Highly enantioselective tandem cyclopropanation/Wittig reaction of α,β-unsaturated aldehydes with arsonium ylides catalyzed by recyclable dendritic catalyst
作者:Yun-Hui Zhao、Chang-Wu Zheng、Gang Zhao、Wei-Guo Cao
DOI:10.1016/j.tetasy.2008.02.022
日期:2008.4
A novel tandem cyclopropanation/Wittig reaction of alpha,beta-unsaturated aldehydes with arsonium ylides using a chiral 2-trimethylsilanyloxy-methyl-pyrrolidine-based dendritic catalyst is described. Good yields (up to 86%), and high diastereoselectivities (up to dr = 99: 1) and enantioselectivities (up to 99% ee) were obtained under simple and mild reaction conditions. The catalyst can be recycled without any loss in activity. (c) 2008 Elsevier Ltd. All rights reserved.
Preparation of acetylstyrene- and benzoylstyrene-tricarbonylchromium, and of 1-acetyl- and 1-benzoyl-2-ferrocenylethylene
作者:Jiling Huang、Yao-Zeng Huang
DOI:10.1016/0022-328x(91)83240-5
日期:1991.8
The title compounds were synthesized by the reaction of a variety of arsonium salts with benzaldehyde tricarbonyl chromium or monoformyl ferrocene in the presence of K2CO3 at room temperature under phase transfer conditions, giving good yields.
Organocatalytic asymmetric cyclopropanation of α,β-unsaturated aldehydes with arsonium ylides
作者:Yun-Hui Zhao、Gang Zhao、Wei-Guo Cao
DOI:10.1016/j.tetasy.2007.10.007
日期:2007.10
A novel organocatalytic asymmetric cyclopropanation of alpha,beta-unsaturated aldehydes with arsonium ylides using diphenylprolinol silylether as a catalyst is described. A variety of chiral cyclopropyl aldehydes are obtained in moderate to good yields with up to 99:1 dr (diastereomeric ratio) and 99% ee under simple and mild reaction conditions. (c) 2007 Elsevier Ltd. All rights reserved.