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-functionalizedepoxy-immobilized Fe3O4 core-shell magneticnanocatalyst was preparedthrough a simple three-step procedure, and it was identified by variousanalyses such as Fourier transform infrared (FT-IR) spectroscopy,scanning electron microscopy (SEM), differential thermal gravity (DTG),Brunauer-Emmett-Teller (BET) analysis, transmissionelectron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDX),thermogravimetric analysis (TGA), vibration sample magnetometry (VSM),and powder X-ray diffraction (PXRD). BET analysis showed that theas-prepared nanocatalyst was synthesized with a mesoporous structureand high specific area (35.45 m(2) g(-1)).The TEM image clearly showed that the particle size distribution wasin the range of 47-65 nm. The designed magnetic nanocatalystwas used successfully in the synthesis of pyran derivatives via thereaction of dimedone, malononitrile, and various aromatic aldehydesand synthesis of pyrrolidinone derivatives via the reaction of variousaromatic aldehydes, aniline, and diethyl acetylenedicarboxylate. Thenanocatalyst was simply isolated from the reaction mixture utilizingan external magnet and reused several times according to the modelreactions without significant loss in its efficiency.