An extremely highly recoverable clay-supported Pd nanoparticle catalyst for solvent-free Heck-Mizoroki reactions

Palladium nanoparticles supported on LAPONITE (R), a synthetic clay, are shown to constitute a highly robust and stable catalytic system for Heck-Mizoroki reactions carried out under solventless conditions. Both the preparation and the use of the catalyst are straightforward, allowing easy separation of the reaction products in pure form. In the case of the reaction between butyl acrylate and iodobenzene, up to 50 catalyst cycles can be performed before observing a noticeable decrease in activity. After reactivation of the catalyst by calcination, it can be further used for at least an additional 25 reactions. The stability of the catalyst seems to be related to the electronic density of the reacting alkene, as illustrated by the results obtained using the same catalyst with other alkenes.