Copper NPs supported on hematite as magnetically recoverable nanocatalysts for a one-pot synthesis of aminoindolizines and pyrrolo[1,2-a]quinolines

Abstract

Cu NPs such as CuO and Cu₂O mixed oxides supported on a hematite surface (Cu@Fe₂O₃) were achieved using a facile hydrothermal method in a single step. Various techniques such as X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM), EDAX elemental analysis, inductively coupled plasma atomic emission spectroscopy (ICP-AES) and X-ray photoelectron spectroscopy (XPS) were used for the characterization of the synthesized Cu@Fe₂O₃ magnetically recoverable nanoparticles (MNPs). The catalytic potential of the Cu@Fe₂O₃ NPs was explored for the synthesis of aminoindolizines and pyrrolo[1,2-a]quinolines via an A3 coupling reaction. The present catalytic system offers advantages such as high catalytic activity in a short reaction time, recovery of the catalyst by an external magnetic field and the catalyst being recycled six times without significant loss of its activity.