Copper-Catalyzed Selective ortho-C-H/N-H Annulation of Benzamides with Arynes: Synthesis of Phenanthridinone Alkaloids.

An efficient and convenient copper-catalyzed method has been developed to achieve direct ortho-C-H/N-H annulation to synthesize phenanthridinones with arynes. This method highlights an emerging strategy to transform inert C-H bonds into versatile functional groups in organic synthesis and provides a new way to synthesize phenanthridinone alkaloids efficiently.