In this thesis, Cu0.5Cd0.5Fe2O4 magnetic nanoparticles were prepared by a green synthesis route and used as a heterogeneous catalyst for the synthesis of tetrahydrobenzo[b]pyran derivatives. The prepared Cu0.5Cd0.5Fe2O4 nanoparticles were examined using several characterization techniques, including XRD, FESEM, TEM, EDX, elemental mapping, BET, and VSM. A spinel ferrite structure was identified from the XRD pattern. TEM showed mostly spherical particles, generally within a size range of 35-45 nm. At room temperature, the nanoparticles exhibited superparamagnetic behavior with a saturation magnetization (Ms) of 18.63 emu g-1. Their catalytic activity was subsequently examined in the three-component reaction of aromatic aldehydes, malononitrile, and dimedone under solvent-free microwave irradiation. The model reaction gave the best result using 0.03 g of catalyst at 360 W, providing the corresponding tetrahydrobenzo[b]pyran in 93% yield after 9 min. Under these conditions, different substituted aromatic aldehydes afforded the desired products in 82-95% isolated yields within 9-13 min. The catalyst was readily separated from the reaction mixture with an external magnet and could be reused for four consecutive runs with only a slight reduction in product yield. These findings indicate that Cu0.5Cd0.5Fe2O4 MNPs can serve as a practical magnetic catalyst for the rapid synthesis of tetrahydrobenzo[b]pyran derivatives under solvent-free microwave conditions.
