Real and Formal Pericyclic Processes of Reactive Intermediates

该项目将继续研究使用活性中间体的周环反应或其等效反应。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。后者尚未得到广泛的研究，并正式提供了C-H活化发生的过程。研究探索这一过程的范围，在分子间和分子内的背景下，将进行。这一基本方案很自然地适用于对同质- cope重排的研究，这一研究也将继续进行。烯酮与烯烃发生环加成反应生成环丁酮。在这种环加成中控制区域化学的细节是不完整的。对这一过程的研究，与具体控制与乙烯基环丙烷反应的结果有关，将导致合成环丁酮选择性地取代环丙烷。设想这种底物在某些过渡金属的催化量的影响下经历环膨胀以形成七元环。最后，取代基对某些电环反应速率的影响是当前关注的一个话题。六萜的电环化通常是一个缓慢的过程，具有较高的活化能。最近的证据表明，电子效应可以对这一过程的速度产生深远的影响。碳离子提供了在该类中发展极快的电环反应的机会，这种电环反应也具有非对映选择性和对映选择性，这取决于碳离子生成的确切方法，从而制备高度取代的六元环。将进行这种反应的发展。有了这个奖项，有机和大分子化学项目支持密苏里-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，特别是烯丙基阳离子和环戊二烯酮的反应，开发新的碳-碳键形成反应。将要进行的研究将扩大反应物质的知识范围，导致发现/发明新的、强大的合成工艺，用于合成复杂有机化学品，对合成新药、新材料和新农用化学品以及对广泛科学界具有根本兴趣的新实体有潜在影响。

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.