Research in our laboratory of organometallic is focused the on synthesis of organometallic compounds, the discovery of new reaction pathways, and the applications of organo-transition metal (TM) chemistry to homogeneous catalysis. We target in particular the chemistry of nickel, the development of its transition metal organometallic chemistry, its C–H activation reactions and its catalytic chemistry.
Our recent research has focused on the chemistry of relatively thermally- and air-stable nickel(II) complexes which bear both cyclopentadienyl ligands and N-heterocyclic carbene ligands. Nickel is a cheap metal in comparison with its catalytically active neighbors in the periodic table, palladium and platinum but is much cheaper and much more abundant in the earth’s crust. The use of earth abundant materials and metals is becoming increasingly important in a world of diminishing natural resources and our research is keenly aware of this. Furthermore, the complexes we are investigating are readily prepared from inexpensive starting materials.
Our research has led us to discover efficient nickel based catalysts for the important Suzuki-Miyaura coupling reaction. Related nickel-based compounds prepared by our group are also catalytically active in the hydrosilylation of aldehydes and ketones.
A serendipitous discovery has led us into the field of C–H activation. A number of readily prepared nickel(II) complexes are able, in the presence of a base, to activate sp3 C–H bonds that are in an alpha-position relative to a coordinated nitrile or ketone group. This has led us to isolate a remarkable molecule that results from the double activation of acetone and contains a –CH2–C(=O)–CH2– group that is bridging two nickel centers. This research subsequently led to the development of nickel(II) based catalysts for the alpha-arylation of aromatic ketones, a reaction that has important potential applications in organic syntheses.
Current and future research is based on enlarging our current library of nickel NHC complexes with potential applications in catalysis and also towards the grafting of NHC ligands onto calixarenes to investigate the catalytic, and the complexation-of-anion potential of such species. Investigations into nickel NHC chemistry in other oxidation states and indeed with other metals are under development.