Interest in catalysis by palladium nanoparticles is increasing dramatically due to the advantages offered by these “semi-heterogeneous catalysts” [1]. These advantages combine the characteristics of heterogeneous catalysis (recovery and recyclability) with those of homogeneous catalysis (relatively low catalyst loadings and good selectivity) [2]. Since the heterogeneous catalysis reaction occurs entirely on the surface of the metal particles, a high dispersion or size control is required to improve the catalytic activity and reduce the consumption of the catalysts [3]. Unfortunately, aggregation of naked nanoparticles often prohibits tailoring of particle size. For this reason, many attempts have been made to immobilize or stabilize Pd nanoparticles in a wide variety of supports, such as polymers, organic-inorganic hybrid materials, and glass-polymer composites, as well as on common inorganic substrates, such as carbon, silica, zeolites or carbon nanotubes [1-2]. Herein hyperbranched polyglycidole (HPG) is used as support, it also functions as reducing agent and stabilizer. We report green and innovative magnetic semi-heterogeneous efficient palladium catalyst system that has been immobilized hyperbranched polyglycidole (acting as support, reducing agent and stabilizer) coated magnetic Fe3O4 nanoparticles (Fe3O4@HPG/Pd0) for effective palladium-catalyzed Suzuki–Miyaura coupling reactions in room temperature and aqueous media.

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