Starchderived magnetic nanoparticles (Fe3O4@CSO3H): Synthesis, Characterization and Its application on the preparation of dihydropyrano[c]chromenes, 2-Amino-3-cyano-4H-pyrans and 2-amino-4H-chromenes derivatives

In this study, a novel biomass and Starchderived carbonaceous solid acid catalyst (Fe3O4@CSO3H) that has superparamagnetism with high acid density was successfully prepared for the first time by incomplete hydrothermal carbonization of Starch followed by Fe3O4 grafting and –SO3H groups functionalization. The characterization of physicochemical properties of Fe3O4@CSO3H NPs was achieved by Xray diffraction (XRD), Fouriertransform infrared spectra (FTIR) and Field Emission scanning electron microscope (FESEM). The resulted catalyst contained SO3H, COOH, and phenolic OH groups and exhibited good catalytic activity for the onepot synthesis of dihydropyrano[c]chromenes, 2‑Amino3cyano‑4H‑pyrans and 2amino4Hchromenes derivatives (chromenes and pyrans) via multicomponent reactions. High catalytic activity and easy magnetical separation from the reaction mixture are two significant factors for evaluating the performance of Fe3O4@CSO3H nanoparticles in the organic transformations.