N-acetyl-PABA@Cu(II) supported on Fe3O4 as the new heterogeneous catalytic system to assist the MCR derived synthesis of 2,2-dimethyl-2H-[1,3]dioxino[4,5-b]pyrrol-4(7H)-ones heterocyclic scaffolds

Abstract

The present work elicits the synthesis of 2,2-dimethyl-2H-[1,3]dioxino[4,5-b]pyrrole-4(7H)-ones derivatives catalyzed by heterogeneous Fe3O4 magnetic nanoparticles supported N-acetyl-PABA@Cu(II), which address the limitations of traditional organic synthesis approaches in terms of sustainable and efficient, resulting in improved yields, higher selectivity with no waste. The decorum embraces four-component reactions (4CRs) of amines, aldehydes, meldrum’s acid, and nitromethane facilitated by Fe3O4-N-acetyl-PABA-Cu(II) in the presence of ethanol (CH3CH2OH) as an ecologically benign solvent under ultrasonic irradiation at room temperature. Outstanding conversion rates and selectivity were attained by the heterogeneous catalyst through great catalytic performance. The simple work-up, easy catalyst recovery, and no base or additional activators were required. Characterization of the structures of synthesized compounds and catalysts was corroborated through different spectroanalytical techniques viz; FTIR, 1H &13C NMR, Mass elemental analyses, Energy-Dispersive X-ray Spectroscopy (EDX), Field-Emission Scanning Electron Microscope (FE-SEM), Powder X-ray Diffraction (XRD), Thermal Gravimetric Analysis (TGA), Differential Thermal Analysis (DTA), Particle size analysis and Zeta potential.