Organo‐photocatalytic Synthesis of 6‐β‐Disubstituted Phenanthridines from α‐Diazo‐β‐Keto Compounds and Vinyl Azides

Abstract

An efficient organo-photocatalytic method for the synthesis of 6-β-disubstituted phenanthridines has been developed. The reaction documents unprecedented generation of enolate vinyl radicals from corresponding diazo compounds in the presence of photocatalyst Rh-6G. Subse-quent trapping of these radical intermediates by o-aryl vinyl azides followed by intramolecular cyclization affords the final products in excellent yields and regioselectivity. The reaction is notable for its mild conditions, high yields and wide substrate scope.