Three-component synthesis of 1,4-benzothiazines via iodide-catalyzed aerobic C-H sulfuration with elemental sulfur.

Herein, iodide-catalyzed aerobic synthesis of 1,4-benzothiazines via functionalization of multiple C-H bonds with elemental sulfur is described. Beyond the well-established thiazole formation from elemental sulfur, this method provides the first access to the corresponding six-membered N,S-heterocyclic products via direct functionalization of multiple C-H bonds. Hence, 1,4-benzothiazine products were generated in satisfactory yields with a range of compatible functionalities.