SO₃H-Functionalized Epoxy-Immobilized Fe₃O₄ Core–Shell Magnetic Nanoparticles as an Efficient, Reusable, and Eco-Friendly Catalyst for the Sustainable and Green Synthesis of Pyran and Pyrrolidinone Derivatives

A SO3H-functionalized epoxy-immobilized Fe3O4 core–shell magnetic nanocatalyst was prepared through a simple three-step procedure, and it identified by various analyses such as Fourier transform infrared (FT-IR) spectroscopy, scanning electron microscopy (SEM), differential thermal gravity (DTG), Brunauer–Emmett–Teller (BET) analysis, transmission (TEM), energy-dispersive X-ray spectroscopy (EDX), thermogravimetric analysis (TGA), vibration sample magnetometry (VSM), powder diffraction (PXRD). BET showed that the as-prepared synthesized with mesoporous structure high specific area (35.45 m2 g–1). The TEM image clearly particle size distribution in range of 47–65 nm. designed used successfully synthesis pyran derivatives via reaction dimedone, malononitrile, aromatic aldehydes pyrrolidinone aldehydes, aniline, diethyl acetylenedicarboxylate. simply isolated from mixture utilizing an external magnet reused several times according to model reactions without significant loss its efficiency.