Asymmetric Assembly of Cobalt Metallocenes - Accessible Building Blocks for Novel Catalysts

Molecules that exist in 'handed' form are of growing importance to many research areas, not least the pharmaceutical industry where sales of such compounds now exceed $100 billion per annum. 'Handed' molecules exist in two non-superimposable mirror image forms of which only one usually displays the desired property such as an ability to mediate biological activity. One of the most efficient and cost effective means to generate such molecules is to employ a small quantity of a metal/ligand catalyst that selectively generates one 'handed' form over the alternative. Central to this strategy is the ligand which contains the information required to successfully control the reaction taking place at the metal, to which it is attached. Thus many different ligand types have been synthesised and tested, yet it is striking how certain groups, or privileged structures as they have been coined, are successful for a wide range of applications. One of these groups is the metallocenes, normally derivatives of iron-based compounds called ferrocenes. In this proposal a new strategy is outlined for the synthesis of cobalt based metallocenes that is significantly simpler than the existing ferrocene methodology. Furthermore, it has much greater variability and flexibility that will enable rapid access to, and optimisation of, a ligand for a given metal catalysed 'handed' synthesis.