Concise synthesis of pyrrolophenanthridine alkaloids using a Pd-catalyzed biaryl coupling reaction with regioselective C-H activation

The concise synthesis of the pyrrolophenanthridine alkaloids such as anhydrolycorine, assoanine, anhydrolycorin-7-one, and oxoassoanine, was achieved using the Pd-catalyzed biaryl coupling reaction of 1-(2-halobenzyl)-2,3-dihydroindole by applying the regioselective C-H activation method with intramolecular coordination of the benzylamino group to Pd.