Palladium-Catalyzed Synthesis of Phenanthridine/Benzoxazine-Fused Quinazolinones by Intramolecular CH Bond Activation

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