Highly enantioselective tandem cyclopropanation/Wittig reaction of α,β-unsaturated aldehydes with arsonium ylides catalyzed by recyclable dendritic catalyst

Abstract

A novel tandem cyclopropanation/Wittig reaction of α,β-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.