NiII-containing l-glutamic acid cross-linked chitosan anchored on Fe3O4/f-MWCNT: a sustainable catalyst for the green reduction and one-pot two-step reductive Schotten–Baumann-type acetylation of nitroarenes

Abstract

In this research, new and eye-catching catalytic applications of the nickel^II (Ni^II) nanoparticles (NPs)-containing L-glutamic acid cross-linked chitosan anchored on magnetic carboxylic acid-functionalized multi-walled carbon nanotube (Fe₃O₄/f-MWCNT-CS-Glu/Ni^II) system, which was characterized by Fourier transform infrared (FT-IR), powder X-ray diffraction (PXRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), SEM-based energy-dispersive X-ray (EDX) and elemental mapping, inductively coupled plasma-optical emission spectrometry (ICP-OES), thermogravimetric analysis (TGA), differential thermal analysis (DTA), and vibrating sample magnetometry (VSM), have been introduced for the environmentally benign and efficient reduction and one-pot two-step reductive Schotten–Baumann-type acetylation of nitroarenes in water at 60 °C under an air atmosphere. It is worth noting that the Ni^II-containing hybrid nanocatalyst, in the mentioned organic reactions, showed short reaction times, high yields of the desired products, acceptable turnover numbers (TONs) and turnover frequencies (TOFs), and also satisfactory magnetic recycling and reusability performance even after ten times of reuse. As another significant point, all the titled organic transformations have been carried out in water as an entirely favorable and green solvent for chemical reactions.