Catalytic ortho C–H methylation and trideuteromethylation of arylthianthrenium salts via the Catellani strategy†

We report a Pd/NBE cooperative catalyzed ortho C–H methylation and trideuteromethylation of arylthianthrenium salts, enabling the efficient synthesis of a wide variety of (trideutero)methylated arenes in moderate to good yields. This method demonstrates excellent tolerance towards functional groups, scalability, and potential extension toward the late-stage functionalization of biorelevant molecules. In combination with the C–H thianthrenation of arenes, this approach provides an effective method for the site-selective C–H (trideutero)methylation of arenes.