Core-shell structured Fe3O4@MgO: magnetically recyclable nanocatalyst for one-pot synthesis of polyhydroquinoline derivatives under solvent-free conditions

Core-shell nanostructured Fe3O4@MgO catalyst was synthesized using a two-fold co-precipitation technique. High-resolution transmission electron microscopy (HR-TEM) images demonstrated that the catalyst had a core-shell framework with spherical morphology. In present study, Fe3O4@MgO is successfully used as an effective, novel, and recoverable nanocatalyst in an easy-to-follow, affordable, environment-friendly, and productive process for the synthesis of polyhydroquinoline derivatives via one-pot four-component Hantzsch condensation reaction. Importantly, magnetically retrievable Fe3O4@MgO nanoparticles provides high catalytic efficiency in solvent-free condition and can be used repeatedly up to six cycles without significant loss of catalytic activity. The study provides a greener route to yield 82-94% of polyhydroquinoline in a short reaction time under ultrasonication.