LaMnO3 Supported Ionic Liquid; an Efficient Catalyst for One-Pot Three-Component Synthesis of Tetrahydrobenzo[b]Pyran Derivatives Under Solvent-Free Conditions

A new recyclable nanocatalyst consisting of heteropoly acid grafted on ionic liquid modified LaMnO3 nanoparticles was synthesized and accomplished as an efficient catalyst in condensation reaction for the preparation of tetrahydrobenzo[b]pyrans under solvent-free conditions. In addition, it was clarified that supported heteropoly acid (HPA) is the active site for the catalytic reaction, whereas the LaMnO3, ionic liquid functionalized lanthanum manganite nanoparticles are inactive. Different physicochemical methods such as Fourier transform infrared (FT-IR), X-ray powder diffraction (XRD), and field emission scanning electron microscopy (FESEM) were used to characterize the hybrid nanomaterial. The nanocatalyst reusability was affirmed by the use of five consecutive runs. Compared with the various previously reported catalyst, the new synthesized catalyst was found to be the most efficient with regard to reaction time, yield and ease of catalyst separation.