Palladium-catalyzed annulation of N-alkoxy benzsulfonamides with arynes by C-H functionalization: access to dibenzosultams

Palladium-catalyzed C-H/N-H functionalization of easily prepared N-alkoxy benzsulfonamides with arynes provides dibenzosultams in good yields via C-C/C-N bond formation, accompanied by an unexpected N-O bond cleavage. A mechanistic study shows that the reaction proceeds through a rate-determining C-H bond cleavage.