Synthesis of Polysubstituted Phenanthridines via Ligand-FreeCopper-Catalyzed Annulation.

A novelprocedure for the cascade reaction of the addition of aGrignard reagent to a nitrile with a copper-catalyzed C–N bondcoupling was developed, which afforded various polysubstituted phenanthridinesin moderate to good yields with tolerance for a wide variety of substrates.Experimental data demonstrated that the reaction proceeded more likelythrough a Cu(I/III) catalytic cycle. [ABSTRACT FROM AUTHOR]