Concise Synthesis of Carbocycle‐Fused γ‐Carbolinones via Regio‐/Chemoselective Reaction of Indole‐3‐Carboxamides with Cyclic Diazo Compounds

γ‐Carboline and γ‐carbolinone are privileged structural scaffolds for the development of new pharmaceuticals and functional materials. A concise and effective synthesis of carbocycle‐fused γ‐carbolinone derivatives via the regio‐ and chemoselective cascade reactions of indole‐3‐carboxamides with cyclic diazo compounds is presented. The formation of product is initiated by the regioselective C2H bond metalation of the indole moiety and carbene formation with the diazo coupling partner (CP), followed by migratory insertion, protodemetallation, chemoselective intramolecular aza‐nucleophilic addition, and water elimination. In this cascade process, the amide group plays a dual role by acting as a directing group for the CH bond functionalization and N ‐nucleophilic site for the pyridone ring formation. In general, this newly developed protocol features simple and affordable substrates, concise one‐pot procedure without using redundant additives, excellent regio‐/chemoselectivity, and step‐/atom‐economy, as well as ready scalability.