Structure-Energy Relationships of Lithium Enolate Aggregates

有机和高分子化学的这项资助提供了 支持杜克大学的爱德华·阿内特博士的研究。 这项工作的重点是结构-能量关系， 表征有机阴离子的聚集和反应性 在溶液中。理解这些关系对于 反应物之间相互作用的完整结构 和溶液中的溶剂。 研究了下列过程：（1） 一些基本过程，如相互作用的热， 锂阳离子与中性配体如醚、酯， 酮、醛和胺，以及与烯醇盐、酚盐和 醇盐离子;（2）与反应直接相关的反应热 烯醇化锂如羟醛和 Michael凝聚;（3） 选择烯醇化物离子在不同溶剂的光谱 极性-环己烷，苯，二氧六环，DMSO和环丁砜- 通过凝固点降低（这样的结果将与 X射线晶体结构，异相NMR， 络合，并在有利的情况下，动力学分析 烷基化或羟醛缩合反应）;（4） 碳正离子、碳负离子和自由基， 可以直接比较单电子转移的动力学 配位（双电子转移）。

This grant in Organic and Macromolecular Chemistry provides support for the research of Dr. Edward Arnett, Duke University. The work is focused on the structure-energy relationships which characterize the aggregation and reactivity of organic anions in solution. Understanding such relationships is essential for a complete construction of the interactions between reactants and solvents in solution. The following processes will be studied: (1) the energies for a number of fundamental processes such as heats of interaction of lithium cation with neutral ligands such as ethers, esters, ketones, aldehydes, and amines and with enolate, phenolate and alkoxide ions; (2) heats of reaction of direct relevance to the important reactions of lithium enolates such as the aldol and Michael condensations; (3) the degrees of aggregation for selected enolate ions in a spectrum of solvents of varied polarity --cyclohexane, benzene, dioxane, DMSO and sulfolane-- by freezing point depression (such results will be related to x-ray crystal structures, heteronuclear NMR, heats of complexing and, in favorable cases, to kinetic analysis of alkylation or aldol reactions); (4) equilibration of carbocations, carbanions, and radicals where thermodynamics and kinetics for single electron transfer may be compared directly with coordination (two electron transfer).