Construction of water-soluble phosphines, new advances in aqueous organometallic chemistry

Interest in aqueous organometallic chemistry stems from the fact that water-soluble transition metal compounds have found applications as catalysts in commercially-viable industrial processes for bulk and fine chemicals synthesis and also for their continued utility in biomedicine. As a solvent, water is unique because it displays polar and protic properties. The strong propensity of water to involve in hydrogen bonding interactions and its ability to act as a donor ligand to transition metals makes it even more unique, non-toxic and environmentally-benign, medium for chemical and biological use. In order to make the best use of some of the properties of water as a solvent, it is important that the transition metal complexes exhibit high solubility and good kinetic stability (in some instances) in water. Traditionally, phosphines functionalized with charged/polar substituants (e.g. -SO3H, -COOH or -OH) have been used as ligands to produce aqueous-soluble transition metal complexes. Recently, studies in our laboratories have demonstrated that a new generation of hydroxymethyl-functionalized bis, tris and tetradentate phosphines, upon complexation with the early and late transition metals, produce transition metal complexes possessing water-soluble characteristics. In this presentation, the design and development of water-soluble hydroxymethyl-functionalized phosphines and their application in the development of aqueous-organometallic chemistry will be discussed.