Tetramethylammonium Iodide (TMAI)‐Promoted Sulfenylation/Annulation of Enaminones with Thiosulfonates

Abstract A highly efficient and eco‐friendly method for the tetramethylammonium iodide‐mediated sulfenylation/annulation of enaminones using thiosulfonates as the sulfenyl source was described under open‐air, metal‐, and oxidant‐free conditions. This method provides an alternative way of constructing C−S bonds, affords various substituted sulfenylated chromones in moderate to good yields, and shows broad substrate scope, and good functional group tolerance.