Carbon coated magnetic nanoparticles as supports in microwave-assisted palladium catalyzed Suzuki-Miyaura couplings

A palladium bis-N-heterocyclic carbene complex was immobilized on polystyrene modified, magnetic carbon coated iron nanoparticles and evaluated in Suzuki-Miyaura cross-coupling reactions under conventional and microwave heating. Under the latter conditions, both aryl bromides and aryl chlorides could be employed as substrates at low loading of catalyst (0.2 mol%), which could be readily recovered by an external magnet and reused in at least four cycles. As a possible deactivation pathway of the catalyst, the formation of palladium nanoparticles in the course of the reaction that became encapsulated in the polystyrene matrix of the support is suggeste