Organocatalytic Enantioselective (4+2) Annulation of Cyclopropane Carbaldehydes with 2‐Mercapto‐1‐Arylethanones

Abstract

AbstractHere, we report the organocatalytic enantioselective synthesis of dihydrothiopyran derivatives from trans racemic donor–acceptor cyclopropane carbaldehydes (DACCs) and 2‐mercapto‐1‐arylethanone via formal thio (4+2) cycloaddition involving thia‐Michael aldol condensation and annulation. Mechanistic studies indicate a typical kinetic resolution (KR) is involved in this transformation, which results in moderate yields and enantiomeric ratios. Remarkably, this method is characterized by its one‐pot simplicity, mild reaction conditions, and resilience towards air and moisture interference.