Cu nanoparticles were prepared in successive stages: preparation of the Fe3O4 magnetic nanoparticles (Fe3O4 MNPs), coating of the Fe3O4 MNPs with tetraethyl orthosilicate (Fe3O4@SiO2), functionalization of Fe3O4@SiO2 with 3-chloropropyltrimethoxysilane (CPTMS) and 4-amino-1,2,4-triazole (AT) ligands (Fe3O4@SiO2@CPTMS@AT), and the complexation of Fe3O4@SiO2@CPTMS@AT with CuCl2 (Fe3O4@SiO2@CPTMS@AT@Cu). The obtained Cu nano-catalyst was then used for the synthesis of diverse tetrazoles from the reaction of various amino acids with sodium azide and triethyl orthoformate (TEOF) in ethanol at 80 °C.
