Visible-Light-Induced 1,7-Enyne Dicyclization: Synthesis of Ester-Substituted Benzo[ j ]phenanthridines.

A novel alkoxycarbonyl-radical-triggered cascade cyclization of 1,7-enynes, with alkyloxalyl chlorides as the ester units, for the synthesis of benzo[ j ]phenanthridines is described. The reaction conditions exhibit excellent compatibility with a broad range of alkoxycarbonyl radical sources and realize the installation of an ester group in the polycyclic compound. This radical cascade cyclization reaction features excellent functional group tolerance, mild reaction conditions, and good to excellent yields.