[EN] ORGANOCATALYSTS AND METHODS OF USE IN CHEMICAL SYNTHESIS [FR] ORGANOCATALYSEURS ET PROCEDES D'UTILISATION DE CES DERNIERS DANS LA SYNTHESE CHIMIQUE
A Highly Enantioselective Amino Acid-Catalyzed Route to Functionalized α-Amino Acids
作者:Armando Córdova、Wolfgang Notz、Guofu Zhong、Juan M. Betancort、Carlos F. Barbas
DOI:10.1021/ja017270h
日期:2002.3.1
enantiomerically pure α-amino acids has intrigued generations of chemists and been the subject of intense research. This report describes a general approach to functionalized α-amino acids based on catalytic asymmetric synthesis. Proline catalyzed Mannich-type reactions of N-PMP-protected α-imino ethyl glyoxylate with a variety of unmodified ketones to provide functionalized α-amino acids in high yields with
提供对映异构纯 α-氨基酸的合成方法的发展引起了几代化学家的兴趣,并成为深入研究的主题。本报告描述了基于催化不对称合成的功能化 α-氨基酸的一般方法。脯氨酸催化 N-PMP 保护的 α-亚氨基乙醛酸乙酯与各种未修饰的酮的曼尼希型反应,以高产率提供功能化的 α-氨基酸,具有出色的区域选择性、非对映选择性和对映选择性。对七个实例的研究产生了六个,产品 ee 值≥99%。在涉及可以形成非对映异构产物的酮供体的反应中,两个相邻的立体中心在碳-碳键形成时同时产生,具有完全的同步立体控制。显着地,
The Scope of the Direct Proline-Catalyzed Asymmetric Addition of Ketones to Imines
作者:Wolfgang Notz、Shin-ichi Watanabe、Naidu S. Chowdari、Guofu Zhong、Juan M. Betancort、Fujie Tanaka、Carlos F. Barbas
DOI:10.1002/adsc.200404114
日期:2004.8
A full account of catalytic direct asymmetric Mannich-type reactions is presented describing the scope of amino acid-catalyzed additions of unmodified ketones to a large variety of imines. These reactions are performed under very mild, operationally simple, and environmentally friendly and benign conditions employing a one-pot, three-component protocol as well as preformed imines. Typically, products
Catalysis of highly stereoselective Mannich-type reactions of ketones with α-imino esters by a pyrrolidine-sulfonamide. Synthesis of unnatural α-amino acids
作者:Wei Wang、Jian Wang、Hao Li
DOI:10.1016/j.tetlet.2004.08.032
日期:2004.9
The novel pyrrolidine-sulfonamide I has been prepared and used successfully to catalyze Mannich-type reactions between ketones and alpha-imino esters. The process is used to efficiently synthesize functionalized alpha-amino acid derivatives with excellent levels of regio-, diastereo-, and enantio-selectivity. (C) 2004 Elsevier Ltd. All rights reserved.
Insights into the spontaneous emergence of enantioselectivity in an asymmetric Mannich reaction carried out without external catalyst
作者:Felix E. Held、Anja Fingerhut、Svetlana B. Tsogoeva
DOI:10.1016/j.tetasy.2012.10.021
日期:2012.12
ESI-MS, chiral HPLC, time-resolved H-1 NMR and optical rotation measurements were performed to gain insights into the nature of spontaneous mirror symmetry breaking in the catalyst-free Mannich reaction of PMP protected alpha-iminoethylglyoxylate with hydroxyacetone. Spontaneous temporary generation of enantiomeric excesses of up to 7.4% in the major syn diastereomer is reproducibly observed in aqueous phosphate buffers, starting from achiral conditions. The syn-product ee values for both enantiomers [(2S,3S) and (2R,3R)], although not with stochastic distribution, have been observed with no clear preference for either enantiomer. (C) 2012 Elsevier Ltd. All rights reserved.