Highly Effective Asymmetric Hydrogenation of Cyclic <i>N</i>-Alkyl Imines with Chiral Cationic Ru-MsDPEN Catalysts

Abstract

A range of cyclic N-alkyl imines were efficiently hydrogenated by using a chiral cationic Ru(η(6)-cymene)(MsDPEN)(BArF) complex (MsDPEN = N-(methanesulfonyl)-1,2-diphenylethylenediamine) in high yields and up to 98% ee. A one-pot synthesis of chiral 2-phenylpyrrolidine via reductive amination was also developed.