Hollow composite nanoparticles with a carbon coating can be made cheaply and easily. Nevertheless, their recycling is now possible using a magnetic field according to researchers at Seoul National University, Korea, which would make their use even more efficient. The team points out that their approach sidesteps complicated preparations required of other such systems and makes them more amebnable to large-scale production. Moreover, the magnetic extraction precludes the need for sophisticated filtration or centrifugation steps and the “tedious workup of the final reaction mixture to recover the catalyst”.

The team has demonstrated efficacy of the nanoparticles in the selective reduction of nitroarenes (nitrobenzene in their proof of principle) and Suzuki cross-coupling reactions of bromobenzene, two important recipes in organic syntheses. Excellent catalytic activity is reported. The particles can be recycled five times.

• Magnetically recyclable hollow nanocomposite catalysts for heterogeneous reduction of nitroarenes and Suzuki reactions,
  Mohammadreza Shokouhimehr, Ji Eun Lee, Sang Ihn Han, Taeghwan Hyeon,
  Chem. Commun. 2013.
  DOI: 10.1039/C3CC41034J