Synthesis of Multifunctionalized Thiazolidine‐4‐thiones via [2+2+1] Annulation of Isothiocyanates and CF₃‐Imidoyl Sulfoxonium Ylides

Abstract

2‐Iminothiazolidin‐4‐one, 5‐ethylidenethiazolidin‐4‐one, and thiazolidine‐4‐thione are all medicinally relevant structures. In this work, a NaSO2CF3‐promoted [2+2+1] cascade annulation reaction of CF3‐imidoyl sulfoxonium ylides and isothiocyanates was reported to synthesize a variety of decorated thiazolidine‐4‐thiones in 35‐91% yields with exclusive stereoselectivity. The gram‐scale reaction and further chemoselective S‐alkylations demonstrated the synthetic utilities of this transformation.