Structure-Reactivity Relationships in Carbanion Chemistry

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With this renewal award the Organic and Macromolecular Chemistry Program supports the work of Dr. David B. Collum at Cornell University in Ithaca, New York. The work involves a detailed study of the solution structures and reactivities of organolithium aggregates in the presence of N,N,N',N'-tetramethylethylenediamine (TMEDA) and related diamines, as well as ethers such as tetrahydrofuran (THF). The organolithium reagents will include n-BuLi, PhLi, and lithium acetylides. Part of the work will focus on how BF3.amine complexes and other Lewis acid adducts influence the reactivities of the organolithium compounds.Organolithium compounds, containing carbon-lithium bonds, are often written simply as RLi, where R is an organic group. They are used as reagents to prepare a variety of more complex structures, with the formation of new carbon-carbon bonds. The rates of these reactions, and the products formed, depend strongly on the presence of amine, ether, and Lewis acid additives. Dr. Collum and his group are trying to understand what species are present in solution, and how their structures influence their reactivities. The work is likely to be of interest to chemists in both academia and industry, and to provide excellent training for the students involved.