Palladium Nanoparticles Supported on MIL-101 as a Recyclable Catalyst in Water-Mediated Heck Reaction

Pd nanoparticles supported on the chromium terephthalate metal organic framework, Pd-0 9/MIL-101, was prepared by simple Pd-acetate adsorption on MIL-101 followed by reduction in acetone. The material was characterized by XRD, N-2 adsorption-desorption isotherm, TEM and ICP analysis. Pd0 9/MIL-101 was found to be an effective heterogeneous catalyst for the water-mediated Heck cross-coupling reaction of various aryl iodides and alkenes under mild reaction conditions with product yields of 81 to 97%. The electron-withdrawing group attached to aryl iodide reacted faster than the electron-donating one, and the activity increased in the sequence of 4-methoxy-1-iodobenzene << iodobenzene < 1-iodo-4-nitrobenzene. The catalyst could be reused several times without losing its initial catalytic activity, and XRD and TEM confirmed that the crystallinity of Pd-0.9/MIL-101 had been retained during the reaction with no metal leaching or agglomeration observed.