Synthesis of in situ immobilized iron oxide nanoparticles (Fe3O4) on microcrystalline cellulose: Ecofriendly and recyclable catalyst for Michael addition

Microcrystalline cellulose‐immobilized Fe3O4 magnetic nanoparticles (Fe3O4@MCC) with iron loading 5%–20% are synthesized and characterized by scanning electron microscopy (SEM), X‐ray diffraction (XRD), and thermogravimetric analysis (TGA). The synthesized nanocomposites were studied for their catalytic activity towards Michael addition reaction by employing 1,3‐cyclohexadione/dimedone and styrylisoxazole in an aqueous ethanolic medium. The catalyst with 15% iron loading showed the highest efficiency with an excellent yield. Michael addition reaction is one of the most important reaction for the creation of a carbon–carbon bond and widely used in organic synthesis under mild condition. The prepared catalyst performed well in Michael addition reaction and afforded the product in excellent yield. The products were isolated by simple filtration without use of any chromatographic techniques. The scale‐up experiment on 10‐mmol scale proved the sustainability of the methodology. The catalyst was recycled, and the recovered catalyst data showed no considerable depreciation in catalytic activity even after 5 consecutive cycles. The advantages of this green and safe procedure include a simple reaction set‐up, very mild reaction conditions, high yields, moderate reaction time, recyclable catalyst, and easy separation of the products without use of any tedious separation techniques.