Strategic\nMethodologies for Efficient Synthesis of\nImidazo[1,5‑<i>a</i>]pyridine and Benzazepine Analogs\nvia the Unique Ritter-Type Reaction

We have developed\nnovel approaches for synthesizing imidazo[1,5-<i>a</i>]pyridine\nand benzazepine analogs through a Ritter-type\nreaction. These methods utilize bismuth(III) trifluoromethanesulfonate\n(Bi(OTf)<sub>3</sub>), an efficient catalyst for converting benzylic\nalcohol into benzylic cations, in combination with <i>para</i>-toluenesulfonic acid (<i>p</i>-TsOH·H<sub>2</sub>O). The procedures offer a wide substrate scope and deliver the desired\nproducts in yields ranging from moderate to excellent.