Water-soluble palladacycles containing hydroxymethyl groups: synthesis, crystal structures and use as catalysts for amination and Suzuki coupling of reactions

Abstract

Two water-soluble monophosphine [PPh3 and 2-dicyclohexylphosphino-2′,6′-dimethoxybiphenyl(Sphos)]-palladacycles containing hydroxymethyl groups 2–3 were prepared by cyclopalladation and chloride bridge-splitting reactions. The complexes were characterized by elemental analysis, ESI–MS and NMR. In addition, single-crystal X-ray analysis reveals that they have one-dimensional lamellar structures involving intermolecular hydrogen bonds and π–π interactions. The use of these palladacycles as catalysts for amination and Suzuki coupling of aryl chlorides in water was investigated. Complex 3 was found to be very efficient for these coupling reactions. Additionally, it was also successfully used in Suzuki coupling of (hydroxymethyl)phenylboronic acid for the synthesis of substituted 2-N-heterocyclic biarylmethanols.