Catalytic application of new manganese Schiff-base complex immobilized on chitosan-coated magnetic nanoparticles for one-pot synthesis of 3-iminoaryl-imidazo[1,2-a]pyridines

In this paper, new chitosan (CS) coated magnetic iron oxide nanoparticles (MNPs) supported manganese Schiffbase complex was designed, synthesized and screened as an efficient, reusable nanocatalyst by the three-component reaction of various aldehyde derivatives with trimethylsilyl cyanide and 2-aminopyridine for the synthesis of 3-iminoaryl-imidazo[1,2-a]pyridine (IAIP) derivatives. Fourier transform infrared spectroscopy (FT-IR), X-ray powder diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), vibrating sample magnetometry (VSM) and inductively coupled plasma atomic emission spectroscopy (ICP-AES) have been used to characterize the nanocatalyst before reaction. For the first time, earlier than immobilizing of manganese complex, the chitosan-coated Fe3O4 nanoparticles prepared through covalent bond formation between CS and chlorosilane-modified MNPs which were treated with triethylamine. It is a promising nanocatalyst providing high yield, short reaction times, and excellent turnover number. The recycle studies show a significant loss of activity after recycling six times. (c) 2019 Elsevier B.V. All rights reserved.