Fe3O4@SiO2 nanoparticles: An efficient, green and magnetically reusable catalyst for the one-pot synthesis of 14-aryl-14H-dibenzo[a,i]xanthene-8,13-dione derivatives

An efficient and eco-friendly method for the one-pot synthesis of 14-aryl-14H-dibenzo [a,i]xanthene-8,13-dione derivatives has been developed in the presence of Fe3O4@SiO2 core-shell nanoparticles. The multi-component reactions of 2-hydroxy-1,4-naphthoquinone, β-naphthol and aldehydes were efficiently catalyzed using novel nano-scale materials under reflux conditions. The present method offers several advantages such as environmentally benign, simple work-up, excellent yield of products, short reaction times, little catalyst loading and facile catalyst separation. The nanomagnetic catalyst could be readily recovered using a simple external magnet and reused several times without any significant loss in activity. The catalyst was fully characterized by FT-IR, SEM, XRD, EDX and VSM analysis.