Chlorotrimethylsilane as a mild and effective source of acid catalyst in reductive benzylation

Abstract

New reductive benzylation of hydroxy functions was effected by using the combination of benzaldehyde, TMSCl, and Et3SiH. TMSCl first reacts with alcohols to form HCl, which is probably the ultimate catalyst for this reaction system. TMSCl can also trap water and thus effectively promote dehydration reactions when more than stoichiometric amount of TMSCl is used. Although excess TMSCl was required for the foregoing reactions, TMSCl could be readily removed by simple evaporation. Copyright © 2005 The Chemical Society of Japan.