STEREOSELECTIVE SYNTHESIS WITH TRANSITION METAL ENOLATES

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Because of the importance of synthetic organic compounds in medicine and in biochemical research, organic synthesis is fundamental to the health sciences. A crucial aspect of organic synthesis is stereoselectivity. In the last decade, chemists have developed a number of methods that allow the enantioselective preparation of chiral compounds. However, effective methods for achieving catalytic asymmetric induction are still rare. The two most important of these methods, the enantioselective synthesis of animo acids by hydrogenation of alkenes and the enantioselective epoxidation of unsaturated alcohols, do not involve carbon-carbon bond formation. No catalytic, enantioselective versions exist for the one of the most important synthetic reactions, the aldol addition reaction. In this project, it is proposed to search for such a method. Research will begin with the preparation and characterization of a series of transition metal enolates. The reactions of these materials with various organic substrates, including aldehydes, ketones, nitriles, esters, enones, isonitriles, azo compounds, alkenes, and alkynes, will be investigated. Attempts will be made to establish catalytic cycles, so that desirable transformations may be carried out with only small amounts of active catalyst. Finally, the effects of chiral ligands will investigated, with the ultimate goal of achieving catalytic asymmetric induction.