Real and Formal Pericyclic Processes of Reactive Intermediates

反应中间体的实数和形式周环过程

• 批准号: 0910208
• 负责人: Michael Harmata
• 金额: $ 42万
• 依托单位: University of Missouri-Columbia
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-09-01 至 2012-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0910208&HistoricalAwards=false
• 关键词: Real; Formal; Pericyclic; Processes; Reactive

This project will continue studies involving pericyclic reactions or their equivalents using reactive intermediates. Allylic cations offer a wide range of reactive motives, including cycloadditions and ene reactions. The latter have not been studied extensively and formally offer a process by which C-H activation occurs. Studies to explore the scope of this process, both in an inter- and intramolecular context, will be undertaken. The basic scheme lends itself naturally to an investigation of the homo-Cope rearrangement, which will also be pursued. Ketenes undergo a cycloaddition reaction with alkenes to form cyclobutanones. Details of the control of regiochemistry in such cycloadditions are incomplete. A study of this process, linked to specifically controlling the outcome of the reaction with vinylcyclopropanes will lead to the synthesis of cyclobutanones substituted regioselectively with cyclopropanes. Such substrates are envisioned to undergo a ring expansion to form seven-membered rings, under the influence of catalytic amounts of certain transition metals.Finally, the influence of substituents on the rates of certain electrocyclic reactions is a topic of current interest. The electrocyclization of hexatrienes is generally a slow process with a relatively high activation energy. Recent evidence suggests that electronic effects can have a profound influence on the rate of such processes. Carbanions offer the opportunity to develop extremely rapid electrocyclizations in this class that are also diastereoselective and enantioselective, depending on the exact means by which the carbanion is generated, resulting in the preparation of highly substituted six-membered rings. The development of such reactions will be undertaken.With this award, the Organic and Macromolecular Chemistry Program is supporting the research of Professor Michael Harmata of the Department of Chemistry at University of Missouri-Columbia. Professor Michael Harmata's research efforts revolve around the development of new carbon-carbon bond forming reactions based on pericyclic reactions of reactive intermediates, especially those of allylic cations and cyclopentadienones, among others. The studies to be undertaken will expand the scope of knowledge of reactive species, resulting in the discovery/invention of new, powerful synthetic processes of use for the synthesis of complex organic chemicals of potential impact to the synthesis of new pharmaceuticals, new materials, and new agrochemicals, as well as new entities of fundamental interest to a broad scientific community.

该项目将继续研究涉及周环反应或使用反应中间体的等效反应。 烯丙基阳离子提供广泛的反应动机，包括环加成和烯反应。 后者尚未得到广泛研究并正式提供 C-H 激活发生的过程。 将在分子间和分子内进行研究来探索这一过程的范围。 基本方案自然适合对同型科普重排的研究，这也将被继续进行。 乙烯酮与烯烃发生环加成反应形成环丁酮。 这种环加成中区域化学控制的细节并不完整。 对该过程的研究，与具体控制与乙烯基环丙烷的反应结果相关，将导致合成被环丙烷区域选择性取代的环丁酮。 在某些过渡金属的催化量的影响下，此类底物预计会经历环膨胀形成七元环。最后，取代基对某些电环反应速率的影响是当前感兴趣的话题。 六三烯的电环化通常是一个缓慢的过程，具有相对较高的活化能。 最近的证据表明，电子效应可以对此类过程的速率产生深远的影响。 碳负离子提供了在此类中开发极快速电环化的机会，这些电环化也是非对映选择性和对映选择性的，具体取决于生成碳负离子的确切方式，从而制备高度取代的六元环。 将进行此类反应的开发。有机和高分子化学项目通过该奖项支持密苏里大学哥伦比亚分校化学系 Michael Harmata 教授的研究。 Michael Harmata 教授的研究工作围绕基于反应中间体的周环反应开发新的碳-碳键形成反应，特别是烯丙基阳离子和环戊二烯酮等。即将开展的研究将扩大活性物质的知识范围，从而发现/发明新的、强大的合成工艺，用于合成对新药物、新材料和新农用化学品的合成具有潜在影响的复杂有机化学品，以及对广大科学界具有根本利益的新实体。