Structure-Reactivity Relationships in Carbanion Chemistry

本研究的重点是调查如何 N，N，N ′，N ′-四甲基乙二胺（TMEDA）和相关的二胺改性， 或不能改变有机锂聚集体结构和反应性。 NMR的结构研究将使用TMEDA和相关的二胺， 正丁基锂、苯基锂、乙炔锂及相关 有机锂衍生物。 二胺的比较和竞争 四氢呋喃和相关的醚配体将确定 醚类竞争性结合的情况，或 与有机锂协同作用。 定量配体结合研究 将为后续速率研究建立热化学基础。 二胺溶剂化有机锂的代表性反应速率数据 衍生物，在完善的解决方案结构的背景下， 作业，将提供深入了解溶剂化和聚集 事件进行到速率限制转换结构。 夹层 溶剂化效应的基态和过渡态贡献 将是理解TMEDA在有机锂中作用的核心 化学. 有了这个更新奖，有机和高分子 化学项目正在支持大卫B博士的研究。颈 康奈尔大学化学系。 科勒姆教授将 他的工作重点是挑战现有的观念， N，N，N '，N'-四甲基乙二胺（TMEDA）及相关二胺 影响有机锂结构和反应性。 这项研究 由于广泛的使用，对有机合成的实质性影响 有机锂试剂

The focus of this research is the investigation of how N,N,N',N'-tetramethylethylenediamine (TMEDA) and related diamines modify, or fail to modify, organolithium aggregate structures and reactivity. Structural studies with NMR will use TMEDA and related diamines with n-butyllithium, phenyllithium, lithium acetylides and related organolithium derivatives. Comparisons and competitions of diamines with tetrahydrofuran and related ethereal ligands will ascertain the circumstances under which the ethers bind competitively or cooperatively to organolithiums. Quantitative ligand binding studies will establish thermochemical foundations for subsequent rate studies. Rate data for representative reactions of diamine-solvated organolithium derivatives, in the context of well-established solution structure assignments, will afford insights into the solvation and aggregation events proceeding to the rate limiting transition structures. Dissection of solvation effects into ground state and transition state contributions will be central to an understanding of TMEDA's role in organolithium chemistry. With this renewal award, the Organic and Macromolecular Chemistry Program is supporting the research of Dr. David B. Collum of the Department of Chemistry at Cornell University. Professor Collum will focus his work on challenging the existing notions on how N,N,N',N'-tetramethylethylenediamine (TMEDA) and related diamines influence organolithium structures and reactivities. The research has substantial implications for organic synthesis due to the wide spread use of organolithium reagents.