Palladium-decorated o-phenylenediamine-functionalized Fe3O4/SiO2 magnetic nanoparticles: A promising solid-state catalytic system used for Suzuki-Miyaura coupling reactions

Palladium-supported o-phenylenediamine-functionalized Fe3O4 magnetic nanoparticles are presented. A convenient synthetic route for the nanocatalyst and also its application in Suzuki-Miyaura coupling of various aryl halides with phenylboronic acids are described. A high reaction yield (98%) was been obtained in a short reaction time (10 min) through use of this highly efficient nanocatalyst. From a mechanistic aspect, firstly, effective electronic interactions between heteroatoms such as oxygen and Pd(II) provide a suitable condition for covalent bonding by the ingredients in the Suzuki-Miyaura coupling reaction. Secondly, Pd(II) is converted to Pd (0) by use of sodium borohydride in the presence of triphenylphosphine in basic conditions, and then it plays a main role in the catalytic process. However, the most distinguished properties of this catalytic system are the ease of catalyst separation and great reusability. The palladium-supported o-phenylenediamine-functionalized Fe3O4 nanoparticles can be easily recovered by use of an external magnet and can reused at least ten times with no significant decline in catalytic activity. This novel system was structurally characterized by various analytical methods, and the results obtained are well interpreted in the context.