About the Research

A project has been initiated at the University of Burgundy based on ligand chemistry for catalysis under ultra-low metal loading. For this purpose, novel polyphosphine ligands based on a ferrocene backbone have been developed (see for example Figure 1). A library of more than fifty ferrocenyl di-, tri- and tetraphosphines has been obtained, from which some ligands displaying outstanding performance have been identified. Carbon–carbon and carbon–nitrogen bond formation (Suzuki, Heck, Sonogashira and Tsuji-Trost reactions) proceeded with high turnover numbers and catalyst loadings as low as 10^–4 mol% relative to the substrates.

The mechanistic features of cooperating polydentate ligands are being explored with electrochemistry for measuring kinetics and the identification of intermediary species. Additionally, internationally recognised work has been done in the field of phosphines characterisation through the discovery and investigation of nonbonded ‘through-space’ NMR spin–spin couplings in organophosphorus and organometallic compounds. Recently a patent was deposited, jointly held by the CNRS and the University of Burgundy, on the heterogenisation of a new family of ligands for recycling and heterogeneous catalysis. Low-loading palladium catalysis is now being explored for direct functionalisation of C–H bonds in heteroaromatics and for the formation of C–N, C–O and C–S bonds. C–C coupling for C–H funtionalisation has been achieved in cooperation with Henri Doucet at the University of Rennes, France, and the success of ferrocenyl polyphosphine ligands in low-loading catalysis has led to their commercialisation under the name “HiersoPHOS”.

In addition to the work on screening conditions for palladium-catalysed C–C bond and C–X bond formation (X = S, O, N), iridium and rhodium precursor salts are now also being investigated for direct specific C–H functionalisation.

This fundamental research in synthesis methodology may find many applications in total synthesis or synthesis of fine chemicals, including pharmaceuticals, agrochemicals and molecular materials.