Diverse Ring Opening and Annulation Catalyses of Isoxazole To Construct Valuable Functionalized Pyrroles, Pyridines, and Nicotinamides

This study introduces microwave-assisted, Fe(III)-catalyzed ring-opening annulations of isoxazoles, enabling the rapid and selective synthesis of 1,4-diacyl pyrroles and substituted pyridines. By leveraging microwave irradiation and transition metal catalysis, this approach enhances the reaction efficiency, reduces reaction times, and promotes high regioselectivity under mild conditions. Under thermal conditions, the Ru(II) catalyst led to the synthesis of nicotinamide derivatives. These heterocyclic products are pivotal in pharmaceutical, agrochemical, and materials science applications due to their unique physicochemical properties.