Carbanions and Physical Organic Chemistry

碳负离子和物理有机化学

• 批准号: 9221277
• 负责人: Andrew Streitwieser
• 金额: $ 46.7万
• 依托单位: University of California-Berkeley
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1993
• 资助国家: 美国
• 起止时间: 1993-04-01 至 1996-03-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9221277&HistoricalAwards=false
• 关键词: Carbanions; Physical; Organic; Chemistry

Experimental and computational methods will be applied to determine the kinetic acidities of a variety of hydrocarbons. Experimental methods will include the determination of exchange rates from cyclohexylamine-N-t catalyzed by cesium and lithium cyclohexylamides by tritium NMR. Some rates will be determined for deuterium exchange with cyclohexylamine-N-d2 using mass spectroscopy and deuterium NMR. Theoretical calculations will be carried out for proton transfer reaction between various hydrocarbons and bases, and compared to experimental results. Calculations of ion-pair SN2 displacement reactions will be continued. These reactions show unusual highly bent transition states and may give relative reactivities different from the corresponding ionic reactions. %%% This grant from the Organic Dynamics Program supports the continuing work of Professor Andrew Streitwieser at the University of California, Berkeley. The acidity of very weakly acidic hydrocarbons will be determined by recently developed sensitive techniques. This will extend an important body of knowledge. Theoretical calculations will be made that relate to the acidity of hydrocarbons and the results will be compared to the experimental findings. This work will provide a fundamental understanding of weakly acidic hydrocarbons and the consequences to chemical reactivity of the carbon-hydrogen bond in hydrocarbons. Additional calculations will be carried out on a fundamental displacement reaction process in organic chemistry. Preliminary calculations have shown an unusual geometry in the course of this reaction and this work will be continued.

实验和计算方法将应用于确定各种烃的动力学酸度。实验方法将包括通过tritium nmr催化的环己胺-N-T催化的环己胺-N-T的汇率。使用质谱和NMR氘进行环己酰胺-N-D2的氘交换，将确定一些速率。理论计算将用于各种烃和碱之间的质子转移反应，并与实验结果进行比较。 离子对SN2位移反应的计算将继续。这些反应显示出异常的高度弯曲过渡态，并且可能给出的相对反应性与相应的离子反应不同。 %% %%来自有机动力学计划的这笔赠款支持加利福尼亚大学伯克利分校的安德鲁·斯特雷特维耶斯教授的持续工作。非常弱酸性烃的酸度将由最近开发的敏感技术确定。这将扩展重要的知识体系。 将进行与烃酸度有关的理论计算，并将结果与​​实验结果进行比较。这项工作将提供对弱酸性碳氢化合物的基本理解，以及对碳氢化合物中碳氢键的化学反应性的后果。在有机化学中的基本位移反应过程中将进行其他计算。初步计算表明在此反应过程中的几何形状，这项工作将继续进行。