Efficient Synthesis of Phenanthridines Using Hendrickson Reagent Initiated Cascade Reaction under Mild Conditions

A number of variously substituted phenanthridines have been synthesized using the newly developed methodology under mild conditions. The Hendrickson reagent initiated cascade annulation, which is composed of a mild conversion of stable amide precursor to highly reactive imido-carbonium intermediate and a subsequent intramolecular Friedel-Crafts reaction, successfully served as the key method.