Enantioselective Synthesis (enantioselective + synthesis)

Distribution by Scientific Domains
Distribution within Chemistry

Kinds of Enantioselective Synthesis

  • catalytic enantioselective synthesis
  • efficient enantioselective synthesis
  • highly enantioselective synthesis


  • Selected Abstracts


    Asymmetric Dihydroxylation of ,,,-Unsaturated Carboxylic Esterswith Trisubstituted C=C Bonds , Enantioselective Syntheses of Trisubstituted ,-Butyrolactones

    EUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 9 2006
    Tobias Kapferer
    Abstract ,,,-Unsaturated esters with stereodefined trisubstitued C=C double bonds were prepared by the Arndt,Eistert homologation of ,,,-unsaturated carboxyl halides, by two-step methoxycarbonylation of allylbarium reagents, by deconjugation of ,,,-unsaturated esters, and by Horner,Wadsworth,Emmons variants of the Stobbe condensation. Sharpless asymmetric dihydroxylation of the ,,,-unsaturated esters, followed by spontaneous cyclization, afforded ,-hydroxy-,-lactones in moderate to good yields and with enantiomeric excesses of up to 97,%. Similarly, tetrahydroxy-,-lactones were obtained from diunsaturated esters; these lactones were converted into a bislactone and an unsaturated ,-hydroxy ,-lactone. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006) [source]


    Stereoselective and Enantioselective Syntheses of the Four Stereoisomers of Muscol from (3RS)-Muscone

    HELVETICA CHIMICA ACTA, Issue 5 2007
    Yoshifumi Yuasa
    Abstract Two trans stereoisomers of 3-methylcyclopentadecanol (=muscol), (1R,3R)- 2 and (1S,3S)- 2, were efficiently synthesized from (3RS)-3-methylcyclopentadecanone (=muscone; (3RS)- 1) by a highly stereoselective reduction (Scheme). L-Selectride® (=lithium tri(sec -butyl)borohydride) was used, followed by the enantiomer resolution by lipase QLG (Alcaligenes sp.). The cis stereoisomers of muscol, (1S,3R)- 2 and (1R,3S)- 2, were obtained by the Mitsunobu inversion of (1R,3R)- 2 and (1S,3S)- 2, respectively (Scheme). The absolute configuration of (1R,3R)- 2 was determined by X-ray crystal-structure analysis of its 3-nitrophthalic acid monoester, 2-[(1R,3R)-3-methylcyclopentadecyl hydrogen benzene-1,2-dicarboxylate ((1R,3R)- 3b), and by oxidation of (1R,3R)- 2 to (3R)-muscone. [source]


    Efficient Enantioselective Syntheses of Sertraline, 2-Epicatalponol and Catalponol from Tetralin-1,4-dione

    ADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 13 2010
    Alvaro Enriquez Garcia
    Abstract Tetralin-1,4-dione, the stable tautomer of dihydroxynaphthalene, was reduced with catecholborane in the presence of 3,3-diphenyl-1-butyltetrahydro-3H -pyrrolo[1,2- c][1,3,2]oxazaborole as catalyst to give enantiomerically highly enriched 4-hydroxy-1-tetralone (99% ee) in an efficient one-pot procedure. The R -enantiomer provided a rapid access to sertraline while the S -enantiomer was converted into 2-epicatalponol and catalponol. A more selective enantioselective route to the antithermitic catalponol made use of the planar chiral tricarbonylchromium complex of hydroxytetralone. Its precursor chromium(tricarbonyl)[,6 -(1-4,4a,8a)-tetralin-5,8-dione] was obtained via direct complexation of 1,4-dihydroxynaphthalene using chromium(tricarbonyl)- tris(ammonia) and boron trifluoride etherate as source of the chromium(tricarbonyl) fragment. Enolate prenylation was best carried out in the presence of a tetraamine ligand. Complete inversion of the stereogenic center bearing the prenyl group of the initially obtained tetralone complex was achieved via enolate formation followed by protonation. [source]


    Enantioselective Syntheses of Poison-Frog Alkaloids: 219F and 221I and an Epimer (I) of 193E.

    CHEMINFORM, Issue 19 2006
    Naoki Toyooka
    Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF. [source]


    De Novo Enantioselective Syntheses of Galacto-Sugars and Deoxy Sugars via the Iterative Dihydroxylation of Dienoate.

    CHEMINFORM, Issue 27 2005
    Md. Moinuddin Ahmed
    Abstract For Abstract see ChemInform Abstract in Full Text. [source]


    Enantioselective Syntheses of Two Diastereomers of 223V, an Alkaloid from the Poison Frog Dendrobates pumilio.

    CHEMINFORM, Issue 24 2005
    Naoki Toyooka
    Abstract For Abstract see ChemInform Abstract in Full Text. [source]


    Highly Enantioselective Syntheses of Functionalized ,-Methylene-,-butyrolactones via Rh(I)-Catalyzed Intramolecular Alder Ene Reaction: Application to Formal Synthesis of (+)-Pilocarpine.

    CHEMINFORM, Issue 44 2002
    Aiwen Lei
    Abstract For Abstract see ChemInform Abstract in Full Text. [source]


    ChemInform Abstract: Enantioselective Syntheses of Dopaminergic (R)- and (S)-Benzyltetrahydroisoquinolines.

    CHEMINFORM, Issue 35 2001
    Nuria Cabedo
    Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source]


    Enantioselective Syntheses and Configuration Assignments of ,-Chiral Butenolides from Plagiomnium undulatum: Butenolide Synthesis from Tetronic Acids

    CHEMISTRY - A EUROPEAN JOURNAL, Issue 7 2005
    Tobias Kapferer Dipl.-Chem.
    Abstract Both enantiomers of the ,-chiral ,,,-dimethylated butyrolactones nat - 1 and nat - 2 from the moss Plagiomnium undulatum were synthesized stereoselectively through butenolides and tetronic acids, respectively. The configuration of the natural products was determined by GLC comparisons with mono(3- O -acetyl-6- O - tert -butyldimethylsilyl-2- O -methyl)hexakis(6- O - tert -butyldimethylsilyl-2,3-di- O -methyl)-,-cyclodextrin as a stationary phase. [source]


    Amino Acid Ligand Chirality for Enantioselective Syntheses

    CHEMISTRY & BIODIVERSITY, Issue 6 2010
    Károly Micskei
    Abstract Amino acids are attractive sources of chirality in stoichiometric or catalytic transition metal/organic chemistry. In spite of easy availability and other advantages, the application of these ligands is hindered by several problems. Now, at the dawn of emerging d- amino acid biochemistry, efforts in this direction are becoming increasingly important. The results of research on application of amino acid ligands for transition-metal reagents in organic syntheses are reviewed in the present work. [source]


    Novel Enantioselective Synthesis of Functionalized Pyridylarsanes by a Chiral Palladium Template Promoted Asymmetric Hydroarsanation Reaction

    EUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 27 2009
    Fengli Liu
    Abstract The asymmetric hydroarsanation reactions between diphenylarsane and (E)-1-phenyl-3-(pyridin-2-yl)-2-propenone and (E)-1-methyl-3-(pyridin-2-yl)-2-propenoate have been achieved by use of the organopalladium complex containing ortho -metalated (R)-[1-(dimethylamino)ethyl]naphthalene as the chiral reaction template in high regio- and stereoselectivities under mild conditions. Hydroarsanation of (E)-1-phenyl-3-(pyridin-2-yl)-2-propenone with diphenylarsane generated two stereoisomeric products in the ratio of 3:1 as five-membered As,N bidentate chelates on the chiral naphthylamine palladium template. Using the same chiral metal template, the corresponding hydroarsanation reaction with (E)-1-methyl-3-(pyridin-2-yl)-2-propenoate gave only one product as a six-membered As,N bidentate chelate. The naphthylamine auxiliary could be removed chemoselectively by treatment with concentrated hydrochloric acid to form the corresponding optically pure neutral complexes. Subsequent ligands displacement from the palladium using aqueous potassium cyanide generated the optically pure keto- and ester-functionalized chiral pyridylarsane ligands. The absolute configuration and the coordination properties of the pyridylarsanes have been established by single-crystal X-ray analysis.(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009) [source]


    Enantioselective Synthesis of Functionalized 1-Benzoxepines by Phenoxide Ion Mediated 7- endo - tet Carbocyclization of Cyclic Sulfates,,

    EUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 2 2009
    Sajal Kumar Das
    Abstract A new asymmetric synthesis of 2,3-disubstituted 1-benzoxepines is described. Key steps include Sharpless asymmetricdihydroxylation of trans -,,,-unsaturated esters and phenoxide ion mediated intramolecular 7- endo - tet carbocyclization of syn -2,3-dihydroxy ester derived cyclic sulfates. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009) [source]


    Lactone Kinetic Resolution by Acylation , Application to the Enantioselective Synthesis of Estrane Derivatives

    EUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 22 2005
    Serge Wilmouth
    Abstract The acylation of an excess of racemic spirolactone 1 (6,9-divinyl-1-oxaspiro[4.4]nonan-2-one) enolate by protected methyl (S)-lactate or (,)-bornyl carbonate occurs with a kinetic resolution. The resulting lactones were alkylated with 1-iodobenzocyclobutenes to afford compounds that serve as precursors to nonracemic steroids such as 11,-alkyloxycarbonyl-11,,13,-(,-carbolactone)-17,-vinylgonatri-1,3,5(10)-enes. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005) [source]


    Highly Enantioselective Synthesis of No-Carrier-Added 6-[18F]Fluoro- L -dopa by Chiral Phase-Transfer Alkylation

    EUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 13 2004
    Christian Lemaire
    Abstract [18F]Fluoro- L -dopa, an important radiopharmaceutical for positron emission tomography (PET), has been synthesized using a phase-transfer alkylation reaction. A chiral quaternary ammonium salt derived from a Cinchona alkaloid served as phase-transfer catalyst for the enantioselective alkylation of a glycine derivative. The active methylene group of this Schiff-base substrate was deprotonated with cesium hydroxide and rapidly alkylated by the 2-[18F]fluoro-4,5-dimethoxybenzyl halide (X = Br, I). The reaction proceeded with high yield (> 90%) at 0 °C or room temperature in various solvents such as toluene or dichloromethane. Preparation of the [18F]alkylating agent on a solid support was developed. After labelling, the labeled [18F]fluoroveratraldehyde was trapped on a tC18 cartridge and then converted on the cartridge into the corresponding benzyl halide derivatives by addition of aqueous sodium borohydride and gaseous hydrobromic or -iodic acid. Hydrolysis and purification by preparative HPLC made 6-[18F]fluoro- L -dopa ready for human injection in a 25,30% decay-corrected radiochemical yield in a synthesis time of 100 min. The product was found to be chemically, radiochemically and enantiomerically pure (ee > 95%). (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004) [source]


    Enantioselective Synthesis of the Originally Proposed Usneoidone Structure: Evidence for a Structural Revision

    EUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 9 2004
    Michčle Danet
    Abstract The enantioselective synthesis of the initially proposed structure of usneoidone has been completed according to a convergent strategy in which the key steps were an enantioselective Michael addition involving chiral imines to set up the C12 quaternary center, and the final assembly of the chiral pyran moiety with the aromatic subunit through a cyanohydrin anion alkylation step. The obtained product displays spectroscopic data that significantly differ from the reported values. A putative revised structure in which the pyran ring is opened is proposed for usneoidones. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004) [source]


    Preparation of N -Glycosylhydroxylamines and Their Oxidation to Nitrones for the Enantioselective Synthesis of Isoxazolidines

    EUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 21 2003
    Stefano Cicchi
    Abstract N -benzyl- and N -methyl- N -glycosylhydroxylamines 3a,i were conveniently obtained by reaction of sugars with N -substituted hydroxylamines according to a novel procedure. Subsequent oxidation occurred at the alkyl group, selectively affording the corresponding C -phenyl- and C -unsubstituted N -glycosylnitrones. C -phenyl- N -glycosylnitrones 10 and 13 underwent highly stereoselective 1,3-dipolar cycloaddition with dimethyl maleate, with the sugar moiety acting as a chiral auxiliary. Final removal of the glycosyl moiety afforded enantiopure enantiomeric isoxazolidines 17 and ent -17 which are oxa-analogues of proline diester derivatives. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003) [source]


    Enantioselective Synthesis of , -Blockers via Hydrolytic Kinetic Resolution of Terminal Oxiranes by Using Bimetallic Chiral {{2,2,-[Cyclohexane-1,2-diylbis(nitrilomethylidyne)]bis[phenolato]}(2,)}cobalt ([Co(salen)])-Type Complexes

    HELVETICA CHIMICA ACTA, Issue 2 2008
    Rahul
    Abstract The synthesis of chirally pure , -blockers was successfully achieved via hydrolytic kinetic resolution of butyl (±)-4-(oxiran-2-ylmethoxy)benzeneacetate ((±)- 1) and (±)-4-(oxiran-2-ylmethoxy)benzeneacetonitrile ((±)- 2) in the presence of bimetallic chiral [Co(salen)]-type complexes. The newly synthesized bimetallic chiral [Co(salen)]-type complexes exhibited excellent enantioselectivities of up to >98% ee in good yields (Tables,1,3). [source]


    The Development of a Convergent and Efficient Enantioselective Synthesis of the Bengamides via a Common Polyol Intermediate

    HELVETICA CHIMICA ACTA, Issue 12 2002
    Robert
    An efficient, general synthetic route to the bengamide family of antitumor agents from a common polyol thioester is described. Consecutive aldol condensations afford the protected polyol thioester side chain suitable for coupling to the bengamides. A novel chiral-phase-transfer-catalyzed enantioselective alkylation affords the properly functionalized caprolactams required for the synthesis of more-complex members of the bengamide family. Use of the methyl 2-naphthyl ether protecting group, compatible with the boron Lewis acids required for enantioselective aldol condensation, allows direct access to all the bengamides. [source]


    An Organocatalytic Domino Thia-Michael/Aldol Condensation Reaction: Highly Enantioselective Synthesis of Functionalized Dihydrothiophenes

    ADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 13 2010
    Jie Tang
    Abstract An organocatalytic domino thia-Michael/aldol condensation reaction of ,, ,-unsaturated aldehydes with 1, 4-dithiane-2,5-diol catalyzed by chiral diphenylprolinol TMS ether has been developed, which provides a new practical and direct route to chiral dihydrothiophenes with high yields (up to 90%) and excellent enantioselectivities (up to>99% ee). The catalytic mechanism of the domino reaction was further confirmed through the APCI-MS detection of proposed reaction intermediates. [source]


    Enantioselective Synthesis of Spirocyclic Oxindole-,-lactones via N-Heterocyclic Carbene-Catalyzed Cycloaddition of Ketenes and Isatins

    ADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 11-12 2010
    Xiao-Na Wang
    Abstract Chiral N-heterocyclic carbenes were found to be efficient catalysts for the formal [2+2] cycloaddition reaction of disubstituted ketenes and isatins to give the corresponding spirocyclic oxindole-,-lactones in good yields with good diastereoselectivities and excellent enantioselectivities. Ring opening with Grignard reagents or decarboxylation of the oxindole spirocyclic-,-lactone gave the corresponding 3-hydroxy- or 3-alkylenyloxindoles in good yields. [source]


    Enantioselective Synthesis of Chiral ,-Aryloxy Alcohols by Ruthenium-Catalyzed Ketone Hydrogenation via Dynamic Kinetic Resolution (DKR)

    ADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 1 2010
    Wen-Ju Bai
    Abstract A highly efficient enantioselective synthesis of chiral ,-aryloxy alcohols by the {RuCl2[(S)-SDP][(R,R)-DPEN]} [(Sa,R,R)- 1a; SDP=7,7,-bis(diarylphosphino)-1,1,-spirobiindane; DPEN=trans -1,2-diphenylethylenediamine] complex-catalyzed asymmetric hydrogenation of racemic ,-aryloxydialkyl ketones via dynamic kinetic resolution (DKR) has been developed. Enantioselectivities of up to 99% ee with good to high cis/anti -selectivities (up to>99:1) were achieved. [source]


    Enantioselective Synthesis of Chiral Tetrahydroisoquinolines by Iridium-Catalyzed Asymmetric Hydrogenation of Enamines

    ADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 18 2009
    Pu-Cha Yan
    Abstract Chiral iridium complexes based on spiro phosphoramidite ligands are demonstrated to be highly efficient catalysts for the asymmetric hydrogenation of unfunctionalized enamines with an exocyclic double bond. In combination with excess iodine or potassium iodide and under hydrogen pressure, the complex Ir/(Sa,R,R)- 3a provides chiral N -alkyltetrahydroisoquinolines in high yields with up to 98% ee. The L/Ir ratio of 2:1 is crucial for obtaining a high reaction rate and enantioselectivity. A deuterium labeling experiment showed that an inverse isotope effect exists in this reaction. A possible catalytic cycle including an iridium(III) species bearing two monophosphoramidite ligands is also proposed. [source]


    Enantioselective Synthesis of Dihydrocoumarins via N-Heterocyclic Carbene-Catalyzed Cycloaddition of Ketenes and o -Quinone Methides

    ADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 17 2009
    Hui Lv
    Abstract Chiral N-heterocyclic carbenes were found to be efficient catalysts for the formal [4+2],cycloaddition reaction of alky(aryl)ketenes and o -quinone methides to give the corresponding 3,3,4-trisubstituted 3,4-dihydrocoumarins in good yields with good diastereoselectivities and excellent enantioselectivities. [source]


    Efficient Solvent-Free Robinson Annulation Protocols for the Highly Enantioselective Synthesis of the Wieland,Miescher Ketone and Analogues

    ADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 14-15 2009
    Ben Bradshaw
    Abstract A highly efficient (93% overall yield) and enantioselective (94% ee) synthesis of the Wieland,Miescher ketone (10-g scale) through a solvent-free Robinson annulation procedure is reported. The process involves only 1,mol% triethylamine as the base in the initial Michael process and the organocatalyst N -tosyl-(Sa)-binam- L -prolinamide (2,mol%) and benzoic acid (0.5,mol%) for the intramolecular aldol process. This green protocol is applied to a wide range of valuable building block analogues of the Wieland,Miescher ketone (10 examples). Among these, a noteworthy compound for terpene synthesis is the 8a-allyl derivative, which is prepared in 93% yield and 97% ee in a process allowing the recovery and reutilization of the organocatalyst. Furthermore, a one-pot, two-step process has also been developed. [source]


    Alkylzinc-Mediated Addition of Alkynes to N -Tosylaldimines: Enantioselective Synthesis of (E)-(2-En-3-ynyl)-amines

    ADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 10 2009
    Chao Yin
    Abstract An alkylzinc-mediated simple and efficient procedure for the catalytic enantioselective synthesis of N- tosyl-(E)-(2-en-3-ynyl)-amines has been developed. The method works well with various N -tosylaldimines and alkynes. [source]


    A Catalytic and Enantioselective Synthesis of trans- 2-Amino-1- aryltetralins

    ADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 6 2009
    Saumen Hajra
    Abstract The bis-oxazoline-copper complex-catalyzed aziridination of alkenes followed by an intramolecular Friedel,Crafts alkylation of the tethered and in situ generated aziridine provides a one-pot, general and efficient method for the synthesis of trans -2-amino - 1-aryltetralins from a mixture of 2- arylethylstyrenes (E/Z,85:15) with excellent dia- stereo- (dr>99:1) and enantioselectivities (up to 92% ee). [source]


    Enantioselective Synthesis of Chiral ,-Aryloxy Alcohols by Asymmetric Hydrogenation of ,-Aryloxy Aldehydes via Dynamic Kinetic Resolution

    ADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 3 2009
    Zhang-Tao Zhou
    Abstract A catalytic enantioselective hydrogenation of racemic ,-aryloxy aldehydes via dynamic kinetic resolution has been developed by using (diamine)(spirodiphosphine)ruthenium(II) chloride [RuCl2(SDPs)(diamine)] catalysts. Employing this new reaction system a variety of optically active ,-aryloxy primary alcohols were synthesized in high yields and moderate to good enantioselectivities. [source]


    Enantioselective Synthesis of Phospholenes via Asymmetric Organocatalytic Alkene Isomerization

    ADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 10 2008
    Lukas Hintermann
    Abstract An asymmetric synthesis of the 2,5-diphenylphosphol-2-ene fragment (,95% ee) has been realized via enantioselective Cinchona -alkaloid catalyzed double bond isomerization of a meso -2,5-diphenylphosphol-3-ene amide to a 2,5-diphenylphosphol-2-ene amide (up to 83% ee), followed by enantiomeric enrichment to ,95% ee by crystallization. The 2,5-diphenylphosphol-2-ene amide (a cyclic phosphinic acid amide) was hydrolyzed to the 2,5-diphenylphosphol-2-ene acid (a cyclic phosphinic acid) with retention of configuration at C-5. [source]


    Nitrilase-Catalyzed Enantioselective Synthesis of Pyrrolidine- and Piperidinecarboxylic Acids

    ADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 8-9 2007
    Margit Winkler
    Abstract The enantioselective synthesis of the non-proteinogenic amino acids ,-proline and nipecotic acids from their readily available nitriles is achieved in high enantiomeric excess by commercially available nitrilases. The presented procedure comprises not more than 4 steps, thus considerably reducing the multiple steps generally required. Amide formation is also observed for specific heterocyclic nitriles. [source]


    Enantioselective Synthesis of 4-(Dimethylamino)pyridines through a Chemical Oxidation-Enzymatic Reduction Sequence.

    ADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 18 2006
    Application in Asymmetric Catalysis
    Abstract Enantiomerically pure 4-(dimethylamino)-3-(1-hydroxyalkyl)pyridines and 4-(dimethylamino)-3-[hydroxy(phenyl)methyl]pyridine have been prepared through efficient chemoenzymatic routes. For this purpose different lipases and oxidoreductases have been tested in the preparation of optically active 4-chloro derivatives and baker's yeast was found to be an excellent catalyst for the bioreductions of the corresponding ketones. Their applications as enantioselective nucleophilic catalysts have been studied, important catalytic properties were observed in the stereoselective construction of quaternary centers. [source]