Strategic Methodologies for Efficient Synthesis of Imidazo[1,5-a]pyridine and Benzazepine Analogs via the Unique Ritter-Type Reaction

Abstract

We have developed novel approaches for synthesizing imidazo[1,5-a]pyridine and benzazepine analogs through a Ritter-type reaction. These methods utilize bismuth(III) trifluoromethanesulfonate (Bi(OTf)₃), an efficient catalyst for converting benzylic alcohol into benzylic cations, in combination with para-toluenesulfonic acid (p-TsOH·H₂O). The procedures offer a wide substrate scope and deliver the desired products in yields ranging from moderate to excellent.