Palladium-catalyzed annulation of benzynes with N-substituted-N-(2-halophenyl)formamides: synthesis of phenanthridinones

A novel and efficient procedure for the synthesis of N-substituted phenanthridinones via palladium-catalyzed annulation of benzynes with N-substituted-N-(2-halophenyl)formamides has been developed. This methodology constructs two new C-C bonds via an arylation/annulation process, and provides the desired products in good yields.