Synthesis of 12b‐Methyl‐Isoindoloisoquinolin‐8‐ones via Iridium‐Catalyzed Intramolecular Hydroarylation of Phenacyl Enamides

An intramolecular iridium‐catalyzed hydroarylation process is described for the synthesis of the title scaffold from phenacyl enamide substrates. This method achieves high yields while eliminating the requirement for prefunctionalized substrates, as compared to Heck‐type cyclization methodologies. Substrate scope and mechanistic studies indicate that the presence of electron‐donating substituents in the incipient ring D moiety is essential for the cyclization, consistent with a pathway involving electrophilic aromatic substitution of iridium in ring D.