Microwave-assisted DABCO-promoted regioselective [3 + 3] tandem cyclization: synthesis of pyrrolo[3,4-b]pyridine-4-ones from trifluoromethyl-alkynyl esters and α-aminomaleimide

A microwave-assisted DABCO-promoted strategy for the regioselective synthesis of pyrrolo[3,4-b]pyridine-4-one derivatives has been developed from the [3 + 3] annulation of α-aminomaleimide with substituted ethyl 2-butynoate. The characteristic features of this methodology include operational simplicity, high regioselectivity, metal-free reaction conditions, and short reaction times. The potential utility of these methods in biological chemistry and medicinal science applications is highlighted.