New P-functionalised (chiral) phosphine ligands can be incorporated in the coordination sphere of transition metal complexes by insertion of polar multiple-bond systems into M-P or M=P bonds. The resulting phosphorus systems are not (or hardly) available using other synthetic routes. (Chiral) phosphine ligands are of essential importance for homogeneous catalysis. In the long term, the goal is to conduct these reactions catalytically.Insertion of isonitrile into the Ta=P bond of a tantalum phosphinidene complex
Complexes containing early (electron-poor) and late (electron-rich) metals connected by bridging ligands are of high interest because they can display cooperative synergistic effects between the metals.
Furthermore, functionalised bridging ligands (ferrocene, aromatics, heterocycles, conjugated systems, etc.) are used to modify in situ the donor-acceptor properties of phosphines (i.e. electrochemically, UV-Vis spectroscopically, by modifying the temperature or the pH, etc.) and to develop in this way "switchable" phosphines with possible catalytic application.
"Switchable" bisphosphine ligand
The cluster framework of ortho-carbaboranes (three-dimensional electron-poor aromatic analogues) can be functionalised at the C-H groups through phosphorus-containing groups.
The newly formed carbaboranylphosphines,
-phosphonites, etc., are potential electron-poor (chiral) ligands for use in homogeneous catalysis.
Mono- and multinuclear transition metal complexes as models for metallo-enzymes are used in homogeneous catalysis, i.e. oxidation and CO2 activation reactions.