The objectives of this work are two fold. 1) Diene-iron tricarbonyl complexes with appended olefins will be coupled to make spirocyclic compounds. This coupling reaction allows stereospecific construction of densely functionalized molecules that contain proximal quaternary centers. This methodology will be applied to the synthesis of the core structures of the natural products, stemodinone and aphidicolin. 2) Diene-iron tricarbonyl complexes with proximal hydroxyl groups will be used in stereoselective intramolecular cyclization reactions. The diene-iron complex stabilizes cations formed by acid promoted ionization of the hydroxyl group allowing stereocontrolled intramolecular cyclizations to be effected. Use of optically pure complexes in these cyclizations should lead to asymmetric cascade reactions.
With this award, the Organic and Macromolecular Chemistry Program is supporting the research of Dr. Anthony J. Pearson of the Department of Chemistry at Case Western Reserve University. Dr. Pearson will explore stereoselective cyclization reactions of organoiron reagents. The ability to form carbon-carbon bonds in molecules which are chiral (have two nonsuperimposable mirror images) and make only one of the two possible forms (a single enantiomer) is one of the most important problems facing the pharmaceutical industry today. When developed, Dr. Pearson's work could be applied to the synthesis of natural products such as stemodinone and aphidicolin. Students trained during the course of this work will gain skills needed by the pharmaceutical industry which now produces a number of single enantiomer compounds.
