共查询到19条相似文献,搜索用时 93 毫秒
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二烷基锌对醛的不对称加成反应是合成手性二级醇的有效方法,反应产物手性二级醇是药物、精细化学品、天然产物的重要中间体,手性氨基醇是诱导这类反应手性配体的重要组成部分并且表现出了很高的对映选择性。综述了催化该类反应手性氨基醇配体的一些研究新进展。 相似文献
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介绍了樟脑及其衍生物在不对称还原反应、加成反应、烷基化反应、Diels-Alder 反应、氧化反应和卤化反应中的应用。同时还列举了樟脑及其衍生物在不对称合成中用作手性试剂和手性催化剂的一些例子。 相似文献
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3,3’-位杂原子取代的BINOL类手性催化剂在不对称合成中的应用 总被引:1,自引:0,他引:1
从一系列3,3’-位杂原子取代的BINOL(1,1’-联二萘酚)类手性催化剂不对称催化反应类型的不同,探讨了3,3’-位杂原子取代的BINOL类手性催化剂在不对称合成中应用的研究进展,指出3,3’-位杂原子取代的BINOL类手性催化剂不对称催化底物高效的对映体选择性,并对该类手性催化剂的发展进行了展望。 相似文献
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近年来,有机小分子催化的串联反应已成为众多有机化学家们的研究热点,是合成手性化合物的有效方法。在众多不同催化体系中,手性叔胺催化的不对称串联反应得到了空前的发展。氧化吲哚螺环骨架是很多具有药理活性分子普遍存在的结构形式,含有该骨架的化合物是众多药物及有机化学家们的目标产物,不对称催化串联反应是合成氧化吲哚螺环化合物的重要理论基础和有力学术支撑。本文对近四年手性叔胺催化的不对称串联反应构建氧化吲哚螺环化合物的研究进行介绍。 相似文献
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Stefan Brse Frank Lauterwasser RobertE. Ziegert 《Advanced Synthesis \u0026amp; Catalysis》2003,345(8):869-929
The synthesis of enantiomerically pure compounds is one of the major challenges in organic synthesis. In this review, we present the state of the art in asymmetric catalysis using immobilized chiral ligands and complexes for asymmetric C C and C‐heteroatom bond forming reactions. Chiral catalysts based on dendrimers and soluble polymeric supports are considered. In particular, addition reactions to carbon‐carbon double bonds, asymmetric 1,2‐addition reactions using, e.g., dialkylzinc reagents, metal‐catalyzed substitution reactions and cycloaddition reactions are covered. Specific emphasis is placed on enantioselective epoxidation and aldol reactions. A further aspect is the (hetero) Diels–Alder reaction catalyzed by immobilized ligands. 相似文献
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Allemann C Gordillo R Clemente FR Cheong PH Houk KN 《Accounts of chemical research》2004,37(8):558-569
Computational studies have led to models to understand some classic and contemporary asymmetric reactions involving organocatalysts. The Hajos-Parrish-Eder-Sauer-Wiechert reaction and intermolecular aldol reactions as well as Mannich reactions and oxyaminations catalyzed by proline and other amino acids, and Diels-Alder reactions catalyzed by MacMillan's chiral amine organocatalysts have been studied with density functional theory. Quantitative predictions for several new catalysts and reactions are provided. 相似文献
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相转移催化反应的反应条件温和,反应产率高,操作简单,是不对称合成反应中发展起来的一个新兴领域。本文主要阐述了C_2对称的手性季铵盐相转移催化剂的研究进展及其在不对称催化反应中的应用。 相似文献
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相转移催化反应的反应条件温和,反应产率高,操作简单,是不对称合成反应中发展起来的一个新兴领域。本文主要阐述了C2对称的手性季铵盐相转移催化剂的研究进展及其在不对称催化反应中的应用。 相似文献
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In the first successful catalytic asymmetric Diels-Alder reaction in 1979, Koga and colleagues used a chiral aluminum complex as a Lewis acid catalyst, but since then, researchers have developed numerous catalytic systems for these reactions. By 2000, several chiral organic compounds, such as the salts of imidazolidinones or TADDOLs, emerged as robust catalysts in the asymmetric Diels-Alder reactions. According to frontier molecular orbital theory, most of these catalysts employ a LUMO-lowering strategy as a means of activating electron-deficient dienophiles. Only rarely do chiral catalysts take advantage of the alternative strategy of activating the HOMO. In this Account we will discuss the development of asymmetric Diels-Alder reactions based on the HOMO-raising effects of chiral amines. First, we show that enamine intermediates formed in situ between an amine catalyst and enolizable aliphatic aldehydes can act as electron-rich dienophiles in inverse-electron-demand Diels-Alder reactions. We describe the preparation of a variety of oxygen- or nitrogen-containing heterocycles with high optical purity. Then, we demonstrate that the dienamine species from α,β-unsaturated aldehydes can act either as electron-rich dienes in normal-electron-demand Diels-Alder reactions or as dienophiles in inverse-electron-demand Diels-Alder reactions. These reactions generally occur with high chemo-, regio-, and stereoselectivity. Finally, we introduce a new activation mode for Diels-Alder reactions, in which reactive trienamine intermediates derived from 2,4-dienals or even 2,4-dienones play a key role. Notably, we observe remarkable β,ε-regioselectivity and obtain excellent stereocontrol even at the very remote ε-reactive center-up to seven bonds away from the chiral center of the amine catalyst. These results demonstrate that a HOMO-activation strategy via aminocatalysis could become a significant tool in asymmetric Diels-Alder reactions. In addition, these reactions using enamine, dienamine, or trienamine intermediates produce a diverse array of densely functionalized cyclic scaffolds, which may serve as valuable structures in drug discovery and natural product synthesis. 相似文献
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手性亚砜是重要的手性中间体和辅剂、手性配体和催化剂、手性药物。手性金属络合物催化硫醚的不对称氧化是合成手性亚砜最有效的方法。文章简要的介绍了钛,钒,铌,铁四种金属的络合物不对称催化硫醚氧化的一些最新的研究现状。 相似文献
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