Preparation of a new clay-immobilized highly stable palladium catalyst and its efficient recyclability in the Heck reaction

The immobilization of a series of bis-carbene-pincer complexes of palladium(II) on montmorillonite K-10 affords the preparation of effective catalysts for the C-C coupling in a standard Heck reaction. The supported catalysts so obtained, show catalytic activity similar to their homogeneous counterparts. The determination of Pd content on the supported catalysts by XPS and elemental analysis, before and after each catalytic reaction, shows that leaching is negligible. Once the reaction conditions were optimized, we were able to recycle the catalyst at least ten times, without significant loss of activity.