关键词： DNA分子荧光探针   三维有序大孔材料   胶晶模板法   制备   生物催化去消旋化   不对称合成   硫酸钡   结晶动力学   湿法磷酸   Heck反应   负载型钯催化剂  

关键词： fluorine and compounds   asymmetric synthesis   amino aldehydes   amino acids   oxidation  

摘要： Asymmetric synthesis of beta-trifluoromethylated beta-amino aldehyde and acid derivatives via the oxidation of enantiopure alpha-trifluoromethylated homoatlylamine as a new trifluoromethylated chiral building block is described. (C) 2004 Elsevier B.V. All rights reserved.

关键词： SPARTEINE   MYOCARDIAL depressants   ASYMMETRIC synthesis   ASYMMETRY (Chemistry)   ORGANIC synthesis (Chemistry)   ORGANIC chemistry  

摘要： Three new (+)-sparteine-like diamines were prepared from (-)-cytisine and evaluated as sparteine surrogates in the alpha-lithiation rearrangement of cyclooctene oxide and the palladium(II)/diamine catalyzed oxidative kinetic resolution of I-indanol. The new diamines exhibited opposite enantioselectivity to that observed with (-)-sparteine but increasing the steric hindrance of the N-alkyl group beyond N-Et had a detrimental effect on enantioselectivity. The optimal N-Me diamine was evaluated with much success in five other (-)-sparteine-mediated processes involving different metals (lithium, magnesium, and copper) and different types of reaction mechanisms.

关键词： ORGANOSULFUR compounds   ORGANIC synthesis (Chemistry)   CYCLIC compounds   RING formation (Chemistry)   CHIRALITY   OXIDATION  

摘要： A novel and efficient enantioselective synthesis of both enantiomers of syn-(3-trifluoromethyl)isoserine was achieved. Ring opening of trifluoromethylated cyclic sulfates 3, derived from enantiopure trifluoromethylated vicinal diols 2, with various nucleophiles occurred exclusively at C2 with inversion of chirality. Treatment of 4c and 4d, obtained by nucleophilic opening of 3a and 3b with PhCO2NH4, with (CF3SO2)(2)O followed by substitution with sodium azide, Jones oxidation, and hydrogenolysis furnished (2S,3S)-(N-benzoyl)-3-(trifluoromethyl)isoserine 9a and (2R,3R)-(N-benzoyl)-3-(trifluoromethyl)isoserine 9b, respectively.

关键词： CYCLOADDUCT   Bond cleavage   Asymmetric synthesis   precursors  

摘要： Enantiopure N,N-dialkylhydrazones 3 smoothly react with N-benzyloxycarbonyl-N-benzyl glycine as an aminoketene precursor to afford trans-3-amino-4-alkylazetidin-2-ones 4 as single diasteromers. As an exception, hydrazone 3f (R = OBn) affords cis-(3R,4R)-4f under modified conditions. N-N Bond cleavage of cycloadducts 4 afforded free azetidinones 5 in high yields.

关键词： AZIRIDINE 2-PHOSPHONATES   ACID DERIVATIVES   MICHAEL ADDITION   AMINO-ACIDS   SULFINIMINES   IMINES   EQUIVALENTS   ROUTE  

摘要： Addition of differentially N-protected glycine enolates to enantiopure sulfinimines affords syn- and anti-alpha,beta-diamino esters with high diastereoselectivities and good yields.

关键词： AMINO acids   BIOACTIVE compounds   ALDEHYDES   NATURAL products   ORGANIC acids   CHEMICALS  

摘要： beta-Hydroxy-alpha-amino acids are ubiquitous,important components of variousnitrogen-containing biologically active compounds and natural *** example,the vancomycinclass of antibiotics incorporates an erythro- and a threo-beta-arylserine moiety,and the promisingantifungal agents,sphingofungins,contain a beta-hydroxy-alpha-amino acid in the polar headgroup oftheir *** addition,beta-hydroxy-alpha-amino carbonyl compounds are often used asintermediates for synthesis of 2-amino-l,3-diols,beta-lactams,aziridines,and so *** a number ofmethods reported to date for the asymmetric synthesis of beta-hydroxy-alpha-amino acids,the aldolreaction of glycine derivatives with aldehydes has been considered to be the most syntheticallyefficient approach.

关键词： 不对称合成   手性环氧化物   烯烃   生物催化  

摘要： 手性环氧化物在合成上具有重要的应用价值。近年来,制取这些手性合成物的合成方法取得了很大的发展。文章重点讨论了生物催化手性前体烯烃不对称合成光学活性环氧化合物的发展状况。

关键词： 电化学   不对称合成   手性  

摘要： 随着近年来不对称合成的兴起和迅速发展,电化学不对称合成也得到了广大科研工作者的重视,取得了快速的发展。详细的总结了该领域特别是近十年以来的研究现状,探讨了电化学不对称合成的意义和特点,表明了电化学方法在不对称合成中的重要性和发展趋势。

关键词： 不对称合成   金属配合物   手性催化剂   有机配体   有机化学   领域   最新进展   热点  

摘要： 不对称合成是有机化学合成领域的热点。