Rationally‐Designed <i>S‐</i>Chiral Bissulfinamides as Highly Enantioselective Organocatalysts for Reduction of Ketimines

Abstract

Abstract We recently reported the first example of S ‐chiral organocatalysts, that are highly efficient and enantioselective in substoichometric amounts, and which use a chiral monosulfinamide group as Lewis base to activate trichlorosilane (HSiCl 3 ) to reduce N ‐arylketimines. A plausible mechanism involving two molecules of the monosulfinamde catalyst for the activation of HSiCl 3 prompted us to design S ‐chiral bissulfinamides as new catalysts. We herein describe our findings that an easily prepared S ‐chiral bissulfinamide bearing a five‐methylene linkage not only inherited the excellent substrate generality from the monosulfinamide catalysts, but also exhibited further improved enantioselectivity.