Stabilization of copper species on the functionalized magnetic metal-organic framework (Fe3O4@Zn-MOF-NH2-Cya@Cu) as a heterogeneous catalyst for synthesis of tetrahydrobenzopyran derivatives

Designing heterogeneous catalysts supported on stable solid materials is a promising approach for achieving efficient and reusable catalytic systems. Metal–organic frameworks (MOFs) are particularly attractive in this regard due to their high surface area, controllable porosity, and modifiable chemical functionality, which enable the stabilization of active metal centers and prevent species aggregation, thereby improving performance. In this work, a new magnetic copper-based nanocatalyst was fabricated using Zn-MOF as an MOF scaffold. Magnetic properties were introduced through the incorporation of Fe 3 O 4 nanoparticles, allowing for facile recovery of the catalyst via an external magnetic field. The framework was further functionalized with 1,3-diamino urea and cyanuric chloride (cya), providing active coordination sites for the immobilization of Cu species. The resulting material, Fe 3 O 4 @Zn-MOF-NH₂-Cya@Cu, efficiently promoted the synthesis of tetrahydro-benzo-pyran derivatives under mild conditions, affording excellent yields. Remarkably, the catalyst maintained its activity and structural integrity over five consecutive reaction cycles, confirming its magnetic recyclability and long-term stability.