Hybrid magnetic Irish moss/Fe3O4 as a nano-biocatalyst for synthesis of imidazopyrimidine derivatives†
Irish moss (IM), derived from the Chondrus crispus is a family of sulphated polysaccharide that are extracted from certain kinds of algae (red edible seaweeds). In this study, new magnetically separable, recoverable Fe3O4 nanoparticles were synthesized in the presence of natural Irish moss (IM) to afford Fe3O4@IM. FT-IR analysis, scanning electron microscopy (SEM), transmission electron microscopy (TEM), VSM analysis, Energy-Dispersive X-ray Spectroscopy (EDX) and X-ray diffraction (XRD) were combined for the characterization of the Fe3O4@IM nanocomposite. Afterward, the first catalytic report of Fe3O4@IM with no post-modification was achieved by studying its catalytic activity in the synthesis of imidazopyrimidine derivatives via a three-component reaction of 2-aminobenzimidazole, aldehyde, and C–H acidic compounds under reflux in ethanol. 1H nuclear overhauser effect (NOE) experiments have been used to ascertain the regioselectivity of addition and condensation reactions. Based on this study, Fe3O4@IM is an efficient, magnetically separable, recyclable, and green catalyst.