ION PAIR CARBON ACIDITY

碳离子，通常以离子对或聚集体的形式存在， 许多有机合成中的重要中间体 具有生物活性的天然产品、药品、药品等。 一种常见的合成过程是衬底的金属化。 在乙醚中加入烷基锂或锂酰胺，然后 与合适的电泳液反应。我们建议将这一点 以定量科学为基础的主要经验性技术 继续我们对平衡常数的测定 指示性碳氢化合物的反应R-M++R‘H=R’-M++RH (例如，荧烯、芳基甲烷等)在四氢呋喃(THF)中 铯和锂离子。这些指标体系将是 用于测定碳酸与不同种类的碳酸的平衡 在合成中很重要的官能团。重要的强调将 被放置在用于控制区域的官能团上-和 立体化学在生物活性化合物合成中的应用 天然产物，如肟醚和二甲基肼 羰基化合物的衍生物。这项研究将包括其他 羰基化合物及其衍生物，如酰胺和恶唑啉 以及硫、硒和硅衍生物、乙烯基、烯丙基、 苯基和芳基化合物杂环化合物及相关 二阴离子，如肟基二阴离子。作为以下因素的函数的确定 集中程度将提供定量的估计 聚合。对于那些被证明以单体和 二聚体离子对，烷基化和缩合的动力学研究 作为集中注意力的功能来完成，以显示角色 这两个物种在这样的反应中。均衡测量作为 温度函数将提供热力学量 和铯平衡的比较，已知的 涉及接触离子对，与相应的锂 平衡，其中各种类型的离子对是可能的， 将有助于理解更复杂的锂案件。 电导率研究将把离子对与离解离子联系起来。 结果将借助相关动力学进行解释。 酸度测量，聚合体系的研究，理论 分子的量子化学计算和计算机图形分析 电子密度分布。本文的理论研究包括ab. 结构和反应路径的从头计算。

Carbanions, generally involved as ion pairs or aggregates, are important intermediates in the organic synthesis of many biologically active natural products, pharmaceuticals, drugs, etc. A common synthetic procedure is the metallation of a substrate with an alkyllithium or lithium amide in an ether followed by reaction with a suitable electrophile. We propose to put this largely empirical technique on a quantitative scientific basis by continuing our determination of equilibrium constants for the reactions, R-M+ + R'H = R'-M+ + RH, for indicator hydrocarbons (e.g., fluorenes, arylmethanes, etc.) in tetrahydrofuran (THF) with cesium and lithium as gegenions. These indicator systems will be used to determine equilibria for carbon acids with various functional groups important in synthesis. Important emphasis will be placed on functional groups used to control regio- and stereochemistry in synthesis of biologically active compounds and natural products, such as oxime ethers and dimethylhydrazone derivatives of carbonyl compounds. The study will include other carbonyl compounds and derivatives such as amides and oxazolines as well as sulfur, selenium and silicon derivatives, vinyl, allyl, benzyl and aryl compounds heterocyclic compounds, and related dianions such as oxime dianions. Determinations as a function of concentration will provide quantitative estimates of the degree of aggregation. For those systems shown to exist as monomer and dimer ion pairs, kinetic studies of alkylation and condensation will be accomplished as a function of concentration to show the role of both species in such reactions. Equilibrium measurements as a function of temperature will provide thermodynamic quantities and comparison of the cesium equilibria, which are known to involve contact ion pairs, with the corresponding lithium equilibria, in which a variety of types of ion pairs are possible, will facilitate understanding of the more complex lithium cases. Conductivity studies will relate the ion pairs to dissociated ions. The results will be interpreted with the help of related kinetic acidity measurements, studies of aggregated systems, theoretical quantum chemical calculations and computer graphics analysis of electron density distributions. The theoretical studies include ab initio computations of structure and reaction paths.