关键词： AROMATIC amines   ORGANIC compounds   ALIPHATIC compounds   STEREOCHEMISTRY   BROMIDES   ORGANIC chemistry  

摘要： An efficient method for the asymmetric synthesis of C-aliphatic homoallylic amines with up to 94% yield and 80% de is reported. Ring-closing metathesis of several chiral homoallylic amines using the second-generation Grubbs catalyst provided easy access to a wide variety of cyclohexenylamines.

关键词： L-[4-C-13] lysine   labeled amino acid   chiral glycine equivalent   oxazinone  

摘要： L-[4-C-13]Lysine (2) was synthesized from sodium [2-C-13]acetate (3) and Dellaria's oxazinone 1 as a chiral glycine equivalent. Wittig reaction of the glycinal 7 and C-13-labeled phosphonium ylide 5, prepared from sodium [2-C-13]acetate (3), gave the a, beta-unsaturated ester 8. The ester 8 was converted to the allylic bromide 10. Alkylation of the oxazinone I with 10 proceeded with high diastereoselectivity. Ethanolysis, hydrogenation of the double bond with diimide, removal of the chiral auxiliary, and hydrolysis gave L-[4-C-13]Iysine (2). Copyright (C) 2004 John Wiley Sons, Ltd.

关键词： TRANSFER-RNA SYNTHETASE   OPENING METATHESIS POLYMERIZATION   GREEN-FLUORESCENTPROTEIN   LIQUID-CRYSTALLINE POLYMERS   NONNATURAL AMINO-ACIDS   PHOTO-CROSS-LINKING   GENETIC-CODE   ESCHERICHIA-COLI   IN-VIVO   1   4-POLYBUTADIENE SYSTEM  

摘要： L-alpha-(1-Cyclobutenyl)glycine (1-Cbg) was targeted as a potentially translatable analogue of isoleucine and valine and as a useful building block for peptides. An enantioselective synthesis was executed in which the key step was diastereoselective addition of 1-cyclobutenylmagnesium bromide to the sulfinimine 2b derived from (S)-t-butanesulfinimide and tert-butyl glyoxylate. 1-Cbg was found to substitute efficiently for isoleucine and valine, but not leucine, in the translation of green fluorescent protein in vitro.

关键词： 潜手性Schiff碱   不对称合成   催化氢化反应   均相反应   非均相反应   氢转移  

摘要： 对近年来潜手性Schiff碱的不对称催化氢化的发展状况按照均相。

关键词： 脂肪氧化酶   区域选择性   生物催化   不对称合成  

摘要： 介绍了脂肪氧化酶在不对称氧化中的生物催化作用。讨论了影响脂肪氧化敏生物催化作用的区域特异性和立体特异性因素。

关键词： asymmetric synthesis   carbohydrates   chiral auxilia   2 Background   ries   Michael additions   pericyclic reactions  

摘要： Highly diastereoselective carbon-carbon bond-forming reactions achieved on a variety of sugar templates were found. For example, methyl 6-deoxy-2,3-di-O-(t-butyldimethylsilyl)-alpha-D-glucopyranoside can serve as a versatile and effective chiral auxiliary. Namely, the 1,4-addition reactions to its 4-O-crotonyl ester of some carbon nucleophiles or alkyl radicals proceeded highly diastereoselectively to afford the corresponding adducts. The alkylation of the enolate generated from its 4-O-propionyl ester afforded the alpha-alkylated product with a useful level of stereoselectivity. Furthermore, the Diels-Alder reaction of its 4-O-acryloyl ester with cyclopentadiene afforded an endo-adduct stereoselectively. In the case of the 1,3-dipolar cycloaddition of the acryloyl ester, again the cycloadduct was obtained highly stereoselectively. Some other types of sugar templates prepared from methyl alpha-D-glucopyranoside, alpha-D-mannopyranoside and alpha-D-galactopyranoside were explored to verify their ability to function as chiral templates. In some cases, these templates afforded complementary results in the sense of diastereoselectivity. Methodologies for the removal of the sugar template from the products were developed.

关键词： 不对称合成   N-烃基化   N-磺酰化   硼烷   胺基醇  

摘要： 为研究不对称催化合成反应,以L 亮氨酸为原料,由酯化、格式反应、还原N 烃基化反应合成3个新手性胺醇(6a,6b,6c),6b和6c经磺酰化得7a和7b.将手性配体6a,6b,6c,7a,7b分别与BH3·Me2S络合,由2种方法对芳香酮进行不对称还原,得芳香醇,不对称还原收率(ee)为3.9%～60.5%,其中手性磺胺醇的不对称催化收率较胺醇高.

关键词： 三氟甲基磺酸铜   不对称合成   手性催化剂   手性双噁唑啉   手性亚磷酸胺酯   手性亚磷酸酚酯  

摘要： 三氟甲基磺酸铜 [Cu(OTf) 2 ]与各种手性磷氮配体络合催化不对称合成已取得了巨大进展 .

关键词： asymmetric synthesis   Mannich reaction   organic catalysis   oxidation   proline  

摘要： trans-4-tert-Butyldimethylsiloxy-L-proline displays a greater catalytic activity than the parent proline without compromising the enantioselectivity, which widens the substrate scope in the alpha-aminoxylation of carbonyl compounds, as well as O-nitrosoaldol/Michael, and Mannich reactions.

关键词： Additives   Organic synthesis   Selectivity   Nitrogen compounds   Stereoselectivity  

摘要： Highly diastereoselective intra- and intermolecular self-condensation reactions of N-tert-butanesulfinyl aldimines have been developed and applied to the rapid, asymmetric synthesis of trans-2-aminocyclopentanecarboxylic acid and the drug candidate SC-53116. Key to both syntheses is a novel microwave-assisted reaction in which N-sulfinyl aldimines are cleanly converted into nitriles in high-yielding concerted elimination processes.