Rhodium(III)-Catalyzed Annulation of N-Methoxybenzamides with Heterobicyclic Alkenes by C-H Functionalization: Synthesis of Benzo[b]phenanthridinones

A protocol for the rhodium(III)-catalyzed annulation of N-methoxybenzamides with 7-oxa/azabenzonorbornadienes by C-H activation was developed. This method allowed the synthesis of polycyclic products containing an oxygen/nitrogen-bridged structure in excellent yields. The annulated products were successfully transformed into benzo[b] phenanthridinones by a ring-opening/aromatization sequence.