Mechanisms of Complex Carbocation Rearrangements

在这个由化学系化学结构、动态和机制B项目资助的项目中，加州大学戴维斯分校化学系的Dean J. Tantillo教授将使用现代计算机建模技术，结合实验室实验，揭示控制复杂分子形成机制的化学反应的基本原理。这项研究将揭示反应性的原理，并测试它们的普遍性。本文所建立的机制模型对有机合成、生物、有机物理、化学等领域的教学工作者具有一定的参考价值。除了通过这项研究发现的化学的基本重要性之外，所进行的项目将用于培养学生（研究生和本科生，一些来自代表性不足的群体）在机械化学的多学科方法，并使他们接触到使用这些技术的职业。此外，将开发新的方法，使盲人和视障学生能够使用应用计算化学，作为鼓励这一群体在STEM领域从事职业的努力的一部分。这项研究将通过构建复杂碳正离子重排的新机制模型来推进机制化学的知识。将开发特定形成萜烯的碳正离子重排的特定机制模型，并且将从跨越不同类别的碳正离子的广泛研究中得出具有复杂分子结构的碳正离子的一般反应性原理。本研究的目标是：(a)利用现代量子化学方法评估导致萜烯天然产物的各种碳正离子环化和重排机制的能量可行性，表征这些过程中涉及的中间体和过渡态结构的电子结构，并评估与这些重排的势能面相关的动力学趋势；(b)评估这些中间体和过渡态结构与酶活性位点上的官能团进行非共价/分子间相互作用的能力，并评估这些相互作用的后果；(c)揭示复杂体系中碳正离子反应性的基本、一般原则。

In this project funded by the Chemical Structure, Dynamic & Mechanism B Program of the Division of Chemistry, Professor Dean J. Tantillo of the Department of Chemistry at the University of California-Davis will use modern computer modeling techniques, coupled with laboratory experiments, to uncover fundamental principles of chemical reactivity that govern mechanisms of formation of complex molecules. This research will uncover principles of reactivity and test their generality. The mechanistic models resulting from this work will be of utility to those working in the synthetic organic, biological, physical organic and chemical education fields. In addition to the fundamental importance of the chemistry uncovered through this research, the projects pursued will be used to train students (graduate and undergraduate, several from underrepresented groups) in multidisciplinary approaches to mechanistic chemistry and expose them to careers that employ such techniques. In addition, new methods for making applied computational chemistry accessible to blind and visually impaired students will be developed as part of an effort to encourage this group to pursue careers in STEM fields.This research will advance knowledge in mechanistic chemistry through the construction of new mechanistic models for rearrangements of complex carbocations. Specific mechanistic models for particular terpene-forming carbocation rearrangements will be developed, and general principles of reactivity for carbocations with complex molecular architectures will be derived from extensive studies spanning different classes of carbocations. The goals of this research are to (a) use modern quantum chemical methods to assess the energetic viability of various carbocation cyclization and rearrangement mechanisms leading to terpene natural products, characterize the electronic structures of the intermediates and transition state structures involved in these processes, and assess the dynamical tendencies associated with the potential energy surfaces for these rearrangements, (b) assess the ability of these intermediates and transition state structures to engage in noncovalent/intermolecular interactions with functional groups present in enzyme active sites and assess the consequences of these interactions, and (c) uncover fundamental, general principles of carbocation reactivity in complex systems.