关键词： 有机合成   不对称合成   (S)-3-甲基-1   1-二苯基-1   2-丁二醇   结构  

摘要： 本文合成了 (S) - 3-甲基 - 1 ,1 -二苯基 - 1 ,2 -丁二醇 ,并通过元素分析、核磁共振、红外光谱测定了其结构。

关键词： 手性技术   绿色化学   不对称合成   手性催化   生物技术  

摘要： 手性技术不仅与我们的生活中的医药、农药等密切相关 ,而且对生命起源等问题具有重要的理论意义 .本文全面地介绍了手性技术 ,特别是不对称合成 .其中 ,从绿色化学的观点看 ,与生物技术有关的各种手段较有前途 ;而手性催化不仅符合绿色化学潮流而且经济实惠 ,目前在工业上已被广泛应用 ,为此 2 0 0 1年诺贝尔化学奖授予了该领域的三位开拓者 .

关键词： 不对称合成   4,4-二取代-3,4-二氢-2(1H)喹唑啉酮   医药   中间体  

关键词： asymmetric synthesis   amino acids   chiral auxiliaries   nickel(II) complexes  

摘要： The synthesis of new chiral auxiliaries (S)-N-(2-benzoylphenyl)-1-(3,4-dichlorobenzyl)pyrrolidine-2-carboxamide (1a), (,S)-N-(2-benzoylphenyl)-1-(pentafluorobenzyl)pyrrolidine2-carboxamide (1b), and (S)-N-(2-benzoylphenyl)-1-(4-isopropoxytetrafluorobenzyl)pyrrolidine-2-carboxamide (1c) and their application in the asymmetric synthesis of amino acids using Ni-II complexes of their Schiff's bases with alanine and glycine are described. Compound la is particularly appropriate for highly stereoselective synthesis of a-methyl-a-amino acids with high enatiomeric purity (ee >95%).

关键词： Addition reactions   Enantioselective synthesis   Catalysts   Metathesis   Lithium  

摘要： [GRAPHIC] An enantioselective total synthesis of (-)-adaline has been achieved starting from a chiral 6,6-disubstituted piperidone derivative previously prepared by diastereoselective allylation of a chiral tricyclic N-acyl-N,O-acetal. The key steps include lithium ion-activated S(N)2-type alkynylation of the tricyclic NO-acetal leading to exclusive formation of the (6S)-ethynylpiperidine and ring-closing olefin metathesis of the (2R,6S)-cis-2,6-dialkenylpiperidine for constructing the bridged azabicyclononane.

关键词： Aldehydes   Ligands   Enantioselective synthesis   Catalysts   Lewis acids  

摘要： [GRAPHICS] A new bifunctional catalytic system based on a monometallic aluminum complex is used for the efficient enantioselective cyanation of aldehydes. The ligand (S)- or (R)-2,2'-bis(diethylaminomethyl)-substituted binaphthol (BINOLAM) used is recovered for recycling. This methodology is used for the synthesis of a precursor of epothilone A.

关键词： Alkenes   Catalysis   Copper   Cyclohexanes   Hydrocarbons   Cyclic   Ketones   Nitro Compounds   Organometallic Compounds   Support   Non-U.S. Gov't   Support   U.S. Gov't   P.H.S.  

摘要： An efficient and highly enantioselective (>/=92% ee) catalytic method for conjugate addition of alkylzinc reagents to cyclic nitroalkenes is reported. Reactions are promoted in the presence of 0.5-5 mol % (CuOTf)2.C6H6 and 1-10 mol % of chiral amino acid-based phosphine ligands at 0 degrees C in toluene. The Cu-catalyzed reactions can be effectively carried out with small-, medium-, and large-ring nitroalkenes. Depending on the reaction conditions used, either the nitro or the corresponding alpha-substituted ketone product can be readily accessed by the present protocol.

关键词： Amides   Stereoisomerism   Sulfinic Acids   Sulfur Oxides   Thiazoles  

摘要： Simple and practical asymmetric synthesis of functionally differentiated aminoindanol based endo-N-sulfonyl 1,2,3-oxathiazolidine-2-oxide as sulfinyl transfer agents are developed. The importance of these new and unique sulfinyl transfer reagents are exemplified by the expedient production of several sulfinamide ligands, including either enantiomer of (R)-tert-butanesulfinamide in excellent yields and enantiopurities.

关键词： Amino Acids   Crystallography   X-Ray   Esters   Imino Acids   Organometallic Compounds   Stereoisomerism   Sulfones   Support   Non-U.S. Gov't   Titanium  

摘要： Selective addition of the chiral, sulfonimldoyl substituted bis(allyl)titanium complexes 5a-d, which are configurationally labile in regard to the Calpha-atoms, to N-toluenesulfonyl (Ts)-, N-2-trimethylsilylethanesulfonyl (SES)-, and N-tert-butylsulfonyl (Bus) alpha-imino ester (9a-c) in the presence of Ti(OiPr)(4) and ClTj(OiPr)(3) afforded with high regio- and diastereoselectivities in good yields the (syn, E)-configured beta-alkyl-gamma,delta-unsaturated alpha-amino acid derivatives 2a-g, which carry a chiral, electron-withdrawing nucleofuge at the delta-position and a cyclohexyl, an isopropyl, a phenyl, and a methyl group at the beta-position. Addition of the cyclic bis(allyl)titanium complex 14 to N-Bus alpha-imino ester 9c afforded with similar high regio- and diastereoselectivities the (E)- and (Z)-configured amino acid derivatives (E)-8 and (Z)-8. Reaction of complexes 5a-d with alpha-imino esters 9a-c in the presence of Ti(OiPr)(4) occurs stepwise to give first the mono(allyl)titanium complexes containing 2a-g as ligands, which react in the presence of CITi(OiPr)(3) with a second molecule of 9a-c with formation of two molecules of 2a-g. Formation of (S,R,E)-configured homoallylic amines 2a-g entails SiRe,E processes of alpha-imino esters 9a-c with the (R,R)-configured bis(allyl)titanium complexes (R,R)-5a-d and (R)-configured mono(allyl)titanium complexes (R)-17a-d, both of which are most likely in rapid equilibrium with their (S,S)-diastereomers and (S)-diastereomers, respectively, Interestingly, in the reaction of 5a-d with aldehydes, the (S,S)-configured complexes (S,S)5a-d are the ones which react faster. Reaction of the N-titanated amino acid derivatives Ti-2a and Ti-2b with N-Ts alpha-imino ester 9a led to the highly diastereoselective formation of imidazoldinones 15a and 15b, respectively. Cleavage of the sulfonamide group of the N-Bus amino acid derivative 2d with CF3SO3H gave quantitatively the sulfonimidoyl functionalized amino acid H-2d. A Ni-cat

关键词： 市场展望   手性合成   拆分技术   生物催化   不对称合成   手性药物  

摘要： 2000年全球手性技术市场总值为66.3亿美元,预计到2007年将增长到160.3亿美元。医药行业是手性技术的最大市场,2000年占市场总额的81.2％,并会以13.4％的速度继续增长。农用化学品和香精香料是手性技术的另外两个主要的终端用户市场,但预计市场份额将会下滑。手性源、拆分技术、生物催化技术和不对称合成是目前4种主要的手性技术。