This grant in the Organic and Macromolecular Chemistry Program supports research by Dr. Philip Warner, Iowa State University, which aims at elucidating the chemical reactivity of carbenes, carbenoids, and organolithium species. Carbenes and carbenoids are reactive chemical fragments which occur as transient intermediates in many important chemical reactions. Understanding their chemical behavior is the key to effective utilization for organic synthesis of such carbenic processes as cyclopropanation, the Skattebol rearrangement, and other reactions. Dr. Warner's research will probe particular aspects of the structure and reactivity of carbenes and carbenoids, including the net loss of carbon from cyclopropylidenes upon interaction with certain nucleophiles, and from cyclopropylidenoids upon oxidation. A method of photogenerating three-membered ring carbenes, including oxiranylidene, will be developed for application to measurement of fast reaction kinetics and cryogenic studies. Laser flash photolytic methodology will be applied to the analysis of intramolecular carbene rearrangements, and NMR methods will be employed for determination of the structure of dilithiocyclopropanes.
