Study of asymmetric aldol and Mannich reactions catalyzed by proline–thiourea host–guest complexes in nonpolar solvents
摘要:
A proline-thiourea host-guest complex has been described as a good catalyst for asymmetric reactions such as aldol and Mannich reactions. High stereoselectivities were obtained under optimal conditions. Thiourea was observed to have an important effect on the reactivity and selectivity, even in an unconventional nonpolar reaction medium and without the need to utilize low temperatures. This proline-thiourea host-guest system has the ability to participate in a hydrogen bonding network. (C) 2013 Elsevier Ltd. All rights reserved.
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
The Proline-Catalyzed Direct Asymmetric Three-Component Mannich Reaction: Scope, Optimization, and Application to the Highly Enantioselective Synthesis of 1,2-Amino Alcohols
作者:Benjamin List、Peter Pojarliev、William T. Biller、Harry J. Martin
DOI:10.1021/ja0174231
日期:2002.2.1
We have developed proline-catalyzed direct asymmetric three-component Mannich reactions of ketones, aldehydes, and amines. Several of the studied reactions provide beta-amino carbonyl compounds (Mannich products) in excellent enantio-, diastereo-, regio-, and chemoselectivities. The scope of each of the three components and the influence of the catalyst structure on the reaction are described. Reaction