Intramolecular Aryne Cycloadditions and Rearrangements

描述(由申请人提供)：本提案的长期目标是了解导致各种有趣和新颖的分子内芳烃环加成(IMAC)和重排的结构、电子、构象和空间参数，并将这些过程发展成一系列强大的应用，以构建复杂和重要的天然产品。为了实现这些目标，我们将设计、合成和研究各种系统，这些系统导致一些重要的IMAC类型，如重排的[4+2]、[2+2]和[2+2]，类型II[4+2]和烯反应流形。除了我们自己的工作外，文献中只报道了另外六个分子内芳烃环加成化学的例子，所有这些都局限于[4+2]反应流形，然后只与芳香族二烯反应。因此，探索这一系列反应的必要性是令人信服的，具有很高的学术价值。我们将从合成和力学两个角度研究这些环加成流形。值得注意的是，我们认为这一提议代表了有史以来第一次系统地评估芳烃分子内环加成行为的全面反应谱。此外，这些过程有可能产生新的、令人兴奋的结构主题，而现有的技术和方法很难或不可能制备这些主题。这一研究将为理解芳烃环加成化学提供重要的基础和重要的贡献。我们已发表的关于[4+2]、串联[2+2]环加成-重排和烯过程的初步研究，除其他外，清楚地证明了进一步开展这一研究的概念和内在价值。我们还将合成选择性胆碱酯酶抑制剂加兰他明，以展示分子内芳烃环加成化学在构建一系列复杂和结构多样的天然产物方面的合成潜力。

DESCRIPTION (provided by applicant): The long term goals of this proposal are to understand the structural, electronic, conformational and steric parameters that lead to the various types of interesting and novel intramolecular aryne cycloadditions (IMACs) and rearrangements, and to develop these processes into a powerful set of applications for the construction of complex and important natural products. To accomplish these goals we will design, synthesize and investigate various systems that lead to some of the important classes of IMACs such as the [4+2], [2+2] and [2+2] with rearrangement, Type II [4+2], and ene reaction manifolds. With the exception of our own work just six other examples of intramolecular aryne cycloaddition chemistry have been reported in the literature, and all of these have been limited to the [4+2] reaction manifold and then only with aromatic dienes. The need to explore this suite of reactions is therefore compelling and of high intellectual merit. We will examine these cycloaddition manifolds from both synthetic as well as mechanistic perspectives. Significantly, we believe this proposal represents the first ever systematic attempt to assess the comprehensive reaction profile of arynes with respect to their intramolecular cycloaddition behavior. Moreover, these processes have the potential to generate new and exciting structural motifs that would be difficult or impossible to prepare by existing technologies and methods. This study will provide an important foundation and contribute significantly to the understanding of aryne cycloaddition chemistry. Our published and preliminary studies with respect to the [4+2], tandem [2+2]cycloaddition-rearrangement, and ene processes clearly demonstrate, inter alia, the proof of concept and the intrinsic value of pursuing this line of research further. We will also synthesize the selective cholinesterase inhibitor galanthamine as a demonstration of the synthetic potential of intramolecular aryne cycloaddition chemistry in the construction of a wide range of complex and architecturally diverse natural products.