Palladium-Catalyzed Oxidative Annulation of Sulfoximines and Arynes by C-H Functionalization as an Approach to Dibenzothiazines

This work reports a novel and efficient palladium-catalyzed synthesis of tricyclic dibenzothiazines using easily prepared aryl sulfoximines and aryne precursors via C-H functionalization and cyclization. A mechanistic investigation indicated that the C-H bond cleavage at the position ortho to the sulfoximine group is the rate-determining step.