Asymmetric Conjugate Hydrocyanation of α,β-Unsaturated <i>N</i>-Acylpyrroles with the Ru(phgly)₂(binap)–CH₃OLi Catalyst System

Abstract

Asymmetric conjugate hydrocyanation of α,β-unsaturated carboxylic acid derivatives catalyzed by a Ru[(S)-phgly]2[(S)-binap]-CH3OLi system was examined. The N-acylpyrrole gave the best result in terms of reactivity and enantioselectivity. A series of substrates with alkyl or heterosubstituted alkyl groups at the β-position reacted with a substrate-to-catalyst molar ratio of 200-2000 to afford the β-cyano products in the range of 88%->99% ee. The mode of enantioselection in the hydrocyanation was proposed.