Direct asymmetric aldol reactions between aldehydes and ketones catalyzed by l-tryptophan in the presence of water
作者:Zhaoqin Jiang、Hui Yang、Xiao Han、Jie Luo、Ming Wah Wong、Yixin Lu
DOI:10.1039/b921460g
日期:——
Primary amino acids and their derivatives were investigated as catalysts for the direct asymmetric aldol reactionsbetween ketones and aldehydes in the presence of water, and L-tryptophan was shown to be the best catalyst. Solvent effects, substrate scope and the influence of water on the reactions were investigated. Quantum chemical calculations were performed to understand the origin of the observed
A Green and Efficient Asymmetric Aldol Reaction Catalyzed by a Chiral Anion Modified Ionic Liquid
作者:Yunbo Qian、Xin Zheng、Yongmei Wang
DOI:10.1002/ejoc.201000304
日期:2010.7
A chiral anion modified ionic liquid derivedfrom L -proline proves as a green and efficient asymmetric organocatalyst for direct asymmetric aldolreactions in [BMIm]BF 4 at room temperature. The corresponding aldol products with moderate to good isolated yields (up to 99 %), anti-diastereoselectivities (up to 97:3), and excellent enantioselectivities (up to 99 % ee) were afforded. Recycling of the
2-Hydroxy-3-[(S)-prolinamido]pinanes as novel bifunctional organocatalysts for asymmetric aldol reactions in aqueous media
作者:Dmitry E. Siyutkin、Alexander S. Kucherenko、Larisa L. Frolova、Alexander V. Kuchin、Sergei G. Zlotin
DOI:10.1016/j.tetasy.2011.07.013
日期:2011.6
Novel (S)-prolinamides with stereoisomeric 2-hydroxy-3-aminopinane units have been synthesized. In the presence of (1R,2R,3S,5R)-2-hydroxy-3-[(S)-prolinamido]pinane (5 mol %) cyclic ketones reacted with (hetero-)aromatic aldehydes in aqueous media to afford chiral aldols in high yields. The reaction had moderate to high diastereo- (dr up to 91/9) and enantioselectivities (up to 83% ee). (C) 2011 Elsevier Ltd. All rights reserved.