Magnetic Cu0@HAP@γ-Fe2O3 nanoparticles: An efficient catalyst for one-pot three-component reaction for the synthesis of imidazo[1,2-a]pyridines

Cu(0) incorporated magnetic hydroxyapatite nanoparticles (Cu-0@HAP@gamma-Fe2O3 NPs) was conveniently synthesized via the ion exchange reaction, oxidation, and reduction steps. The structure and composition of the nanohybrid were confirmed by FT-IR, SEM, EDS, TEM, XPS, and TGA. The magnetic Cu-0@HAP@gamma-Fe2O3 NPs hybrid can efficiently catalyzed a one-pot multicomponent synthesis of imidazo[1,2-a]pyridine derivatives from 2-aminopyridine, aldehydes or glyoxylic acids, and alkynes or alkynyl carboxylic acid in excellent yields. The magnetic nanocatalyst was easily separated from reaction mixture using an external magnet and was successfully examined for three runs with a slight loss of catalytic activity. (C) 2018 Elsevier B.V. All rights reserved.