ROS-dependent fashion. Interestingly, in comparison with compound 2, compound 1 displayed a relatively weak ability to generate ROS but increased cell cycle arrest activity and cytotoxicity probably due to its Michael acceptor-dependent microtubule-destabilizing effect and greater GST-inhibitory activity, as well as its enhanced cellular uptake. This work provides useful information for understanding Michael acceptor-dependent and redox-mediated cytotoxic mechanisms of curcumin and its active analogues.

  4. Michael Field’s “A Dance of Death”

    Directory of Open Access Journals (Sweden)

    LeeAnne Richardson

    2012-03-01

    Full Text Available The 1912 poem "A Dance of Death" by Michael Field (pen name of Katherine Bradley and her niece Edith Cooper depicts Salome in an alternate version of the biblical story: this Salome dances on a frozen river, falls through the ice, and is decapitated on a jagged edge. Nonetheless, her beautiful head continues dancing over the frozen river. This poem is highly unusual, especially in the context of the other poems in the postconversion volume Poems of Adoration, because it questions, rather than submits to, authority. In re-writing a familiar Christian tale, as well as a familiar decadent theme, Field uses the poem to assert the supremacy of their artistic vision, which (despite their ardent Catholicism cannot be subject to any law outside themselves. Like the continually dancing head of Salome, which continues to create beauty even after nature (and perhaps God has struck it down, the poet is subjugate only to her own law and creates without boundaries or restrictions on her art. Bradley and Cooper were acutely aware of their authorial persona (actively taking not only a masculine but also a singular poetic identity, and their mode of reconciling the apparent contradictions of this identity are mirrored in their presentation of Salome in a "Dance of Death."

  5. A Musical Italy: Michael W. Balfe’s Italian Experiences

    Directory of Open Access Journals (Sweden)

    Basil Walsh

    2016-06-01

    Full Text Available The Dublin-born musician, Michael W. Balfe, was a singer, composerand conductor whose brilliant musical career was heavily influenced byformative experiences in Italy. In 1825, Balfe, interested in broadeninghis musical studies first went to Paris where he was introduced to thegreat composers, Luigi Cherubini and Gioachino Rossini, who took apersonal interest in him and his musical talents. On the advice of Rossinihe spent the next few years in Italy studying singing with the famousRossini singer, Filippo Galli, and taking music composition lessonsfrom Ferdinando Paer, in Rome. Later in Milan he studied harmonyand counterpoint with Vincenzo Federici. By 1831, when he was only23 years old, his first three operas had been produced in Palermo, Pavia,and Milan. He returned to London in August 1835, participatingwith the great Lablache, Tamburini, Rubini and Grisi in a concert inVauxhall Gardens. In 1834 he made his debut at La Scala, Milan, singingopposite the renowned mezzo-soprano, Maria Malibran in Rossini’sOtello. He appeared again with Malibran in Venice early in 1835,singing once more in Rossini and Bellini operas. Balfe worked as a singerand composer throughout the Italian peninsula/states during the years,1825-1835 and this article will chart these experiences and demonstratehow the time he spent in Italy and the people he met, influenced hislife and later career as an important and popular European composer.

  6. New eco-friendly animal bone meal catalysts for preparation of chalcones and aza-Michael adducts

    Directory of Open Access Journals (Sweden)

    Riadi Yassine

    2012-06-01

    Full Text Available Abstract Two efficient reactions were successfully carried out using Animal Bone Meal (ABM and potassium fluoride or sodium nitrate doped ABMs as new heterogeneous catalysts under very mild conditions. After preparation and characterization of the catalysts, we first report their use in a simple and convenient synthesis of various chalcones by Claisen–Schmidt condensation and then in an aza-Michael addition involving several synthesized chalcones with aromatic amines. All the reactions were carried out at room temperature in methanol; the chalcone synthesis was also achieved in water environment under microwave irradiation. Doping ABM enhances the rate and yield at each reaction. Catalytic activities are discussed and the ability to re-use the ABM is demonstrated. Results For Claisen–Schmidt the use of ABM alone, yields never exceeded 17%. In each entry, KF/ABM and NaNO3/ABM (79-97% gave higher yields than using ABM alone under thermic condition. Also the reaction proceeded under microwave irradiation in good yields (72-94% for KF/ABM and 81-97% for NaNO3/ABM and high purity. For aza-Michael addition the use of ABM doped with KF or NaNO3 increased the catalytic activity remarkably. The very high yields could be noted (84-95% for KF/ABM and 81-94% for NaNO3/ABM. Conclusion The present method is an efficient and selective procedure for the synthesis of chalcones an aza-Michael adducts. The ABM and doped ABMs are a new, inexpensive and attractive solid supports which can contribute to the development of catalytic processes and reduced environmental problems.

  7. Visualization of Stereoselective Supramolecular Polymers by Chirality-Controlled Energy Transfer.

    Science.gov (United States)

    Sarkar, Aritra; Dhiman, Shikha; Chalishazar, Aditya; George, Subi J

    2017-10-23

    Chirality-driven self-sorting is envisaged to efficiently control functional properties in supramolecular materials. However, the challenge arises because of a lack of analytical methods to directly monitor the enantioselectivity of the resulting supramolecular assemblies. Presented herein are two fluorescent core-substituted naphthalene-diimide-based donor and acceptor molecules with minimal structural mismatch and they comprise strong self-recognizing chiral motifs to determine the self-sorting process. As a consequence, stereoselective supramolecular polymerization with an unprecedented chirality control over energy transfer has been achieved. This chirality-controlled energy transfer has been further exploited as an efficient probe to visualize microscopically the chirality driven self-sorting. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Stereoselective Catalytic Synthesis of Active Pharmaceutical Ingredients in Homemade 3D-Printed Mesoreactors.

    Science.gov (United States)

    Rossi, Sergio; Porta, Riccardo; Brenna, Davide; Puglisi, Alessandra; Benaglia, Maurizio

    2017-04-03

    3D-printed flow reactors were designed, fabricated from different materials (PLA, HIPS, nylon), and used for a catalytic stereoselective Henry reaction. The use of readily prepared and tunable 3D-printed reactors enabled the rapid screening of devices with different sizes, shapes, and channel dimensions, aimed at the identification of the best-performing reactor setup. The optimized process afforded the products in high yields, moderate diastereoselectivity, and up to 90 % ee. The method was applied to the continuous-flow synthesis of biologically active chiral 1,2-amino alcohols (norephedrine, metaraminol, and methoxamine) through a two-step sequence combining the nitroaldol reaction with a hydrogenation. To highlight potential industrial applications of this method, a multistep continuous synthesis of norephedrine has been realized. The product was isolated without any intermediate purifications or solvent switches. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. Stereoselective toxicity of etoxazole to MCF-7 cells and its dissipation behavior in citrus and soil.

    Science.gov (United States)

    Sun, Dali; Pang, Junxiao; Fang, Qi; Zhou, Zhiqin; Jiao, Bining

    2016-12-01

    The stereoselective cytotoxicity of new chiral acaricide etoxazole and its dissipation in citrus and soil were investigated for the first time. Enantioselective toxicity and oxidative stress of etoxazole toward MCF-7 cells was conducted. The phenomenon of dose- and form-dependent cytotoxicity was demonstrated by MTT and LDH assays, ROS generation, and SOD and CAT activity alternation. Cytotoxicity ranks were found to be consistent with oxidative damage as (R)- > Rac- > (S)-etoxazole. Moreover, the results of enantioselective degradation showed that (S)-etoxazole degraded faster than its antipode (R)-etoxazole. The gradual raise of EF values indicated the achievement of enantioselective degradation in citrus and soil, leaving the enrichment of (R)-etoxazole isomer. Significant differences of environmental behavior and cytotoxicity of etoxazole enantiomers were found in this study which provided valuable insight into the mechanism of potential toxicity and warranted more careful assessment of this pesticide before its agricultural application.

  10. 75 FR 62635 - Proposed Information Collection (Patient Satisfaction Survey Michael E. DeBakey Home Care Program...

    Science.gov (United States)

    2010-10-12

    ... Collection (Patient Satisfaction Survey Michael E. DeBakey Home Care Program) Activity: Comment Request... determine patients' satisfaction with services provided by or through the Michael E. DeBakey Home Care...: Patient Satisfaction Survey Michael E. DeBakey Home Care Program, VA Form 10-0476. OMB Control Number...

  11. Synthesis of Heavy Fluorous Ruthenium Metathesis Catalysts Using the Stereoselective Addition of Polyfluoroalkyllithium to Sterically Hindered Diimines

    Czech Academy of Sciences Publication Activity Database

    Hošek, J.; Rybáčková, M.; Čejka, J.; Cvačka, Josef; Kvíčala, J.

    2015-01-01

    Roč. 34, č. 13 (2015), s. 3327 -3334 ISSN 0276-7333 Institutional support: RVO:61388963 Keywords : ring-closing metathesis * form tetrasubstituted olefins * N-heterocyclic carbene Subject RIV: CC - Organic Chemistry Impact factor: 4.186, year: 2015

  12. Theory and practice in action: the contributions of Michael Perkins to clinical linguistics.

    Science.gov (United States)

    Damico, Jack S; Lynch, Karen E

    2013-01-01

    This article reviews the scholarly contributions of Michael R. Perkins in the discipline of clinical linguistics and provides some indication of the reasons that he has been so successful. Three primary attributes were described through an analysis of his publications.

  13. Tõsine fotoelamus Dubrovnikus / Wade Goddard, Heidi Levine, Michael Robinson Chaver ; interv. Ahto Külvet

    Index Scriptorium Estoniae

    Goddard, Wade

    2007-01-01

    Dubrovniku vanalinnas asub Sõjafotokeskus. Intervjuu keskuse asutaja, kanadalasest fotograafi Wade Goddardi ja kahe seal augustis avatud näitusel osalenud fotograafi Heidi Levine'i ja Michael Robinson Chavez'iga. Sõjafotograafi tööst

  14. Joseph and Michael Haydn in the Bohemian music archives. An anniversary tribute

    Czech Academy of Sciences Publication Activity Database

    Freemanová, Michaela

    2012-01-01

    Roč. 20, č. 1 (2012), s. 117-126. ISBN 978-3-486-58949-8. ISSN 1865-5696 Institutional support: RVO:68378076 Keywords : Joseph Haydn * Michael Haydn * music archives Subject RIV: AL - Art, Architecture, Cultural Heritage

  15. Eesti disain on kõva, ent see tuleb moondada ekspordiks / Michael Thomson ; interv. Urmas Oja

    Index Scriptorium Estoniae

    Thomson, Michael

    2008-01-01

    Euroopa Disainiassotsiatsioonide Liidu presidendi ja Tallinnas toimunud festivali Disainiöö Eesti disainiauhinna Bruno žürii juhi Michael Thomsoni arvamus eesti disainist ning disainipoliitika vajalikkusest Eestis. Auhinnasaajate nimekiri

  16. Reports of the working groups / Eino Tamm, Sahlin Michael, Valve Kirsipuu...[jt.

    Index Scriptorium Estoniae

    1999-01-01

    Töögruppide "EU enlargement and relevant institutional reforms" (juhatajad Eino Tamm, Michael Sahlin) ja "Maintaining of competitiveness of Estonia and other candidate countries" (juhatajad Valve Kirsipuu, Terry Calbom) tööst. Autor: Reformierakond

  17. Michael Bloomberg ähvardab USA valimised "ära rikkuda" / Heiki Suurkask

    Index Scriptorium Estoniae

    Suurkask, Heiki, 1972-

    2008-01-01

    New Yorgi praegune linnapea Michael Bloomberg võib kolmanda kandidaadina sekkuda presidendikandidaatide valimiskampaaniasse, probleem on aga tema vähene tuntus. Lisa: Seni on riigipeakoha jaganud kaks suurparteid

  18. Prints Charles ja prints Michael külastasid Tallinna kirikuid / Allan Tammiku

    Index Scriptorium Estoniae

    Tammiku, Allan

    2001-01-01

    Prints Charles külastas 6. novembril Eesti-visiidi ajal Tallinna toomkirikut ja Pühavaimu kirikut, prints Michael viibis Tallinnas 11. novembril eravisiidil, ta külastas toomkirikut, Niguliste ja Pühavaimu kirikut

  19. Chinese Middle Classes: Taiwan, Hong Kong, Macao and China. Edited by Hsin-Huang Michael Hsiao

    DEFF Research Database (Denmark)

    Brødsgaard, Kjeld Erik

    2018-01-01

    Book review of: Chinese Middle Classes:Taiwan, Hong Kong, Macao and China. Edited by Hsin-Huang Michael Hsiao. Abingdon: Routledge, 2014. Pp. 268. ISBN 10: 1138120847; ISBN 13: 978-1138120846......Book review of: Chinese Middle Classes:Taiwan, Hong Kong, Macao and China. Edited by Hsin-Huang Michael Hsiao. Abingdon: Routledge, 2014. Pp. 268. ISBN 10: 1138120847; ISBN 13: 978-1138120846...

  20. Highly Stereoselective Gold-Catalyzed Coupling of Diazo Reagents and Fluorinated Enol Silyl Ethers to Tetrasubstituted Alkenes.

    Science.gov (United States)

    Liao, Fu-Min; Cao, Zhong-Yan; Yu, Jin-Sheng; Zhou, Jian

    2017-02-20

    We report a highly stereoselective synthesis of all-carbon or fluorinated tetrasubstituted alkenes from diazo reagents and fluorinated enol silyl ethers, using C-F bond as a synthetic handle. Cationic Au I catalysis plays a key role in this reaction. Remarkable fluorine effects on the reactivity and selectivity was also observed. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. Operational Cybersecurity Risks and Their Effect on Adoption of Additive Manufacturing in the Naval Domain

    Science.gov (United States)

    2017-12-01

    CYBERSECURITY RISKS AND THEIR EFFECT ON ADOPTION OF ADDITIVE MANUFACTURING IN THE NAVAL DOMAIN by Michael D. Grimshaw December 2017 Thesis...OF ADDITIVE MANUFACTURING IN THE NAVAL DOMAIN 5. FUNDING NUMBERS 6. AUTHOR(S) Michael D. Grimshaw 7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES...DISTRIBUTION CODE 13. ABSTRACT (maximum 200 words) Additive manufacturing (AM) has been proven to provide multiple benefits over traditional

  2. Stereoselective synthesis of an active metabolite of the potent PI3 kinase inhibitor PKI-179.

    Science.gov (United States)

    Chen, Zecheng; Venkatesan, Aranapakam M; Dos Santos, Osvaldo; Delos Santos, Efren; Dehnhardt, Christoph M; Ayral-Kaloustian, Semiramis; Ashcroft, Joseph; McDonald, Leonard A; Mansour, Tarek S

    2010-03-05

    The synthesis and stereochemical determination of 1-(4-(4-((1R,5R,6R)-6-hydroxy-3-oxa-8-azabicyclo[3.2.1]octan-8-yl)-6-morpholino-1,3,5-triazin-2-yl)phenyl)-3-(pyridin-4-yl)urea (2), an active metabolite of the potent PI3 kinase inhibitor PKI-179 (1), is described. Stereospecific hydroboration of the double bond of 2,5-dihydro-1H-pyrrole 8 gave the 2,3-trans alcohol 9 exclusively. The configuration of the 3-hydroxyl group in 9 was inverted by an oxidation and stereoselective reduction sequence to give the corresponding 2,3-cis isomer 23. Both exo (21) and endo (27) isomers of the metabolite 2 were prepared via a practical synthetic route from 9 and 23, respectively, and the stereochemistry of 2 was determined to be endo. The endo isomer (27) was separated into two enantiomers 28 and 29 by chiral HPLC. Compound 2 was found to be enantiomerically pure and identical to the enantiomer 28. The absolute stereochemistry of the enantiomer 28 was determined by Mosher's method, thus establishing the stereochemistry of the active metabolite 2.

  3. Stereoselective synthesis of an iodinated resveratrol analog: Preliminary bioevaluation studies of the radioiodinated species

    Energy Technology Data Exchange (ETDEWEB)

    Dhyani, Manish V.; Kameswaran, Mythili; Korde, Aruna G.; Pandey, Usha [Radiopharmaceuticals Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Chattopadhyay, Subrata [Bio-Organic Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Banerjee, Sharmila, E-mail: sharmila@barc.gov.i [Radiopharmaceuticals Division, Bhabha Atomic Research Centre, Mumbai 400085 (India)

    2011-07-15

    Stereoselective synthesis of an E-hydroxystilbene has been carried out using the McMurry reaction. Synthesis of a monoiodinated hydroxystilbene has been carried out by a McMurry cross-coupling reaction. For the purpose of biological evaluation, the facile electrophilic substitution route has been attempted to radioiodinate it with {sup 125}I. The HPLC pattern of the radioiodinated hydroxystilbene, which could be obtained in >90% radiochemical purity, was found to be identical to that of its non-radioactive analog that has been independently prepared using the McMurry cross-coupling route. In vitro cell uptake studies were carried out in breast cancer cells MCF7, overexpressing estrogen receptors. In vivo biodistribution studies in female Swiss mice show a uterine uptake of 0.85{+-}0.4% ID/g at 3 h.p.i. with a uterus to muscle ratio of 2.83. Uptake in the thyroid was insignificant indicating good in vivo stability of the radioiodinated hydroxystilbene.

  4. Stereoselective biodegradation of tricyclic terpanes in heavy oils from the Bolivar Coastal Fields, Venezuela

    Energy Technology Data Exchange (ETDEWEB)

    Alberdi, M. [Stanford University (United States). Dept. of Geological and Environmental Sciences; PDVSA-Intevep, Caracas (Venezuela); Moldowan, J.M.; Dahl, J.E. [Stanford University (United States). Dept. of Geological and Environmental Sciences; Peters, K.E. [Mobil Technology Co., Dallas, TX (United States)

    2001-07-01

    Gas chromatography-mass spectrometry (GC-MS) and GC-MS-MS analyses of heavy oils from Bolivar Coastal Fields (Lagunillas Field) show a complete set of demethylated tricyclic terpanes. As is the case for the 25-norhopanes, the demethylated tricyclics are probably formed in reservoirs by microbially-mediated removal of the methyl group from the C-10 position, generating putative 17-nor-tricyclic terpanes. Diastereomeric pairs of tricyclic terpanes are resolved above C{sub 24} due to resolution of 22S and 22R epimers, but the elution order of the 22S and 22R epimers is unknown. Early-eluting diastereomers (EE) predominate over late-eluting diastereomers (LE) (C{sub 25}-C{sub 29}) in the heavily degraded oils, indicating a stereoselective preference for the LE stereoisomers during biodegradation. Conversely, the LE diastereomers predominate over the EE diastereomers in the 17-nor tricyclic series (C{sub 24}-C{sub 28}), indicating that tricyclic terpanes and 17-nor-tricyclic terpanes are directly linked as precursors and products, respectively. A good correlation exists between the destruction of steranes and the demethylation of hopanes and tricyclic terpanes. This suggests that terpane demethylation occurs during sterane destruction and hopane demethylation, although the rate is slower, indicating that tricyclic terpanes are more resistant to biodegradation. (Author)

  5. Stereoselective potencies and relative toxicities of γ-coniceine and N-methylconiine enantiomers.

    Science.gov (United States)

    Lee, Stephen T; Green, Benedict T; Welch, Kevin D; Jordan, Glenn T; Zhang, Qian; Panter, Kip E; Hughes, David; Chang, Cheng-Wei Tom; Pfister, James A; Gardner, Dale R

    2013-04-15

    γ-Coniceine, coniine, and N-methylconiine are toxic alkaloids present in poison hemlock (Conium maculatum). We previously reported the comparison of the relative potencies of (+)- and (-)-coniine enantiomers. In this study, we synthesized γ-coniceine and the enantiomers of N-methylconiine and determined the biological activity of γ-coniceine and each of the N-methylconiine enantiomers in vitro and in vivo. The relative potencies of these piperidine alkaloids on cells expressing human fetal muscle-type nicotinic acetylcholine receptors had the rank order of γ-coniceine > (-)-N-methylconiine > (±)-N-methylconiine > (+)-N-methylconiine. The relative lethalities of γ-coniceine and (-)-, (±)-, and (+)-N-methylconiine in vivo using a mouse bioassay were 4.4, 16.1, 17.8, and 19.2 mg/kg, respectively. The results from this study suggest γ-coniceine is a more potent agonist than the enantiomers of N-methylconiine and that there is a stereoselective difference in the in vitro potencies of the enantiomers of N-methylconiine that correlates with the relative toxicities of the enantiomers in vivo.

  6. Hammond Postulate Mirroring Enables Enantiomeric Enrichment of Phosphorus Compounds via Two Thermodynamically Interconnected Sequential Stereoselective Processes.

    Science.gov (United States)

    Rajendran, Kamalraj V; Nikitin, Kirill V; Gilheany, Declan G

    2015-07-29

    The dynamic resolution of tertiary phosphines and phosphine oxides was monitored by NMR spectroscopy. It was found that the stereoselectivity is set during the formation of the diastereomeric alkoxyphosphonium salts (DAPS), such that their initial diastereomeric excess (de) limits the final enantiomeric excess (ee) of any phosphorus products derived from them. However, (31)P NMR monitoring of the spontaneous thermal decomposition of the DAPS shows consistent diastereomeric self-enrichment, indicating a higher rate constant for decomposition of the minor diastereomer. This crucial observation was confirmed by reductive trapping of the unreacted enriched DAPS with lithium tri-sec-butylborohydride (commercially distributed as L-Selectride reagent) at different time intervals after the start of reaction, which gives progressively higher ee of the phosphine product with time. It is proposed that the Hammond postulate operates for both formation and decomposition of DAPS intermediate so that the lower rate of formation and faster subsequent collapse of the minor isomer are thermodynamically linked. This kinetic enhancement of kinetic resolution furnishes up to 97% ee product.

  7. Stereoselectivity in the disposition and metabolism of the uricosuric-diuretic agent, indacrinone, in Rhesus monkeys

    Energy Technology Data Exchange (ETDEWEB)

    Zacchei, A.G.; Dobrinska, M.R.; Wishousky, T.I.; Kwan, K.C.; White, S.D.

    The physiological disposition following intravenous dosing of the separate enantiomers of indacrinone-/sup 14/C (I), and of their major metabolite, 4'-hydroxyindacrinone-/sup 14/C (M), was studied in the rhesus monkey. Pharmacokinetic analysis indicated that the disposition of I and M was stereoselective. In the case of the enantiomers of I, the areas under the curves of plasma concentration vs. time were about sevenfold greater for the (S)(+)- as compared to the (R)(-)-enantiomer. Renal and plasma clearances of (R)(-)-I were five to seven times greater than those of (S)(+)-I. Total urinary recovery of unchanged drug and metabolite accounted for 70% of the administered dose of either enantiomer. The systemic availability of (R)(-)-M from (R)(-)-I was approximately 21% of the dose, whereas that of (S)(+)-M from (S)(+)-I was only 4%. More pronounced differences were noted in the kinetics of metabolite disposition. The AUC values were about 27 times greater for (S)(+)-M than (R)(-)-M, and the renal and plasma clearances were approximately 25-fold higher for (R)(-)-M as compared to (S)(+)-M. The volume of distribution of (S)(+)-M was only 12% of that observed with (R)(+)-M. There was no evidence of glucuronide or sulfate conjugates of any of the enantiomers. These findings are consistent with the pharmacological activity attributed to the different enantiomers.

  8. Stereoselective hydrogenation of olefins using rhodium-substituted carbonic anhydrase--a new reductase.

    Science.gov (United States)

    Jing, Qing; Okrasa, Krzysztof; Kazlauskas, Romas J

    2009-01-01

    One useful synthetic reaction missing from nature's toolbox is the direct hydrogenation of substrates using hydrogen. Instead nature uses cofactors like NADH to reduce organic substrates, which adds complexity and cost to these reductions. To create an enzyme that can directly reduce organic substrates with hydrogen, researchers have combined metal hydrogenation catalysts with proteins. One approach is an indirect link where a ligand is linked to a protein and the metal binds to the ligand. Another approach is direct linking of the metal to protein, but nonspecific binding of the metal limits this approach. Herein, we report a direct hydrogenation of olefins catalyzed by rhodium(I) bound to carbonic anhydrase (CA-[Rh]). We minimized nonspecific binding of rhodium by replacing histidine residues on the protein surface using site-directed mutagenesis or by chemically modifying the histidine residues. Hydrogenation catalyzed by CA-[Rh] is slightly slower than for uncomplexed rhodium(I), but the protein environment induces stereoselectivity favoring cis- over trans-stilbene by about 20:1. This enzyme is the first cofactor-independent reductase that reduces organic molecules using hydrogen. This catalyst is a good starting point to create variants with tailored reactivity and selectivity. This strategy to insert transition metals in the active site of metalloenzymes opens opportunities to a wider range of enzyme-catalyzed reactions.

  9. Stereoselectivity of the demethylation of nicotine piperidine homologues by Nicotiana plumbaginifolia cell suspension cultures.

    Science.gov (United States)

    Bartholomeusz, Trixie Ann; Molinié, Roland; Roscher, Albrecht; Felpin, François-Xavier; Gillet, Françoise; Lebreton, Jacques; Mesnard, François; Robins, Richard J

    2005-08-01

    The metabolism of (R,S)-N-methylanabasine and (R,S)-N-methylanatabine has been studied in a cell suspension culture of Nicotiana plumbaginifolia. Both substrates are effectively demethylated, anabasine or anatabine, respectively, accumulating in the medium. Similarly, there is strong stereoselectivity for the (R)-isomers of both substrates. The kinetics of metabolism of (R,S)-N-methylanabasine differ significantly from those of nicotine in that no further degradation of the initial demethylation product occurs. (R,S)-N-Methylanatabine, however, shows kinetics closer to those of nicotine, with loss of alkaloid from the system. Further more, (R,S)-N-methylanabasine does not diminish (S)-nicotine demethylation, indicating a lack of competition. However, the metabolism of (S)-nicotine is affected by the presence of (R,S)-N-methylanabasine. Hence, the demethylation of the piperidine homologues of nicotine is seen to be similar but not identical to that of the pyridine analogues. The implications of these different metabolic profiles in relation to the demethylation activity are discussed.

  10. Phospholyl(borane) Amino Acids and Peptides: Stereoselective Synthesis and Fluorescent Properties with Large Stokes Shift.

    Science.gov (United States)

    Arribat, Mathieu; Rémond, Emmanuelle; Clément, Sébastien; Lee, Arie Van Der; Cavelier, Florine

    2018-01-24

    The synthesis of phospholyl(borane) amino acids was stereoselectively achieved by reaction of phospholide anion with iodo α-amino ester derived from l-aspartic acid or l-serine, followed by in situ complexation with borane. Phospholyl(borane) amino acids are easy to store and can be subjected to direct transformation into the corresponding free phospholyl, gold complex, oxide or sulfur derivatives as well as phospholinium salts, thus offering a variety of side chains. After selective deprotection of carboxylic function or amine, C- or N- peptide coupling with an alanine moiety proved the possible incorporation into peptides. Such phospholyl amino acid and peptide derivatives exhibit fluorescent properties with a large Stokes shift (160 nm) and fluorescence up to 535 nm, depending on the phosphole aromaticity and the chemical environment. These phospholyl(borane) amino acids constitute a new class of unnatural amino acids useful for structure-activities relationship studies and appear to be promising fluorophores for the development of labeled peptides.

  11. The tobacco carcinogen NNK is stereoselectively reduced by human pancreatic microsomes and cytosols.

    Science.gov (United States)

    Trushin, Neil; Leder, Gerhard; El-Bayoumy, Karam; Hoffmann, Dietrich; Beger, Hans G; Henne-Bruns, Doris; Ramadani, Marco; Prokopczyk, Bogdan

    2008-07-01

    Cigarette smoking increases the risk of cancer of the pancreas. The tobacco-specific nitrosamine 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) is the only known environmental compound that induces pancreatic cancer in laboratory animals. Concentrations of NNK are significantly higher in the pancreatic juice of smokers than in that of nonsmokers. The chiral NNK metabolite, (R,S)-4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL) is itself a potent pancreatic carcinogen in rats. The carcinogenicity of NNAL is related to its stereochemistry; (S)-NNAL is a more potent lung tumorigen in the A/J mouse than is (R)-NNAL. In this study, we determined the potential of the human pancreas to convert NNK into NNAL. Human pancreatic microsomes and cytosols were incubated with [5-(3)H]NNK, and the metabolic products were determined by high-performance liquid chromatography (HPLC). (S)-NNAL was the predominant isomer formed in all cytosolic incubations. In ten microsomal samples, NNAL was formed at an average rate of 3.8 +/- 1.6 pmol/mg/min; (R)-NNAL was the predominant isomer in this group. The average rate of NNAL formation in 18 other microsomal samples was significantly lower, 0.13 +/- 0.12 pmol/mg/min (p < 0.001); (S)-NNAL was the predominant isomer formed in this group. In human pancreatic tissues, there is intraindividual variability regarding the capacity for, and stereoselectivity of, carbonyl reduction of NNK.

  12. Direct enantioselective conjugate addition of carboxylic acids with chiral lithium amides as traceless auxiliaries.

    Science.gov (United States)

    Lu, Ping; Jackson, Jeffrey J; Eickhoff, John A; Zakarian, Armen

    2015-01-21

    Michael addition is a premier synthetic method for carbon-carbon and carbon-heteroatom bond formation. Using chiral dilithium amides as traceless auxiliaries, we report the direct enantioselective Michael addition of carboxylic acids. A free carboxyl group in the product provides versatility for further functionalization, and the chiral reagent can be readily recovered by extraction with aqueous acid. The method has been applied in the enantioselective total synthesis of the purported structure of pulveraven B.

  13. Direct Enantioselective Conjugate Addition of Carboxylic Acids with Chiral Lithium Amides as Traceless Auxiliaries

    Science.gov (United States)

    2016-01-01

    Michael addition is a premier synthetic method for carbon–carbon and carbon–heteroatom bond formation. Using chiral dilithium amides as traceless auxiliaries, we report the direct enantioselective Michael addition of carboxylic acids. A free carboxyl group in the product provides versatility for further functionalization, and the chiral reagent can be readily recovered by extraction with aqueous acid. The method has been applied in the enantioselective total synthesis of the purported structure of pulveraven B. PMID:25562717

  14. Dr. O.S Michael Department of Pharmacology and Therapeutics ...

    African Journals Online (AJOL)

    its machinery just as much as he has in the anatomical laboratory, and ...to combine ... nurses, and other health professionals, in addition to delivering medical care to patients. ... better understanding of human physiology and was the earliest ...

  15. Michael Goodsite gæsteprofessor på Thunderbird School of Global Management

    DEFF Research Database (Denmark)

    Pedersen, Jens Christian

    2010-01-01

    Professor Michael Goodsite er blevet udnævnt til "Visiting Professor of Global Processes and Senior Research Fellow in Climate Strategy" ved Thunderbird School of Global Management, som har verdens højst rangerede MBA uddannelse inden for international handel.......Professor Michael Goodsite er blevet udnævnt til "Visiting Professor of Global Processes and Senior Research Fellow in Climate Strategy" ved Thunderbird School of Global Management, som har verdens højst rangerede MBA uddannelse inden for international handel....

  16. Stereoselective uptake and distribution of chiral neoniconoid insecticide paichongding in chinese pak choi (Brassica campestris ssp. Chinenesis)

    International Nuclear Information System (INIS)

    Wang Haiyan; Yang Zhen; Liu Ruyang; Fu Qiuguo; Zhang Sufen; Li Juying; Zhao Xiaojun; Ye Qingfu; Wang Wei; Li Zhong

    2014-01-01

    Paichongding, a neonicotinoid chiral insecticide containing two chiral centers, is a promising substitute for the widely used imidacloprid because it is effective against many imidacloprid-resistant insects. In this study, four optically-pure stereoisomers of Paichongding with 5R, 7R, 5S, 7S, 5S, 7R, and 5R, 7S were employed in both foliar and root of Chinese pak choi to investigate the stereoselective uptake and distribution of the insecticide in pak choi. The results showed, after foliar application, total absorption of individual "1"4C-Paichongding stereoisomers into pak-choi plants demonstrated no stereoselectivity between the enantiomers. The translocation of the four absorbed stereoisomers within pak choi occurred in both acropetal and basipetal directions and the transport of "1"4C from enantiomers 5R, 7R and 5S, 7S were significantly higher than enantiomers 5R, 7S and 5S, 7R. The statistically significant stereoselective translocation inside plants was observed between Paichongding epimers. Root treatment revealed that enantioselective and diastereoselective root uptake into pak-choi plants were both found between the four enantiomers. The enantiomers of 5R, 7S and 5S, 7R were more readily taken up by roots, and more readily accumulated in edible leaves than 5R, 7R and 5S, 7S. These results will help to develop an understanding of the proper application of Paichongding isomers in vegetables, and give useful information for food and environmental assessments of chiral pesticides. (authors)

  17. Stereoselective synthesis of functionalized cyclic amino acid derivatives via a [2,3]-Stevens rearrangement and ring-closing metathesis.

    Science.gov (United States)

    Nash, Aaron; Soheili, Arash; Tambar, Uttam K

    2013-09-20

    Unnatural cyclic amino acids are valuable tools in biomedical research and drug discovery. A two-step stereoselective strategy for converting simple glycine-derived aminoesters into unnatural cyclic amino acid derivatives has been developed. The process includes a palladium-catalyzed tandem allylic amination/[2,3]-Stevens rearrangement followed by a ruthenium-catalyzed ring-closing metathesis. The [2,3]-rearrangement proceeds with high diastereoselectivity through an exo transition state. Oppolzer's chiral auxiliary was utilized to access an enantiopure cyclic amino acid by this approach, which will enable future biological applications.

  18. Stereoselective uptake and distribution of the chiral neonicotinoid insecticide, Paichongding, in Chinese pak choi (Brassica campestris ssp. chinenesis)

    International Nuclear Information System (INIS)

    Wang, Haiyan; Yang, Zhen; Liu, Ruyang; Fu, Qiuguo; Zhang, Sufen; Cai, Zhiqiang; Li, Juying; Zhao, Xiaojun; Ye, Qingfu; Wang, Wei; Li, Zhong

    2013-01-01

    Highlights: • Absorption of foliar applied Paichongding by pak choi was not stereoselective. • Foliar uptake and downward transport of Paichongding were both found in pak choi. • Enantioselective and epimer-selective root uptake were observed for Paichongding. • Foliage/root uptake showed diastereoselective transport of Paichongding epimers. • The SR and RS are more easily taken up by roots and accumulated in edible parts. -- Abstract: Neonicotinoid chiral insecticidal Paichongding is a promising substitute for the widely used imidacloprid. Four stereoisomers of Paichongding, 5R,7R, 5S,7S, 5S,7R and 5R,7S, were employed in both foliage and roots of Chinese pak choi to investigate their stereoselective uptake and distribution in pak choi. Results showed that after foliar application, no stereoselective absorption into pak-choi plants was observed among the enantiomers. Total absorptions were 35.40% of the applied amount for 5R,7R, 36.66% for 5S,7S, 36.80% for 5S,7R and 38.20% for 5R,7S at 96 HAT. The translocation of the four absorbed stereoisomers within pak choi occurred both acropetally and basipetally and the transport of 14 C from enantiomers 5R,7R and 5S,7S were significantly higher than for 5R,7S and 5S,7R. Significant stereoselective translocation inside plants was observed between Paichongding epimers. Total root uptake reached 16.49–19.85% for 5R,7R and 5S,7S, and 24.57–28.82% for 5S,7R and 5R,7S at 144 HAT. Both enantioselective and diastereoselective root uptake into pak-choi occurred between the four stereoisomers. The 5R,7S and 5S,7R enantiomers were more readily uptaken by the roots than 5R,7R and 5S,7S and accumulated in the edible leaves. These results will help to develop an understanding of Paichongding using only the target-active enantiomer of pesticides

  19. Total Synthesis of Bryostatins. Development of Methodology for Atom-Economic and Stereoselective Synthesis of the C-ring Subunit

    Science.gov (United States)

    Trost, Barry M.; Frontier, Alison J.; Thiel, Oliver R.; Yang, Hanbiao; Dong, Guangbin

    2012-01-01

    Bryostatins, a family of structurally complicated macrolides, exhibit an exceptional range of biological activities. The limited availability and structural complexity of these molecules makes development of an efficient total synthesis particularly important. This article describes our initial efforts towards the total synthesis of bryostatins, in which chemoselective and atom-economical methods for stereoselective assembly of the C-ring subunit were developed. A Pd-catalyzed tandem alkyne-alkyne coupling/6-endo-dig cyclization sequence was explored and successfully pursued in the synthesis of a dihydropyran ring system. Elaboration of this methodology ultimately led to a concise synthesis of the C-ring subunit of bryostatins. PMID:21793057

  20. Stereoselective uptake and distribution of the chiral neonicotinoid insecticide, Paichongding, in Chinese pak choi (Brassica campestris ssp. chinenesis)

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Haiyan; Yang, Zhen; Liu, Ruyang; Fu, Qiuguo; Zhang, Sufen; Cai, Zhiqiang; Li, Juying; Zhao, Xiaojun [Institute of Nuclear Agricultural Sciences, Key Laboratory of Nuclear Agricultural Sciences of Ministry of Agriculture and Zhejiang Province, Zhejiang University, Hangzhou 310029 (China); Ye, Qingfu, E-mail: qfye@zju.edu.cn [Institute of Nuclear Agricultural Sciences, Key Laboratory of Nuclear Agricultural Sciences of Ministry of Agriculture and Zhejiang Province, Zhejiang University, Hangzhou 310029 (China); Wang, Wei [Institute of Nuclear Agricultural Sciences, Key Laboratory of Nuclear Agricultural Sciences of Ministry of Agriculture and Zhejiang Province, Zhejiang University, Hangzhou 310029 (China); Li, Zhong, E-mail: lizhong@ecust.edu.cn [School of Pharmacy, East China University of Science and Technology, 130 Meilong Road, Shanghai 200237 (China)

    2013-11-15

    Highlights: • Absorption of foliar applied Paichongding by pak choi was not stereoselective. • Foliar uptake and downward transport of Paichongding were both found in pak choi. • Enantioselective and epimer-selective root uptake were observed for Paichongding. • Foliage/root uptake showed diastereoselective transport of Paichongding epimers. • The SR and RS are more easily taken up by roots and accumulated in edible parts. -- Abstract: Neonicotinoid chiral insecticidal Paichongding is a promising substitute for the widely used imidacloprid. Four stereoisomers of Paichongding, 5R,7R, 5S,7S, 5S,7R and 5R,7S, were employed in both foliage and roots of Chinese pak choi to investigate their stereoselective uptake and distribution in pak choi. Results showed that after foliar application, no stereoselective absorption into pak-choi plants was observed among the enantiomers. Total absorptions were 35.40% of the applied amount for 5R,7R, 36.66% for 5S,7S, 36.80% for 5S,7R and 38.20% for 5R,7S at 96 HAT. The translocation of the four absorbed stereoisomers within pak choi occurred both acropetally and basipetally and the transport of {sup 14}C from enantiomers 5R,7R and 5S,7S were significantly higher than for 5R,7S and 5S,7R. Significant stereoselective translocation inside plants was observed between Paichongding epimers. Total root uptake reached 16.49–19.85% for 5R,7R and 5S,7S, and 24.57–28.82% for 5S,7R and 5R,7S at 144 HAT. Both enantioselective and diastereoselective root uptake into pak-choi occurred between the four stereoisomers. The 5R,7S and 5S,7R enantiomers were more readily uptaken by the roots than 5R,7R and 5S,7S and accumulated in the edible leaves. These results will help to develop an understanding of Paichongding using only the target-active enantiomer of pesticides.

  1. Photochemistry and stereoselectivity of cellular retinaldehyde-binding protein from bovine retina

    International Nuclear Information System (INIS)

    Saari, J.C.; Bredberg, D.L.

    1987-01-01

    11-cis-Retinaldehyde bound to cellular retinaldehyde-binding protein (CRALBP) is unaffected in bovine eyecup preparations by illumination that bleaches approximately 70% of the rhodopsin. Illumination of retinal homogenates to which CRALBP X [ 3 H]11-cis-retinaldehyde had been added did not result in a reduction of the specific activity of recovered 11-cis-retinaldehyde, ruling out a bleaching regeneration cycle. The quantum efficiency of photoisomerization for CRALBP X 11-cis-retinaldehyde was determined by comparing the rate of photoisomerization of 11-cis-retinaldehyde bound to purified CRALBP and opsin. The low value obtained (0.07), coupled with a low molar extinction coefficient (15,400 M-1 cm-1), results in a photosensitivity only about 4% that of rhodopsin. CRALBP binds 9-cis- and 11-cis-retinaldehyde, producing complexes with absorption maxima at 405 and 425 nm, respectively. No complexes were detected with 13-cis- and all-trans-retinaldehyde. Following incubation of CRALBP X 11-cis-retinol with an equimolar mixture of 9-, 11-, 13-cis-, and all-trans-retinaldehydes, only 11-cis-retinaldehyde and residual 11-cis-retinol are present on the protein following separation from excess retinoids. A similar result is obtained following incubation of CRALBP X 11-cis-retinol with mixtures of 9- and 11-cis-retinaldehyde ranging in composition from 9:1 to 1:9 (9-cis-:11-cis-,mol/mol). The results indicate that CRALBP X 11-cis-retinol is sufficiently stereoselective in its binding properties to warrant consideration as a component of the mechanism for the generation of 11-cis-retinaldehyde in the dark

  2. Passings to note: Paul Michael Packman, MD; S. Charles Schulz, MD.

    Science.gov (United States)

    Black, Donald W

    2018-02-01

    One of the keys to the success of Annals of Clinical Psychiatry has always been the tireless efforts of our dedicated Editorial Board. We recently lost 2 longtime Editorial Board members, Drs. Paul Michael Packman and S. Charles Schulz. Both will be greatly missed.

  3. Michael Perelman: An ecological future in view of Marxist Economics (Ⅱ)

    Institute of Scientific and Technical Information of China (English)

    Ren Xiaomei

    2009-01-01

    @@ Interviewee profile: Michael Perelman, currently professor of Economics Department of California State University, USA, American economist and economic historian with nearly 20 publications in the field of economics criticism, including Railroading Economics, Manufacturing Discontent, The Perverse Economy, and The Invention of Capitalism.

  4. Wolff-Michael Roth's passibility: at the limits of the constructivist metaphor: a book review

    Science.gov (United States)

    Brendel, Michelle

    2014-12-01

    Wolff-Michael Roth deconstructs the preeminent role conceded to constructivism in Science Education and demonstrates how we learn and know through pain, suffering, love or passion. This review explores his book "Passibility: At the Limits of the Constructivist Metaphor" through the eyes of an outsider to the world of science education.

  5. Assessment of lipid profile of a group of undergraduates in Michael ...

    African Journals Online (AJOL)

    Objective: The aim of this study was to measure the lipid fractions in serum blood samples of apparently healthy undergraduates of Michael Okpara University of Agriculture, Umudike. Methods: A total of one hundred consenting males and females aged between 19-30 years were purposively selected from the ...

  6. Briti ekspert : euroliidus kaob Eestist tööpuudus / Michael Richardson ; interv. Airi Ilisson

    Index Scriptorium Estoniae

    Richardson, Michael

    2003-01-01

    Eestis Suurbritannia tööreformi tutvustava töö- ja sotsiaalnõuniku sõnul on Suurbritannias peaaegu kadunud pikaajaline töötus noorte hulgas, vanematest inimestest on vaid üksikud tööta kauem kui aasta. Vt. samas: Kes on Michael Richardson?

  7. Moral Education and Education in Altruism: Two Replies to Michael Hand

    Science.gov (United States)

    White, John

    2016-01-01

    This article is a critical discussion of two recent papers by Michael Hand on moral education. The first is his "Towards a Theory of Moral Education", published in the "Journal of Philosophy of Education" in 2014 (Volume 48, Issue 4). The second is a chapter called "Beyond Moral Education?" in an edited book of new…

  8. Recollections of Jack Michael and the Application of Skinner's Analysis of Verbal Behavior

    Science.gov (United States)

    Sundberg, Mark L.

    2017-01-01

    Jack Michael offered a course on verbal behavior almost every year throughout his teaching career. Jack was also interested in the application of Skinner's work and in 1976 began to offer a graduate course at Western Michigan University titled Verbal Behavior Applications. Jack and his students pursued the application of Skinner's work on verbal…

  9. From Gouldner to Gramsci: The Making of Michael Apple's "Ideology and Curriculum"

    Science.gov (United States)

    Gottesman, Isaac

    2012-01-01

    Michael Apple's "Ideology and Curriculum", published in 1979, helped initiate a broad turn in the field of education in the United States to Marxist thought as a lens through which to analyze the relationship between school and society. This classic text continues to inform scholarship in the field. While "Ideology" has…

  10. Outside in America: George Michael's music video, public sex and global pop culture

    NARCIS (Netherlands)

    Kooijman, J.

    2004-01-01

    Six months after his controversial arrest for ‘lewd conduct’ at a men’s public restroom in Beverly Hills, British pop star George Michael released the song and music video ‘Outside’ which can be seen as an explicit commentary on the controversy. In this article, I read the music video in three ways:

  11. "Raising Standards" or Reducing Aspirations and Opportunities Still Further? Michael Gove and Examination Reforms

    Science.gov (United States)

    Allen, Martin

    2013-01-01

    Well before the examinations grade crisis of 2012, Michael Gove had set out clear intentions for reforming public examinations. Though he claimed to be improving examinations and assessment by replicating practices that took place in high-performing countries and thus improving the ability of the UK economy to "compete", this…

  12. The Educational Philosophies of Mordecai Kaplan and Michael Rosenak: Surprising Similarities and Illuminating Differences

    Science.gov (United States)

    Schein, Jeffrey; Caplan, Eric

    2014-01-01

    The thoughts of Mordecai Kaplan and Michael Rosenak present surprising commonalities as well as illuminating differences. Similarities include the perception that Judaism and Jewish education are in crisis, the belief that Jewish peoplehood must include commitment to meaningful content, the need for teachers to teach from a position of…

  13. Astronaut C. Michael Foale is briefed on use of Sky Genie

    Science.gov (United States)

    1994-01-01

    Astronaut C. Michael Foale, STS-63 mission specialist, is briefed on the use of Sky Genie device by Karin L. Porter. The device would aid in emergency egress operations aboard a troubled Space Shuttle. Porter, an employee of Rockwell International, helps train astronauts in egress procedures at JSC's Shuttle mockup and integration laboratory.

  14. Gender Relations and Sexual Harassment in the Workplace: Michael Crichton's "Disclosure" as a Teaching Tool.

    Science.gov (United States)

    Comer, Debra R.; Cooper, Elizabeth A.

    1998-01-01

    Describes how to use Michael Crichton's novel "Disclosure" and the film based on it for class discussions of such issues as what constitutes sexual harassment, harassment of men, relationship between sexual harassment and power, organizational responses to harassment, and gender differences in career advancement tactics. (SK)

  15. The power of virtual integration: an interview with Dell Computer's Michael Dell. Interview by Joan Magretta.

    Science.gov (United States)

    Dell, M

    1998-01-01

    Michael Dell started his computer company in 1984 with a simple business insight. He could bypass the dealer channel through which personal computers were then being sold and sell directly to customers, building products to order. Dell's direct model eliminated the dealer's markup and the risks associated with carrying large inventories of finished goods. In this interview, Michael Dell provides a detailed description of how his company is pushing that business model one step further, toward what he calls virtual integration. Dell is using technology and information to blur the traditional boundaries in the value chain between suppliers, manufacturers, and customers. The individual pieces of Dell's strategy--customer focus, supplier partnerships, mass customization, just-in-time manufacturing--may be all be familiar. But Michael Dell's business insight into how to combine them is highly innovative. Direct relationships with customers create valuable information, which in turn allows the company to coordinate its entire value chain back through manufacturing to product design. Dell describes how his company has come to achieve this tight coordination without the "drag effect" of ownership. Dell reaps the advantages of being vertically integrated without incurring the costs, all the while achieving the focus, agility, and speed of a virtual organization. As envisioned by Michael Dell, virtual integration may well become a new organizational model for the information age.

  16. Kunstlik viljastamine - kas rahva püsimajäämise võti? / Michael Cook

    Index Scriptorium Estoniae

    Cook, Michael

    2007-01-01

    Kunstlikust viljastamisest pole üksi abi - vaid siis, kui noored mehed ja naised pööravad selja tarbimiskultusele ja individualismile, hakkab sündimus tõusma taastootmisest kõrgemale, kirjutab BioEdge toimetaja Michael Cook

  17. Training and Mastery of Techniques in Wittgenstein's Later Philosophy: A Response to Michael Luntley

    Science.gov (United States)

    Stickney, Jeff

    2008-01-01

    Responding to Michael Luntley's article, "Learning, Empowerment and Judgement," the author shows he cannot successfully make the following three moves: (1) dissolve the analytic distinction between learning by training and learning by reasoning, while advocating the latter; (2) diminish the role of training in Wittgenstein's philosophy, nor…

  18. Vision and Elusiveness in Philosophy of Education: R. S. Peters on the Legacy of Michael Oakeshott

    Science.gov (United States)

    Williams, Kevin

    2009-01-01

    Despite his elusiveness on important issues, there is much in Michael Oakeshott's educational vision that Richard Peters quite rightly wishes to endorse. The main aim of this essay is, however, to consider Peters' justifiable critique of three features of Oakeshott's work. These are (1) the rigidity of his distinction between vocational and…

  19. Hydrogeochemical and stream sediment reconnaissance basic data for St. Michael Quadrangle, Alaska

    International Nuclear Information System (INIS)

    1981-01-01

    Field and laboratory data are presented for 159 water samples from the St. Michael Quadrangle, Alaska. The samples were collected by Los Alamos National Laboratory; laboratory analysis and data reporting were performed by the Uranium Resource Evaluation Project at Oak Ridge, Tennessee

  20. Gulliver's Travels: Michael Moore the Explorer in "Who to Invade Next"

    Science.gov (United States)

    Beck, Bernard

    2016-01-01

    America is identified as a nation of immigrants. These immigrants are thought to be the source of its subcultures. It is also a nation of individual explorers and inventors. Their activities are also a source of diverse subcultures. Many notable movies have made heroes of such innovators in different fields of endeavor. Michael Moore's movie…

  1. A Critical Analysis of Michael Tippett's "A Child of Our Time"

    Science.gov (United States)

    Vallee, Jean-Sebastien

    2009-01-01

    After more than ten years of thoughtful planning, Michael Tippett (1905-1998) summed up his musical, political, spiritual and philosophical beliefs in his first oratorio, "A Child of Our Time" (1941). Representing the emergence of a new level of confidence and musical maturity for Tippett, the oratorio has become the composer's most widely known…

  2. Q & A with Ed Tech Leaders: Interview with Michael W. Allen

    Science.gov (United States)

    Shaughnessy, Michael F.

    2014-01-01

    Michael W. Allen, the Chairman and CEO of Allen Interactions, is an architect of interactive multimedia learning and is recognized for his many insights, inventions, and presentations. With over 50 years of experience in e-learning, both in academic and corporate settings, he is known for his role in creating Authorware and overseeing the work of…

  3. European Management: an emerging competitive advantage of European nations : A reply to Michael Porter

    NARCIS (Netherlands)

    F.A.J. van den Bosch (Frans); A.A. van Prooijen

    1992-01-01

    textabstractThis article extends the debate begun in the June 1992 issue of EMJ when the authors first criticized Michael Porter's explanatory framework in his Competitive Advantage of Nations (1990), over the role of national culture on the competitive advantage of nations. In this paper, Frans van

  4. New Models at Lasell: Q&A with President Michael Alexander

    Science.gov (United States)

    Harney, John O.

    2018-01-01

    The "New England Journal of Higher Education" ("NEJHE") Executive Editor John O. Harney had the chance to catch up with Lasell College President Michael Alexander about the small Newton, Massachusetts, college's plans to challenge the higher education business model. The interview is presented in this article.

  5. Subjectivity and Cultural Adjustment in Mathematics Education: A Response to Wolff-Michael Roth

    Science.gov (United States)

    Brown, Tony

    2012-01-01

    In this volume, Wolff-Michael Roth provides a critical but partial reading of Tony Brown's book "Mathematics Education and Subjectivity". The reading contrasts Brown's approach with Roth's own conception of subjectivity as derived from the work of Vygotsky, in which Roth aims to "reunite" psychology and sociology. Brown's book, however, focuses on…

  6. Little Mosie from the Margaree: A Biography of Moses Michael Coady.

    Science.gov (United States)

    Welton, Michael R.

    This book examines the life of the Reverend Moses Michael Coady (1890-1959), a Roman Catholic priest who led the Antigonish Movement. During the Antigonish Movement, residents of the small maritime town of Antigonish, Nova Scotia, worked to achieve a nonviolent alternative to communism and fascism and to effect the social and economic…

  7. What Work Do the Concepts of "Language" and "Literature" Do for Michael Rosenak?

    Science.gov (United States)

    Levisohn, Jon A.

    2014-01-01

    Michael Rosenak uses the twin metaphors of "language" and "literature," borrowed from Oakeshott and Peters, to argue that the goal of education is initiation into a language. This goal transcends the study of literature in that language. It includes, as well, the development of the capacity both to critique literature and to…

  8. Michael Faraday on the Learning of Science and Attitudes of Mind.

    Science.gov (United States)

    Crawford, Elspeth

    1998-01-01

    Makes use of Michael Faraday's ideas on learning, focusing on his attitudes toward the unknowns of science and the development of an attitude that improves scientific decision making. This approach acknowledges that there is an inner struggle involved in facing unknowns. (DDR)

  9. An Interview with Michael Horn: Blending Education for High-Octane Motivation

    Science.gov (United States)

    Patterson, Gregory A.

    2012-01-01

    Blended learning holds the potential of improving the way we educate students and of making them more motivated. Blended education--the melding of information technology based distance learning with school attendance--is perhaps the best way to educate students for 21st century skills, says Michael Horn in a "Kappan" interview. Horn points out…

  10. C. P. Snow's "The Two Cultures": Michael Polanyi's Response and Context

    Science.gov (United States)

    Jacobs, Struan

    2011-01-01

    C. P. Snow's "The Two Cultures" controversially contrasted science and literature, suggesting that neither scientists nor literary intellectuals have much in common with, and seldom bother speaking to, the other. Responding to Snow, Michael Polanyi argued that specialization has made modern culture, not twofold but manifold. In his major work,…

  11. Noted astrophysicist Michael S. Turner to Head NSF'S mathematical and physical sciences directorate

    CERN Multimedia

    2003-01-01

    "The National Science Foundation has named celebrated astrophysicist Michael S. Turner of the University of Chicago as Assistant Director for Mathematical and Physical Sciences. He will head a $1 billion directorate that supports research in mathematics, physics, chemistry, materials and astronomy, as well as multidisciplinary programs and education" (1/2 page).

  12. 77 FR 69550 - Proposed Information Collection (Patient Satisfaction Survey Michael E. DeBakey Home Care Program...

    Science.gov (United States)

    2012-11-19

    ... (Patient Satisfaction Survey Michael E. DeBakey Home Care Program) Activity: Comment Request AGENCY.... DeBakey Home Care Program. DATES: Written comments and recommendations on the proposed collection of...: Patient Satisfaction Survey Michael E. DeBakey Home Care Program, VA Form 10-0476. OMB Control Number...

  13. 76 FR 624 - Proposed Information Collection (Patient Satisfaction Survey Michael E. DeBakey Home Care Program...

    Science.gov (United States)

    2011-01-05

    ... Collection (Patient Satisfaction Survey Michael E. DeBakey Home Care Program) Activity: Comment Request... satisfaction with the quality of services/care provided by home care program staff. An agency may not conduct... Form 10-0476).'' SUPPLEMENTARY INFORMATION: Title: Patient Satisfaction Survey Michael E. DeBakey Home...

  14. 78 FR 6851 - Proposed Information Collection (Patient Satisfaction Survey Michael E. DeBakey Home Care Program...

    Science.gov (United States)

    2013-01-31

    ... (Patient Satisfaction Survey Michael E. DeBakey Home Care Program) Activity: Comment Request AGENCY... Satisfaction Survey Michael E. DeBakey Home Care Program, VA Form 10-0476. OMB Control Number: 2900-0775. Type... home care program staff. An agency may not conduct or sponsor, and a person is not required to respond...

  15. 77 FR 30047 - Notice of Opportunity for Public Comment on Surplus Property Release at Michael J Smith Field...

    Science.gov (United States)

    2012-05-21

    ... Comment on Surplus Property Release at Michael J Smith Field, Beaufort, NC AGENCY: Federal Aviation... J Smith Field, be used for aeronautical purposes. DATES: Comments must be received on or before June... property at the Michael J Smith Field. The property consists of one parcel located on the north side of...

  16. Pentanidium-catalyzed enantioselective phase-transfer conjugate addition reactions

    KAUST Repository

    Ma, Ting

    2011-03-09

    A new chiral entity, pentanidium, has been shown to be an excellent chiral phase-transfer catalyst. The enantioselective Michael addition reactions of tert-butyl glycinate-benzophenone Schiff base with various α,β- unsaturated acceptors provide adducts with high enantioselectivities. A successful gram-scale experiment at a low catalyst loading of 0.05 mol % indicates the potential for practical applications of this methodology. Phosphoglycine ester analogues can also be utilized as the Michael donor, affording enantioenriched α-aminophosphonic acid derivatives and phosphonic analogues of (S)-proline. © 2011 American Chemical Society.

  17. Gas-chromatographic resolution of enantiomeric secondary alcohols. Stereoselective reductive metabolism of ketones in rabbit-liver cytosol.

    Science.gov (United States)

    Gal, J; DeVito, D; Harper, T W

    1981-01-01

    Chiral secondary alcohols were treated with (S)-(-)-1-phenylethyl isocyanate. For each racemic alcohol, the resulting diastereomeric urethane derivatives were resolved on flexible fused-silica capillary GLC columns with retention times of 15 min or less. Derivatization of individual enantiomers showed that the urethane derivatives of (R)-(-)-2-octanol, (R)-(+)-1-phenylethyl alcohol, and (S)-(+)-2,2,2-trifluoro-1-phenylethanol are eluted before the corresponding diastereomers. The procedure is simple and rapid, and is suitable for the determination of the enantiomeric composition of chiral alcohols extracted from biological media. A series of aliphatic alcohols, aryl alkyl carbinols, and arylalkyl alkyl carbinols were resolved with the procedure, and the degree of resolution varied from good to excellent. Eight achiral ketones were incubated, individually, with rabbit-liver 90,000 g supernatant fractions, and the enantiomeric composition of the alcohol metabolites was determined with the GLC procedure. The reductions proceeded with high stereoselectivity to give alcohol products of 90% or greater enantiomeric purity. The reduction of 2-octanone and acetophenone gave predominant alcohols of (S)-configuration, in agreement with the Baumann-Prelog rule. The configuration of the predominant alcohols arising in the reduction of the remainder of the ketones could not be firmly established, but the evidence suggests that they are also of the (S)-configuration. Fluorine or methyl substitution in the ortho position of acetophenone produced an increase in the stereoselectivity, and the alcohol produced from ortho-methylacetophenone was enantiomerically greater than 99% pure.

  18. Mechanistic basis for high stereoselectivity and broad substrate scope in the (salen)Co(III)-catalyzed hydrolytic kinetic resolution.

    Science.gov (United States)

    Ford, David D; Nielsen, Lars P C; Zuend, Stephan J; Musgrave, Charles B; Jacobsen, Eric N

    2013-10-16

    In the (salen)Co(III)-catalyzed hydrolytic kinetic resolution (HKR) of terminal epoxides, the rate- and stereoselectivity-determining epoxide ring-opening step occurs by a cooperative bimetallic mechanism with one Co(III) complex acting as a Lewis acid and another serving to deliver the hydroxide nucleophile. In this paper, we analyze the basis for the extraordinarily high stereoselectivity and broad substrate scope observed in the HKR. We demonstrate that the stereochemistry of each of the two (salen)Co(III) complexes in the rate-determining transition structure is important for productive catalysis: a measurable rate of hydrolysis occurs only if the absolute stereochemistry of each of these (salen)Co(III) complexes is the same. Experimental and computational studies provide strong evidence that stereochemical communication in the HKR is mediated by the stepped conformation of the salen ligand, and not the shape of the chiral diamine backbone of the ligand. A detailed computational analysis reveals that the epoxide binds the Lewis acidic Co(III) complex in a well-defined geometry imposed by stereoelectronic rather than steric effects. This insight serves as the basis of a complete stereochemical and transition structure model that sheds light on the reasons for the broad substrate generality of the HKR.

  19. Cyclohexenones Through Addition of Ethyl Acetoacetate to 3-Aryl-1 ...

    African Journals Online (AJOL)

    Chalcone derivatives 3a–i containing a thiophene ring were prepared by the condensation of 1-(thiophen-3-yl)ethanone with aromatic aldehydes in excellent yields. The Michael addition of ethyl acetoacetate 4 to chalcone derivatives 3a–i resulted in the formation of nine novel ethyl 6-aryl ...

  20. Additional Responses to Hugh Heclo's "On Thinking Institutionally"

    Science.gov (United States)

    Lincoln, Timothy D.; Fennell, Robert C.

    2011-01-01

    Issue 13:3 of this journal (July 2010) included a "Conversation" on Hugh Heclo's recent publication "On Thinking Institutionally" (Paradigm Publishers, 2008) with a book review by Robert Fennell and responses by Richard Ascough, Tat-siong Benny Liew, Michael McLain, and Lynne Westfield. Here we publish two additional responses to this same book.…

  1. Spiro(phosphoamidite) ligand (SIPHOS)/Cu(OTf)2-catalyzed highly regio-and stereo-selective hydroborations of internal alkynes with diborane in water

    Institute of Scientific and Technical Information of China (English)

    Qing-Qing Xuan; Ya-Hui Wei; Qiu-Ling Song

    2017-01-01

    The highly regio-and stereoselective hydroborations of unactivated internal alkynes with diboron compound catalyzed by Cu(OTf)2 with spiro(phosphoamidite) as ligand in the presence of Cs2CO3 in water was developed.This protocol was applied efficiently in the aqueous synthesis of multi-substituted vinylboranes.

  2. Microfluidic Chip Reactor and the Stereoselective Hydrogenation of Methylacetoacetate over (R)-Ru-BINAP in the [N8222][Tf2N]/Methanol/ Water Mixed Phase.

    Czech Academy of Sciences Publication Activity Database

    Klusoň, Petr; Stavárek, Petr; Pěnkavová, Věra; Vychodilová, Hana; Hejda, Stanislav; Bendová, Magdalena

    2017-01-01

    Roč. 115, May (2017), s. 39-46 ISSN 0255-2701 R&D Projects: GA ČR GA15-04790S Institutional support: RVO:67985858 Keywords : stereoselectivity * microfluidic chip * ionic liquids Subject RIV: CI - Industrial Chemistry, Chemical Engineering OBOR OECD: Chemical process engineering Impact factor: 2.234, year: 2016

  3. Interactions of the (R) Ru-BINAP Catalytic Complex with an Inorganic Matrix in Stereoselective Hydrogenation of Methylacetoacetate – Kinetic, XPS and DRIFT Studies.

    Czech Academy of Sciences Publication Activity Database

    Klusoň, Petr; Krystyník, Pavel; Dytrych, Pavel; Bártek, L.

    2016-01-01

    Roč. 119, č. 2 (2016), s. 393-413 ISSN 1878-5190 R&D Projects: GA ČR GA15-14228S Institutional support: RVO:67985858 Keywords : (R)-Ru-BINAP complex * stereoselective hydrogenation * montmorillonite Subject RIV: CC - Organic Chemistry Impact factor: 1.264, year: 2016

  4. Stereocontrolled generation of nucleophilic (Z)- or (E)-α-fluoroalkenylchromium reagents via carbon-fluorine bond activation: highly stereoselective synthesis of (E)- or (Z)-β-fluoroallylic alcohols.

    Science.gov (United States)

    Nihei, Takashi; Yokotani, Saya; Ishihara, Takashi; Konno, Tsutomu

    2014-02-14

    Highly nucleophilic (Z)- or (E)-α-fluoroalkenylchromium species could be generated in a stereoselective manner via C-F bond activation of CBrF2-containing molecules, and they reacted smoothly with various aldehydes to give (E)- or (Z)-β-fluoroallylic alcohol derivatives in high yields, respectively.

  5. Stereoselectivity and substrate specificity in the kinetic resolution of methyl-substituted 1-oxaspiro[2.5]octanes by Rhodotorula glutinis epoxide hydrolase

    NARCIS (Netherlands)

    Weijers, C.A.G.M.; Meeuwse, P.; Herpers, R.L.J.M.; Franssen, M.C.R.; Sudhölter, E.J.R.

    2005-01-01

    [GRAPHICS] The kinetic resolution of a range of methyl-substituted 1-oxaspiro[2.5]octanes by yeast epoxide hydrolase (YEH) from Rhodotorula glutinis has been investigated. The structural determinants of substrate specificity and stereoselectivity of YEH toward these substrates appeared to be the

  6. Palladium-catalyzed aerobic regio- and stereo-selective olefination reactions of phenols and acrylates via direct dehydrogenative C(sp2)-O cross-coupling.

    Science.gov (United States)

    Wu, Yun-Bin; Xie, Dan; Zang, Zhong-Lin; Zhou, Cheng-He; Cai, Gui-Xin

    2018-04-26

    An efficient olefination protocol for the oxidative dehydrogenation of phenols and acrylates has been achieved using a palladium catalyst and O2 as the sole oxidant. This reaction exhibits high regio- and stereo-selectivity (E-isomers) with moderate to excellent isolated yields and a wide substrate scope (32 examples) including ethyl vinyl ketone and endofolliculina.

  7. Michael Faraday and the concept of atomic structure

    International Nuclear Information System (INIS)

    Pocock, R.F.

    1991-01-01

    Written to commemorate the bicentenary of Faraday's birth, this article surveys his influence on atomic theory during the 19th and early 20th centuries. It identifies which developments were derived from projects which he had started; it shows that his ideas and methods determined the direction of researches which he had not himself initiated. The account is in the form of a chronological narrative. This is based entirely on published sources, and the treatment is non-mathematical. In consequence it contains no new factual data. The presentation of Faraday's work in this particular context is, however, original. Although not covering studies of the nucleus - which were mostly later than the period considered -this article describes the origins of modern theories of atomic structure reasonably completely. It is a useful overview for engineers unfamiliar with details of the history of physics. In addition, it is a case-study of the persistence of scientific ideas in researches occupying a century or more. (author)

  8. Free-radical-mediated conjugate additions. Enantioselective synthesis of butyrolactone natural products: (-)-enterolactone, (-)-arctigenin, (-)-isoarctigenin, (-)-nephrosteranic acid, and (-)-roccellaric acid.

    Science.gov (United States)

    Sibi, Mukund P; Liu, Pingrong; Ji, Jianguo; Hajra, Saumen; Chen, Jian-xie

    2002-03-22

    Lewis acid-mediated conjugate addition of alkyl radicals to a differentially protected fumarate 10 produced the monoalkylated succinates with high chemical efficiency and excellent stereoselectivity. A subsequent alkylation or an aldol reaction furnished the disubstituted succinates with syn configuration. The chiral auxiliary, 4-diphenylmethyl-2-oxazolidinone, controlled the stereoselectivity in both steps. Manipulation of the disubstituted succinates obtained by alkylation furnished the natural products (-)-enterolactone, (-)-arctigenin, and (-)-isoarctigenin. The overall yields for the target natural products were 20-26% over six steps. Selective functionalization of the disubstituted succinates obtained by aldol condensation gave the paraconic acid natural products (-)-nephrosteranic acid (8) and (-)-roccellaric acid (9). The overall yield of the natural products 8 and 9 over four steps was 53% and 42%, respectively.

  9. Brändi näkyy musiikkivideossa : Esimerkkitapaus Michael Jackson

    OpenAIRE

    Kontinen, Noora

    2016-01-01

    Tutkin opinnäytetyössäni brändin ja musiikkivideon suhdetta toisiinsa. Työssä käsitellään lyhyesti myös tähteyttä. Esittelen ensin vähän historiaa ja peruskäsitteitä, minkä jälkeen käytän Michael Jacksonin Billie Jean -musiikkivideota esimerkkinä tutkiessani Michael Jacksonin brändiä. Teoksessa käytetään lähdeaineistoa sekä omaa analyysia. Keskityn tarkastelemaan musiikkivideoita, ja niihin liittyviä sisältöjä yleisesti, ei niinkään teknisesti. Toivon, että työstäni on apua jollekin,...

  10. Interviews with Michael Baxandall, February 3rd and 4th, 1994, Berkeley, CA

    Directory of Open Access Journals (Sweden)

    Allan Langdale

    2009-12-01

    Full Text Available The following interviews with Michael Baxandall were conducted in Berkeley on February 3rd and 4th of 1994. The content of these interviews include general responses about developments in art history in the years between 1960 and 1985, a period of dramatic modifications in the discipline. Among the issues are the rise of the social history of art and the sources from anthropology that informed Baxandall’s concept of the ‘Period Eye’. Baxandall talks about his own work, his personal intellectual history, and the scholars of past and current generations who influenced him. Other topics include Baxandall’s professional trajectory, the Warburg Library, and aspects of cultural history having to do with Renaissance Humanism. These interviews first appeared as an appendix to the PhD dissertation by Allan Langdale, Art History and Intellectual History: Michael Baxandall’s Work between 1963 and 1985, U. C. Santa Barbara, 1995.

  11. [An exceptional human relationship (Michael P. Kierkegaard, Søren Kierkegaard)].

    Science.gov (United States)

    Jacobs, R

    1978-01-01

    There were a father and a son, Michael and Sören Kierkegaard, both highly talented, imaginitive, witty, humorous, especially interested in shrewd dialectrical dialogues respectively debates, both profound melancholy ponderers. But according to very own individuality their congeniality wasn't absolute. The father, being under a questionable rigorous opinion of sin, suffered from undeserved divine grace since early childhood. And Michael Kierkegaard made Sören anxious with the religious experience of original sin. This anxiety moved (touched or affected) the sensitive son mighty. Nevertheless he should not despair hopelessly like his unlucky father. On the contrary: Sørens incomparable melancholy, mental agony and anxiety (fear or anguish) forced the faith, existing independently of them, in a radical refining. That is why Sören Kierkegaard succeeded in sublimation of all psychological and philosophic (al) attitudes (or opinions) in the sphere of religiousness. And the result? A novel philosophy of life: Christian existentialism.

  12. Michael K. Scullin: Psi Chi/APA Edwin B. Newman Graduate Research Award.

    Science.gov (United States)

    2011-11-01

    Presents Michael K. Scullin as the 2011 winner of the American Psychological Association Psi Chi/APA Edwin B. Newman Graduate Research Award. "For an outstanding research paper that examines the relationship between prospective memory in executing a goal and various lapses of time from 20 minutes up to a 12- hour wake delay and a 12-hour sleep delay. The results suggest that consolidation processes active during sleep increase the probability of goal execution. The paper, titled 'Remembering to Execute a Goal: Sleep On It!' was published in Psychological Science in 2010 and was the basis for Michael K. Scullin's selection as the recipient of the 2011 Psi Chi/APA Edwin B. Newman Graduate Research Award. Mark A. McDaniel, PhD, served as faculty research advisor." (PsycINFO Database Record (c) 2011 APA, all rights reserved). 2011 APA, all rights reserved

  13. Navigating Transition: Freedom, Limitation and the Post-colonial Persona in Michael Ondaatje's The Cat's Table

    Directory of Open Access Journals (Sweden)

    Alaa Alghamdi

    2012-11-01

    Full Text Available Michael Ondaatje's 2011 novel The Cat's Table follows a young boy's voyage from Colombo, Sri Lanka to London, England. Through this character and the unique environment of the ship, which forms a compelling sense of transitory place, Ondaatje explores liminality and its relationship with limitations or barriers. The young protagonist, Michael, and his companions enjoy an unusual level of freedom aboard the contained and hierarchically segmented ship. Polarization and transition between Eastern and Western culture is present but pales in importance compared to the validation of the self that is located within and defined by the sense of the in-between, an essential rite of passage undertaken before re-joining society.

  14. Learned Helplessness Encountered by Michael Oher in the Blind Side Movie

    OpenAIRE

    PAMUNGKAS, DIMAS PROBO

    2014-01-01

    Pamungkas, Dimas Probo. 2014. Learned Helplessness Encountered by Michael Oher in The Blind Side Movie. Study Program of English, Department of Languages and Literature, Faculty of Culture Studies, Universitas Brawijaya. Supervisor: Dyah Eko Hapsari;Co-supervisor: Sarlettina Vidyayani EkaKeywords: Learned Helplessness, African-American, Psychological, Social Behavior, Depression, The Blind Side.Social behavior shows several interactions between person and social situations, which stress...

  15. Dropping The Bomb? On Critical and Cinematic Reactions to Michael Ondaatje's The English Patient

    OpenAIRE

    Pesch, Josef

    2018-01-01

    This paper analyses Anthony Minghella's film adaptation of Michael Ondaatje’s The English Patient. It aims at establishing patterns of transformation and strategies of adaptation. Not only the nostalgie romanticisation, but also the de-politicisation of the novel is critically scrutinized. As dropping all reference to the atomic bomb from the film is the most blatant example of deviation from the novel, critical and political background is provided which may explain this act of self-censorshi...

  16. Horror movie aspects and experimentation in Michael Jackson’s Thriller music video

    OpenAIRE

    Vargas, Herom; Universidade Municipal de São Caetano do Sul - USCS; Gonçalves, Rafael; Universidade Municipal de São Caetano do Sul - USCS

    2016-01-01

    This article analyzes the use of elements from the horror fi lm genre in the music video Thriller (1982), by Michael Jackson, as experimentation within the field of pop music. Based on the semiotics of culture, grounded on the concepts of cultural text, semiosphere, border and modeling, developed by Iuri Lotman, the analysis identified innovations in the use of horror as humor and, in the music, modeling of creatures, moving among horror, the fantastic and the reality.Keywords: horror, music ...

  17. Review: Cornelia Behnke & Michael Meuser (1999). Geschlechterforschung und qualitative Methoden [Gender Research and Qualitative Methods

    OpenAIRE

    Nicola Döring

    2001-01-01

    In less than 100 pages Cornelia BEHNKE and Michael MEUSER explain how gender studies evolved from women's studies and what feminist methodology is all about. They also discuss the interrelation of qualitative research and gender studies. The great potential of qualitative research based on a constructivist gender concept is demonstrated with a group discussion study involving different men only groups. Finally the authors deal with the question of how the researcher's gender affects both data...

  18. Feeding Health: Michael Pollan on Improving Public Health through the Food Systems

    Centers for Disease Control (CDC) Podcasts

    2009-08-19

    In this podcast, author Michael Pollan discusses his March 2009 visit to CDC and offers his thoughts on the intersection between the government, the food systems, and public health.  Created: 8/19/2009 by National Center for Environmental Health (NCEH), National Center for Chronic Disease Prevention and Health Promotion (NCCDPHP), Office of Sustainability.   Date Released: 4/15/2010.

  19. En memoria de Michael Jiménez (1948-2001

    Directory of Open Access Journals (Sweden)

    Mauricio Archila Neira

    2001-01-01

    Full Text Available El 1 de septiembre de 2001 murió el historiador Michael Jiménez. Su apellido provenía de España de donde emigró su abuelo en busca de mejor suerte al otro lado del Atlántico. Nacido en el pequeño pueblo de Merced, California (Estados Unidos en agosto de 1948 en el seno de una familia obrera, Michael vivió su infancia en Colombia. A fines de ese año, su padre se desplazó a estas tierras para ser funcionario de la Texas, una multinacional petrolera que tenía sus reales en Puerto Boyacá. Michael estudió en el colegio Nueva Granada -becado por la Texas- hasta los catorce años. En dicho colegio fue compañero de pupitre de Herbert Braun, descendiente a su vez de una familia de emigrantes a Colombia, y con quien la vida lo juntaría de nuevo en las tierras del norte y en oficios similares.

  20. Between Irish National Cinema and Hollywood: Neil Jordan’s Michael Collins

    Directory of Open Access Journals (Sweden)

    Raita Merivirta-Chakrabarti

    2007-03-01

    Full Text Available When Neil Jordan’s film Michael Collins was released in 1996, it was seen by some as a Hollywood epic, by others as a great national film. I would argue that Michael Collins combines these two traditions and occupies a space between Irish national cinema and Hollywood. The subject matter, the creative talent and the locations were Irish and the film was produced by using the Irish filmmaking infrastructure and the Irish government’s support mechanisms, but it was largely financed and distributed by a Hollywood studio. Also, to make it more appealing especially globally, but probably also locally (since Hollywood is now the international standard, it makes use of Hollywood conventions, making it accessible to international audiences as well. Despite the Hollywood mode, the fact remains that Michael Collins is a national film text, and Jordan does not make too many concessions to the non-Irish audiences.

  1. A celebration of mechanics: from nano to macro. The J. Michael T. Thompson Festschrift issue.

    Science.gov (United States)

    Elishakoff, Isaac

    2013-06-28

    This Theme Issue is dedicated to the topic 'Mechanics: from nano to macro' and marks the 75th birthday of Dr J. Michael T. Thompson, Fellow of the Royal Society, whose current affiliations are as follows: (i) Honorary Fellow, Department of Applied Mathematics and Theoretical Physics, Centre for Mathematical Sciences, University of Cambridge; (ii) Emeritus Professor of Nonlinear Dynamics, Department of Civil, Environmental and Geomatic Engineering, University College London; and (iii) Professor of Theoretical and Applied Dynamics (Distinguished Sixth Century Chair, part-time), University of Aberdeen. He also serves as Chairman of the Board of Directors at ES-Consult (consulting engineers) in Copenhagen, Denmark. The pertinent question that arises from the very start is: should we first salute Michael and then describe the Theme Issue, or vice versa? Indeed, according to Blaise Pascal (1623-1662), the last thing one discovers in composing a work is what to put first. I would like to take the liberty of deviating from the tradition of the Philosophical Transactions and start with the tribute to Michael; after all he is the prime cause of this Theme Issue.

  2. The conceptualization of love in religious thought of George Florovsky and Michael Pomazansky

    Directory of Open Access Journals (Sweden)

    Pavenkov Oleg Vladimirovich

    2015-04-01

    Full Text Available The present article is concerned with the question of conceptualization of love in works of Fr. George Florovsky and Fr. Michael Pomazansky, Russian religious thinkers and theologists. We are studying the meaning and appropriacy of two words, ‘love’ (English and ‘любовь’ (Russian, that are the best to represent the agapelogical positive evaluation in Russian religious thought. Data for study was taken from ten different articles and extracts from books written by Fr. George Florovsky and Fr. Michael Pomazansky. On the basis of this analysis we develop semantic explications of words ‘love’ and ‘любовь’ as Christian spiritual concepts within the framework of theoretical approach of Natural Semantic Metalanguage (NSM. In summary we state that this article discusses, describes and determines some similarities and differences in understanding of concept ‘love’ in the affore-referenced works by Fr. George Florovsky and Fr. Michael Pomazansky.

  3. Stereoselective Synthesis of 8,12-Furanoeudesmanes from Santonin. Absolute Stereochemistry of Natural Furanoeudesma-1,3-diene and Tubipofurane.

    Science.gov (United States)

    Blay, Gonzalo; Cardona, Luz; García, Begoña; Pedro, José R.; Sánchez, Juan J.

    1996-05-31

    Ketobutenolide 3, easily obtained from santonin (1), has been transformed into two natural furanoeudesmanes 4 and 5, isolated from Commiphora molmol and Tubipora musica, respectively. trans- And cis-decalin systems were obtained by stereoselective reduction of the C(4)-C(5) double bond in 3 in the following way: hydrogenation of 3 over Pd/C followed by acidic treatment gave the cis isomer 10 as the major product; selective hydrogenation of the C(1)-C(2) double bond with the Wilkinson's catalyst followed by reduction with NaTeH yielded mainly the trans isomer 9. Compounds 9 and 10 were transformed into 4 and 5 in parallel sequences. Optical rotation and CD measurements of the synthetic products revealed that the stereochemistry of both natural products should be revised to their enantiomeric form.

  4. Stereoselective aminoacylation of a dinucleoside monophosphate by the imidazolides of DL-alanine and N-(tert-butoxycarbonyl)-DL-alanine

    Science.gov (United States)

    Profy, A. T.; Usher, D. A.

    1984-01-01

    The aminoacylation of diinosine monophosphate was studied experimentally. When the acylating agent was the imidazolide of N-(tert-butoxycarbonyl)-DL-alanine, a 40 percent enantiomeric excess of the isomer was incorporated at the 2' site and the positions of equilibrium for the reversible 2'-3' migration reaction differed for the D and L enantiomers. The reactivity of the nucleoside hydroxyl groups was found to decrease on the order 2'(3') less than internal 2' and less than 5', and the extent of the reaction was affected by the concentration of the imidazole buffer. Reaction of IpI with imidazolide of unprotected DL-alanine, by contrast, led to an excess of the D isomer at the internal 2' site. Finally, reaction with the N-carboxy anhydride of DL-alanine occurred without stereoselection. These results are found to be relevant to the study of the evolution of optical chemical activity and the origin of genetically directed protein synthesis.

  5. A perspectiva de Michael Apple para os estudos das políticas educacionais

    Directory of Open Access Journals (Sweden)

    Luís Armando Gandin

    Full Text Available Resumo Este artigo tem como objetivo analisar as contribuições de Michael Apple para o campo da pesquisa em políticas educacionais. Na extensa obra de Michael Apple, destacamos seis elementos que podem auxiliar aqueles que estão interessados na área de políticas em educação: o princípio epistemológico da análise relacional; o exame do Estado como relação; a herança de Antonio Gramsci e de Raymond Williams que Michael Apple incorpora no uso de conceitos como hegemonia e senso comum; a análise que Michael Apple faz das políticas educacionais como políticas culturais, como disputas por visão de mundo, como luta por consolidação de uma hegemonia que vai além do econômico; a sua postura de pesquisador; e a capacidade que Michael Apple tem de ir além da lógica da reprodução e determinação para enfatizar o papel da agência e da contra-hegemonia. Através de exemplos práticos da própria obra de Apple e de outras pesquisas empíricas, apresentam-se as implicações de cada um dos seis pontos acima citados para os pesquisadores interessados na área de políticas educacionais. Conclui-se que muitas das contribuições de Apple podem auxiliar em pesquisas nessa área, tendo em vista a discussão que o autor realiza em sua obra e sua crítica ao determinismo econômico nas análises do campo educacional, salientando a importância, assim, de aspectos que estão relacionados à esfera da cultura.

  6. Tagasipöördumine esteetika juurde = Return to aesthetics / Keith Moxey, Michael Ann Holly ; interv. Anu Allas

    Index Scriptorium Estoniae

    Moxey, Keith

    2007-01-01

    Ameerika kunstiajaloolased Keith Moxey ning Michael Ann Holly tutvustavad uut lähenemist kunstiajaloole (new art history). Nn. naasmine esteetika juurde tähendab püüet integreerida kunstiajalukku ja -teooriasse uuesti ja tugevamalt kunstiteos

  7. Review: Barr, Michael and Zlatko Skrbiš (2008, Constructing Singapore. Elitism, Ethnicity and the Nation-Building Project

    Directory of Open Access Journals (Sweden)

    Boris Michel

    2009-01-01

    Full Text Available Review of the monograph: Barr, Michael and Zlatko Skrbiš, Constructing Singapore. Elitism, Ethnicity and the Nation-Building Project, Copenhagen: NIAS Press, 2008, ISBN 978-87-7694-029-4, 304 pages

  8. Tandem Knoevenagel–Michael reactions in aqueous diethylamine medium: A greener and efficient approach toward bis-dimedone derivatives

    Directory of Open Access Journals (Sweden)

    Abdullah Mohammed Al-Majid

    2017-02-01

    The use of inexpensive, eco-friendly and readily available reagents, easy work-up, and high purity products makes the procedure a convenient and robust method for the synthesis of tandem Knoevenagel–Michael adducts.

  9. Michael T. Westrate. Living Soviet in Ukraine from Stalin to Maidan: Under the Falling Red Star in Kharkiv.

    Directory of Open Access Journals (Sweden)

    Charitie V. Hyman

    2017-09-01

    Full Text Available Book review of Michael T. Westrate. Living Soviet in Ukraine from Stalin to Maidan: Under the Falling Red Star in Kharkiv. Rowman & Littlefield, 2016. xx, 232 pp. Illustrations. Appendices. Bibliography. Index. $85.00, cloth.

  10. The big picture : What the Baltics may learn from Ireland's success story / Michael Bourke ; interv. Maris Biezaitis

    Index Scriptorium Estoniae

    Bourke, Michael

    2002-01-01

    Ilmunud ka: Baltiiskii kurss 2002/Zima/Vesna nr. 20 lk. 14-17. Iirimaa aukonsul Lätis, Michael Joseph Bourke arutleb Iirimaa majandusedu teemal ning pakub välja, mida Baltimaad saaksid sellest õppida. Tabel, diagramm. Lisa

  11. Review: Michael Crandall & Karen E. Fisher (Eds) Digital Inclusion: Measuring the Impact of Information and Community Technology

    DEFF Research Database (Denmark)

    Pors, Niels Ole

    2010-01-01

    Review: Michael Crandall & Karen E. Fisher (Eds) Digital Inclusion: Measuring the Impact of Information and Community Technology. Medford. Information Today. ASIS&T Monographs, 2009. 185 pages. $ 59.50. ISBN 978-1-57387-373-4......Review: Michael Crandall & Karen E. Fisher (Eds) Digital Inclusion: Measuring the Impact of Information and Community Technology. Medford. Information Today. ASIS&T Monographs, 2009. 185 pages. $ 59.50. ISBN 978-1-57387-373-4...

  12. Additive manufacturing.

    Science.gov (United States)

    Mumith, A; Thomas, M; Shah, Z; Coathup, M; Blunn, G

    2018-04-01

    Increasing innovation in rapid prototyping (RP) and additive manufacturing (AM), also known as 3D printing, is bringing about major changes in translational surgical research. This review describes the current position in the use of additive manufacturing in orthopaedic surgery. Cite this article: Bone Joint J 2018;100-B:455-60.

  13. Use of (S)-trans-gamma-monocyclofarnesol as a useful chiral building block for the stereoselective synthesis of diterpenic natural products.

    Science.gov (United States)

    Serra, Stefano; Cominetti, Alessandra A; Lissoni, Veronica

    2014-03-01

    A comprehensive study of the exploitation of (S)-trans-gamma-monocyclofarnesol as a useful chiral building block for the stereoselective synthesis of natural diterpene derivatives is here described. The farnesol derivative (+)-1 was used as starting material in the preparation of the diterpenes (S)-dehydroambliol-A and (S)-trixagol, as well as for the syntheses of the dinorditerpene (S)-dinortrixagone and of the guanidine-interrupted terpenoid (S)-dotofide. Key steps of the presented syntheses were the cross-coupling between an allyl acetate and a Grignard reagent, the Wittig reaction, the selective preparation ofa diacylguanidine derivative and the alkylation of a sulfone derivative, followed by the reductive removal of the same functional group. It is worth noting that the natural products (+)-8, (+)-12 and (+)-15 were prepared stereoselectively for the first time, thus allowing the unambiguous assignment of their absolute configuration.

  14. Food additives

    Science.gov (United States)

    ... GO About MedlinePlus Site Map FAQs Customer Support Health Topics Drugs & Supplements Videos & Tools Español You Are Here: Home → Medical Encyclopedia → Food additives URL of this page: //medlineplus.gov/ency/article/ ...

  15. Facile construction of structurally diverse thiazolidinedione-derived compounds via divergent stereoselective cascade organocatalysis and their biological exploratory studies.

    Science.gov (United States)

    Zhang, Yongqiang; Wang, Shengzheng; Wu, Shanchao; Zhu, Shiping; Dong, Guoqiang; Miao, Zhenyuan; Yao, Jianzhong; Zhang, Wannian; Sheng, Chunquan; Wang, Wei

    2013-06-10

    In this article, we present a new approach by merging two powerful synthetic tactics, divergent synthesis and cascade organocatalysis, to create a divergent cascade organocatalysis strategy for the facile construction of new "privileged" substructure-based DOS (pDOS) library. As demonstrated, notably 5 distinct molecular architectures are produced facilely from readily available simple synthons thiazolidinedione and its analogues and α,β-unsaturated aldehydes in 1-3 steps with the powerful strategy. The beauty of the chemistry is highlighted by the efficient formation of structurally new and diverse products from structurally close reactants under the similar reaction conditions. Notably, structurally diverse spiro-thiazolidinediones and -rhodanines are produced from organocatalytic enantioselective 3-component Michael-Michael-aldol cascade reactions of respective thiazolidinediones and rhodanines with enals. Nevertheless, under the similar reaction conditions, reactions of isorhodanine via a Michael-cyclization cascade lead to structurally different fused thiopyranoid scaffolds. This strategy significantly minimizes time- and cost-consuming synthetic works. Furthermore, these molecules possess high structural complexity and functional, stereochemical, and skeletal diversity with similarity to natural scaffolds. In the preliminary biological studies of these molecules, compounds 4f, 8a, and 10a exhibit inhibitory activity against the human breast cancer cells, while compounds 8a, 9a, and 9b display good antifungal activities against Candida albicans and Cryptococcus neoformans. Notably, their structures are different from clinically used triazole antifungal drugs. Therefore, they could serve as good lead compounds for the development of new generation of antifungal agents.

  16. Effect of buffer general acid-base catalysis on the stereoselectivity of ester and thioester H/D exchange in D2O.

    Science.gov (United States)

    Mohrig, Jerry R; Reiter, Nicholas J; Kirk, Randy; Zawadski, Michelle R; Lamarre-Vincent, Nathan

    2011-04-06

    As part of a comprehensive investigation on the stereochemistry of base-catalyzed 1,2-elimination and H/D exchange reactions of carbonyl compounds, we have found that the stereoselectivity of H/D exchange of 3-hydroxybutyryl N-acetylcysteamine (3) in D(2)O is strongly influenced by the presence of buffers. This buffer effect is also operative with a simple acyclic ester, ethyl 3-methoxybutanoate (7). Buffers whose general-acid components are cyclic tertiary ammonium ions are particularly effective in changing the stereoselectivity. (2)H NMR analysis showed that without buffer, H/D exchange of 3 produces 81-82% of the 2R*, 3R* diastereomer of 2-deuterio 3 (the anti product). In the presence of 0.33 M 3-quinuclidinone buffer, only 44% of the 2R*, 3R* diastereomer was formed. With ester 7, the stereoselectivity went from 93-94% in DO(-)/D(2)O to 60% in the presence of buffer. Phosphate buffer, as well as others, also showed substantial effects. The results are put into the context of what is known about the mechanism of H/D exchange of esters and thioesters, and the relevance of the buffer effect on the mechanism of the enoyl-CoA hydratase reaction is discussed. It is likely that hydrogen bonding in the enolate-buffer acid encounter complex is an important stereochemical determinant in producing a greater amount of the 2R*, 3S* diastereomer (the syn product). Studies that involve the protonation of enolate anions in D(2)O need to include the buffer general acid in any understanding of the stereoselectivity. © 2011 American Chemical Society

  17. Entrevista com Michael R. KatzDOI: 10.5007/2175-7968.2011v1n27p329

    Directory of Open Access Journals (Sweden)

    Maria Lúcia Barbosa de Vasconcellos

    2011-11-01

    Full Text Available Michael R. Katz graduated from Horace Mann School (New York and attended Williams College (Massachusetts, where he was the very first Russian major. Following graduation in 1966, he studied at Oxford University and the University of Leningrad, where he received his D.Phil. (or Ph.D. in Literature from Oxford. He first taught Russian at Williams and in 1984 became Chair of the Department of Slavic Language and Director of the Title VI Center for Russian and East European Studies at the University of Texas at Austin,. In 1998, he accepted a position as Dean of Language Schools and Schools Abroad at Middlebury College (Vermont. Since his term as Dean ended in 2004, he has been a full-time professor at the Russian Department. Prof. Katz has published several articles on literary translation and written two books. Additionally, he is a published translator of more than a dozen works into English, including novels by Herzen, Chernyshevsky, Dostoevsky, Turgenev, Tolstoy. In this interview, Katz explains how he became a translator, and addresses some important issues concerning the market for translation, his relationship with editors and publishing houses, translation and its critics, and some of the challenges he encountered translating from Russian into English.

  18. Compassionate leadership? Some reflections on the work and life of Michael Lapsley

    Directory of Open Access Journals (Sweden)

    Ian A. Nell

    2016-03-01

    Full Text Available In June 2007, I had the privilege of attending a Healing of Memories workshop lead by Father Michael Lapsley, one of the founder members of the Institute for Healing of Memories. The purpose of the workshop was to help the predominantly white members of a middle class Dutch Reformed congregation in the Northern Suburbs of Cape Town and the predominantly coloured members of a congregation of the Evangelical Lutheran Church in Elsies River on the Cape Flats, to share their stories of the past with regard to apartheid with each other. Apart from the stories that were told and the sharing of experiences about the apartheid history that took place, I was struck by the way in which Father Lapsley conducted the workshop. There was a deep compassion for all the participants as was embodied through the way in which he treated each of us with respect. But apart from his cordiality in leading the workshop, one could sense a deeper source of compassion, a source revealing a compassionate understanding of God�s presence amidst the violence and turmoil in our broken world. The aim of this article is to reflect on whether one could speak of something like �compassionate leadership�, and to take a closer look at the relationship between compassion and God images in the life and work of Michael Lapsley. Special attention will be given to the way in which he exercises leadership through his many involvements related to his own personal story of trauma.Intradisciplinary and/or interdisciplinary implications: This article presents literary research on the notion of compassionate leadership as a specific kind of leadership. The results indicate that the leadership of Father Michael Lapsley does indeed portray features of this kind of leadership. The research can become the source for finding new strategies for religious leadership.

  19. An Interview with Michael Betancourt, author of Agnotology & Crisis in Digital Capitalism

    OpenAIRE

    Sean Scanlan; Michael Betancourt

    2015-01-01

    Sean Scanlan, NANO's editor, interviews artist, curator, art historian and critical theorist Michael Betancourt to discuss the nature of agnotology, a term that means the “creation of uncertainty and ambivalent ‘fact’; it is a competitive tool incompatible with the idealized ‘free market’ of capitalism.” Betancourt is skeptical of Big Data and the ways that the consumers who unknowingly “produce” data for business interpretation are increasingly becoming transformed into a “token of exchange ...

  20. Athlete endorsement as a marketing strategy: a case study of Nike and Michael Jordan

    OpenAIRE

    Masár Vieites, Laura Virginia

    2014-01-01

    Les empreses intenten obrir mercats nous constantment, aconseguint atraure nous clients objectiu i augmentar el reconeixement de la marca. Aquest treball investiga el cóm i per què el patrocini d'atletes, per a que aquests representin els productes d'una empresa, ja que és una eina cada vegada més àmplia i popular en el màrqueting mix de les empreses. Michael Jordan, un estel retirada de bàsquet, ha rebut molta atenció dels mitjans publicitaris i ha representat sota patrocini a diversos produ...

  1. [The problem of evil in families--the filmmaker Michael Haneke].

    Science.gov (United States)

    Skårderud, Finn

    2010-09-23

    With the beautiful and dark film "The white ribbon", from 2009, the Austrian film director Michael Haneke consolidated his status as an international success. A central theme in his films is evilness and its roots. But just as important is his ambition to develop films where evil is not only portrayed, but where spectators are challenged to relate to their own ethical standards and their role as spectators. Haneke is a highly original filmmaker with his consistent search for a film aesthetic that stimulates ethical self-reflection and mentalizing. He partly succeeds in this quest.

  2. Organocatalytic Michael and Friedel–Crafts reactions in enantioselective synthesis of biologically active compounds

    International Nuclear Information System (INIS)

    Maltsev, O V; Beletskaya, Irina P; Zlotin, Sergei G

    2011-01-01

    Recent applications of organocatalytic Michael and Friedel–Crafts reactions in enantioselective synthesis of biologically active compounds: natural products, pharmaceutical agents and plant protection agents are reviewed. The key mechanisms of stereoinduction, types of organocatalysts and reagents used in these reactions are considered. The material is classified according to the type of newly formed bonds incorporating the asymmetric carbon atom, and the information for the most numerous C–C coupling reactions is systematized according to the natures of the electrophile and the nucleophile. The bibliography includes 433 references.

  3. The Great War and All That in A Hundred Doors by Michael Longley

    Directory of Open Access Journals (Sweden)

    Elisabeth Delattre

    2015-03-01

    Full Text Available The Great War has featured regularly in Michael Longley’s poetry, for personal, family, aesthetic and political reasons. His collection published in 2011 under the title A Hundred Doors contains a number of poems relating to his father and the so-called War Poets, in connection with others in which love and nature, life and death are also dominant themes. This article will show how, as elsewhere in his poetry, everything is interrelated, “the nature poetry”, in Longley’s words, “fertilizing the war poetry”.

  4. European Management: an emerging competitive advantage of European nations: A reply to Michael Porter

    OpenAIRE

    Bosch, Frans; Prooijen, A.A.

    1992-01-01

    textabstractThis article extends the debate begun in the June 1992 issue of EMJ when the authors first criticized Michael Porter's explanatory framework in his Competitive Advantage of Nations (1990), over the role of national culture on the competitive advantage of nations. In this paper, Frans van den Bosch and Arno van Prooijen stress that Europe is a locus of competitive advantage if one is prepared to pay attention to the possibility of ‘European Management’ as a potential asset of Europ...

  5. POLYETHYLENEIMINE (PEI ON SILICA AS CATALYST IN KNOEVENAGEL AND MICHAEL REACTIONS

    Directory of Open Access Journals (Sweden)

    FATIHA ZAOUI

    2017-03-01

    Full Text Available After the synthesis of polyethylenimine supported on silica, it has been used as a new and efficient catalyst in Knoevenagel and Michael condensations. The presence of the polyethylenimine in the catalytic system together with silica displays an acido-basic character allows a better catalytic activity in the condensations. Carried out under microwave irradiation, without organic solvent and during short time, the syntheses are respectful towards green chemistry. The solid catalyst can be easily reused. This catalyst has the acido-basic character at the same time.

  6. LECTURE CANCELLED - “The power of collaboration - innovating collaborative relationships" by Michael Kimmel | 8 March

    CERN Multimedia

    2013-01-01

    PLEASE NOTE THAT THIS LECTURE IS CANCELLED Friday, 8 March -  from 11.30 a.m. to 1 p.m. Globe of Science and Innovation Route de Meyrin, 1211 Geneva International Women’s Day Conference Lecture will be in English - Interpreting available in French Limited number of seats - registration is essential Reservation: + 41 22 767 76 76 or cern.reception@cern.ch Dr. Michael Kimmel, a renowned sociologist and an expert on male-female relationships, will share his latest findings on gender collaboration and how it can lead to innovation and improved relationships both at work and in the world outside. Michael Kimmel is among the world’s leading experts on male-female relationships. A Professor of Sociology at the State University of New York at Stony Brook, he is the author or editor of more than 20 books on the topic. He consults corporations, NGOs and public sector organisations all over the world on gender equity issues, including work-family balance, reducing workplac...

  7. Michael Polanyi and his generation origins of the social construction of science

    CERN Document Server

    Nye, Mary Jo

    2011-01-01

    In Michael Polanyi and His Generation, Mary Jo Nye investigates the role that Michael Polanyi and several of his contemporaries played in the emergence of the social turn in the philosophy of science. This turn involved seeing science as a socially based enterprise that does not rely on empiricism and reason alone but on social communities, behavioral norms, and personal commitments. Nye argues that the roots of the social turn are to be found in the scientific culture and political events of Europe in the 1930s, when scientific intellectuals struggled to defend the universal status of scientific knowledge and to justify public support for science in an era of economic catastrophe, Stalinism and Fascism, and increased demands for applications of science to industry and social welfare. At the center of this struggle was Polanyi, who Nye contends was one of the first advocates of this new conception of science. Nye reconstructs Polanyi’s scientific and political milieus in Budapest, Berlin, and Manchester f...

  8. Adapting Shakespeare – Converting Shylock in Michael Radford’s the Merchant of Venice

    Directory of Open Access Journals (Sweden)

    Oakes Luke

    2016-08-01

    Full Text Available This article aims to explore the extension and evolution of Shakespeare’s The Merchant of Venice through Michael Radford’s 2004 cinematic adaptation. By investigating the concept of adaptation and the significance of intertextuality, Shakespeare’s source text is considered alongside Radford’s twenty-first century recreation to reimagine and redefine the construction of Shylock as both a comic and tragic device utilized across film and play. Issues of racial and religious prejudices alongside anti- Semitic views were particularly prominent in Elizabethan England and, by concentrating on recontextualisation, this article looks to expose Shakespeare’s characterization as a reflective commentary concerning societal discriminations at the time of the play’s performance. By focusing primarily on Shakespeare’s Jewish Usurer, Radford is able to reconstruct and reestablish the dramatic devices and characters within the cinematic version, metaphorically converting Shylock from comic villain to tragic victim. Finally, it argues that this dynamic shift inevitably metamorphoses Shylock from a spectator’s perspective and provides Michael Radford with an opportunity to offer a social commentary on social inequality in the twenty-first century.

  9. Insights into the Diels-Alder Reaction between 3-Vinylindoles and Methyleneindolinone without and with the Assistance of Hydrogen-Bonding Catalyst Bisthiourea: Mechanism, Origin of Stereoselectivity, and Role of Catalyst.

    Science.gov (United States)

    Yan, Chao-Xian; Yang, Fan; Yang, Xing; Zhou, Da-Gang; Zhou, Pan-Pan

    2017-03-17

    The Diels-Alder reaction between 3-vinylindoles and methyleneindolinone can proceed both under catalyst-free conditions and with bisthiourea as the catalyst. The reaction with bisthiourea is much faster and results in higher stereoselectivity of the product. The reaction mechanism, origin of stereoselectivity, and role of the catalyst were elaborated based on quantum mechanical calculations and theoretical methods of reactivity indices, NCI, QTAIM, and distortion/interaction models. In the uncatalyzed reaction, the two C-C bonds that are formed undergo conversion from noncovalent to covalent bonding via a concerted asynchronous mechanism. The weak intermolecular interactions formed in the transition state play important roles. The difference between the interaction and distortion energies is responsible for the stereoselectivity. In the catalyzed reaction, bisthiourea induces both the diene and dienophile to approach it via weak intermolecular interactions, which greatly lowers the energy barrier of the reaction and leads to the product with excellent stereoselectivity. The possible pathways of this reaction were explored, which suggested that the formation of the two C-C bonds goes through either a stepwise or concerted asynchronous mechanism. These results detail the reaction mechanism and shed light on both the significant role of the bisthiourea catalyst and the origin of stereoselectivity for this type of Diels-Alder reaction and related ones.

  10. Stereoselective Behavior of the Chiral Herbicides Diclofop-Methyl and Diclofop During the Soy Sauce Brewing Process.

    Science.gov (United States)

    Lu, Yuele; Zhang, Dong; Liao, Yahui; Diao, Jinling; Chen, Xiaolong

    2016-01-01

    Chiral pesticides are now receiving more and more attention in the food-making process. This experiment studied the enantioselective behavior of diclofop-methyl (DM) and its main metabolite, diclofop (DC), during the soy sauce brewing process. Two kinds of commonly used strains, Aspergillus oryzae and Saccharomyces rouxii, were investigated. However, they showed a different degradation ability to the enantiomers of DM and DC. It was observed that (-)-(S)-DM was degraded much faster than (+)-(R)-DM by Saccharomyces rouxii, while no stereoselective degradation was found by Aspergillus oryzae. DC represented a relatively long residue period in this fermentation process and both strains showed a weak degradation ability to DC, especially Saccharomyces rouxii. There was little DC detected in the final product, while most of the DC residues persisted in the lees, which were usually used as animal feeds or discarded into the environment directly as waste. Therefore, more attention should be paid to the soy sauce brewing process concerning pesticide residues both in the final product and byproducts. © 2015 Wiley Periodicals, Inc.

  11. Cuestión de tiempo: Michael Fried y el tiempo del arte moderno A matter of time: Michael Fried and modernist art the time of modernist art

    Directory of Open Access Journals (Sweden)

    David Díaz Soto

    2011-07-01

    Full Text Available En el siglo XIX, autores fundacionales del formalismo, como Fiedler o Hildebrand, contrapusieron estrictamente las artes plásticas, «puramente visuales», a las artes verbales del discurso, proscribiéndoles la narración y disociándolas de la temporalidad: se trata del «principio de exclusión del tiempo», vinculado al formalismo. Más tarde, el crítico «modernista» de arte Clement Greenberg planteó la instantaneidad, en tanto que opuesta a la duración, como modalidad ideal de la experiencia artística. Pero el historiador y crítico de arte Michael Fried, en sus textos de los años 60 sobre arte abstracto, se distancia de Greenberg, desarrollando un discurso sobre la temporalidad en las artes plásticas, con nociones como «tiempo visual»; y en sus posteriores textos historiográficos investiga las modalidades temporales de la representación pictórica. La aparente paradoja entre la crítica de Fried a la hipóstasis «literalista» de la duración en las tardovanguardias y el papel crucial que concede a Manet y a la instantaneidad en el origen del arte moderno, la resolveremos atendiendo a su reivindicación de la temporalidad durativa de «lo cotidiano». Así cabe comprender la concepción de la modalidad temporal característica de la modernidad y del arte moderno, a la que apunta su noción teórica de presentness.In the nineteenth century, seminal authors of Formalism, like Fiedler or Hildebrand, strictly compared the «purely visual» plastic arts to the discursive arts of verbal language, ruling out narrativity from plastic arts, which they dissociated from temporality - the formalist «principle of exclusion of time». Later on, «modernist» art critic Clement Greenberg claimed that instantaneousness, as opposed to duration, was the ideal modality for artistic experience. Art critic and historian Michael Fried did not share Greenberg's position, but developed instead a discourse about time in plastic arts. In his early

  12. Las relaciones entre la Iglesia y el Estado en la teoría de la justicia de Michael Walzer

    OpenAIRE

    Roldán, Alberto Fernando

    2009-01-01

    Roldan, A. F. (2009). Las relaciones entre la Iglesia y el Estado en la teoría de la justicia de Michael Walzer (Tesis de Maestría). Universidad Nacional de Quilmes, Bernal, Argentina. En la presente tesis, se discuten las relaciones entre la Iglesia –término que se utiliza no en el sentido confesional sino en tanto institución religiosa- y el Estado moderno. Se escoge como marco teórico la filosofía política del pensador judío americano Michael Walzer, exponente del “comunitarismo”, un...

  13. Michael Fordham and the Journal of Analytical Psychology: the view from Hangman's Hill.

    Science.gov (United States)

    Urban, Elizabeth

    2015-09-01

    This short paper was presented to a conference in honour of the 60(th) year of the JAP and was one of others that acknowledged the contribution of Michael Fordham. The subtitle refers to the paper's overview of Fordham's published oeuvre and the particular place of the Journal of Analytical Psychology, for which he was the founding editor. Fordham's contribution to a Jungian-based model of development is discussed, with reference to his papers in the British Journal of Medical Psychology. The paper notes miscellaneous pieces from Fordham's commentaries, obituaries, papers and reviews which capture not only the development of Fordham as a thinker but also his character. There is discussion of his reviews of Melanie Klein's Envy and Gratitude and manuscripts by Erich Neumann. A reminiscence of Fordham as supervisor is recounted. © 2015, The Society of Analytical Psychology.

  14. Lizards, ticks and contributions to Australian parasitology: C. Michael Bull (1947-2016).

    Science.gov (United States)

    Godfrey, Stephanie S; Gardner, Michael G

    2017-12-01

    Professor C. Michael Bull was a great scientist and mentor, and an Associate Editor of this journal. While his research career spanned the fields of behavioural ecology, conservation biology and herpetology, in this article, we pay tribute to his major contribution to Australian parasitology. Mike authored more than eighty articles on host-parasite ecology, and revealed major insights into the biology and ecology of ticks from his long term study of the parapatric boundary of two tick species ( Amblyomma limbatum and Bothriocroton hydrosauri ) on the sleepy lizard ( Tiliqua rugosa ). In this article, we provide an overview of how this research journey developed to become one of the longest-running studies of lizards and their ticks, totalling 35 years of continuous surveys of ticks on lizards, and the insights and knowledge that he generated along that journey.

  15. A History of Experiences and Thinking Men. The History of Political Thought according to Michael Oakeshott

    Directory of Open Access Journals (Sweden)

    Spartaco Pupo

    2014-12-01

    Full Text Available Michael Oakeshott conceives the history of European political thought as a structuring of ideas and arguments of the practical experience aimed to understanding political expressions in vogue in the culture of a people. It is not a continuous and cumulative history of abstract and disembodied ideas, as it is wrongly conceived, but of some men who thought politics in a certain way on the basis of the language and of the set of actions, moral beliefs and contingencies of the people which they belong to. The article highlights the comparison between Oakeshott, Quentin Skinner and Gianfranco Miglio on the search for the most appropriate method to be applied in the study of the history of political thought.

  16. 'Introducing Michael Gove to Loïc Wacquant': Why Social Work Needs Critical Sociology.

    Science.gov (United States)

    Michael Garrett, Paul

    2016-06-01

    In 2013, Michael Gove, then Secretary of State for Education and Health in the UK coalition government, criticised social workers for laying insufficient emphasis on the 'agency' of individuals and for being too preoccupied with social and economic inequalities. Such a perspective, which is not unique to Gove, needs to be countered by reaffirming the significance of an expansively critical sociology for social work. In this context, the thematic concerns of the French theorist, Loïc Wacquant, illuminates key aspects of social work engagement with clients which Gove and his ideological associates appear intent on ignoring. The issues raised have significant political resonances given the pending UK General Election taking place in May 2015.

  17. Modalities of representation and perception in Michael Ondaatje’s Anil’s Ghost

    Directory of Open Access Journals (Sweden)

    Sigrid Renaux

    2017-01-01

    Full Text Available http://dx.doi.org/10.5007/2175-8026.2017v70n1p113 This study analyses the way in which the interdependence of the representation and perception of reality is exemplified and questioned in Michael Ondaatje’s Anil’s Ghost (2000. As we enter this work of resistance literature by way of an omniscient narrator, we enter not just the geographical spaces and cultural history of Sri Lanka, but find ourselves taking part in the daily struggle of the people to survive, to identify and do justice to the many dead in this conflict between ethnic groups and the government. This fragmentation of the narrative structure – casting doubt on the conflicting relationships established between the characters’ present and the past, between western and eastern values in relation to the concept of truth, the search for lost identity and love – highlights still further the interchangeability of representation and perception of reality.

  18. Michael Oakeshott´s Work as a Liberal-Conserv ative Paradigm

    Directory of Open Access Journals (Sweden)

    Josep Baqués

    2014-01-01

    Full Text Available As is the case with other thinkers linked to what can be broadly defined as conservatism, it is arguable whether Michael Oakeshott was just a conservative, or whether he was also a liberal. He often rejected this last label. He also tried to avoid the classic debate between the left/right wing divide, conferring instead a mantle of neutrality on his work. This analysis shows, on the one hand, that Oakeshott´s work is ideologically orientated and, on the other hand, that it contains a substantial liberal component. In fact, he offered a liberal-conservative synthesis in which the free market appears to be not only the best, but the only feasible outcome in the proposed scenario of political prudence. I will fi rst connect Oakeshott with the main traditions of thought, then analyse the theoretical implications of his position, and finally explore the consequences derived from all this for everyday political practice.

  19. The role of Michael Pupin in solving of Serbian national question

    Directory of Open Access Journals (Sweden)

    Grčić Mirko D.

    2004-01-01

    Full Text Available Michael I. Pupin was a professor at the University of Columbia, member and the president of Academy of Science in New York; one of the esteemed members of USA National Academy of Science; member and president of many experts and scientific institutions and societies in the USA; member of State Council for Scientific Research by president of the USA during the World War I. Of the great importance for political geography and geopolitics was his activity in Paris during the Peace Conference after the World War I in 1919 also as his great contribution to establishment of state borders of Kingdom of Serbs, Croats and Slovenians (later Yugoslavia, which helped those nations to establish their national borders at maximum level. Pupin claimed that he was Yugoslav patriot and American citizen. Role of M. Pupin in battle for national interests and Yugoslav borders after the World War I is shown in this article.

  20. Rationalism and traditionalism in politics. The correspondence between Karl R. Popper and Michael Oakeshott

    Directory of Open Access Journals (Sweden)

    Spartaco Pupo

    2016-07-01

    Full Text Available The correspondence of 1948 between Karl Popper and Michael Oakeshott, translated for the first time in Italian and published in the appendix to this paper, demonstrates the existence of two different ways of thinking about politics: the rationalist approach, founded on the “argumentation” as a rational means for the non-violent solution of problems (Popper, and the traditionalist mode, inspired by the method of “conversation” as a guarantee of constant openness to the diversity of identities (Oakeshott. To rise from the letters is a mutual influence on the interpretation of the key concepts that characterize the thought of the two authors, which however does not cancel the fundamental divergence of their political orientation.

  1. "Alarme de incêndio": Michael Löwy e a crítica ecossocialista da civilização capitalista moderna "Fire alarm": Michael Löwy and the ecosocialist critique of the modern capitalist civilization

    Directory of Open Access Journals (Sweden)

    Fabio Mascaro Querido

    2013-04-01

    Full Text Available A emergência da crise ecológica, como sintoma mais nítido de uma verdadeira crise civilizató-ria, impôs novos desafios ao pensamento crítico e, em especial, ao marxismo. Partindo desse pressuposto, o objetivo deste artigo é apresentar a defesa de Michael Löwy de uma radicalização ecossocialista da crítica marxista da modernidade, tarefa para a qual a grande recusa de Walter Benjamin das ideologias do pro- gresso é uma das fontes decisivas de inspiração. Para Michael Löwy, a ruptura com as ideologias do progresso e com o paradigma civilizatório capitalista moderno é uma condição indispensável para a atua-lização ecossocialista do marxismo.The emergence of the ecological crisis as a clearer symptom of a true civilizatory crisis has imposed new challenges to critical thought and, in particular, to Marxism. Based on this assumption, this article aims to present Michael Löwy's defense of an ecosocialist radicalization of the Marxist critique of modernity, a task for which Walter Benjamin's great refusal of the ideologies of progress is one of the critical sources of inspiration. To Michael Löwy, breaking away from the ideologies of progress and from the modern capitalistic civilizatory paradigm is a prerequisite for the ecosocialist updating of Marxism.

  2. Stereoselective cathodic synthesis of 8-substituted (1R,3R,4S-menthylamines

    Directory of Open Access Journals (Sweden)

    Carolin Edinger

    2015-02-01

    Full Text Available The electrochemical generation of menthylamines from the corresponding menthone oximes equipped with an additional substituent in position 8 is described. Due to 1,3-diaxial interactions a pronounced diastereoselectivity for the menthylamines is found.

  3. Free energy calculations give insight into the stereoselective hydroxylation of α-ionones by engineered cytochrome P450 BM3 mutants.

    Science.gov (United States)

    de Beer, Stephanie B A; Venkataraman, Harini; Geerke, Daan P; Oostenbrink, Chris; Vermeulen, Nico P E

    2012-08-27

    Previously, stereoselective hydroxylation of α-ionone by Cytochrome P450 BM3 mutants M01 A82W and M11 L437N was observed. While both mutants hydroxylate α-ionone in a regioselective manner at the C3 position, M01 A82W catalyzes formation of trans-3-OH-α-ionone products whereas M11 L437N exhibits opposite stereoselectivity, producing trans-(3S,6S)-OH-α-ionone and cis-(3S,6R)-OH-α-ionone. Here, we explore the stereoselective C3 hydroxylation of α-ionone by Cytochrome P450 BM3 mutants M01 A82W and M11 L437N using molecular dynamics-based free energy calculations to study the interaction between the enzyme and both the substrates and the products. The one-step perturbation approach is applied using an optimized reference state for substrates and products. While the free energy differences between the substrates free in solution amount to ~0 kJ mol(-1), the differences in mutant M01 A82W agree with the experimentally obtained dissociation constants K(d). Moreover, a correlation with experimentally observed trends in product formation is found in both mutants. The trans isomers show the most favorable relative binding free energy in the range of all four possible hydroxylated diastereomers for mutant M01 A82W, while the trans product from (6S)-α-ionone and the cis product from (6R)-α-ionone show highest affinity for mutant M11 L437N. Marcus theory is subsequently used to relate the thermodynamic stability to transition state energies and rates of formation.

  4. N-Heterocyclic-Carbene-Catalysed Diastereoselective Vinylogous Mukaiyama/Michael Reaction of 2-(Trimethylsilyloxy)furan and Enones

    KAUST Repository

    Wang, Ying; Du, Guang Fen; Xing, Fen; Huang, Kuo-Wei; Dai, Bin; He, Lin

    2015-01-01

    N-heterocyclic carbenes have been utilised as highly efficient nucleophilic organocatalysts to mediate vinylogous Mukaiyama/Michael reactions of 2-(trimethylsilyloxy)furan with enones to afford γ-substituted butenolides in 44-99% yield with 3:1-32:1 diastereoselectivity. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. Komparativistlikke ja kultuuriteaduslikke ärgitusi Baltimaade germanistikale / Michael Schwidtal ; saksa keelest tõlkinud Vahur Aabrams

    Index Scriptorium Estoniae

    Schwidtal, Michael

    2001-01-01

    3. - 5. sept. 2001 toimus Riias sümpoosion "Unter diesem braunen Himmel. Jakob Michael Reinhold Lenz und die deutsche Literatur des Baltikums", 7. - 9. sept. Tartus "Torm ja tung Liivimaal. Mässu mudelid", pühendatud J. M. R. Lenzi ja Kristian Jaak Petersoni loomingule. Ülevaade

  6. A Symposium on the Relevance of Michael Polanyi's Insights to a Reformulated Understanding of Science, Technology, and Society

    Science.gov (United States)

    Mead, Walter B.

    2011-01-01

    This is intended as an introductory statement to the explorations undertaken in the essays that follow. The authors of these essays attempt to introduce the reader to some of the insights of Michael Polanyi and their implications for the reader who wishes to come to a greater understanding of modern technological society, which--for better or…

  7. Jack Michael's Musings on the 60th Anniversary of Skinner's "Verbal Behavior"

    Science.gov (United States)

    Esch, Barbara E.; Esch, John W.; Palmer, David C.

    2017-01-01

    When the B. F. Skinner Foundation reprinted Skinner's "Verbal Behavior" in 1992, Jack Michael wrote one of its two forewords, a detailed outline of the book's purpose and scope. On the 60th anniversary of the first publication (1957) of "Verbal Behavior", Jack reflects on the book's impact and its importance to the…

  8. What I Think I May Have Learned--Reflections on 50 Years of Teaching: An Interview with Michael Wertheimer

    Science.gov (United States)

    Michael, Kurt D.

    2006-01-01

    Kurt Michael is an associate professor in the Department of Psychology at Appalachian State University (ASU) where he teaches history and systems of psychology, abnormal psychology, child psychopathology, and interventions for children and adolescents. He received his BA (cum laude) from the University of Colorado at Boulder and his MS and PhD in…

  9. Effective Integration of Technology and Instruction. Q&A with Michael Jay. REL Mid-Atlantic Educator Effectiveness Webinar Series

    Science.gov (United States)

    Regional Educational Laboratory Mid-Atlantic, 2015

    2015-01-01

    In this webinar, long-time educator and developer of education technology Michael Jay discussed the importance of using technology to support learning and gave examples of how teachers can integrate technology into their instruction based on the Common Core State Standards and the Next Generation Science Standards. The PowerPoint presentation and…

  10. N-Heterocyclic-Carbene-Catalysed Diastereoselective Vinylogous Mukaiyama/Michael Reaction of 2-(Trimethylsilyloxy)furan and Enones

    KAUST Repository

    Wang, Ying

    2015-10-15

    N-heterocyclic carbenes have been utilised as highly efficient nucleophilic organocatalysts to mediate vinylogous Mukaiyama/Michael reactions of 2-(trimethylsilyloxy)furan with enones to afford γ-substituted butenolides in 44-99% yield with 3:1-32:1 diastereoselectivity. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. Progress in ultrasonic spray pyrolysis for condensed matter sciences developed from ultrasonic nebulization theories since Michael Faraday

    CSIR Research Space (South Africa)

    Mwakikunga, BW

    2014-01-01

    Full Text Available This review outlines, in great detail, the history of the phenomenon of ultrasonic nebulization of liquids since the discovery of such an effect by Michael Faraday and the explanation of the phenomenon by capillary wave mechanism and “cavitation...

  12. Jack Michael's Appointments at the University of Houston and Arizona State University: Reflections from a Former Student

    Science.gov (United States)

    Mabry, John H.

    2016-01-01

    Jack Michael was an early enthusiast for what is now called applied behavior analysis. His many seminal contributions were through early publications in applied behavior analysis and the work of the students he trained (e.g., T. Ayllon, M. M. Wolf). His close mentorship of students earned him acclaim as a teacher along with his many theoretical…

  13. Thomas DaCosta Kaufmann and Michael North (eds., Mediating Netherlandish Art and Material Culture in Asia

    Directory of Open Access Journals (Sweden)

    Claartje Rasterhoff

    2015-12-01

    Full Text Available Book notice of: Thomas DaCosta Kaufmann and Michael North (eds., Mediating Netherlandish Art and Material Culture in Asia (Amsterdam Studies in the Dutch Golden Age Amsterdam, Amsterdam University Press, 2014. 348 pp. ISBN 978-90-8964-569-2. € 99,00.

  14. Der Wert von Worten. Michael Serrer aus dem Literaturbüro Düsseldorf im Interview mit der Textpraxis-Redaktion

    Directory of Open Access Journals (Sweden)

    Michael Serrer

    2014-11-01

    Full Text Available Die Textpraxis-Redaktion unterhält sich mit Michael Serrer über Literaturvermittlung in Zeiten der Digitalisierung, über Kanonisierung und die Rolle der Literatur in der Gesellschaft. Michael Serrer ist Leiter des Literaturbüros NRW und Feuilletonist.

  15. Book Review: America’s Blind Spot: Chávez, Oil and US Security by Andrés Cala and Michael Economides

    DEFF Research Database (Denmark)

    Boscan, Luis

    2014-01-01

    Review of: America’s Blind Spot: Chávez, Oil and US Security. Andrés Cala and Michael Economides. Continuum Books. 2012.......Review of: America’s Blind Spot: Chávez, Oil and US Security. Andrés Cala and Michael Economides. Continuum Books. 2012....

  16. High-level Computational Study of the Site-, Facial- and Stereoselectivities for the Diels-Alder Reaction Between o-Benzoquinone and Norbornadiene

    Directory of Open Access Journals (Sweden)

    Ronald N. Warrener

    2000-12-01

    Full Text Available Ab initio and DFT quantum chemical calculations have been applied to a study of the Diels-Alder reaction of o-benzoquinone as diene and norbornadiene as dienophile. Transition states for the different reactions are located and activation energies estimated. The prefered exo-π-facial selectivity and exo,endo-stereoselectivity exhibited in this cycloaddition are readily predicted using RHF/3-21G or higher levels of calculations. Differences between experimentally observed results and calculations may be explained by the postulation of a second, nonconcerted biradical mechanism leading to formation of hetero Diels-Alder products.

  17. Stereoselective synthesis of the Halaven C14-C26 fragment from D-quinic acid: crystallization-induced diastereoselective transformation of an α-methyl nitrile.

    Science.gov (United States)

    Belanger, Francis; Chase, Charles E; Endo, Atsushi; Fang, Francis G; Li, Jing; Mathieu, Steven R; Wilcoxen, Annie Z; Zhang, Huiming

    2015-04-20

    Crystallization-induced diastereoselective transformation (CIDT) of an α-methyl nitrile completes an entirely non-chromatographic synthesis of the halichondrin B C14-C26 stereochemical array. The requisite α-methyl nitrile substrate is derived from D-quinic acid through a series of substrate-controlled stereoselective reactions via a number of crystalline intermediates that benefit from a rigid polycyclic template. Therefore, all four stereogenic centers in the Halaven C14-C26 fragment were derived from the single chiral source D-quinic acid. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. Acid-base-controlled stereoselective metalation of overhanging carboxylic acid porphyrins: consequences for the formation of heterobimetallic complexes.

    Science.gov (United States)

    Le Gac, Stéphane; Najjari, Btissam; Dorcet, Vincent; Roisnel, Thierry; Fusaro, Luca; Luhmer, Michel; Furet, Eric; Halet, Jean-François; Boitrel, Bernard

    2013-08-12

    Overhanging carboxylic acid porphyrins have revealed promising ditopic ligands offering a new entry in the field of supramolecular coordination chemistry of porphyrinoids. Notably, the adjunction of a so-called hanging-atop (HAT) Pb(II) cation to regular Pb(II) porphyrin complexes allowed a stereoselective incorporation of the N-core bound cation, and an allosterically controlled Newton's cradle-like motion of the two Pb(II) ions also emerged from such bimetallic complexes. In this contribution, we have extended this work to other ligands and metal ions, aiming at understanding the parameters that control the HAT Pb(II) coordination. The nature of the N-core bound metal ion (Zn(II), Cd(II)), the influence of the deprotonation state of the overhanging COOH group and the presence of a neutral ligand on the opposite side (exogenous or intramolecular), have been examined through (1)H NMR spectroscopic experiments with the help of radiocrystallographic structures and DFT calculations. Single and bis-strap ligands have been considered. They all incorporate a COOH group hung over the N-core on one side. For the bis-strap ligands, either an ester or an amide group has been introduced on the other side. In the presence of a base, the mononuclear Zn(II) or Cd(II) complexes incorporate the carbonyl of the overhanging carboxylate as apical ligand, decreasing its availability for the binding of a HAT Pb(II). An allosteric effector (e.g., 4-dimethylaminopyridine (DMAP), in the case of a single-strap ligand) or an intramolecular ligand (e.g., an amide group), strong enough to compete with the carbonyl of the hung COO(-), is required to switch the N-core bound cation to the opposite side with concomitant release of the COO(-), thereby allowing HAT Pb(II) complexation. In the absence of a base, Zn(II) or Cd(II) binds preferentially the carbonyl of the intramolecular ester or amide groups in apical position rather than that of the COOH. This better preorganization, with the

  19. Examination and comparative study of the Ascension of The Prophet of Islam In The View Of Michael Sells And Anne-mari e Shamil with Inter- Religious Attitude

    Directory of Open Access Journals (Sweden)

    Mahdi Azadi

    2015-09-01

    Full Text Available Michael Sells, American scholar of Quran,about the Ascension (Mi,raj of the prophet (PBUH focuses on three issues: First, the Mi,raj term is not used in the Quran and the ascension of the explanation is not enough. second, Mohammad is no different from the miracle of the Quran is the miracle of God,he is not anything else, Quran states. Third, Ascension of the prophet (PBUH has been in sleep and dream.According to him, the discussion about the layers of the subject is based mainly on the evidence of Quran.In this case, only limited information can be found in the Asra chapter (sooreh of the Quran.In addition, he has tried to make the Ascension event from Jewish traditions and the effects Bvdaysm.actually the orientalist`s goal is to prove the absence of ascension of the prophet(PBUH.  In contrast, Anne-marie Shamil stayes that prophet`s ascension derived from the first verse of Asra sura and believes that two processes(horizontal and verticalfor prophet happened.and unlike Michael,he knows mi,raj from the God miracles.Anne-Marie because her sufficient the Sunni sources is doubt with belief in the physical and spiritual ascension,in some of her votes,such as; visible or not visible in the ascension of God by the prophet.Despite the fundamental criticism that some elements of the theory of two Orientalists arrived,positive points are observed in their ideas.in this article we have tried to express the views of the Orientalists, then to review their ideas considered

  20. Entrevista com Mathieu Dosse, Gian Luigi de Rosa e Michael Kegler

    Directory of Open Access Journals (Sweden)

    Andréia Guerini

    2017-09-01

    Full Text Available O conjunto das três entrevistas que seguem aborda a mesma temática, isto é, aspectos de tradução/adaptação em geral e da tradução do romance Estive em Lisboa e lembrei de você de Luiz Ruffato em particular. O romance de Ruffato foi escrito em 2009, editado em Portugal (Quetzal, 2010 e traduzido para diferentes línguas, como italiano (La Nuova Frontiera, 2011, espanhol (Eterna Cadencia, 2011, francês (Chandeigne, 2015, alemão (Assoziation A, 2016 e, nos próximos meses será publicado em finlandês (Into. O livro foi adaptado para o cinema em 2015, pelo cineasta português José Barahona, sendo exibido em festivais nacionais e internacionais. As entrevistas abaixo foram feitas com os tradutores Gian Luigi De Rosa, Mathieu Dosse e Michael Kegler em 2016. Gian Luigi De Rosa (Itália/1969-- possui doutorado em “Culture e Istituzioni dei paesi di lingue iberiche in età moderna e contemporanea” e é professor de português na Universidade do Salento, em Lecce. É autor de livros e ensaios sobre língua e linguística portuguesa, literatura portuguesa e brasileira e tradução audiovisual e intersemiótica. É também responsável pela elaboração das legendas em italiano do filme Estive em Lisboa e lembrei de você. Mathieu Dosse (Brasil/1978-- é formado pela Université Paris 8, onde estudou Teoria da Tradução. Traduziu para o francês Graciliano Ramos, Luiz Ruffato e João Guimarães Rosa. Michael Kegler (Alemanha/1967-- estudou literatura brasileira e portuguesa na universidade de Frankfurt, sem concluir o curso. Trabalhou como livreiro no Centro do Livro de Língua Portuguesa, antes de se tornar tradutor literário. Traduziu para o alemão José Eduardo Agualusa, Moacyr Scliar, Luiz Ruffato, entre outros autores. Em julho de 2016, junto com Ruffato, recebeu o prêmio literário Hermann Hesse na Alemanha, pela qualidade da obra publicada em conjunto com a sua tradução.

  1. An Oral History Interview with MICHAEL M. CERNEA (interviewer: Judith Freidenberg

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    MICHAEL M. CERNEA

    2008-01-01

    Full Text Available The editors and editorial board of Human Organization are pleased to introduce readers to the following oral history interview with Michael M. Cernea, a development social scientist who has militated throughout his academic career and applied work for "putting people first", in the forefront of development projects and policies. Working for a long time for the promotion of anthropological and sociological knowledge, either in the activities of the World Bank or in the policies and programs of governments of both developed and developing countries, Dr. Cernea cleared pathways for applied social science that are sure to benefit people in development settings for many years to come. Undoubtedly many readers already know Dr. Cernea's work well, especially those of us who teach the anthropology of development or work in applied settings and organizations, but this interview embeds his broad body of work into a personal, human, and at times tragic context that opens with brushes with death, Nazi brutality, and exile. It also provides valuable insights for carrying out the work of development anthropologists within large-scale organizations and governments.This interview with Dr. Cernea was conducted by Dr. Judith Freidenberg, of the University of Maryland, on June 30, 2003, for the Society for Applied Anthropology Oral History Project, headquartered at the University of Kentucky Libraries. This Project aims to create, through the vehicle of oral histories, a record of the life, activities and experiences of number of selected scholars-anthropologists who devoted a great part of their scientific work to research, to applied work in different settings, to inducing development, including to hands-on work on crafting public social policies and actual development programs. The present transcript of the interview was reviewed by both participants for editorial purposes. Michael M. Cernea expanded some of his oral responses, for historical accuracy or to add

  2. Ecossocialismo, romantismo e (autocrítica da modernidade em Michael Löwy

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    Fabio Mascaro Querido

    2008-12-01

    Full Text Available Partindo da concreticidade da crise ecológica e das transformações contemporâneas no âmbito dos processos de acumulação capitalista, o objetivo geral deste artigo é versar algumas notas preliminares a propósito da perspectiva teórica e política do assim chamado ecossocialismo, tal qual formulado em Michael Löwy. “Corrente de pensamento e de ação” cuja resposta à crise ecológica, a um só tempo romântica e socialista, constitui igualmente uma crítica às potencialidades destrutivas contidas no interior do paradigma societário e produtivo da modernidade. Neste trajeto, busca -se uma aproximação à apropriação löwiniana da obra de Walter Benjamin, especialmente de sua crítica do “progresso” moderno e das ideologias apologetas da “modernização”. Almeja -se assim antever a forma através da qual Michael Löwy e os ecossocialistas respondem às profundas transformações da (pós modernidade capitalista contemporânea, com ênfase particular sobre um argumento central projetado na obra do intelectual franco -brasileiro, qual seja: a defesa da necessidade de que o marxismo radicalize “sua crítica da modernidade, do paradigma da civilização ocidental, industrial, moderna, burguesa” (LÖWY, 2000c, p.242, argumento que o levaria, já em meados da década de 1980, a valorizar as potencialidades revolucionárias subjacentes a crítica romântica da modernidade. Por fim, indaga -se sobre a projeção ecossocialista da necessidade de superação revolucionária do paradigma civilizatório propalado pelo capitalismo moderno

  3. Synthesis of purines bearing functionalized C-substituents by the conjugate addition of nucleophiles to 6-vinylpurines and 6-ethynylpurines

    Czech Academy of Sciences Publication Activity Database

    Kuchař, Martin; Pohl, Radek; Votruba, Ivan; Hocek, Michal

    -, č. 22 (2006), s. 5083 -5098 ISSN 1434-193X R&D Projects: GA MŠk(CZ) 1M0508; GA AV ČR(CZ) 1QS400550501 Institutional research plan: CEZ:AV0Z40550506 Keywords : purines * Michael addition * conjugate additions * cross-coupling Subject RIV: CC - Organic Chemistry Impact factor: 2.769, year: 2006

  4. Stereoselective analysis of thioridazine-2-sulfoxide and thioridazine-5-sulfoxide: an investigation of rac-thioridazine biotransformation by some endophytic fungi.

    Science.gov (United States)

    Borges, Keyller Bastos; De Souza Borges, Warley; Pupo, Mônica Tallarico; Bonato, Pierina Sueli

    2008-04-14

    The purpose of this study was to develop a method for the stereoselective analysis of thioridazine-2-sulfoxide (THD-2-SO) and thioridazine-5-sulfoxide (THD-5-SO) in culture medium and to study the biotransformation of rac-thioridazine (THD) by some endophytic fungi. The simultaneous resolution of THD-2-SO and THD-5-SO diastereoisomers was performed on a CHIRALPAK AS column using a mobile phase of hexane:ethanol:methanol (92:6:2, v/v/v)+0.5% diethylamine; UV detection was carried out at 262 nm. Diethyl ether was used as extractor solvent. The validated method was used to evaluate the biotransformation of THD by 12 endophytic fungi isolated from Tithonia diversifolia, Viguiera arenaria and Viguiera robusta. Among the 12 fungi evaluated, 4 of them deserve prominence for presenting an evidenced stereoselective biotransformation potential: Phomopsis sp. (TD2) presented greater mono-2-sulfoxidation to the form (S)-(SE) (12.1%); Glomerella cingulata (VA1) presented greater mono-5-sulfoxidation to the forms (S)-(SE)+(R)-(FE) (10.5%); Diaporthe phaseolorum (VR4) presented greater mono-2-sulfoxidation to the forms (S)-(SE) and (R)-(FE) (84.4% and 82.5%, respectively) and Aspergillus fumigatus (VR12) presented greater mono-2-sulfoxidation to the forms (S)-(SE) and (R)-(SE) (31.5% and 34.4%, respectively).

  5. Michael Jackson, Bin Laden and I: functions of positive and negative, public and private flashbulb memories.

    Science.gov (United States)

    Demiray, Burcu; Freund, Alexandra M

    2015-01-01

    This study examined the perceived psychosocial functions of flashbulb memories: It compared positive and negative public flashbulb memories (positive: Bin Laden's death, negative: Michael Jackson's death) with private ones (positive: pregnancy, negative: death of a loved one). A sample of n = 389 young and n = 176 middle-aged adults answered canonical category questions used to identify flashbulb memories and rated the personal significance, the psychological temporal distance, and the functions of each memory (i.e., self-continuity, social-boding, directive functions). Hierarchical regressions showed that, in general, private memories were rated more functional than public memories. Positive and negative private memories were comparable in self-continuity and directionality, but the positive private memory more strongly served social functions. In line with the positivity bias in autobiographical memory, positive flashbulb memories felt psychologically closer than negative ones. Finally, middle-aged adults rated their memories as less functional regarding self-continuity and social-bonding than young adults. Results are discussed regarding the tripartite model of autobiographical memory functions.

  6. Nacionalismos e internacionalismo: um debate entre Michael Löwy e Michel Cahen

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    Ângela Lazagna

    2008-11-01

    Full Text Available Este artigo consiste em um debate realizado entre Michel Löwy e Michael Cahen em meados dos anos 1990 e revisto para esta publicação. Mesmo que a discussão refira-se a acontecimentos que até certo ponto podem ser considerados datados, a preocupação de fundo que é comum a esses artigos concede-lhes atualidade: a necessidade do aprofundamento de uma reflexão, a partir da teoria marxista, sobre o problema dos nacionalismos e do internacionalismo em tempos de mundialização. Esse aprofundamento, segundo os autores, faz-se necessário sobretudo por meio de uma reflexão que rompa criticamente com uma visão eurocêntrica dos diferentes nacionalismos e que supere a atitude de muitos marxistas de desprezarem tudo aquilo que não seja diretamente relevante à "consciência de classe".

  7. A man and his island: The island mirror in Michael Crummey’s Sweetland

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    Laurie Brinklow

    2016-05-01

    Full Text Available Between 1946 and 1975, dozens of islands and outports in the Canadian province of Newfoundland and Labrador were abandoned as part of a government resettlement policy. Families and communities were torn apart, and a culture and way of life that revolved around the fishery changed irrevocably. The practice, which continues to this day, has been well documented, particularly by artists and writers. Michael Crummey’s 2014 novel Sweetland is a recent iteration. The relationship between humans and place is complex: on an island, with compressed space and a very real boundary that is the ocean, emotional attachments to one’s place are often heightened and distilled. What happens when a person is displaced from his or her island; when bonds of attachment are severed and one’s mirrored double is destroyed? Sweetland offers a fictional lens through which we see an example of a mirrored relationship between an island protagonist and his island setting. Exploring themes of attachment to place, and what Barry Lopez calls a “storied” or “reciprocal” relationship with the land, this paper examines what happens to a man when confronted with leaving an island he knows as deeply as his own body and soul; and how the island reacts.

  8. Selective bird predation on the peppered moth: the last experiment of Michael Majerus.

    Science.gov (United States)

    Cook, L M; Grant, B S; Saccheri, I J; Mallet, J

    2012-08-23

    Colour variation in the peppered moth Biston betularia was long accepted to be under strong natural selection. Melanics were believed to be fitter than pale morphs because of lower predation at daytime resting sites on dark, sooty bark. Melanics became common during the industrial revolution, but since 1970 there has been a rapid reversal, assumed to have been caused by predators selecting against melanics resting on today's less sooty bark. Recently, these classical explanations of melanism were attacked, and there has been general scepticism about birds as selective agents. Experiments and observations were accordingly carried out by Michael Majerus to address perceived weaknesses of earlier work. Unfortunately, he did not live to publish the results, which are analysed and presented here by the authors. Majerus released 4864 moths in his six-year experiment, the largest ever attempted for any similar study. There was strong differential bird predation against melanic peppered moths. Daily selection against melanics (s ≈ 0.1) was sufficient in magnitude and direction to explain the recent rapid decline of melanism in post-industrial Britain. These data provide the most direct evidence yet to implicate camouflage and bird predation as the overriding explanation for the rise and fall of melanism in moths.

  9. Creative Industries, Value Theory and Michael Heinrich’s New Reading of Marx

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    Frederick H. Pitts

    2015-06-01

    Full Text Available This article utilises the new reading of Marx found in the work of Michael Heinrich to analyse the creative industries. It considers the role played in the production of value by the labour that takes place in the sphere of circulation. The specific focus is on creative industries such as graphic design, advertising and branding. It applies Heinrich's conceptualisation of 'social validation' to these sectors. This suggests that valorisation depends upon goods and services attaining commodity status by selling for money. Value is subject to this validation. The capitalist use of advertising, graphic design and branding guarantees the possibility of this validation. Using Heinrich, it reevaluates claims made about the creative industries and cognate fields in three main respects. First, it exposes as inadequate certain Marxist understandings of productive and unproductive labour and the place of circulation activities within this distinction. Second, it refutes autonomist Marxist claims as to the immeasurability of immaterial labour and the redundancy of the law of value. Third, it suggests that creative industries possess a significant role in a capitalist economy blighted by a necessity towards the overproduction of commodities.

  10. Diffusible gradients are out - an interview with Lewis Wolpert. Interviewed by Richardson, Michael K.

    Science.gov (United States)

    Wolpert, Lewis

    2009-01-01

    In 1969, Lewis Wolpert published a paper outlining his new concepts of "pattern formation" and "positional information". He had already published research on the mechanics of cell membranes in amoebae, and a series of classic studies of sea urchin gastrulation with Trygve Gustavson. Wolpert had presented his 1969 paper a year earlier at a Woods Hole conference, where it received a very hostile reception: "I wasnt asked back to America for many years!". But with Francis Crick lining up in support of diffusible morphogen gradients, positional information eventually became established as a guiding principle for research into biological pattern formation. It is now clear that pattern formation is much more complex than could possibly have been imagined in 1969. But Wolpert still believes in positional information, and regards intercalation during regeneration as its best supporting evidence. However, he and others doubt that diffusible morphogen gradients are a plausible mechanism: "Diffusible gradients are too messy", he says. Since his retirement, Lewis Wolpert has remained active as a theoretical biologist and continues to publish in leading journals. He has also campaigned for a greater public understanding of the stigma of depression. He was interviewed at home in London on July 26th, 2007 by Michael Richardson.

  11. Regression and new beginnings: Michael, Alice and Enid Balint and the circulation of ideas.

    Science.gov (United States)

    Sklar, Jonathan

    2012-08-01

    This article offers a new evaluation of Michael Balint's history. It starts with his growing up in Hungary and examines the central concepts of his writing: the analytic pair, regression and the basic fault and creativity, up to and including his renowned work on the eponymous Balint groups (which forged a unique link between psychoanalysis and medicine). While his name is, of course, well known, this article aims to bring his ideas to the attention of a modern analytic audience. Having trained in the 1920s with Ferenczi, Balint brought Ferenczi's literary inheritance to England where he lived until his death in 1970. His connections to Klein, Winnicott and Lacan, all of whom respected his analytic stance, are also examined. Furthermore, this article argues that his ideas were filtered through the theoretical lens of his first wife Alice Balint and later through Enid Balint, both of whom played a key - and rarely recognised - role in the development of his thought. It ends with a brief discussion of his ideas on analytic training and his quest, successful only after his death, to publish the complete Freud-Ferenczi correspondence, together with Ferenczi's diary. Copyright © 2012 Institute of Psychoanalysis.

  12. Losing Touch: A Theology of Death for Michael Haneke’s Amour

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    Taylor Worley

    2016-11-01

    Full Text Available This proposed theology of death for Michael Haneke’s Amour, a fraught but poignant piece of cinema, will employ Martin Heidegger’s existentialism to reframe the ethical structure of the film and apply a “lived theology” rejoinder to its perceived hopelessness. The proposal will address the question of ethics in relation to Haneke’s cinema, in particular his seemingly nihilistic perspective and confrontational style. To do so, it will revisit the film itself and examine the ways that Georges and Anne’s love is tested. Principally, we examine the film’s great question, which—in the filmmaker’s own words—is: “How do I cope with the suffering of a loved one?” With aid from the theologian Dietrich Bonhoeffer, this ‘lived theology’ proposal will attempt to give an account of love’s irrepressible strength in the midst of even astounding suffering. While Heidegger’s ethic of resoluteness calls for interiority and solitude, Bonhoeffer’s account of death more satisfactorily invokes a transcendent summons contained within our own pledges to loved ones. Such a theological reading of Haneke’s Amour will draw two distinct conclusions: first, the film exposes the superficiality of any hoped-for solitude or escape from a loved one’s death, and secondly, it demonstrates that the mutuality of authentic love entails impossible sacrifices.

  13. La figura del libro in Die unendliche Geschichte di Michael Ende: da finestra a varco

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    Elena Di Cesare

    2015-01-01

    Full Text Available The book is an object which can be considered as a window in the novel Die unendliche Geschichte (1979 written by Michael Ende. It allows Bastian to look at the world of Phantasien and to communicate indirectly with the Childlike Empress. Furthermore, this object will show its function as an symbol of evolution, which will enable the passage of the protagonist into the world of Phantasien: first the book appears as a window, then it becomes a two-way-mirror that allows Bastian and Atreju to look at each other, and finally it turns into a gate which enables them to live many adventures together. Die unendliche Geschichte can be considered as a modern Bildungsroman in which the young protagonist gradually reaches his maturation. This progress must be seen in a psychological perspective: it is the growth of a child-mind through literature which makes reference to the German novel tradition but also (as children’s literature to the world of unconsciousness.

  14. Structural diversity through intramolecular cycloaddition and modulation of chemical reactivity in excited state. Synthesis and photoreactions of 3-oxa-tricyclo[5.2.2.0(1,5)]undecenones: novel stereoselective route to oxa-triquinanes and oxa-sterpuranes.

    Science.gov (United States)

    Singh, V; Alam, S Q

    2000-11-20

    Synthesis of 11-methyl-3-oxa-tricyclo[5.2.2.0(1,5)]undecenones by intramolecular Diels-Alder reaction of highly labile spiroepoxycyclohexa-2,4-dienones and its photochemical reactions upon triplet (3T) and singlet (1S) excitation leading to a stereoselective route to oxa-triquinane and oxa-sterpurane, respectively, is described.

  15. Enantiomerization and stereoselectivity in bioaccumulation of furalaxyl in Tenebrio molitor larvae.

    Science.gov (United States)

    Yin, Jing; Gao, Yongxin; Zhu, Feilong; Hao, Weiyu; Xu, Qi; Wang, Huili; Guo, Baoyuan

    2017-11-01

    Furalaxyl is a chiral pesticide and widely used in modern agriculture as racemate mixture. The enantiomerization and enantioselecive bioaccumulation by a single dose of furalaxyl to Tenebrio molitor larvae under laboratory conditions were studied using a high-performance liquid chromatography tandem mass spectroscopy method based on a ChiralPAK IC column. Our results showed that a significant enantiomerization (interconversion between R-enantiomer and S-enantiomer) was observed in Tenebrio molitor larvae under R- or S-furalaxyl exposure. Though the two furalaxyl enantiomers exhibited low-capacity of bioaccumulation in Tenebrio molitor larvae, bioaccumulation of rac-furalaxyl was enantioselective with a preferential accumulation of S-furalaxyl at 10mg/kg dosage exposure. In addition, enantiomerization and enantioselective degradation of the two enantiomers was not observed in wheat bran. These results showed that enantioselectivtiy of furalaxyl enantiomers was an important process combined with degradation, metabolism and enatiomerization in organisms. Copyright © 2017 Elsevier Inc. All rights reserved.

  16. 1,1-Dimetallic reagents for the elaboration of stereoselectively di- or trisubstituted linear substrates.

    Science.gov (United States)

    Normant, J F

    2001-08-01

    Although gem-dimetallic species have been known for a long time, and reacted once or twice with electrophiles, the allyl zincation of substituted vinyl metals has emerged as a particularly efficient access to such species. This is due to a high face selectivity, in the addition to the C=C bond, which can be governed by vicinal or more remote heteroatoms. This strategy has some aspects in common with the well-known allylations or aldol condensations to carbonyl derivatives. But in the present case, the C=C bond has a low polarity. We present here some examples which lead to di- or polysubstituted linear substrates, of given geometry, where the organodimetallic obtained has been doubly protonated by water. Further elaborations (to alkenes, ketones, etc.) are possible.

  17. Transition-metal-free synthesis of N-(1-alkenyl)imidazoles by potassium phosphate-promoted addition reaction of alkynes to imidazoles.

    Science.gov (United States)

    Lu, Linhua; Yan, Hong; Liu, Defu; Rong, Guangwei; Mao, Jincheng

    2014-01-01

    The addition reaction of alkynes to N-heterocycles by simply heating in DMSO with potassium phosphate is reported. Good yields with high stereoselectivity could be achieved for a range of substrates. The scope is quite general for both amines and phenylacetylenes. In addition, internal alkynes and α-bromostyrene were also examined in this reaction. This process is efficient and useful for the synthesis of (Z)-N-(1-alkenyl)imidazoles and related Z products. Thus, the reaction is useful because of the importance of the imidazole scaffold. Copyright © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. STRUCTURAL INSIGHTS INTO SUBSTRATE BINDING AND STEREOSELECTIVITY OF GIARDIA FRUCTOSE-1,6-BISPHOSPHATE ALDOLASE*

    Science.gov (United States)

    Galkin, Andrey; Li, Zhimin; Li, Ling; Kulakova, Liudmila; Pal, Lipika R.; Dunaway-Mariano, Debra; Herzberg, Osnat

    2009-01-01

    Giardia lamblia fructose-1,6-bisphosphate aldolase (FBPA)1 is a member of the Class II zinc-dependent aldolase family that catalyzes the cleavage of D-fructose-1,6-bisphosphate (FBP) into dihydroxyacetone phosphate (DHAP) and D-glyceraldehyde-3-phosphate (G3P). In addition to the active site zinc, the catalytic apparatus of FBPA employs an aspartic acid, Asp83 in the G. lamblia enzyme, which when replaced by an alanine residue renders the enzyme inactive. A comparison of the crystal structures of the D83A FBPA in complex with FBP and of the wild-type FBPA in the unbound state revealed a substrate induced conformational transition of loops in the vicinity of the active site and a shift in the location of Zn2+. Upon FBP binding, the Zn2+ shifts up to 4.6 Å towards the catalytic Asp83, which brings the metal within coordination distance to the Asp83 carboxylate group. In addition, the structure of wild-type FBPA was determined in complex with the competitive inhibitor D-tagatose 1,6-bisphosphate (TBP), a FBP stereoisomer. In this structure, the zinc binds in a site close to that previously seen in the structure of FBPA in complex with phosphoglycolohydroxamate, an analog of the postulated DHAP ene-diolate intermediate. Together, the ensemble of structures suggests that the zinc mobility is necessary to orient the Asp83 side chain and to polarize the substrate for proton transfer from the FBP C(4) hydroxyl group to the Asp83 carboxyl group. In the absence of FBP, the alternative zinc position is too remote for coordinating the Asp83. We propose a modification of the catalytic mechanism that incorporates the novel features observed in the FBPA/FBP structure. The mechanism invokes coordination and co-planarity of the Zn2+ with the FBP’s O-C(3)-C(4)-O concomitant with coordination of Asp83 carboxylic group. Catalysis is accompanied by movement of Zn2+ to a site co-planar with the O-C(2)-C(3)-O of the DHAP. glFBPA exhibit strict substrate specificity towards FBP and

  19. “This fabulous flotsam”: Michael Moorcock’s Urban Anthropology in “London under London”

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    Houswitschka Christoph

    2015-07-01

    Full Text Available Michael Moorcock is often described as “one of the most prolific and varied writers working in Britain” (Malcolm 146. His success as a writer and editor of science fiction and fantasy literature is well established, but he is also the author of two novels about London, Mother London (1988 and King of the City (2000. Hardly known, Mother London by Michael Moorcock, offers itself to a variety of approaches that have been widely discussed in the context of studies on English literature during the Thatcher years, post-modernism, and psycho-geography. The novel resonates with the author’s own childhood in war-time London without being autobiographical. It tells the story of three Londoners who were traumatised during the Blitz. The following article focuses on the mysteries of subterranean London that represents the hidden and unconscious identities of its inhabitants in the post-war period.

  20. O que é a Multidão? Questões para Michael Hardt e Antonio Negri

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    Nicholas Brown

    2006-07-01

    Full Text Available Multidão, livro mais recente de Michael Hardt e Antonio Negri, é uma tentativa de nomear e compreender as condições que envolvem a dinâmica social do século xxi. Na entrevista a seguir, Hardt e Negri discorrem sobre as possibilidades de constituição da multidão como agente político, discutem os fundamentos do livro e defendem conceitos que consideram determinantes para a compreensão dos novos tempos, tais como biopolítica e biopoder.Multitude, Michael Hardt and Antonio Negri’s latest book, is an attempt at understanding conditions involving social dynamics in the xxi century. In the interview below, Hardt and Negri consider the constitution of the multitude as a political agent, discuss the structure of their book and support concepts seen as crucial for the comprehension of our time, such as biopolitics and biopower.

  1. The works of Joseph and Michael Haydn in Ondřej Horník's collection

    Czech Academy of Sciences Publication Activity Database

    Freemanová, Michaela

    2017-01-01

    Roč. 9, 1-2 (2017), s. 14-23 ISSN 1803-7828 Institutional support: RVO:68378076 Keywords : music manuscripts * Joseph Haydn * Michael Haydn * Ondřej Horník's collection * church music Subject RIV: AL - Art, Architecture, Cultural Heritage OBOR OECD: Performing arts studies ( Music ology, Theater science, Dramaturgy) http://www.nm.cz/publikace/archiv.php?id=16

  2. Leadership and creativity in public services: An interview with Lord Michael Bichard, Chair of the National Audit Office

    OpenAIRE

    Bolden, R.; O'Regan, N.

    2018-01-01

    This interview with Lord Michael Bichard, one of the most distinguished public sector leaders in the UK, explores his ideas around the relationship between leadership, creativity and innovation. A champion of place-based approaches to public services, where citizens are actively involved in service design, delivery and appraisal, Bichard advocates the need for inclusive and supportive leadership that enables the emergence of the kinds of creativity required to respond to the financial challen...

  3. Catalytic Enantioselective Synthesis of 3,4-Unsubstituted Thiochromenes through Sulfa-Michael/Julia-Kocienski Olefination Cascade Reaction.

    Science.gov (United States)

    Simlandy, Amit Kumar; Mukherjee, Santanu

    2017-05-05

    A highly enantioselective cascade sulfa-Michael/Julia-Kocienski olefination reaction between 2-mercaptobenzaldehydes and β-substituted vinyl PT-sulfones has been realized for the synthesis of 3,4-unsubstituted 2H-thiochromenes. This reaction, catalyzed by diphenylprolinol TMS ether, proceeds through an aromatic iminium intermediate and furnishes a wide range of 2-substiuted 2H-thiochromenes with excellent enantioselectivities (up to 99:1 er).

  4. Electrochemical Water Oxidation and Stereoselective Oxygen Atom Transfer Mediated by a Copper Complex.

    Science.gov (United States)

    Kafentzi, Maria-Chrysanthi; Papadakis, Raffaello; Gennarini, Federica; Kochem, Amélie; Iranzo, Olga; Le Mest, Yves; Le Poul, Nicolas; Tron, Thierry; Faure, Bruno; Simaan, A Jalila; Réglier, Marius

    2018-04-06

    Water oxidation by copper-based complexes to form dioxygen has attracted attention in recent years, with the aim of developing efficient and cheap catalysts for chemical energy storage. In addition, high-valent metal-oxo species produced by the oxidation of metal complexes in the presence of water can be used to achieve substrate oxygenation with the use of H 2 O as an oxygen source. To date, this strategy has not been reported for copper complexes. Herein, a copper(II) complex, [(RPY2)Cu(OTf) 2 ] (RPY2=N-substituted bis[2-pyridyl(ethylamine)] ligands; R=indane; OTf=triflate), is used. This complex, which contains an oxidizable substrate moiety (indane), is used as a tool to monitor an intramolecular oxygen atom transfer reaction. Electrochemical properties were investigated and, upon electrolysis at 1.30 V versus a normal hydrogen electrode (NHE), both dioxygen production and oxygenation of the indane moiety were observed. The ligand was oxidized in a highly diastereoselective manner, which indicated that the observed reactivity was mediated by metal-centered reactive species. The pH dependence of the reactivity was monitored and correlated with speciation deduced from different techniques, ranging from potentiometric titrations to spectroscopic studies and DFT calculations. Water oxidation for dioxygen production occurs at neutral pH and is probably mediated by the oxidation of a mononuclear copper(II) precursor. It is achieved with a rather low overpotential (280 mV at pH 7), although with limited efficiency. On the other hand, oxygenation is maximum at pH 8-8.5 and is probably mediated by the electrochemical oxidation of an antiferromagnetically coupled dinuclear bis(μ-hydroxo) copper(II) precursor. This constitutes the first example of copper-centered oxidative water activation for a selective oxygenation reaction. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. Solid State Ionics: from Michael Faraday to green energy-the European dimension.

    Science.gov (United States)

    Funke, Klaus

    2013-08-01

    Solid State Ionics has its roots essentially in Europe. First foundations were laid by Michael Faraday who discovered the solid electrolytes Ag 2 S and PbF 2 and coined terms such as cation and anion , electrode and electrolyte . In the 19th and early 20th centuries, the main lines of development toward Solid State Ionics, pursued in Europe, concerned the linear laws of transport, structural analysis, disorder and entropy and the electrochemical storage and conversion of energy. Fundamental contributions were then made by Walther Nernst, who derived the Nernst equation and detected ionic conduction in heterovalently doped zirconia, which he utilized in his Nernst lamp. Another big step forward was the discovery of the extraordinary properties of alpha silver iodide in 1914. In the late 1920s and early 1930s, the concept of point defects was established by Yakov Il'ich Frenkel, Walter Schottky and Carl Wagner, including the development of point-defect thermodynamics by Schottky and Wagner. In terms of point defects, ionic (and electronic) transport in ionic crystals became easy to visualize. In an 'evolving scheme of materials science', point disorder precedes structural disorder, as displayed by the AgI-type solid electrolytes (and other ionic crystals), by ion-conducting glasses, polymer electrolytes and nano-composites. During the last few decades, much progress has been made in finding and investigating novel solid electrolytes and in using them for the preservation of our environment, in particular in advanced solid state battery systems, fuel cells and sensors. Since 1972, international conferences have been held in the field of Solid State Ionics, and the International Society for Solid State Ionics was founded at one of them, held at Garmisch-Partenkirchen, Germany, in 1987.

  6. Solid State Ionics: from Michael Faraday to green energy—the European dimension

    Science.gov (United States)

    Funke, Klaus

    2013-01-01

    Solid State Ionics has its roots essentially in Europe. First foundations were laid by Michael Faraday who discovered the solid electrolytes Ag2S and PbF2 and coined terms such as cation and anion, electrode and electrolyte. In the 19th and early 20th centuries, the main lines of development toward Solid State Ionics, pursued in Europe, concerned the linear laws of transport, structural analysis, disorder and entropy and the electrochemical storage and conversion of energy. Fundamental contributions were then made by Walther Nernst, who derived the Nernst equation and detected ionic conduction in heterovalently doped zirconia, which he utilized in his Nernst lamp. Another big step forward was the discovery of the extraordinary properties of alpha silver iodide in 1914. In the late 1920s and early 1930s, the concept of point defects was established by Yakov Il'ich Frenkel, Walter Schottky and Carl Wagner, including the development of point-defect thermodynamics by Schottky and Wagner. In terms of point defects, ionic (and electronic) transport in ionic crystals became easy to visualize. In an ‘evolving scheme of materials science’, point disorder precedes structural disorder, as displayed by the AgI-type solid electrolytes (and other ionic crystals), by ion-conducting glasses, polymer electrolytes and nano-composites. During the last few decades, much progress has been made in finding and investigating novel solid electrolytes and in using them for the preservation of our environment, in particular in advanced solid state battery systems, fuel cells and sensors. Since 1972, international conferences have been held in the field of Solid State Ionics, and the International Society for Solid State Ionics was founded at one of them, held at Garmisch-Partenkirchen, Germany, in 1987. PMID:27877585

  7. Corrupting Capitalism: Michael Ende’s Momo and “Cathedral Station”

    Directory of Open Access Journals (Sweden)

    Heike Polster

    2016-01-01

    Full Text Available Michael Ende, the well-known author of The Neverending Story , foresaw dramatic changes in the fabric of society resulting from a turn toward neoliberal policies. One such far-reaching and dangerous change has to do with a diminishing of temporal autonomy, the ability to freely determine the use and meaning of our time. This article explores how neoliberalism is shaping our concept of time and our experience of it. In an effort to demonstrate the process and the line of reasoning behind the monetization of time, and to connect time to more qualitative considerations of the human condition, I shall demonstrate how Ende conceptualizes time as an integral part of the accumulation process of capitalism. I also discuss a fairly cryptic short story, “Cathedral Station,” that envisions “the mystery of money.” Utilizing Walter Benjamin’s critique issued in his 1921 fragment “Capitalism as Religion,” I outline Ende’s dystopian vision of the uncontested, unquestioned reign of capitalism as a religious cult. Read together, the novel and the short story offer a way of contrasting two extreme byproducts of capitalism’s colonization of time, namely what I would call an “ideology of work” and an “ideology of growth.” The first of these is a result of capitalism’s commodification of time according to liberal ideals such as choice, freedom, and self-interest. The second is a decidedly neoliberal phenomenon in that the “financialization of everything,” to use David Harvey’s phrase, results in the ever-present expectation of unlimited, exponential growth. By drawing out these two interconnected ideologies through close readings, the subtle processes of capitalism’s colonization of time are revealed.

  8. Solid State Ionics: from Michael Faraday to green energy—the European dimension

    Directory of Open Access Journals (Sweden)

    Klaus Funke

    2013-01-01

    Full Text Available Solid State Ionics has its roots essentially in Europe. First foundations were laid by Michael Faraday who discovered the solid electrolytes Ag2S and PbF2 and coined terms such as cation and anion, electrode and electrolyte. In the 19th and early 20th centuries, the main lines of development toward Solid State Ionics, pursued in Europe, concerned the linear laws of transport, structural analysis, disorder and entropy and the electrochemical storage and conversion of energy. Fundamental contributions were then made by Walther Nernst, who derived the Nernst equation and detected ionic conduction in heterovalently doped zirconia, which he utilized in his Nernst lamp. Another big step forward was the discovery of the extraordinary properties of alpha silver iodide in 1914. In the late 1920s and early 1930s, the concept of point defects was established by Yakov Il'ich Frenkel, Walter Schottky and Carl Wagner, including the development of point-defect thermodynamics by Schottky and Wagner. In terms of point defects, ionic (and electronic transport in ionic crystals became easy to visualize. In an 'evolving scheme of materials science', point disorder precedes structural disorder, as displayed by the AgI-type solid electrolytes (and other ionic crystals, by ion-conducting glasses, polymer electrolytes and nano-composites. During the last few decades, much progress has been made in finding and investigating novel solid electrolytes and in using them for the preservation of our environment, in particular in advanced solid state battery systems, fuel cells and sensors. Since 1972, international conferences have been held in the field of Solid State Ionics, and the International Society for Solid State Ionics was founded at one of them, held at Garmisch-Partenkirchen, Germany, in 1987.

  9. Suspense, culpa y cintas de vídeo. Caché/Escondido de Michael Haneke

    Directory of Open Access Journals (Sweden)

    Miguel Martínez-Cabeza

    2011-12-01

    Full Text Available Caché/Escondido (2005 representa dentro de la filmografía de Michael Haneke el ejemplo más destacado de síntesis de los planteamientos formales e ideológicos del cineasta austriaco. Este artículo analiza el filme como manifiesto cinematográfico y como explotación de las convenciones genéricas para construir un modelo de espectador reflexivo. La investigación del modo en que el director plantea y abandona las técnicas del suspense aporta claves para explicar el éxito casi unánime de crítica y la respuesta mucho menos homogénea de las audiencias. El desencadenante de la trama, unas cintas de vídeo que reciben los Laurent, es alusión directa a Carretera Perdida (1997 de David Lynch; no obstante, el misterio acerca del autor de la videovigilancia pierde interés en relación al sentimiento de culpa que desencadena en el protagonista. El episodio infantil de celos y venganza hacia un niño argelino y la actitud del Georges adulto representan una alegoría de la relación de Francia con su pasado colonial que tampoco cierra la narración de Haneke. Es precisamente la apertura formal con que el filme (desestructura cuestiones actuales como el límite entre la responsabilidad individual y colectiva lo que conforma un espectador tan distanciado de la diégesis como consciente de su propio papel de observador.

  10. Enantioselective organocatalyzed Oxa-Michael-Aldol cascade reactions: Construction of chiral 4H-chromenes with a trifluoromethylated tetrasubstituted carbon stereocenter

    KAUST Repository

    Zhang, Jing; Ajitha, Manjaly John; He, Lin; Liu, Kai; Dai, Bin; Huang, Kuo-Wei

    2015-01-01

    The first organocatalytic asymmetric synthesis of 4H-chromenes bearing a trifluoromethylated tetrasubstituted carbon center is presented. Chiral secondary amines promote the oxa-Michael-aldol cascade reaction between alkynals and 2

  11. Why There Are Certain Parallels Between Joachim C. Fest’s Hitler-Biography and Michael Wolff’s Trump-Book

    Directory of Open Access Journals (Sweden)

    Christian Fuchs

    2018-02-01

    Full Text Available Joachim C. Fest published one of the most widely read Hitler biographies in 1973. Are there parallels of its analytical approach to Michael Wolff’s “Fire and Fury: Inside the Trump White House”?

  12. Highly Regio- and Stereoselective Diels-Alder Cycloadditions via Two-Step and Multicomponent Reactions Promoted by Infrared Irradiation under Solvent-Free Conditions

    Science.gov (United States)

    Flores-Conde, Maria Ines; Reyes, Leonor; Herrera, Rafael; Rios, Hulme; Vazquez, Miguel A.; Miranda, Rene; Tamariz, Joaquin; Delgado, Francisco

    2012-01-01

    Infrared irradiation promoted the Diels-Alder cycloadditions of exo-2-oxazolidinone dienes 1–3 with the Knoevenagel adducts 4–6, as dienophiles, leading to the synthesis of new 3,5-diphenyltetrahydrobenzo[d]oxazol-2-one derivatives (7, 9, 11 and 13–17), under solvent-free conditions. These cycloadditions were performed with good regio- and stereoselectivity, favoring the para-endo cycloadducts. We also evaluated the one-pot three-component reaction of active methylene compounds 20, benzaldehydes 21 and exo-2-oxazolidinone diene 2 under the same reaction conditions. A cascade Knoevenagel condensation/Diels-Alder cycloaddition reaction was observed, resulting in the final adducts 13–16 in similar yields. These procedures are environmentally benign, because no solvent and no catalyst were employed in these processes. The regioselectivity of these reactions was rationalized by Frontier Molecular Orbital (FMO) calculations. PMID:22489113

  13. Highly Regio- and Stereoselective Diels-Alder Cycloadditions via Two-Step and Multicomponent Reactions Promoted by Infrared Irradiation under Solvent-Free Conditions

    Directory of Open Access Journals (Sweden)

    Francisco Delgado

    2012-02-01

    Full Text Available Infrared irradiation promoted the Diels-Alder cycloadditions of exo-2-oxazolidinone dienes 1–3 with the Knoevenagel adducts 4–6, as dienophiles, leading to the synthesis of new 3,5-diphenyltetrahydrobenzo[d]oxazol-2-one derivatives (7, 9, 11 and 13–17, under solvent-free conditions. These cycloadditions were performed with good regio- and stereoselectivity, favoring the para-endo cycloadducts. We also evaluated the one-pot three-component reaction of active methylene compounds 20, benzaldehydes 21 and exo-2-oxazolidinone diene 2 under the same reaction conditions. A cascade Knoevenagel condensation/Diels-Alder cycloaddition reaction was observed, resulting in the final adducts 13–16 in similar yields. These procedures are environmentally benign, because no solvent and no catalyst were employed in these processes. The regioselectivity of these reactions was rationalized by Frontier Molecular Orbital (FMO calculations.

  14. Visible-Light Photocatalytic Decarboxylation of α,β-Unsaturated Carboxylic Acids: Facile Access to Stereoselective Difluoromethylated Styrenes in Batch and Flow

    Science.gov (United States)

    2017-01-01

    The development of synthetic methodologies which provide access to both stereoisomers of α,β-disubstituted olefins is a challenging undertaking. Herein, we describe the development of an operationally simple and stereoselective synthesis of difluoromethylated styrenes via a visible-light photocatalytic decarboxylation strategy using fac-Ir(ppy)3 as the photocatalyst. Meta- and para-substituted cinnamic acids provide the expected E-isomer. In contrast, ortho-substituted cinnamic acids yield selectively the less stable Z-product, whereas the E-isomer can be obtained via continuous-flow processing through accurate control of the reaction time. Furthermore, our protocol is amenable to the decarboxylative difluoromethylation of aryl propiolic acids. PMID:29109904

  15. Total synthesis of bryostatins: the development of methodology for the atom-economic and stereoselective synthesis of the ring C subunit.

    Science.gov (United States)

    Trost, Barry M; Frontier, Alison J; Thiel, Oliver R; Yang, Hanbiao; Dong, Guangbin

    2011-08-22

    Bryostatins, a family of structurally complicated macrolides, exhibit an exceptional range of biological activities. The limited availability and structural complexity of these molecules makes development of an efficient total synthesis particularly important. This article describes our initial efforts towards the total synthesis of bryostatins, in which chemoselective and atom-economical methods for the stereoselective assembly of the ring C subunit were developed. A Pd-catalyzed tandem alkyne-alkyne coupling/6-endo-dig cyclization sequence was explored and successfully pursued in the synthesis of a dihydropyran ring system. Elaboration of this methodology ultimately led to a concise synthesis of the ring C subunit of bryostatins. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. N,2,3,4-Tetrasubstituted Pyrrolidines through Tandem Lithium Amide Conjugate Addition/Radical Cyclization/Oxygenation Reactions

    Czech Academy of Sciences Publication Activity Database

    Kafka, František; Pohl, Radek; Císařová, I.; Mackman, R.; Bahador, G.; Jahn, Ullrich

    2016-01-01

    Roč. 2016, č. 22 (2016), s. 3862-3871 ISSN 1434-193X R&D Projects: GA ČR GA13-40188S Grant - others:COST(XE) CM1201 Institutional support: RVO:61388963 Keywords : tandem reactions * nitrogen heterocycles * Michael addition * radical reactions * cyclization * enolates Subject RIV: CC - Organic Chemistry Impact factor: 2.834, year: 2016

  17. New stereoselective intramolecular

    Science.gov (United States)

    Alajarin; Vidal; Tovar; Ramirez De Arellano MC; Cossio; Arrieta; Lecea

    2000-11-03

    Efficient 1,4-asymmetric induction has been achieved in the highly stereocontrolled intramolecular [2 + 2] cycloadditions between ketenimines and imines, leading to 1,2-dihydroazeto[2, 1-b]quinazolines. The chiral methine carbon adjacent to the iminic nitrogen controls the exclusive formation of the cycloadducts with relative trans configuration at C2 and C8. The stepwise mechanistic model, based on theoretical calculations, fully supports the stereochemical outcome of these cycloadditions.

  18. Late Quaternary vegetation and climate history of the central Bering land bridge from St. Michael Island, western Alaska

    Science.gov (United States)

    Ager, T.A.

    2003-01-01

    Pollen analysis of a sediment core from Zagoskin Lake on St. Michael Island, northeast Bering Sea, provides a history of vegetation and climate for the central Bering land bridge and adjacent western Alaska for the past ???30,000 14C yr B.P. During the late middle Wisconsin interstadial (???30,000-26,000 14C yr B.P.) vegetation was dominated by graminoid-herb tundra with willows (Salix) and minor dwarf birch (Betula nana) and Ericales. During the late Wisconsin glacial interval (26,000-15,000 14C yr B.P.) vegetation was graminoid-herb tundra with willows, but with fewer dwarf birch and Ericales, and more herb types associated with dry habitats and disturbed soils. Grasses (Poaceae) dominated during the peak of this glacial interval. Graminoid-herb tundra suggests that central Beringia had a cold, arid climate from ???30,000 to 15,000 14C yr B.P. Between 15,000 and 13,000 14C yr B.P., birch shrub-Ericales-sedge-moss tundra began to spread rapidly across the land bridge and Alaska. This major vegetation change suggests moister, warmer summer climates and deeper winter snows. A brief invasion of Populus (poplar, aspen) occurred ca. 11,000-9500 14C yr B.P., overlapping with the Younger Dryas interval of dry, cooler(?) climate. During the latest Wisconsin to middle Holocene the Bering land bridge was flooded by rising seas. Alder shrubs (Alnus crispa) colonized the St. Michael Island area ca. 8000 14C yr B.P. Boreal forests dominated by spruce (Picea) spread from interior Alaska into the eastern Norton Sound area in middle Holocene time, but have not spread as far west as St. Michael Island. ?? 2003 University of Washington. Published by Elsevier Inc. All rights reserved.

  19. In situ forming poly(ethylene glycol)- Poly(L -lactide) hydrogels via michael addition: Mechanical properties, degradation, and protein release

    NARCIS (Netherlands)

    Buwalda, S.J.; Dijkstra, Pieter J.; Feijen, Jan

    2012-01-01

    Chemically crosslinked hydrogels are prepared at remarkably low macromonomer concentrations from 8-arm poly(ethylene glycol)-poly(L-lactide) star block copolymers bearing acrylate end groups (PEG-(PLLAn)8-AC, n = 4 or 12) and multifunctional PEG thiols (PEG-(SH)n, n = 2, 4, or 8) through a

  20. Tandem Aldol-Michael Reactions in Aqueous Diethylamine Medium: A Greener and Efficient Approach to Bis-Pyrimidine Derivatives

    Directory of Open Access Journals (Sweden)

    Abdullah M. Al-Majid

    2013-12-01

    Full Text Available A simple protocol, involving the green synthesis for the construction of novel bis-pyrimidine derivatives, 3a–i and 4a–e are accomplished by the aqueous diethylamine media promoted tandem Aldol-Michael reaction between two molecules of barbituric acid derivatives 1a,b with various aldehydes. This efficient synthetic protocol using an economic and environmentally friendly reaction media with versatility and shorter reaction time provides bis-pyrimidine derivatives with high yields (88%–99%.

  1. Kochin, Michael S. 2009. Five Chapters on Rhetoric: Character, Action, Things, Nothing and Art (University Park: Pennsylvania State University Press

    Directory of Open Access Journals (Sweden)

    Eithan Orkibi

    2010-04-01

    Full Text Available Deux constatations traversent le nouvel ouvrage de Michael Kochin, et nous invitent à reconsidérer la rhétorique dans la communication persuasive. D’abord, que ce sont les événements concrets et les faits mis à l’épreuve qui ont la plus grande force de conviction ; et ensuite, que le discours a souvent une fonction autre que la persuasion : celle de maintenir les canaux de communication pour sauvegarder les relations et les institutions humaines. Pour l’auteur de cet ouvrage qui porte sur les...

  2. A propósito del libro "Accounting theory: research, regulation and accounting practice" de Michael Gaffikin

    Directory of Open Access Journals (Sweden)

    Garcia Nohora

    2012-09-01

    Full Text Available En el libro “Accounting theory: research, regulation and accounting practice”, el profesor australiano Michael Gaffikin ofrece al lector una idea del origen y amplio desenvolvimiento de la teoría contable durante el siglo XX “cuyo desarrollo ha sido dominado por Estados Unidos” (Gaffikin, 2008, p. 32. Plantea, igualmente, los desafíos y problemas actuales de la regulación y la profesión contable. Por ejemplo, el autor precisa que ante la incapacidad de lograr un acuerdo sobre las mediciones apropiadas, la tendencia mundial es a instaurar medidas determinadas arbitrariamente (Gaffikin, 2008, p. 154.

  3. New 'Master of Science in Nuclear Engineering' study course launched. Interview with Professor Horst-Michael Prasser

    International Nuclear Information System (INIS)

    Anon.

    2008-01-01

    In the fall of 2008, the Zurich Technical University (ETH) and the Lausanne EPF will launch their joint master course of studies in Nuclear Engineering. Horst-Michael Prasser, Professor for Nuclear Energy Systems at Zurich ETH, is responsible for designing the course. In this interview he comments, among other things, on fundamental questions which may determine a future student's choice of a course of studies, and on the special opportunities offered by the new Nuclear Engineering course. Other subjects addressed include the renaissance of nuclear power and the future prospects of safety research and new reactor developments. (orig.)

  4. ‘Doxographical or Philosophical History of Philosophy: On Michael Frede’s Precepts for Writing the History of Philosophy’

    DEFF Research Database (Denmark)

    Catana, Leo

    2016-01-01

    In a series of articles from the 1980s and 1990s, Michael Frede analysed the history of histories of philosophy written over the last three hundred years. According to Frede, modern scholars have degenerated into what he calls a “doxographical” mode of writing the history of philosophy. Instead, he...... argued, these scholars should write what he called “philosophical” history of philosophy, first established in the last decades of the seventeenth century but since abandoned. In the present article it is argued that Frede’s reconstruction of the history of histories of philosophy is historically...

  5. Constructing Singapore : Elitism, Ethnicity and the Nation-Building Project, Michael D. Barr & Zlatko Skrbis

    Directory of Open Access Journals (Sweden)

    Jean-Louis Margolin

    2010-12-01

    Full Text Available Michael Barr, seul ou en collaboration, est depuis une décennie l’un des auteurs les plus prolifiques et les plus reconnus sur la structuration politique et sociologique du Singapour contemporain. Longtemps attaché à l’université du Queensland (Brisbane, aujourd’hui à Flinders (Adelaide, il est assez représentatif de la nouvelle génération (singapourienne aussi bien qu’étrangère des spécialistes de la cité-état : fermement critique, et parfois même hyper-critique, elle n’en reconnaît pas m...

  6. Advances in Statistical Control, Algebraic Systems Theory, and Dynamic Systems Characteristics A Tribute to Michael K Sain

    CERN Document Server

    Won, Chang-Hee; Michel, Anthony N

    2008-01-01

    This volume - dedicated to Michael K. Sain on the occasion of his seventieth birthday - is a collection of chapters covering recent advances in stochastic optimal control theory and algebraic systems theory. Written by experts in their respective fields, the chapters are thematically organized into four parts: Part I focuses on statistical control theory, where the cost function is viewed as a random variable and performance is shaped through cost cumulants. In this respect, statistical control generalizes linear-quadratic-Gaussian and H-infinity control. Part II addresses algebraic systems th

  7. Tandem Rh-Catalyzed Oxidative C-H Olefination and Cyclization of Enantiomerically Enriched Benzo-1,3-Sulfamidates: Stereoselective Synthesis of trans-1,3-Disubstituted Isoindolines.

    Science.gov (United States)

    Achary, Raghavendra; Jung, In-A; Lee, Hyeon-Kyu

    2018-04-06

    A tandem process, involving Rh(III)-catalyzed oxidative C-H olefination of enantiomerically enriched 4-aryl-benzo-1,3-sulfamidates and subsequent intramolecular aza-Michael cyclization has been developed. The reaction produces trans-benzosulfamidate-fused-1,3-disubstituted isoindolines as major products, in which the configurational integrity of the stereogenic center in the starting material is preserved. Further transformations of the benzosulfamidate-fused-1,3-disubstituted isoindolines are described.

  8. A Large Scale Formal Synthesis of CoQ10: 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

    International Nuclear Information System (INIS)

    Lee, Sang Who; Lee, Hee Bong; Kim, Bong Chan; Sadaiah, Kadivendi; Lee, Kyuwoong; Shin, Hyunik

    2013-01-01

    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

  9. 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.

  10. The chemical foundations of nitroalkene fatty acid signaling through addition reactions with thiols.

    Science.gov (United States)

    Turell, Lucía; Steglich, Martina; Alvarez, Beatriz

    2018-03-22

    Nitroalkene fatty acids can be formed in vivo and administered exogenously. They exert pleiotropic signaling actions with cytoprotective and antiinflammatory effects. The presence of the potent electron withdrawing nitro group confers electrophilicity to the adjacent β-carbon. Thiols (precisely, thiolates) are strong nucleophiles and can react with nitroalkene fatty acids through reversible Michael addition reactions. In addition, nitroalkene fatty acids can undergo several other processes including metabolic oxidation, reduction, esterification, nitric oxide release and partition into hydrophobic compartments. The signaling actions of nitroalkenes are mainly mediated by reactions with critical thiols in regulatory proteins. Thus, the thio-Michael addition reaction provides a framework for understanding the molecular basis of the biological effects of nitroalkene fatty acids at the crossroads of thiol signaling and electrophilic lipid signaling. In this review, we describe the reactions of nitroalkene fatty acids in biological contexts. We focus on the Michael addition-elimination reaction with thiols and its mechanism, and extrapolate kinetic and thermodynamic considerations to in vivo settings. Copyright © 2018 Elsevier Inc. All rights reserved.

  11. Trajetória acadêmica e perspectivas acerca do turismo sob o olhar de Colin Michael Hall

    Directory of Open Access Journals (Sweden)

    Elayne Gouveia da Silva

    2016-04-01

    Full Text Available Este trabalho versa sobre a visão do Colin Michael Hall na temática do turismo. Para analisar essa temática imbricou-se em duas leituras principais como parâmetro para a discussão. A primeira é a obra “Planejamento turístico: política, processo e planejamento” e, a segunda, “Turismo como El Ciencia Social de La Movilidade”. Estas obras marcam a mudança de visão do autor, onde o mesmo se dedica a fomentar um novo olhar sobre o turismo suscitando sete aspectos para se pensar no turismo. O objetivo deste artigo é analisar a visão de Colin Michael Hall acerca do Turismo. Como metas intermediárias pretende-se, a partir da compilação de informações sobre sua vida acadêmica e suas principais contribuições realizar uma breve crítica. Para o trabalho utilizou-se a pesquisa bibliográfica, e entrevista com o autor. Como resultado obteve-se uma reunião das principais ideias e posições ideológicas do autor, e algumas de suas contribuições com o estudo do turismo.

  12. Mechanical Behavior of Additive Manufactured Layered Materials, Part 2: Stainless Steels

    Science.gov (United States)

    2015-04-30

    materials. Elsevier, Oxford; 2007: 416 -420. [19] Deng, D., Chen, R., Sun, Q. and Li, X. Microstructural study of 17-4PH stainless steel after plasma...1 Mechanical Behavior of Additive Manufactured Layered Materials, Part 2: Stainless Steels * Todd M. Mower † and Michael J. Long M.I.T. Lincoln... stainless steel alloys produced with Direct Metal Laser Sintering (DMLS) was measured and is compared to that of similar conventional materials

  13. Invited Commentary: Continuing to Loosen the Constraints on Epidemiology in an Age of Change-A Comment on McMichael's "Prisoners of the Proximate".

    Science.gov (United States)

    Galea, Sandro

    2017-06-01

    Published in 1999, McMichael's "Prisoners of the Proximate: Loosening the Constraints on Epidemiology in an Age of Change" (Am J Epidemiol. 1999;149(10):887-897) outlined an exciting vision for epidemiology as the field that that can help us better understand the drivers of population health so that we may intervene, paving the way for healthier populations. McMichael's paper remains today what it was when it was first published: clear, thoughtful, provocative, and usefully prescriptive in its call to action. McMichael identified 4 constraints facing epidemiology. The field has risen to this challenge and addressed some of these constraints. I discuss how successful (or not) we have been in addressing each of these 4 challenges. © The Author 2017. Published by Oxford University Press on behalf of the Johns Hopkins Bloomberg School of Public Health. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  14. Base-catalyzed tandem Michael/dehydro-Diels-Alder reaction of α,α-dicyanoolefins with electron-deficient 1,3-conjugated enynes: a facile entry to angularly fused polycycles.

    Science.gov (United States)

    Zhang, Mingrui; Zhang, Junliang

    2014-01-07

    Angularly fused carbocyclic frameworks and their heteroatom-substituted analogues exist in many natural products that display a broad and interesting range of biological activities. Preparation of polycyclic products by cycloaddition reactions have been the long-standing hot topic in the synthetic community. Dehydro-Diels-Alder (DDA) reactions are one class of dehydropericyclic reactions that are derived conceptually by systematic removal of hydrogen atom pairs. A base-promoted tandem Michael addition and DDA reaction of α,α-dicyanoolefins with electron-deficient 1,3-conjugated enynes was realized in which a DDA reaction takes place between the arylalkynes and electron-deficient tetrasubstituted olefin. The control experiments support the stepwise anionic reaction pathway rather than the concerted reaction pathway. Copyright © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. Switchable Diastereoselectivity in the Fluoride Promoted Vinylogous Mukaiyama-Michael Reaction of 2-Trimethylsilyloxyfuran Catalyzed by Crown Ethers

    KAUST Repository

    Della Sala, Giorgio

    2017-05-31

    The fluoride promoted vinylogous Mukaiyama-Michael reaction (VMMR) of 2-trimethylsilyloxyfuran with diverse α,β-unsaturated ketones is described. The TBAF catalyzed VMMR afforded high anti-diastereoselectivity irrespective of the solvents used. The KF/crown ethers catalytic systems proved to be highly efficient in terms of yields and resulted in a highly diastereoselective unprecedented solvent/catalyst switchable reaction. Anti-adducts were obtained as single diastereomers or with excellent diastereoselectivities when benzo-15-crown-5 in CH2Cl2 was employed. On the other hand, high syn-diastereoselectivities (from 76:24 to 96:4) were achieved by employing dicyclohexane-18-crown-6 in toluene. Based on DFT calculations, the catalysts/solvents-dependent switchable diastereoselectivities are proposed to be the result of loose or tight cation-dienolate ion pairs.

  16. Analysis of the Competitive Potential of Bioethanol in Colombia: An approach from Michael Porter's 5 Competitive Forces

    International Nuclear Information System (INIS)

    Ramirez Velasquez, Alejandro; Montoya R, Ivan Alonso; Montoya Restrepo, Alexandra

    2012-01-01

    The search for alternative energy production and consumption require a look into the industry of biofuels such as bioethanol as an alternative energy to overcome the disadvantages generated by the traditional methods of production and consumption, especially in the political, environmental and social issues and generate competitive advantages compared to other primary energy sources. In the present document, and from the Michael Porter five (5) Forces model is detailed an evaluation of the bioethanol industry as an alternative fuel and is described how attractive or competitive may become the industry today. To achieve this purpose, an evaluation of the competitive forces was proposed to a group of experts, using a Likert scale. Thus, it was evaluated the potential usefulness of the proposal.

  17. WHEN DYLAN MET THE BARD: TRANSLATING HAMLET FROM TEXT TO SCREEN (SOUND: MICHAEL ALMEREYDA’S HAMLET

    Directory of Open Access Journals (Sweden)

    Marina Gerzic

    2015-12-01

    Full Text Available Director Michael Almereyda’s diverse musical choices in the film are a threshold into understanding his cinematic interpretation of Hamlet (2000. Almereyda recontextualises Hamlet in terms of contemporary social problems. Hamlet and Ophelia are confronted with and battle against urban claustrophobia, conspiracy and global corporate power. A fragment of the Bob Dylan song ‘All Along the Watchtower’ (1966 is used as a filmic shortcut to translate Shakespeare’s iconic ‘gravedigger scene’ between Hamlet and the Gravedigger from playtext to screen. ‘All Along the Watchtower’ encapsulates certain ideas about mortality and the worth of life from the ‘gravedigger scene’ and demonstrates these issues still resonate in the contemporary urban world the film is set.

  18. QCD propagators and vertices from lattice QCD (in memory of Michael Müller-Preußker

    Directory of Open Access Journals (Sweden)

    Sternbeck André

    2017-01-01

    Full Text Available We review lattice calculations of the elementary Greens functions of QCD with a special emphasis on the Landau gauge. These lattice results have been of interest to continuum approaches to QCD over the past 20 years. They are used as reference for Dyson-Schwinger- and functional renormalization group equation calculations as well as for hadronic bound state equations. The lattice provides low-energy data for propagators and three-point vertices in Landau gauge at zero and finite temperature even including dynamical fermions. We summarize Michael Müller-Preußker’s important contributions to this field and put them into the perspective of his other research interests.

  19. ‘Introducing Michael Gove to Loïc Wacquant’: Why Social Work Needs Critical Sociology

    Science.gov (United States)

    Michael Garrett, Paul

    2016-01-01

    In 2013, Michael Gove, then Secretary of State for Education and Health in the UK coalition government, criticised social workers for laying insufficient emphasis on the ‘agency’ of individuals and for being too preoccupied with social and economic inequalities. Such a perspective, which is not unique to Gove, needs to be countered by reaffirming the significance of an expansively critical sociology for social work. In this context, the thematic concerns of the French theorist, Loïc Wacquant, illuminates key aspects of social work engagement with clients which Gove and his ideological associates appear intent on ignoring. The issues raised have significant political resonances given the pending UK General Election taking place in May 2015. PMID:27559203

  20. Mother's love' for bacterial babies: the commitment of Audrey Michael, Mition Yoannes and Tilda Orami to medical research.

    Science.gov (United States)

    Gibbs, Tammy; Vilakiva, Geraldine

    2013-01-01

    Audrey Michael, Mition Yoannes and Tilda Orami are long-term health researchers at the Papua New Guinea Institute of Medical Research (PNGIMR). Face-to-face interviews were conducted with all three women for the purpose of profiling women who are leaders in health and medicine in Papua New Guinea. They were asked questions about their early life and childhood, education, work life and training, and mentors who have supported their career path and leadership role. Audrey, Mition and Tilda have all made significant contributions to the PNGIMR and to the health of the people of PNG. In particular, all three have been part of pneumococcal conjugate vaccine (PCV) studies--looking at the safety, immunogenicity and priming for immunological memory of a 7-valent PCV and investigating the safety and immune responses to two different, recently licensed types of PCV, a 13-valent and a 10-valent vaccine.

  1. Catalyst-Directed Diastereoselective Isomerization of Allylic Alcohols for the Stereoselective Construction of C(20) in Steroid Side Chains: Scope and Topological Diversification.

    Science.gov (United States)

    Li, Houhua; Mazet, Clément

    2015-08-26

    The stereoselective construction of C20 in steroidal derivatives by a highly diastereoselective Ir-catalyzed isomerization of primary allylic alcohols is reported. A key aspect of this strategy is a straightforward access to geometrically pure steroidal enol tosylate and enol triflate intermediates for subsequent high yielding stereoretentive Negishi cross-coupling reactions to allow structural diversity to be introduced. A range of allylic alcohols participates in the diastereoselective isomerization under the optimized reaction conditions. Electron-rich and electron-poor aryl or heteroaryl substituents are particularly well-tolerated, and the stereospecific nature of the reaction provides indifferently access to the natural C20-(R) and unnatural C20-(S) configurations. Alkyl containing substrates are more challenging as they affect regioselectivity of iridium-hydride insertion. A rationale for the high diastereoselectivities observed is proposed for aryl containing precursors. The scope of our method is further highlighted through topological diversification in the side chain and within the polycyclic domain of advanced and complex steroidal architectures. These findings have the potential to greatly simplify access to epimeric structural analogues of important steroid scaffolds for applications in biological, pharmaceutical, and medical sciences.

  2. Robust Crosslinked Stereocomplexes and C60 Inclusion Complexes of Vinyl-Functionalized Stereoregular Polymers Derived from Chemo/Stereoselective Coordination Polymerization

    KAUST Repository

    Vidal, Fernando

    2016-07-07

    The successful synthesis of highly syndiotactic polar vinyl polymers bearing the reactive pendant vinyl group on each repeat unit, which is enabled by perfectly chemoselective and highly syndiospecific coordination polymerization of divinyl polar monomers developed through this work, has allowed the construction of robust crosslinked supramolecular stereocomplexes and C60 inclusion complexes. The metal-mediated coordination polymerization of three representative polar divinyl monomers, including vinyl methacrylate (VMA), allyl methacrylate (AMA), and N,N-diallyl acrylamide (DAA) by Cs-ligated zirconocenium ester enolate catalysts under ambient conditions exhibits complete chemoselectivity and high stereoselectivity, thus producing the corresponding vinyl-functionalized polymers with high (92% rr) to quantitative (>99% rr) syndiotacticity. A combined experimental (synthetic, kinetic, and mechanistic) and theoretical (DFT) investigation has yielded a unimetallic, enantiomorphic-site controlled propagation mechanism. Post-functionalization of the obtained syndiotactic vinyl-functionalized polymers via the thiol-ene click and photocuring reactions readily produced the corresponding thiolated polymers and flexible crosslinked thin film materials, respectively. Complexation of such syndiotactic vinyl-functionalized polymers with isotactic poly(methyl methacrylate) and fullerene C60 generates supramolecular crystalline helical stereocomplexes and inclusion complexes, respectively. Crosslinking of such complexes afforded robust crosslinked stereocomplexes that are solvent resistant and also exhibit considerably enhanced thermal and mechanical properties as compared to the uncrosslinked stereocompexes.

  3. Epoxidation of the methamphetamine pyrolysis product, trans-phenylpropene, to trans-phenylpropylene oxide by CYP enzymes and stereoselective glutathione adduct formation

    International Nuclear Information System (INIS)

    Sanga, Madhu; Younis, Islam R.; Tirumalai, Padma S.; Bland, Tina M.; Banaszewska, Monica; Konat, Gregory W.; Tracy, Timothy S.; Gannett, Peter M.; Callery, Patrick S.

    2006-01-01

    Pyrolytic products of smoked methamphetamine hydrochloride are well established. Among the various degradation products formed, trans-phenylpropene (trans-β-methylstyrene) is structurally similar to styrene analogues known to be bioactivated by CYP enzymes. In human liver microsomes, trans-phenylpropene was converted to the epoxide trans-phenylpropylene oxide (trans-2-methyl-3-phenyloxirane) and cinnamyl alcohol. Incubation of trans-phenylpropene with microsomes in the presence of enzyme-specific P450 enzyme inhibitors indicated the involvement of CYP2E1, CYP1A2, and CYP3A4 enzymes. Both (R,R)-phenylpropylene oxide and (S,S)-phenylpropylene oxide were formed in human liver microsomal preparations. Enantiomers of trans-phenylpropylene oxide were stereoselectively and regioselectively conjugated in a Phase II drug metabolism reaction catalyzed by human liver cytosolic enzymes consisting of conjugation with glutathione. The structure of the phenylpropylene oxide-glutathione adduct is consistent with nucleophilic ring-opening by attack at the benzylic carbon. Exposure of cultured C6 glial cells to (S,S)-phenylpropylene oxide produced a cytotoxic response in a concentration-dependent manner based on cell degeneration and death

  4. Improved stereoselective bioreduction of t-butyl 6-cyano-(5R)-hydroxy-3-oxohexanoate by Rhodotorula glutinis through heat treatment.

    Science.gov (United States)

    Luo, Xi; Wang, Ya-Jun; Zheng, Yu-Guo

    2016-11-01

    Optically pure t-butyl 6-cyano-(3R, 5R)-dihydroxyhexanoate ((R)-1b) is the key precursor for atorvastatin calcium, the most widely used cholesterol-lowering drug. In this work, a strain ZJB-09224 capable of asymmetrically reducing t-butyl 6-cyano-(5R)-hydroxy-3-oxohexanoate (1a) to corresponding optically pure (R)-1b was successfully isolated from soil sample, identified belonging to Rhodotorula glutinis based on the morphology, physiological tests, and the 18S rDNA sequence analysis. It was found that heat treatment of cell suspension at 45 °C for 25 Min significantly improved R. glutinis ZJB-09224 stereoselectivity. The asymmetric bioreduction of 1a was most efficient at pH 7.5, 35 °C, 50 mM (15.0 g L -1 ) substrate concentration, 40.0 g DCW L -1 cell loading size, 0.54 M (60.0 g L -1 ) sodium lactate acting as co-substrate. Under these optimal conditions, 0.046 M (R)-1b was produced with de (diastereomeric excess) value of 99.2% after 40 H conversion. Moreover, R. glutinis ZJB-09224 has a broad substrate spectrum, making it a potential tool for some valuable chiral alcohol pharmaceutical intermediates synthesis. © 2015 International Union of Biochemistry and Molecular Biology, Inc.

  5. Robust Crosslinked Stereocomplexes and C60 Inclusion Complexes of Vinyl-Functionalized Stereoregular Polymers Derived from Chemo/Stereoselective Coordination Polymerization

    KAUST Repository

    Vidal, Fernando; Falivene, Laura; Caporaso, Lucia; Cavallo, Luigi; Chen, Eugene Y.-X.

    2016-01-01

    The successful synthesis of highly syndiotactic polar vinyl polymers bearing the reactive pendant vinyl group on each repeat unit, which is enabled by perfectly chemoselective and highly syndiospecific coordination polymerization of divinyl polar monomers developed through this work, has allowed the construction of robust crosslinked supramolecular stereocomplexes and C60 inclusion complexes. The metal-mediated coordination polymerization of three representative polar divinyl monomers, including vinyl methacrylate (VMA), allyl methacrylate (AMA), and N,N-diallyl acrylamide (DAA) by Cs-ligated zirconocenium ester enolate catalysts under ambient conditions exhibits complete chemoselectivity and high stereoselectivity, thus producing the corresponding vinyl-functionalized polymers with high (92% rr) to quantitative (>99% rr) syndiotacticity. A combined experimental (synthetic, kinetic, and mechanistic) and theoretical (DFT) investigation has yielded a unimetallic, enantiomorphic-site controlled propagation mechanism. Post-functionalization of the obtained syndiotactic vinyl-functionalized polymers via the thiol-ene click and photocuring reactions readily produced the corresponding thiolated polymers and flexible crosslinked thin film materials, respectively. Complexation of such syndiotactic vinyl-functionalized polymers with isotactic poly(methyl methacrylate) and fullerene C60 generates supramolecular crystalline helical stereocomplexes and inclusion complexes, respectively. Crosslinking of such complexes afforded robust crosslinked stereocomplexes that are solvent resistant and also exhibit considerably enhanced thermal and mechanical properties as compared to the uncrosslinked stereocompexes.

  6. Stereoselective and stereospecific effects in the formation of heteronuclear tartrate complexes of 3d- and 4f-elements from proton magnetic relaxation data

    International Nuclear Information System (INIS)

    Sal'nikov, Yu.I.; Chevela, V.V.

    1987-01-01

    A new approach to identification of stereoselective and stereospecific effects in the formation of heteronuclear tartrate complexes of 3d- and 4f-elements according to proton magnetic relaxation data is developed. At the first stage comparison of experimental dependences of the property measured (relaxation efficiency coefficient, Bjerrum function etc.) on the consentrational parameters is conducted. Their different course in systems with dH 4 L (d-tartaric acid) and dlH 4 L (dl-tartaric acid) points out to the presence of stereoeffects. Then, using mathematical simulation the most true stoichiometry of complex particles is determined as well as optimized values of their stability constants and intensity factors. The method is used when investigating the following systems: Fe 3+ -dH 4 L(dlH 4 L), Ln 3+ -dH 4 L(dlH 4 L), Fe 3+ -Ln 3+ -dH 4 L(dlH 4 L)(Ln 3+ -Gd 3+ , Ho 3+ , Er 3+ , Tm 3+ )

  7. On Politics and Education Finance: A Bibliography of Joel S. Berke, James W. Guthrie, and Michael W. Kirst. Vance Bibliographies, Public Administration Series: Bibliography P-821.

    Science.gov (United States)

    Quay, Richard H.

    A bibliography of Joel S. Berke, James W. Guthrie, and Michael W. Kirst on politics and educational finance is presented. Specific topics include the following: whether financial support of public schools should be assumed completely by states, school finance policies and practices, school finance reform versus the spending and tax limitation…

  8. LEBANON AFTER THE CEDAR REVOLUTION/ARE KNUDSEN AND MICHAEL KERR (eds; LEBANON: A HISTORY, 600--2011/by WILLIAM HARRIS

    Directory of Open Access Journals (Sweden)

    Franck Salameh

    2013-05-01

    Full Text Available LEBANON AFTER THE CEDAR REVOLUTION, ARE KNUDSEN AND MICHAEL KERR (eds; London: C. Hurst & Company, 2012. 323 pp. $29.95. LEBANON: A HISTORY, 600--2011, WILLIAM HARRIS; Oxford, New York: Oxford University Press, 2012. 360 pp. $34.95.

  9. How "The Right" Continues to "Do Wrong" by Our Young People: Contemporary Reflections on Michael Apple's Analysis of the "Rightist Turn" in Education

    Science.gov (United States)

    McGregor, Glenda

    2018-01-01

    Michael Apple's 2005 article, "Doing Things the 'Right' Way: Legitimating Educational Inequalities in Conservative Times", is a seminal piece of writing that highlights some of his core concerns with the effects of neo-liberal and neo-conservative ideologies on education. Since its publication, this article has incited much debate about…

  10. Domino Aza-Michael-ih-Diels-Alder Reaction to Various 3-Vinyl-1,2,4-triazines: Access to Polysubstituted Tetrahydro-1,6-naphthyridines.

    Science.gov (United States)

    Jouha, Jabrane; Buttard, Floris; Lorion, Magali; Berthonneau, Clément; Khouili, Mostafa; Hiebel, Marie-Aude; Guillaumet, Gérald; Brière, Jean-François; Suzenet, Franck

    2017-09-15

    A straightforward domino aza-Michael-inverse-electron-demand-hetero-Diels-Alder/retro-Diels-Alder reaction between primary and secondary propargylamine derivatives and 3-vinyl-1,2,4-triazines is developed highlighting not only the uniqueness of this dual-heterocyclic platform but also a novel and unprecedented path to polysubstituted tetrahydro-1,6-naphthyridine scaffolds.

  11. Using Our Voices, Losing Our Bodies: Michael Brown, Trayvon Martin, and the Spirit Murders of Black Male Professors in the Academy

    Science.gov (United States)

    Johnson, Lamar; Bryan, Nathaniel

    2017-01-01

    The recent deaths of Michael Brown, Trayvon Martin, and other Black males have generated new civil rights urgencies in Black communities and spirited academic discourses in higher education regarding the educational and social plight of Black males in America. Connecting the deaths of Black males to our lived experiences in the academy, we use a…

  12. Review Article: Yamada, Jeni "Laura: A Case for the Modularity of Language"; Tomasello, Michael "First Verbs: A Case Study of Early Grammatical Development."

    Science.gov (United States)

    Shatz, Marilyn

    1994-01-01

    Jeni Yamada's "Laura" and Michael Tomasello's "First Verbs" continue a tradition of providing useful information on the language ability of individuals in a depth rarely found in multisubject studies; however, these efforts are unusual for case studies in that both take strong theoretical positions on the essence of language and language learning.…

  13. The Impact of Socio-Cultural Differences on Educational Values: A Comparison of the Pedagogy of Michael Oakeshott and John McGahern

    Science.gov (United States)

    Williams, Kevin

    2017-01-01

    The year 2016 marked the tenth anniversary of the death of John McGahern (born 1934), the widely acclaimed Irish author. There is a shared temper of mind and several common strands in the work of McGahern and that of the English philosopher, Michael Oakeshott (1900-1990). Despite the very different cultural environments in which they grew up and…

  14. What's in a Name? That Which We Call a Crisis? A Commentary on Michael Young's Article "Overcoming the Crisis in Curriculum Theory"

    Science.gov (United States)

    Lundgren, Ulf P.

    2015-01-01

    Michael Young's article "Overcoming the crisis in curriculum theory: a knowledge-based approach" ("JCS, 45", 2) is discussed from the starting point that the claimed crisis is constructed from a decisive solution, that is the solution determines what is a crisis. But curriculum research and curriculum theory are in need of…

  15. A designated centre for people with disabilities operated by St Michael's House, Dublin 5

    LENUS (Irish Health Repository)

    Knox, Shane

    2015-01-01

    In November 2013, the Irish Regulator for emergency medical technicians (EMTs) introduced the first mandatory requirement for registrants to demonstrate evidence of continuous professional development (CPD)\\/continuous professional competence (CPC). This qualitative study assessed the experience of practitioners with CPC-related materials provided to them by the Regulator in addition to identifying perceived or encountered practical challenges and suggested improvements six months following introduction of the requirement.

  16. Cadrage, décadrage et recadrage dans Baa Baa Black Sheep : A Jungle Tale de David Malouf et Michael Berkeley Patrimonial Deconstruction and Reconstruction in David Malouf and Michael Berkeley’s Baa Baa Black Sheep : A Jungle Tale

    Directory of Open Access Journals (Sweden)

    Jean-Philippe Héberlé

    2011-11-01

    Full Text Available This article discusses Michael Berkeley’s first opera, Baa Baa Black Sheep: A Jungle Tale. Premiered under the baton of Paul Daniel on July 3rd 1993 at the Cheltenham International Festival of Music, this opera is based on two texts by Rudyard Kipling: The Jungle Books (1894-1895 and “Baa, Baa, Black Sheep” from the short story collection Wee Willie Winkie and Other Stories, first published in 1888. The libretto was penned by the Australian poet, novelist, playwright and librettist, David Malouf. After a brief survey of some of the earliest transpositions of The Jungle Books, I analyse the way David Malouf deals with both texts. “Baa Baa Black Sheep” is used as the central element of his libretto, and episodes and characters from The Jungle Books are incorporated to draw parallelism between the main topics of the two texts. Both Malouf’s endeavour and Berkeley’s, through the music, aims at deconstructing the preposterous oldest transpositions of The Jungle Books and at focusing on the key elements of Kipling’s famous book, notably identity and hybridism, two important themes of colonial and postcolonial literature. The aim of David Malouf and Michael Berkeley is to address an adult audience and show that The Jungle Books are not only aimed at children as Disney’s or Baden Powell’s appropriations of the work could wrongly make us believe.Cet article porte sur Baa Baa Black Sheep: A Jungle Tale, le premier opéra de Michael Berkeley. Créé au Everyman Theatre de Cheltenham le 3 juillet 1993 sous la direction de Paul Daniel, cette œuvre est le fruit de la collaboration entre le compositeur britannique et l’écrivain australien David Malouf. Le livret de Malouf se fonde sur deux récits de Rudyard Kipling : la nouvelle autobiographique “Baa, Baa, Black Sheep” auquel l’opéra doit son nom et The Jungle Books. Après m’être intéressé aux premières transpositions musicales de The Jungle books, je montre comment

  17. El movimiento como simulacro en el mundo virtual: Michael Betancourt y el arte de la inmediatez. = Movement as simulacrum in the virtual world: Michael Betancourt and the art of immediacy

    Directory of Open Access Journals (Sweden)

    José Manuel García Perera

    2016-05-01

    Full Text Available La creación artística se ha acercado en los últimos tiempos a la imagen mediática que propone Internet, alterando sustancialmente una experiencia estética antes basada en el movimiento del espectador en torno a la obra y definida ahora por pantallas que inducen a la pasividad. El trabajo en vídeo de Michael Betancourt, encuadrado en el denominado arte glitch, ese que se fija en el fallo ocurrido dentro del ámbito digital, ha sido la base para realizar aquí un estudio comparativo entre diferentes concepciones artísticas del movimiento, así como entre un arte pasado y otro actual que permite ver cómo los avances tecnológicos han originado cambios radicales en la naturaleza corpórea, espacial y móvil de la obra. La investigación de Betancourt propone un nuevo arte cinético que, por medio del error, se hace crítico, se mimetiza con el movimiento en tiempo real que la contemporaneidad demanda y destapa el artificio de imágenes que imitan a la realidad como si quisieran sustituirla.In recent times, artistic creation has come closer to the media image proposed by Internet, thus seriously altering an aesthetic experience based before on movement of the viewer around the work and now defined by screens that induce passivity. Michael Betancourt’s video work, part of the so-called glitch art, which focuses on the failure that can occur within the digital realm, has been here the basis for a comparative study between different concepts of movement in art, as well as between a current and a past art, a comparison that allows us to see clearly how technological advances have produced radical changes in the physical, spatial and mobile nature of the artwork. Betancourt’s investigation proposes a new kinetic art that becomes critical through error, mimics the real-time movement that contemporary culture demands, and uncovers the artificiality of images that mimic reality as if they wanted to replace it.

  18. The synthesis of new oxazoline-containing bifunctional catalysts and their application in the addition of diethylzinc to aldehydes.

    Science.gov (United States)

    Coeffard, Vincent; Müller-Bunz, Helge; Guiry, Patrick J

    2009-04-21

    The straightforward preparation of new modular oxazoline-containing bifunctional catalysts is reported employing a microwave-assisted Buchwald-Hartwig aryl amination as the key step. Covalent attachment of 2-(o-aminophenyl)oxazolines and pyridine derivatives generated in good-to-high yields a series of ligands in two or three steps in which each part was altered independently to tune the activity and the selectivity of the corresponding catalysts. These catalysts prepared in situ were subsequently applied in the asymmetric addition of diethylzinc to various aldehydes, producing the corresponding alcohols with enantioselectivities of up to 68%. A transition state model, based on relevant X-ray crystal structures, has also been proposed to explain the observed stereoselectivities.

  19. Stereoselective quantification of methadone and a d(6)-labeled isotopomer using high performance liquid chromatography-atmospheric pressure chemical ionization mass-spectrometry: application to a pharmacokinetic study in a methadone maintained subject.

    Science.gov (United States)

    Foster, David J R; Morton, Erin B; Heinkele, Georg; Mürdter, Thomas E; Somogyi, Andrew A

    2006-08-01

    There is evidence that the apparent oral clearance of rac-methadone is induced during the early phase of methadone maintenance treatment. However, it is not known if this is due to changes in bioavailability or if this phenomenon is stereoselective. This knowledge can be obtained by administering a dose of stable-labeled methadone at selected times during ongoing treatment. Therefore, the authors developed a stereoselective high performance liquid chromatography-atmospheric pressure chemical ionization mass-spectrometry assay for the quantification of the enantiomers of methadone and a d(6)-labeled isotopomer. The compounds were quantified in a single assay after liquid-liquid extraction and stereoselective high performance liquid chromatograph with atmospheric pressure chemical ionization-mass spectrometry detection. The following ions were monitored: m/z 310.15 for unlabeled methadone; m/z 316.15 for methadone-d(6); and m/z 313.15 for the methadone-d(3) (internal standard). Calibration curves ranged from 0.5 to 75 ng/mL for each compound. Extraction recovery was approximately 80% for all analytes, without evidence of differences between the unlabeled and stable-labeled compounds or concentration dependency. Minor ion promotion was observed (d(3)-labeled internal standard, with peak area ratios in extracted samples identical to control injections. The isotopomers did not alter each others' ionisation, even at 10:1 concentration ratios, and 10-fold diluted samples were within 10% of the nominal concentration. Assay performance was acceptable, with interassay and intra-assay bias and precision d(6) in a patient receiving chronic oral methadone maintenance therapy.

  20. Advanced sampling theory with applications how Michael ‘selected’ Amy

    CERN Document Server

    Singh, Sarjinder

    2003-01-01

    This book is a multi-purpose document. It can be used as a text by teachers, as a reference manual by researchers, and as a practical guide by statisticians. It covers 1165 references from different research journals through almost 1900 citations across 1194 pages, a large number of complete proofs of theorems, important results such as corollaries, and 324 unsolved exercises from several research papers. It includes 159 solved, data-based, real life numerical examples in disciplines such as Agriculture, Demography, Social Science, Applied Economics, Engineering, Medicine, and Survey Sampling. These solved examples are very useful for an understanding of the applications of advanced sampling theory in our daily life and in diverse fields of science. An additional 173 unsolved practical problems are given at the end of the chapters. University and college professors may find these useful when assigning exercises to students. Each exercise gives exposure to several complete research papers for researchers/stude...

  1. A designated centre for people with disabilities operated by St Michael's House, Dublin 3

    LENUS (Irish Health Repository)

    McGrath, Bridget

    2012-01-01

    This study explored registered psychiatric nurses\\' (RPNs\\') interactions and level of empathy towards service users with a diagnosis of borderline personality disorder (BPD). A qualitative approach was used, and 17 RPNs were interviewed using a semistructured interview schedule incorporating the "staff-patient interaction response scale" (SPIRS). Four themes emerged following data analysis: "challenging and difficult," "manipulative, destructive and threatening behaviour," "preying on the vulnerable resulting in splitting staff and other service users," and "boundaries and structure." Additionally, low levels of empathy were evident in the majority of participants\\' responses to the SPIRS. The findings provide further insight on nurses\\' empathy responses and views on caring for service users with BPD and further evidence for the need for training and education for nurses in the care of service users diagnosed with BPD.

  2. Stereoselective Synthesis of(Z)-4-(2-Bromovinyl)benzenesulfonyl Azide and Its Synthetic Utility for the Transformation to(2)-N-[4-(2-Bromovinyl)benzenesulfonyl]imidates

    Institute of Scientific and Technical Information of China (English)

    ZHANG Wensheng; KUANG Chunxiang; YANG Qing

    2009-01-01

    A novel method for the stereoselective synthesis of(Z)-4-(2-bromovinyl)benzenesulfonyl azide by simultaneous azidation and debrorninative decarboxylation of anti-2,3-dibromo-3-(4-chlorosulfonylphenyl)propanoic acid using NaN3 only was developed.Facile transformation of(Z)-4-(2-bromovinyl)benzenesulfonyl azide to(Z)-N-[4(2-bromovinyl)benzenesulfonyl]imidates was also achieved by Cu-catalyzed three-component coulping of (Z)-4-(2-bromovinyi)benzenesulfonyl azide,terminal alkynes and alcohols/phenols.

  3. Combining multi-catalysis and multi-component systems for the development of one-pot asymmetric reactions: stereoselective synthesis of highly functionalized bicyclo[4.4.0]decane-1,6-diones.

    Science.gov (United States)

    Ramachary, Dhevalapally B; Sakthidevi, Rajasekar

    2008-07-21

    We have developed a direct amine/acid-catalyzed stereoselective hydrogenation of a variety of Wieland-Miescher (W-M) ketones, Hajos-Parrish (H-P) ketones and their analogs with organic hydrides (Hantzsch esters) as the hydrogen source. This astonishingly simple and biomimetic approach was used to construct highly functionalized chiral bicyclo[4.4.0]decane-1,6-diones in a diastereoselective fashion. This is an example of the development of a new technology by the combination of multiple catalysts and components in one pot to deliver highly functionalized chiral molecules.

  4. The variability of sesquiterpenes emitted from two Zea mays cultivars is controlled by allelic variation of two terpene synthase genes encoding stereoselective multiple product enzymes.

    Science.gov (United States)

    Köllner, Tobias G; Schnee, Christiane; Gershenzon, Jonathan; Degenhardt, Jörg

    2004-05-01

    The mature leaves and husks of Zea mays release a complex blend of terpene volatiles after anthesis consisting predominantly of bisabolane-, sesquithujane-, and bergamotane-type sesquiterpenes. The varieties B73 and Delprim release the same volatile constituents but in significantly different proportions. To study the molecular genetic and biochemical mechanisms controlling terpene diversity and distribution in these varieties, we isolated the closely related terpene synthase genes terpene synthase4 (tps4) and tps5 from both varieties. The encoded enzymes, TPS4 and TPS5, each formed the same complex mixture of sesquiterpenes from the precursor farnesyl diphosphate but with different proportions of products. These mixtures correspond to the sesquiterpene blends observed in the varieties B73 and Delprim, respectively. The differences in the stereoselectivity of TPS4 and TPS5 are determined by four amino acid substitutions with the most important being a Gly instead of an Ala residue at position 409 at the catalytic site of the enzyme. Although both varieties contain tps4 and tps5 alleles, their differences in terpene composition result from the fact that B73 has only a single functional allele of tps4 and no functional alleles of tps5, whereas Delprim has only a functional allele of tps5 and no functional alleles of tps4. Lack of functionality was shown to be attributable to frame-shift mutations or amino acid substitutions that greatly reduce the activity of their encoded proteins. Therefore, the diversity of sesquiterpenes in these two maize cultivars is strongly influenced by single nucleotide changes in the alleles of two terpene synthase genes.

  5. Enantioselective determination of (R)- and (S)-lansoprazole in human plasma by chiral liquid chromatography with mass spectrometry and its application to a stereoselective pharmacokinetic study.

    Science.gov (United States)

    Sun, Luning; Cao, Yang; Jiao, Huiwen; Fang, Yunqian; Yang, Zhicheng; Bian, Mingliang; Zhang, Hongwen; Gong, Xiaojian; Wang, Yongqing

    2015-11-01

    A simple and enantioselective method was developed and validated for the simultaneous determination of (R)- and (S)-lansoprazole in human plasma by chiral liquid chromatography with tandem mass spectrometry. Lansoprazole enantiomers and internal standard (esomeprazole) were extracted from plasma using acetonitrile as protein precipitating agent. Baseline chiral separation was achieved within 9.0 min on a Chiralpak IC column (150 mm × 4.6 mm, 5 μm) with the column temperature of 30°C. The mobile phase consisted of 10 mM ammonium acetate solution containing 0.05% acetic acid/acetonitrile (50:50, v/v). The mass spectrometric analysis was performed using a QTrap 5500 mass spectrometer coupled with an electrospray ionization source in positive ion mode. The multiple reactions monitoring transitions of m/z 370.1→252.1 and 346.1→198.1 were used to quantify lansoprazole enantiomers and esomeprazole, respectively. For each enantiomer, no apparent matrix effect was found, the calibration curve was linear over 5.00-3000 ng/mL, the intra- and inter-day precisions were below 10.0%, and the accuracy was -3.8 to 3.3%. Analytes were stable during the study. No chiral inversion was observed during sample storage, preparation procedure and analysis. The method was applied to the stereoselective pharmacokinetic studies in human after intravenous administration of dexlansoprazole or racemic lansoprazole. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. Dr Michaels® product family (also branded as Soratinex®) versus Methylprednisolone aceponate - a comparative study of the effectiveness for the treatment of plaque psoriasis.

    Science.gov (United States)

    Hercogovấ, J; Fioranelli, M; Gianfaldoni, S; Chokoeva, A A; Tchernev, G; Wollina, U; Tirant, M; Novotny, F; Roccia, M G; Maximov, G K; França, K; Lotti, T

    2016-01-01

    As one of the most common dermatologic chronic-recurrent disease, variable therapeutic options are available today for management of psoriasis. Although topical high potency corticosteroids, alone or in association with salicylic acid or vitamin D analogues, are still considered the best treatment, they do not seem to possess the capability for a long-term control of the disease or prevent recurrences, as their side effects are major contraindications for continuative use. The aim of this study was to investigate whether Dr. Michaels® product family is comparable to methylprednisolone aceponate (MPA) as a viable alternative treatment option for the treatment and management of stable chronic plaque psoriasis. Thirty adults (13 male, 17 female, mean age 40 years) with mild to severe stable chronic plaque psoriasis, were included in the study. Patients were advised to treat the lesions of the two sides of their body (left and right) with two different unknown modalities for 8 weeks; the pack of Dr. Michaels® products on the left side (consisting of a cleansing gel, an ointment and a skin conditioner) and a placebo pack on the right side, consisting of a cleansing gel, methylprednisolone ointment and a placebo conditioner. Assessment was done using the Psoriasis Activity Severity Index (PASI) scores before treatment and after 2, 4, 6 and 8 weeks. The results achieved with the Dr. Michaels® (Soratinex®) product family for the treatment of chronic plaque psoriasis were better than the results achieved with methylprednisolone aceponate (MPA), even though quicker resolution was achieved with the steroid with 45% of patients achieving resolution within 8-10 days in comparison to 5-6 weeks in the Dr. Michaels® (Soratinex®) group. Before therapy, the mean PASI score of the LHS in Dr. Michaels® (Soratinex®) group was 13.8±4.1 SD and 14.2±4.2 SD in the RHS methylprednisolone aceponate (MPA) group. After 8 weeks of treatment 62% of the Dr. Michaels® (Soratinex

  7. A designated centre for people with disabilities operated by St Michael's House, Dublin 9

    LENUS (Irish Health Repository)

    Flinn, AM

    2018-02-01

    Diagnosis of Kawasaki Disease (KD) can be challenging due to lack of a diagnostic test, and some children present with ‘incomplete’ KD when not all diagnostic criteria are met. Treatment with intravenous immunoglobulin (IVIG) and aspirin reduces the risk of coronary artery complications. There is sub-group of patients who are resistant to IVIG\\/aspirin therapy and are at increased risk of complications. Recent evidence suggests that additional treatment of this high-risk group with corticosteroids is beneficial in reducing this risk. We examine the treatment and coronary artery outcomes, by retrospective review of medical records, of a cohort of 32 paediatric patients with KD admitted to a single Irish tertiary centre from January 2010-December 2014. Twenty-eight percent of patients (9\\/32) had an incomplete diagnosis of KD; these patients received IVIG later compared to those with a complete KD diagnosis. 15\\/32 (47%) had abnormal echocardiogram findings in the acute phase, 8\\/32 (25%) had echocardiogram abnormalities at 6-week follow-up, and 4\\/32 (12.5%) had persisting abnormalities. This study highlights the potential for adverse outcome in KD, the difficulty in diagnosis in ‘incomplete’ cases, and the need to identify children at higher risk for adverse outcome where adjunctive therapies would be most beneficial.

  8. Stereoselective Binding of Flurbiprofen Enantiomers and their Methyl Esters to Human Serum Albumin Studied by Time-Resolved Phosphorescence

    NARCIS (Netherlands)

    mr. Lammers, I.; Lhiaubet-Vallet, V.; Jimenez, M.C.; Ariese, F.; Miranda, M.A.; Gooijer, C.

    2012-01-01

    The interaction of the nonsteroidal anti-inflammatory drug flurbiprofen (FBP) with human serum albumin (HSA) hardly influences the fluorescence of the protein's single tryptophan (Trp). Therefore, in addition to fluorescence, heavy atom-induced room-temperature phosphorescence is used to study the

  9. Additive Manufacturing Infrared Inspection

    Science.gov (United States)

    Gaddy, Darrell; Nettles, Mindy

    2015-01-01

    The Additive Manufacturing Infrared Inspection Task started the development of a real-time dimensional inspection technique and digital quality record for the additive manufacturing process using infrared camera imaging and processing techniques. This project will benefit additive manufacturing by providing real-time inspection of internal geometry that is not currently possible and reduce the time and cost of additive manufactured parts with automated real-time dimensional inspections which deletes post-production inspections.

  10. Nobody Knows My Name: The Masquerade of Mourning in the Early 1980s Artistic Productions of Michael Jackson and Prince

    Directory of Open Access Journals (Sweden)

    Pochmara Anna

    2017-12-01

    Full Text Available The article analyses Michael Jackson’s album Thriller and Prince’s movie Purple Rain. We explore their camp aesthetics and their recasting of the cultural representations of the black male. Jackson’s and Prince’s performative personas are both liberatory and burdened with the received cultural scripts of black masculinity. We claim that their employment of camp is political rather than escapist and depoliticized. Camp serves them as a platform to mourn the cultural displacement of the black male body in a postslavery America. In particular, the two artists distance themselves from the extensive ideological and physical pressures exerted on the black male body in the early 1980s. As a result, their performances are complexly de-Oedipalized. Prince in Purple Rain refuses to assume the patriarchal position of the Father. Analogously, Jackson fashions himself as a Peter Pan-like eternal adolescent who never makes his final identification as either heterosexual or LGBTQ desiring agent. In the coda to the article, we reach beyond the 1980s to explore a more flexible approach to camp in the artistic output of twenty-first-century African American performers of Queercore and Afrofuturist scenes, which were partially enabled by Jackson’s and Prince’s performances.

  11. Sustainable shape memory polymers based on epoxidized natural rubber cured by zinc ferulate via oxa-Michael reaction

    Directory of Open Access Journals (Sweden)

    Xuhui Zhang

    2015-10-01

    Full Text Available Although various shape memory polymers (SMPs or diverse applications have been widely reported, the SMPs based on rubbers have been rarely realized due to the low triggering temperature of rubbers. In another aspect, the SMPs based on sustainable substances are highly desired for the growing shortage in fossil resources. In the present study, we accordingly developed the sustainable SMPs with tunable triggering temperature, based on natural rubber (NR and ferulic acid (FA as the raw materials. Specifically, the SMPs are based on a crosslinked network of epoxidized natural rubber (ENR crosslinked by in situ formed zinc ferulate (ZDF via oxa-Michael reaction. The excellent shape memory effect (SME is found in these SMPs, as evidenced by the high fixity/recovery ratio and the tunable triggering temperature. With the incorporation of natural halloysite nanotubes (HNTs, the stress and recovery rate of the SMPs are found to be tunable, which widens the application of this kind of SMPs. The combination of adoption of sustainable raw materials, and the excellent and tunable SME makes these SMPs potentially useful in many applications, such as various actuators and heat-shrinkable package materials.

  12. Latter-day Mother Irelands: The Role of Women in Michael Collins and The Wind that Shakes the Barley

    Directory of Open Access Journals (Sweden)

    Pilar Villar-Argáiz

    2007-03-01

    Full Text Available Despite the experimental and subversive work of Irish feminist filmmakers such as Pat Murphy and Margo Harkin in the 1980s, as Gerardine Meaney has contended, “the image of woman as Ireland, Ireland as woman, remains powerful and pervasive in the new Irish cinema” (1998: 250. The cinematic convention of representing Ireland through female characters becomes particularly relevant in two recent Irish historical films: Michael Collins (1996, directed and written by Irish Neil Jordan, and The Wind that Shakes the Barley (2006, written by Scottish Paul Laverty and directed by English Ken Loach. In their dealing with themes such as military occupation, colonisation and the heated debate about the Treaty, both films maintain the nationalist rhetoric that represents Ireland as a woman/mother in a direct manner. Over the course of this essay, I shall try to chart the implications of both films’ representations of women, with a view to demonstrating how, even at present, the trope of Mother Ireland continues to be deep in the national unconscious.

  13. ANÁLISIS DEL POTENCIAL COMPETITIVO DEL BIOETANOL EN COLOMBIA: UN ENFOQUE DESDE LAS 5 FUERZAS COMPETITIVAS DE MICHAEL PORTER

    Directory of Open Access Journals (Sweden)

    RAMIREZ VELASQUEZ ALEJANDRO

    2012-11-01

    Full Text Available La búsqueda de alternativas de producción y consumo energético requiere una mirada hacia la industria de los combustibles biológicos como el bioetanol que, como alternativa energética, permita superar los inconvenientes generados por los métodos tradicionales de producción y consumo, en especial en los temas políticos, ambientales y sociales y generar ventajas competitivas frente a otras fuentes primarias de energía. En el presente documento,a partir del modelo de las cinco (5 Fuerzas de Michael Porter, se realiza una evaluación de la industria del bioetanol como combustible alternativo y se expone qué tan atractiva o competitiva puede llegar a ser su industria en la actualidad. Para lograr este propósito, se propone una evaluación de las fuerzas competitivas a un panel de expertos, usando escalas deLikert, para encontrar el potencial de la propuesta.

  14. Quality evaluation of commercially sold table water samples in Michael Okpara University of Agriculture, Umudike, Nigeria and surrounding environments

    Directory of Open Access Journals (Sweden)

    D.O. Okorie

    2015-01-01

    Full Text Available In Michael Okpara University of Agriculture, Umudike, Nigeria (MOUAU and surrounding environments, table water of different brands is commercially hawked by vendors. To the best of our knowledge, there is no scientific documentation on the quality of these water samples. Hence this study which evaluated the quality of different brands of water samples commercially sold in MOUAU and surrounding environments. The physicochemical properties (pH, total dissolved solids (TDS, biochemical oxygen demand (BOD, total hardness, dissolved oxygen, Cl, NO3, ammonium nitrogen (NH3N, turbidity, total suspended solids (TSS, Ca, Mg, Na and K of the water samples as indices of their quality were carried out using standard techniques. Results obtained from this study indicated that most of the chemical constituents of these table water samples commercially sold in Umudike environment conformed to the standards given by the Nigerian Industrial Standard (NIS, World Health Organization (WHO and American Public Health Association (APHA, respectively, while values obtained for ammonium nitrogen in these water samples calls for serious checks on methods of their production and delivery to the end users.

  15. A stale challenge to the philosophy of science: commentary on "Is psychology based on a methodological error?" by Michael Schwarz.

    Science.gov (United States)

    Ruck, Nora; Slunecko, Thomas

    2010-06-01

    In his article "Is psychology based on a methodological error?" and based on a quite convincing empirical basis, Michael Schwarz offers a methodological critique of one of mainstream psychology's key test theoretical axioms, i.e., that of the in principle normal distribution of personality variables. It is characteristic of this paper--and at first seems to be a strength of it--that the author positions his critique within a frame of philosophy of science, particularly positioning himself in the tradition of Karl Popper's critical rationalism. When scrutinizing Schwarz's arguments, however, we find Schwarz's critique profound only as an immanent critique of test theoretical axioms. We raise doubts, however, as to Schwarz's alleged 'challenge' to the philosophy of science because the author not at all seems to be in touch with the state of the art of contemporary philosophy of science. Above all, we question the universalist undercurrent that Schwarz's 'bio-psycho-social model' of human judgment boils down to. In contrast to such position, we close our commentary with a plea for a context- and culture sensitive philosophy of science.

  16. Jan Rak and Michael J. Tannenbaum present the book "High-pT physics in the heavy ion era"

    CERN Multimedia

    2013-01-01

    Thursday 13 June 2013 from 4 p.m. to 5 p.m. in the Library, Bldg. 52 1-052 The book provides an overview of the basic concepts of large transverse momentum particle physics, with a focus on pQCD phenomena. It examines high-pT probes of relativistic heavy-ion collisions and will serve as a handbook for those working on RHIC and LHC data analyses. Starting with an introduction and review of the field, the authors look at basic observables and experimental techniques, concentrating on relativistic particle kinematics, before moving onto a discussion about the origins of high-pT physics. The main features of high-pT physics are placed within a historical context and the authors adopt an experimental outlook, highlighting the most important discoveries leading up to the foundation of modern QCD theory. High-pT physics in the heavy ion era, by Jan Rak and Michael J. Tannenbaum,  Cambridge University Press, 2013, ISBN  9780521190299. *Coffee will be served from 3 p.m.*

  17. [Food additives and healthiness].

    Science.gov (United States)

    Heinonen, Marina

    2014-01-01

    Additives are used for improving food structure or preventing its spoilage, for example. Many substances used as additives are also naturally present in food. The safety of additives is evaluated according to commonly agreed principles. If high concentrations of an additive cause adverse health effects for humans, a limit of acceptable daily intake (ADI) is set for it. An additive is a risk only when ADI is exceeded. The healthiness of food is measured on the basis of nutrient density and scientifically proven effects.

  18. The Bases of Chemical Thermodynamics, Volumes 1 and 2 by Michael Graetzel and Pierre Infelta

    Science.gov (United States)

    van Hecke, Gerald R.

    2001-09-01

    calculated and not trying to discuss randomness, which cannot. The second law is introduced via traditional heat engines with arguments as thorough as those of K. G. Denbigh in his classic Chemical Thermodynamics text. However, the authors use quite different examples, which are highly readable. The overworked term "entropy of the universe" has been abandoned in favor of "global entropy", meaning a combination of the system and surroundings. The term works for me. In addition to the Carnot cycle, there are compelling expositions on the Otto, Stirling, and Joule cycles. When discussing chemical reactions, extensive use is made of the extent of reaction concept. In fact a very clever derivation of the temperature dependencies of DrG°, DrH°, and DrS° is offered using the temperature dependency of the extent of reaction. Still on the topic of chemical equilibrium, the authors provide an example (and make the point quite clearly) of how in cases involving simultaneous chemical equilibria, it is quite possible to drive a reaction with a positive DrG° toward completion through the device of coupling the reaction with other favorable reactions. For biochemical systems this is the reason for life. Having (I hope) intrigued the reader of this review to this point, I'd better describe something more of the text. The two volumes would need to be used as companions in the sense that while Volume 1 could be used alone, Volume 2 definitely refers to crucial material contained in Volume 1. The separation into two volumes does seem a bit odd; and in fact, the volumes are continuously numbered. Each volume contains fully worked-out examples pertinent to the material in that volume. The examples, which the authors call problems but that is a stretch, are not the typical three-line, use the formula, plug-and-chug variety, but very elaborate applications of the principles discussed in the text. The examples could be studied on their own, without the benefit of the text. The text proper has

  19. Michael Jäckel, Julia Derra, Cornelia Eck: SchönheitsAnsichten. Geschlechterbilder in Werbeanzeigen und ihre Bewertung. Baden-Baden: Nomos Verlag 2009.

    Directory of Open Access Journals (Sweden)

    Waltraud Posch

    2010-11-01

    Full Text Available Michael Jäckel, Julia Derra, and Cornelia Eck’s cross-generational study answers the question as to which concepts of beauty are presented in magazine advertisements and how recipients react to these concepts. The book provides an important basis for Media Studies and Gender Sociology particularly because it also shows medial constructions of gender that are initially invisible and because it shows gender related illustrations of physicality and beauty.In einer generationenübergreifenden Studie gehen Michael Jäckel, Julia Derra und Cornelia Eck der Frage nach, welche Schönheitsbilder in der Zeitschriftenwerbung präsentiert und wie diese von Rezipient/-innen aufgenommen werden. Das Buch liefert eine wichtige Basis für Medienforschung und Soziologie der Geschlechter, zumal es auch vordergründig nicht sichtbare mediale Konstruktionen von Geschlecht und die geschlechtsbezogene Darstellung von Körperlichkeit und Schönheit aufzeigt.

  20. L-allo-threonine aldolase with an H128Y/S292R mutation from Aeromonas jandaei DK-39 reveals the structural basis of changes in substrate stereoselectivity.

    Science.gov (United States)

    Qin, Hui-Min; Imai, Fabiana Lica; Miyakawa, Takuya; Kataoka, Michihiko; Kitamura, Nahoko; Urano, Nobuyuki; Mori, Koji; Kawabata, Hiroshi; Okai, Masahiko; Ohtsuka, Jun; Hou, Feng; Nagata, Koji; Shimizu, Sakayu; Tanokura, Masaru

    2014-06-01

    L-allo-Threonine aldolase (LATA), a pyridoxal-5'-phosphate-dependent enzyme from Aeromonas jandaei DK-39, stereospecifically catalyzes the reversible interconversion of L-allo-threonine to glycine and acetaldehyde. Here, the crystal structures of LATA and its mutant LATA_H128Y/S292R were determined at 2.59 and 2.50 Å resolution, respectively. Their structures implied that conformational changes in the loop consisting of residues Ala123-Pro131, where His128 moved 4.2 Å outwards from the active site on mutation to a tyrosine residue, regulate the substrate specificity for L-allo-threonine versus L-threonine. Saturation mutagenesis of His128 led to diverse stereoselectivity towards L-allo-threonine and L-threonine. Moreover, the H128Y mutant showed the highest activity towards the two substrates, with an 8.4-fold increase towards L-threonine and a 2.0-fold increase towards L-allo-threonine compared with the wild-type enzyme. The crystal structures of LATA and its mutant LATA_H128Y/S292R reported here will provide further insights into the regulation of the stereoselectivity of threonine aldolases targeted for the catalysis of L-allo-threonine/L-threonine synthesis.