<scp>l</scp>-Piperazine-2-carboxylic Acid Derived <i>N</i>-Formamide as a Highly Enantioselective Lewis Basic Catalyst for Hydrosilylation of <i>N</i>-Aryl Imines with an Unprecedented Substrate Profile

Abstract

[reaction: see text] l-Piperazine-2-carboxylic acid derived N-formamides have been developed as highly enantioselective Lewis basic catalysts for the hydrosilylation of N-aryl imines with trichlorosilane. The arene sulfonyl group on N4 was found to be critical for the high enantioselectivity of the catalyst. High isolated yields (up to 99%) and enantioselectivities (up to 97%) were obtained for a broad range of substrates, including aromatic and aliphatic ketimines, particularly those with R(2) as relatively bulky alkyl groups.