CoFe₂O₄–SiO₂–SO₃H nanocomposite as a magnetically recoverable catalyst for oxidative bromination of alkynes

A hybrid catalyst has been prepared by incorporating sulfonic acid onto cobalt ferrite magnetic nanoparticles. The catalyst was successfully applied for rapid (20 min) synthesis of α,α-dibromoketones directly from alkynes and NBS. The reaction works well in the presence of 10 wt% of the catalyst at room temperature to produce the desired products in high yield. The catalyst could be recovered using an external magnet and reused without appreciable change in activity.