Mechanistic Studies on Halodiazirines, Radical Stabilization by meta Substituents

卤代氮丙啶的机理研究，间位取代基的自由基稳定作用

• 批准号: 8910989
• 负责人: Xavier Creary
• 金额: $ 24.64万
• 依托单位: University of Notre Dame
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1989
• 资助国家: 美国
• 起止时间: 1989-07-01 至 1992-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=8910989&HistoricalAwards=false
• 关键词: Mechanistic; Studies; Halodiazirines; Radical; Stabilization

This project by Xavier Creary of the University of Notre Dame is supported by the Organic Dynamics Program, and is involved in a study of the detailed molecular pathway of certain organic reactions. The reaction of a class of compounds known as bromodiazirines with negative ions will be studied, and in a second part of the project, free radical stabilities are to be examined. This program will provide useful information about how organic reactions proceed on a molecular level. This study is based on the belief that the commonly accepted mechanism of the reaction of bromodiazirines with nucleophiles cannot be correct. A novel N-azidodiazirine is proposed as an intermediate for the reaction of bromophenyldiazirine with azide ion. However, in cases where the nucleophile is highly polarizable (e.g., thiophenoxide), electron transfer may become the preferred pathway. N-15 labeling experiments will be carried out to distinguish among the various mechanistic possibilities. Understanding of substitution reactions will be advanced and insights should be gained into the factors controlling direct nucleophilic attack vs. electron transfer. N-azidoamines will also be generated and factors that affect their stability will be investigated. In a second part of this work, a novel and previously unrecognized mechanism by which meta substituents can stabilize free radicals is proposed. Attempts will be made to verify this hypothesis experimentally by using the methylenecyclopropane rearrangement probe developed by the Notre Dame group. These studies will enhance the state of understanding of factors that contribute to free radical stability.

这个项目由圣母大学的泽维尔·克里里 由有机动力学计划支持， 在一项研究中， 反应. 一类化合物的反应， 将研究具有负离子的溴代二氮丙啶， 项目的第二部分，自由基的稳定性将是 考察 该计划将提供有用的信息， 有机反应如何在分子水平上进行。 这项研究是基于这样一种信念，即普遍接受的 溴代二氮丙啶与亲核试剂的反应机理 不能被纠正。提出了一种新的N-叠氮基二氮杂环丙烷， 溴苯基二氮杂环丙烯与 叠氮离子。 然而，在亲核试剂高度亲核的情况下， 可极化的（例如，噻吩氧化物），电子转移可能成为 首选的路径。 N-15标记实验将在 进行了各种机械之间的区分 可能性 理解取代反应将是 先进的和洞察力应该获得的因素， 控制直接亲核攻击与电子转移。 也将产生N-叠氮基胺，并且影响N-叠氮基胺的因素包括： 将对其稳定性进行研究。 在第二部分中， 工作，一种新的和以前未被认识的机制， Meta取代基可以稳定自由基。 将尝试用实验来验证这一假设 通过使用亚甲基环丙烷重排探针 由Notre Dame集团开发。 这些研究将提高 对有助于自由的因素的理解状态 自由基稳定性