Magnetic Bisphosphonic Acid Nanohybrid Catalyzed Heterogeneous Synthesis of Heterocylcles

摘要

A novel inorganic-organic hybrid nanocomposite (PBA@SMNP) was synthesized by functionalization of starch-coated iron oxide nanoparticles with bisposphonic acid. The particles were characterized by XRD, FT-IR, TEM, SEM, EDS, TGA and VSM. TEM images demonstrate a quasispherical particle shape for the as-synthesized nanocomposite with an average diameter of 11nm. The phosphonic acid functionalized nanoparticles catalysed the synthesis of quinoxaline and benzimidazole derivatives in ethanol. This catalytic system has an extensive substrate domain, and is eco-friendly and cost effective. The heterogeneity of system with simple work-up procedure that uses a green solvent are the advantages of the present high yielding protocol. More importantly, the catalyst is readily removed from the reaction medium with an external magnet and can be retrieved several times without any loss of efficiency.