Enantioselective Applications of Designer Synergic Reagents

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Organo-alkali metal compounds, especially organolithium reagents (that is compounds that contain a direct bond between a lithium atom and a carbon atom) are extremely important synthetic reagents. Indeed, it has been estimated that 98% of all drugs produced by the pharmaceutical industry rely upon the use of these reagents at some point in their synthesis. In general, organolithium compounds are highly reactive; however, this is sometimes coupled with the compounds exhibiting a lack of selectivity. To overcome this situation, less reactive, but more selective compounds (such as organomagnesium reagents) are often used. Recent research has shown that by combining a lithium reagent with a magnesium (or zinc) one, a whole new and in many cases surprising chemistry can be produced. Just as the human body has a left and a right hand, certain organic molecules (commonly known as chiral compounds) which are used to make new drugs can also be considered left or right handed. In medicine, it is common that only one handed form of an organic molecule has the required therapuetic effect; it is also usual that the other handed form induces nasty side effects. It is therefore important that the synthetic chemist can produce only one handed form of a specific organic compound - in chemistry, this is known as enantioselective synthesis.In this research, a detailed systematic investigation of the two aforementioned topics will be combined for the first time - that is enantioselective synthesis using alkali metal-magnesium or alkali metal-zinc complexes. During the first part of this research many new mixed-metal compounds which contain chiral molecules will be synthesised. Various analytical techniques will be used to fully determine the structure - both in solution and in the solid state. Then a full and systematic study of how these compounds react with organic molecules will be conducted.It is envisaged that in the near future these new mixed-metal complexes will be used to complement the well known organolithium reagents in the pharmaceutical industry.