Copper- and phosphine-free Sonogashira coupling reaction catalyzed by silica-(acac)-supported palladium nanoparticles in water

A palladium-based catalyst supported on acac-functionalized silica was used as a heterogeneous catalyst for the Sonogashira cross-coupling reaction of various aryl halides and phenylacetylene under copper- and phosphine-free conditions. This catalytic system serves as an efficient and stable catalyst for this cross-coupling reaction and allows easy separation and recycling of the catalyst. The catalyst could be recycled for five runs without appreciable loss of its catalytic activity. In addition, the reaction was carried out in water as a green solvent. Copyright (C) 2014 John Wiley & Sons, Ltd.