Simple and inexpensive threonine-based organocatalysts for the highly diastereo- and enantioselective direct large-scale syn-aldol and anti-Mannich reactions of α-hydroxyacetone
作者:Chuanlong Wu、Xiangkai Fu、Shi Li
DOI:10.1016/j.tetasy.2011.06.022
日期:2011.5
Simple and inexpensive threonine-based organocatalysts that promote syn-aldol reactions and three-component asymmetric anti-Mannich reactions of alpha-hydroxyacetone achieving a respectable level of enantioselectivities are reported. The syn-aldol products could be obtained with up to a 99:1 syn/anti ratio and > 99% ee while the anti-Mannich products could be obtained with up to a 96:4 anti/syn ratio and > 99% ee. Catalyst 1c can be used efficiently on a large-scale with the enantioselectivities of the syn-aldol and anti-Mannich reactions being maintained at the same level, which offers a great possibility for application in industry. (C) 2011 Elsevier Ltd. All rights reserved.
Simple and inexpensive threonine-based organocatalysts as highly active and recoverable catalysts for large-scale asymmetric direct stoichiometric aldol reactions on water
作者:Chuanlong Wu、Xiaoqin Long、Shi Li、Xiangkai Fu
DOI:10.1016/j.tetasy.2012.02.023
日期:2012.3
direct asymmetric stoichiometric aldolreaction on water by using variable amounts of water. These threonine-based organocatalyst were simple, inexpensive, highly active and could be synthesized on a large-scale. Among them, the threonine-based organocatalyst 1a is applicable to the stoichiometric reactions of a wide range of aromatic and heteroaromatic aldehydes with ketones, with the aldol products