Metal-Catalyzed Domino Synthesis of Benzophenanthridines and 6 H-Naphtho[2,3- c]-chromenes

J Org Chem. 2018 Aug 3;83(15):8139-8149. doi: 10.1021/acs.joc.8b00924. Epub 2018 Jun 20.

Abstract

A new and efficient synthesis of tetracyclic phenanthridines and benzo[ c]chromenes has been described involving a metal-mediated two-step domino strategy. The first step involved efficient palladium-catalyzed domino carbopalladation/cross coupling, and the second step involved iron-catalyzed domino isomerization/cyclodehydration. The important features of this strategy include high yields, generality, wide substrate scope, and broad functional group tolerance. A plausible mechanism has been proposed to explain the formation of the product.