Palladium-Catalyzed Synthesis of Phenanthridine/Benzoxazine-Fused Quinazolinones by Intramolecular C-H Bond Activation.

A highly efficient synthesis of phenanthridine/benzoxazine-fused quinazolinones by ligand-free palladium-catalyzed intramolecular C-H bond activation under mild conditions has been developed. The C-C coupling provides the corresponding N-fused polycyclic heterocycles in good to excellent yields and with wide functional group tolerance.