Green Approach for Preparation of New Hybrids of 5‐Substituted‐1H‐Tetrazoles Using Novel Recyclable Nanocatalyst based on Copper(II) Anchored onto Glucosamine Grafted to Fe₃O₄@SiO₂

Abstract

The novel copper(II) ions decorated Fe3O4@SiO2 composite magnetic spheres were synthesized by grafting copper(II) ions onto glucosamine modified Fe3O4@SiO2 NPs. The magnetic Fe3O4@SiO2−TCT−GA−Cu(II) catalyst were characterized by varies physicochemical techniques such as FT‐IR, FE‐SEM, TEM, DLS, XRD, EDX, VSM, TGA, VSM, ICP, and UV‐Vis. The catalytic performance of this novel catalyst was studied in the green preparation of 5‐substituted 1H‐tetrazole based hybrids via three‐component and one‐pot reaction of sodium azide, hydroxylamine hydrochloride, and various aldehydes in water and ethylene glycol, as a green solvent mixture. This green protocol provides significant advantages such as non‐vigorous conditions, short reaction times, outstanding yield of desired tetrazoles, minimizing of chemical waste, wide‐ranging substrate, quick and efficient work‐up procedure and using environmentally benign, durable, cost effective, magnetically separable, reusable nanocatalyst.

New ecofriendly heterogeneous nano-catalyst for the synthesis of 1-substituted and 5-substituted 1H-tetrazole derivatives

“… Entry Catalyst Conditions Time (min) Yield (%) a Refs. 1 Cu (OAC) 2 EDS (chcl-urea), 100 °C 720 90 51 2 La/THH-CO 2 H@Fe 3 O 4 PEG-600, 100 °C 300 90 52 3 Pd‐isatin‐boehmite PEG-400, 120 °C 480 94 53 4 Fe 3 O 4 @SiO 2 -TCT-GA-Cu(II) Ethylene glycol/H 2 O (1 : 1), 90 °C 90 97 54 5 PDNPs@CS-Zeo DMF, 120 °C 720 90 55 6 Zn-CA-MOFs DMF, 120 °C 480 97 56 7 Cu Nano-catalyst Solvent-free, 100 °C 85 89 57 8 Nano-Fe 3 O 4 /In Solvent-free, 100 °C 150 90 ...…”

Synthesis of a bistriazolyl-phenanthroline–Cu(ii) complex immobilized on nanomagnetic iron oxide as a novel green catalyst for synthesis of imidazoles via annulation reactions

“…Furthermore, there is a broad peak in the 3100-3400 cm −1 range, which is attributed to O-H stretching vibrations. 47 In the FT-IR spectra of the Fe 3 O 4 @L-AHA nanocomposite, the broad absorption peak spanning from 2800-3500 cm −1 can be attributed to the presence of the carboxylic acid moiety of the L-azidohomoalanine linker beneath the surface, overlapping with aliphatic C-H and N-H stretching vibrations (related to methyl groups). The bands observed at 1470 cm −1 , 1401 cm 48,49 The presence of these peaks provides compelling evidence for the existence of crystalline Fe 3 O 4 magnetic nanoparticles (MNPs) within the complex.…”