Structure-Reactivity Relationships in Carbanion Chemistry

Cornell University, Ithaca NY

Investigators

Abstract

In the proposed research funded by the Chemical Synthesis Program of the Chemistry Division, Professor David B. Collum of the Department of Chemistry and Chemical Biology at Cornell University will investigate the structures and reactivities of aryllithiums and heteroaryllithiums. Specifically, the reactivities of these compounds in ortholithiations, equilibrations, silylations, imine additions, the halogen dance, nucleophilic aromatic substitutions, and oxidative cyclizations of dianions will be studied. The work will focus on developing an understanding of the most fundamental principles of reactivity including how substituents influence both their structures and rates that they react with commonly used substrates. The role of solvation and aggregation will be studied. These lithium reagents are commonly used to functionalize aromatic compounds for the synthesis of complex, medicinally important molecules. Despite their widespread use, such organolithium derivatives are poorly understood, which can lead to significant problems in organic synthesis. Therefore, better understanding of the structures and reactivities of these compounds could improve the efficiency of organic synthesis, which is badly needed in pharmaceutical, chemical, and agricultural industries. In terms of educational impacts, this project will provide training of students, including those from groups historically underrepresented in the chemical sciences.