Functionalization of chitosan by grafting Cu(II)-5-amino-1H-tetrazole complex as a magnetically recyclable catalyst for C-N coupling reaction

Abstract

The functionalization of chitosan (as a linear polysaccharide) with a copper complex to expand the areas of its potential applications is an important scientific task. The present work reports the application of Cu(II)-5-amino-1H-tetrazole complex immobilized on modified magnetic chitosan as an effective catalyst (Fe3O4@Chitosan-Tet-Cu(II)) for C-N bond cross-coupling reaction between 5-aminotetrazole and aryl halides under ligand-free conditions in dioxane solvent. The prepared magnetic nanocatalyst was characterized by FT-IR, EDS, TEM, HRTEM, VSM, FFT, XRD, TG-DTG, ICP-MS, and elemental mapping analyses. 1-Aryl-5-amino-1H-tetrazoles were produced in high yields. The advantages of this catalytic process include simple methodology, avoiding the use of harmful catalysts, short reaction times, excellent yields, easy work-up, and environmentally friendly conditions. Fe3O4@Chitosan-Tet-Cu(II) catalyst exhibited high efficacy and reusability/recyclability even after seven consecutive cycles with low loss of catalytic activity.