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.

Iodine-catalyzed convergent aerobic dehydro-aromatization toward benzazoles and benzazines.

An iodine-catalyzed aerobic dehydro-aromatization has been developed, providing straightforward and efficient access to various benzoazoles and benzoazines. The present transition-metal-free protocol enables the dehydro-aromatization of tetrahydrobenzazoles and tetrahydroquinolines with molecular oxygen as the green oxidant, along with some other N-heterocycles. Hence, a broad range of heteroaromatic compounds are generated in moderate to good yields under facile reaction conditions.