One-pot synthesis of 1,4-dihydropyridines and N-arylquinolines in the presence of copper complex stabilized on MnFe2O4 (MFO) as a novel organic–inorganic hybrid material and magnetically retrievable catalyst

In this work, the design and synthesis of a heterogeneous catalyst based on functionalization of manganese ferrite nanoparticles encapsulated in a silica layer with Schiff base and subsequent incorporation of copper is presented. The fabricated hybrid material was characterized by employing Fourier-transform infrared spectroscopy, X-ray powder diffraction, field emission scanning electron microscopy, transmission electron microscopy, energy-dispersive X-ray spectroscopy, differential thermal gravimetric analysis, vibrating sample magnetometry and inductively coupled plasma-optical emission spectrometry techniques. The prepared organic–inorganic hybrid material was successfully used as an efficient and recoverable catalyst for the synthesis of 1,4-dihydropyridines and N-arylquinolines under mild and green reaction conditions. The results showed that the catalyst exhibited excellent catalytic activity under optimum reaction conditions and the desired products were obtained in good to excellent yields. The new 1,4-dihydropyridines and N-arylquinolines were characterized by Fourier-transform infrared spectroscopy, ¹H NMR and Elemental analysis of Carbon, Hydrogen and Nitrogen (CHN) analyses. Study of the catalyst reusability confirmed that the catalyst could be recycled for five reaction runs with slight loss of the catalytic activity and negligible copper leaching.