Synthesis of magnetic Fe3O4@SiO2@Cu-Ni-Fe-Cr LDH: an efficient and reusable mesoporous catalyst for reduction and one-pot reductive-acetylation of nitroarenes

摘要

Magnetically recoverable Fe3O4@SiO2@Cu-Ni-Fe-Cr LDH was prepared under co-precipitation conditions. Characterization of the mesoporous catalyst was confirmed using Fourier-transformed infrared spectroscopy, scanning electron microscopy, energy-dispersive X-ray spectroscopy, X-ray diffraction, vibration sample magnetometer, Brunauer-Emmett-Teller, thermogravimetric, differential thermogravimetric analyses and transmission electron microscopy. Reduction of nitroarenes to the corresponding arylamines and one-pot reductive-acetylation of nitroarenes to acetanilides were carried out successfully by nanoparticles of the immobilized Cu-Ni-Fe-Cr layered double hydroxide on silica-coated Fe3O4 in water as a green solvent. All reactions were carried out within 6-22min affording arylamines and N-arylacetamides in high-to-excellent yields. Reusability of the core-shell nanocatalyst was examined six times without significant loss of its catalytic activity.