Fe3O4@SiO2 nanoparticles: As an efficient, green and magnetically reusable catalyst for the one-pot synthesis of 14-aryl-14H-dibenzo[a,i]xanthene-8, 13-dione derivatives in aqueous media under reflux conditions

Application of solid acids in organic transformations is important because these reagents doless harm to the environment and have no corrosion or disposal problems [1]. Core-shellstructured microspheres have recently been subject to extensive research for the combinedfunctionalities of cores and shells which endow them with great application potentials invarious fields [2].Multicomponent reactions (MCRs) and sequential transformations offer significantadvantages over conventional linear-step syntheses, by reducing time, and saving money,energy, and raw materials, thus resulting in both economic and environmental benefits [3].In this research silica nanoparticles-supported magnetite nanoparticles are employed as aneffective, green and recyclable catalyst for the preparation of 14-aryl-14Hdibenzo[a,i]xanthene-8,13-diones. The biologically active heterocyclic compoundsincluding benzoxanthenes were efficiently synthesized via three-component one-potcondensation of 2-naphthol, aromatic aldehydes and 2-hydroxynaphthalene-1,4-dione in theFe3O4@SiO2 core-shell nanoparticles under reflux conditions. This presented method hassome advantageous such as environmentally friendly media, high yields of products, shortreaction times and little catalyst loading.