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
Abstract
Abstract A hybrid magnetic material γFe 2 O 3 @Sh@cu 2 O was easily prepared from Shilajit (Sh) decorated Fe 3 O 4 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 Fe 3 O 4 @Sh using copper salt (II), synchronized redox sorption of Cu II to Cu I occurs at the same time as the oxidation of Fe 3 O 4 to γFe 2 O 3 . 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 * 10 5 and TOF = 1.0 * 10 6 h −1 respectively), easy separation, and efficient recycling of the catalyst are the strengths of the present method.