Real and Formal Pericyclic Processes of Reactive Intermediates

本项目将继续研究涉及周环反应或使用活性中间体的等效反应。 烯丙基阳离子提供了广泛的反应动机，包括环加成和烯反应。 后者还没有被广泛研究，并正式提供了一个过程，其中C-H活化发生。 将进行研究，以探索这一过程的范围，无论是在分子间和分子内的情况下。 基本计划本身自然适合于调查的homo-Cope重排，这也将继续下去。 烯酮与烯烃发生环加成反应形成环丁酮。 在这种环加成反应中区域化学的控制细节是不完整的。 这个过程的研究，具体控制与乙烯基环丙烷的反应的结果将导致环丁酮取代的环丙烷区域选择性的合成。 这些底物在催化量的某些过渡金属的影响下，可以发生扩环反应，形成七元环。最后，取代基对某些电环化反应速率的影响是当前研究的热点。 己三烯的电环化通常是具有相对高活化能的缓慢过程。 最近的证据表明，电子效应可以对这些过程的速率产生深远的影响。 碳负离子提供了在这类中发展非常快速的电环化的机会，这类电环化也是非对映选择性和对映选择性的，这取决于碳负离子产生的确切方式，从而导致制备高度取代的六元环。 通过该奖项，有机和高分子化学项目将支持密苏里-哥伦比亚大学化学系Michael Harmata教授的研究。Michael Harmata教授的研究工作围绕着基于活性中间体的周环反应的新的碳-碳键形成反应的发展，特别是烯丙基阳离子和环己烯酮等。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，用于合成对合成新药物、新材料和新农用化学品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。

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.