Chiral N-Heterocyclic Carbenes as Organocatalysts and Ligands for Metal-Mediated Asymmetric Processes

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Asymmetric metal-mediated processes are vital in organic synthesis. For many years, chiral phosphines have provided the source of asymmetry in chiral metal complexes. In recent years, however, N-heterocyclic carbenes (NHCs) have begun to play a prominent role as ligands in many metal-mediated processes, to the extent that they now rival, and surpass, phosphines in this role. However, in the more specialised field of asymmetric catalysis, NHCs still lag beh phosphines. The research described herein is directed towards the preparation of new chiral NHC metal complexe their application in asymmetric synthesis, and in particular in asymmetric alkene metathesis processes. It is also important to recognise that NHCs may also form complexes with main group metals and non-metals, and that then complexes may also be useful in synthesis. This area is so far unexplored, and this research project will investigate the potential of NHC main group complexes in organic synthesis. Additionally, the free NHCs themselves display properties that make the chiral NHCs attractive candidates for nucelophilic organocatalysts. Finally, it is proposed to investigate preparation and reactions of completely novel, carbene-like species, which may act as ligands in a similar manner carbenes.