Iridium/Copper‐Catalyzed Oxidative C−H/O−H Annulation of Benzoic Acids with Saturated Ketones for Accessing 3‐Substituted Phthalides

A catalytic annulation cascade is achieved that affords an efficient access to phthalides from readily available benzoic acids and saturated ketones. The reaction is catalyzed by a bimetallic Ir/Cu system and proceeds via the combination of Cu-catalyzed dehydrogenation of ketones and Ir-catalyzed direct C-H functionalization under the assistance of the weakly coordinating carboxyl followed by the beta-H elimination and intramolecular Michael addition. This method shows a broad scope of substrates and good functional group tolerance. The protocol furnishes an alternative strategy for the construction of diverse 3-substituted phthalides.