Synthesis of 2,3,9,10-Tetraoxygenated Benzo[c]phenanthridine Derivatives via Palladium-Mediated Aryl-Aryl Coupling Reaction

Two 2,3,9,10-tetraoxygenated benzo[c]phenanthridine alkaloids, 1 2, originally reported as zanthoxyline and broussonpapyrine, respectively, were synthesized using the Pd-mediated intramolecular aryl-aryl coupling reaction as the key step.