preparation and characterization of fe3o4@sio2/aptposs core–shell composite nanomagnetics and it is application in the synthesis of 2-amino-4h-chromene via multicomponent reactions at room temperature

Octakis[3-(3-aminopropyltriethoxysilane)propyl] octasilsesquioxane (aptposs) as a polyhedral oligomericsilsesquioxanes derivative was prepared and used as a pioneer reagent to obtain novel core/shell composite using magnetic iron oxide nanoparticles as the core and the inorganic-organic hybrid polyhedral oligomericsilsesquioxanes as the shell. fe3o4@sio2/aptposs were confirmed by scanning electron microscope (sem), energy dispersive spectroscopy (eds), x-ray diffraction (xrd). the inorganic-organic hybrid polyhedral oligomericsilsesquioxanes magnetic nanoparticles used as an efficient new heterogeneous catalyst for the one-pot three-component synthesis of 2-amino-4h-chromene via multicomponent reactions at room temperature . moreover, these nanoparticles could be easily separated by using an external magnet device and then reused several times without significant loss of its catalytic activity.