Magnetic γFe2O3@Sh@Cu2O: an efficient solid-phase catalyst for reducing agent and base-free click synthesis of 1,4-disubstituted-1,2,3-triazoles

Fereshteh Norouzi; Shahrzad Javanshir

doi:10.1186/s13065-019-0657-9

Magnetic γFe₂O₃@Sh@Cu₂O: an efficient solid-phase catalyst for reducing agent and base-free click synthesis of 1,4-disubstituted-1,2,3-triazoles

BMC Chem. 2020 Jan 7;14(1):1. doi: 10.1186/s13065-019-0657-9. eCollection 2020 Dec.

Authors

Fereshteh Norouzi¹, Shahrzad Javanshir¹

Affiliation

¹ Heterocyclic Chemistry Research Laboratory, Department of Chemistry, Iran University of Science and Technology, Tehran, 16846-13114 Iran.

Abstract

A hybrid magnetic material γFe₂O₃@Sh@cu₂O was easily prepared from Shilajit (Sh) decorated Fe₃O₄ and copper acetate. The prepared magnetic hybrid material was fully characterized using different analysis, including Fourier transform infrared (FT-IR), X-ray diffraction (XRD), inductively coupled plasma (ICP), scanning electron microscopy (SEM), Energy-dispersive X-ray spectroscopy (EDX), X-ray photoelectron spectroscopy (XPS), vibrating sample magnetometer (VSM) thermal gravimetric analysis (TGA) and Brunauer-Emmett-Teller (BET). All these analysis revealed that during coating of Fe₃O₄@Sh using copper salt (II), synchronized redox sorption of Cu^II to Cu^I occurs at the same time as the oxidation of Fe₃O₄ to γFe₂O₃. This magnetic catalyst exhibited excellent catalytic activity for regioselective synthesis of 1,4-disubstituted-1,2,3-triazoles via one pot three-component click reaction of sodium azide, terminal alkynes and benzyl halides in the absence of any reducing agent. High yields, short reaction time, high turnover number and frequency (TON = 3.5 * 10⁵ and TOF = 1.0 * 10⁶ h^-1 respectively), easy separation, and efficient recycling of the catalyst are the strengths of the present method.

Keywords: Click synthesis; Heterogeneous catalyst; Humic acids; Hybrid magnetic material; Shilajit.