Supported phosphine-free palladium catalysts for the Suzuki-Miyaura reaction in aqueous media

The Suzuki-Miyaura reaction has been performed using a non- symmetrical salen-type palladium(II) catalyst that is readily immobilized onto Merrifield resin and functionalized silica. The catalysts combine high activity with the recoverability and reusability offered by a heterogeneous system, without the need for phosphine ligands or additives. The high content of water used in the reaction, which is more than 96% by volume, represents a green process that should have advantages for industrial applications. Leaching of the metal into solution from the supported catalyst proved to be negligible.