Light-driven redox-relay deracemization of cyclic sulfonamides catalyzed by a chiral-at-metal iridium complex

Abstract

A visible-light-driven redox-relay deracemization of cyclic sulfonamides catalyzed by a chiral-at-metal iridium complex as a single catalyst is described. The octahedral chiral iridium complex first promotes effective photochemical oxidation of cyclic sulfonamides and subsequently acts as a chiral Lewis acid catalyst for the following ATH to enantioselectively reconstruct cyclic sulfonamides with high ee values. This deracemization offers a simple and more sustainable technique for synthesizing sulfonamides directly from racemic starting materials.