Generation of Cu nanoparticles on novel designed Fe₃O₄@SiO₂/EP.EN.EG as reusable nanocatalyst for the reduction of nitro compounds

Abstract

Reusable magnetic Cu nanocatalyst was designed and characterized. An efficient and mild method for the reduction of aromatic nitro compounds.

2‐hydroxyethylammonium formate ionic liquid grafted magnetic nanoparticle as a novel heterogeneous catalyst for the synthesis of substituted imidazoles

“…In the first step, the Fe 3 O 4 @SiO 2 magnetic nanoparticles were synthesized using the stober method . In the next step, the substitution reaction of epichlorohydrin species was accomplished with hydroxyl groups of silica coated magnetic nanoparticles . Finally, Fe 3 O 4 @SiO 2 ‐EP‐HEAF was obtained by simple mixing of Fe 3 O 4 @SiO 2 ‐EP and 2‐hydroxyethylammonium formate in 60°C.…”

“…Therefore, magnetic nanoparticles are the best choice for catalyst support due to their magnetic separation compare to conventional techniques such as filtration or centrifugation as it prevents loss of catalyst and increases the reusability . In continuation of our studies on the preparation and applications of heterogeneous catalysts, in the synthetic organic chemistry, we wish introduce a new strategy for synthesis of a 2‐hydroxyethyl ammonium formate modified Fe 3 O 4 @SiO 2 as a novel and magnetically recyclable heterogeneous catalyst. The catalytic activity of Fe 3 O 4 @SiO 2 ‐EP‐HEAF has investigated for the one‐pot synthesis of 2,4,5‐trisubstituted‐1H‐imidazole.…”

Magnetically recoverable copper nanorods and their catalytic activity in Ullmann cross‐coupling reaction

“…The Fe 3 O 4 magnetic NPs were prepared via a co‐precipitation method and then were coated with silica via the Stober method . The Fe 3 O 4 @SiO 2 @EP.EN.EP was prepared in a three‐step procedure . The Cu nanorods were then obtained by mixing Cu(II) acetate and Fe 3 O 4 @SiO 2 @EP.EN.EP in a refluxing ethanol solution in the presence of NaOH in 12 h. Finally, NaBH 4 was added to mixture reaction for synthesis of Fe 3 O 4 @SiO 2 /EP.EN.EG@Cu (Scheme ).…”

“…After 24 h, the solid was collected, washed with methanol and dried at 80 °C to afford Fe 3 O 4 @SiO 2 /EP.EN. Then the dried precipitate was added to a solution of epibromohydrin (10 mmol, 1.36 g) in ethanol (3 ml) at 60 °C for 5 h. Finally, the product was separated using an external magnet, washed with methanol and dried at 80 °C …”

Cu nanoparticles immobilized on modified magnetic zeolite for the synthesis of 1,2,3‐triazoles under ultrasonic conditions

“…The required copper (0,I) catalysts are usually prepared by in situ reduction of copper (II) salts with sodium ascorbate or NaBH 4 . In recent studies, the CuAAC has been proven to be accelerated by immobilizing copper species on a large variety of solid supports, such as charcoal, silica, zeolite and polymers .…”