Substituent-controlled chemoselective synthesis of multi-substituted pyridones via a one-pot three-component cascade reaction

An efficient and concise one-pot strategy for the synthesis of multisubstituted pyridones via a one-pot three-component cascade reaction catalyzed by Cs₂CO₃ under solvent-free conditions has been developed. The substituent-controlled chemoselective cycloaddition process involved steps including a Michael addition/ethanol elimination/intermolecular cyclization sequence utilizing anilines, diethyl acetylenedicarboxylate, and diethyl ethoxymethylenemalonate. In doing so, various 2-pyridone and 4-pyridone species (41 examples) could be obtained in good to excellent yields.