RAPID AND CONVERGENT ASSEMBLY OF NATURAL BENZO[c]PHENANTHRIDINES BY PALLADIUM/NORBORNENE CATALYSIS

A straightforward total synthesis of a small panel of natural benzo[c]phenanthridines is described. The selective coupling of an aryl triflate with a bromobenzylamine by means of palladium/norbornene joint catalysis and a sequential transfer hydrogenation deliver these alkaloids in one pot. Dihydrophenanthridines initially formed undergo dehydrogenation smoothly while norbornene acts both as a catalyst for their assembly and as a sacrificial olefin in their dehydrogenatio