Sulfonate Functionalisation of Transition Metal Complexes: A Versatile Tool Towards Catalyst Recovery

Abstract

This thesis describes the synthesis and application of sulfonate-functionalised ligands in organometallic chemistry and (aqueous) catalysis. Due to their ability to trigger specific solubility, different NHC ligand precursors bearing a butyl-sulfonate chain were synthesised. The formation of transition metal complexes containing gold and rhodium was enabled by a simple procedure involving the initial synthesis of a silver complex and a transmetallation with a suitable metal precursor and an organic salt. Metallodendrimers containing eight metal complexes immobilised via ionic interactions were synthesised following this straightforward one-pot protocol. This particular strategy was extended to the synthesis of homo-metallodendrimers (Au/Au) and was modified to allow the formation of hetero-metallodendrimers (Au/Pt). In addition, a new class of sulfonate-functionalised arene ruthenium complexes was developed. Due to their highly water-solubility these complexes act as catalysts in the asymmetric transfer hydrogenation of acetophenone in water. The catalyst was recycled and was still active after several runs, giving the alcohol products in excellent enantiopurity.