l -Methionine-Zr complex supported on magnetic ZnFe 2 O 4 as a novel, green, and efficient heterogeneous magnetic nanocatalyst for the synthesis of 1 H -tetrazole and polyhydroquinoline derivatives

Herein, we report the synthesis of ZnFe 2 O 4 @SiO 2 @ l -methionine-Zr as a novel nanomagnetic solid catalyst, containing zirconium catalytic sites on the surface of ZnFe 2 O 4 MNPs. In this study, a new and efficient magnetic material has been designed and prepared via immobilization of the l -methionine complex of zirconium on ZnFe 2 O 4 @SiO 2 nanoparticles. The proposed catalyst was characterized via XRD, EDS, TGA, SEM, TEM, XPS, ICP, X-ray mapping and VSM techniques, and was successfully applied in the synthesis of tetrazoles and polyhydroquinoline derivatives. The use of this heterogeneous nanocatalyst in the mentioned organic reactions offers good results, such as the use of commercially available chemicals, inexpensive starting materials, high reaction efficiencies, easy recovery, and reusability of catalyst for at least five continuous cycles.