Copper(<scp>ii</scp>) complex-decorated ZrFe₂O₄ nanoparticles as a recyclable magnetic nanocatalyst for synthesis of N-containing heterocycles

In this study, a novel and magnetic nanocatalyst [ZrFe₂O₄@SiO₂@GLYMO-oPD-Cu(ii)] was developed by immobilization of an <i>o</i>-phenylenediamine-copper complex on ZrFe₂O₄@SiO₂ nanoparticles. The as-prepared nanocatalyst was identified by physicochemical techniques such as FT-IR, BET, SEM, VSM, XRD, TEM, TGA, DSC, ICP EDX, and EDX elemental mapping. This nanocomposite exhibited remarkable efficiency in promoting the green synthesis of nitrogen-rich heterocycles, including 5-substituted 1<i>H</i>-tetrazoles and 2,3-dihydroquinazolin-4(1<i>H</i>)-one derivatives, through click and cyclization reactions, respectively. The reactions were conducted under mild conditions, affording high yields in short reaction times. Furthermore, the catalyst demonstrated excellent stability and reusability, with minimal copper leaching observed across multiple catalytic cycles.