Recently, nanocatalysts and especially their magnetic types functionalized by appropriate organic groups have been widely used in the synthesis of various materials. In this work, functionalized Fe3O4 nanoparticles by tris(hydroxymethyl)aminomethane/cyanuric chloride/2- pyridineethanol/SO3H were synthesized and characterized by FESEM, EDX, FT-IR, VSM, and XRD analyses. Their catalytic efficiency was tested in the synthesis of polyhydroqunolines (19 entries, 12-25 minutes, 85- 95%, solvent-free, room temperature), 1,4-dihydropyridines (16 entries, 25-50 minutes, 88-92%, solvent-free, 80 °C), and tetrahydrobenzopyranes (17 entries, 10-52 minutes, 90-97%, solvent free, room temperature) derivatives under mild and environmentally friendly reaction conditions. This novel nano organic/inorganic hybrid acidic catalyst was easily separable by an external magnet. Fast reaction times and high purity of the products are the remarkable advantages of this new catalyst.
