CAREER: Mechanistic Study of Radical Initiations for Aromatic Functionalization

在这个由化学系化学结构、动力学机制B计划资助的CAREER项目中，默塞德的加州大学化学生物学系的Ryan巴克斯特教授正在开发通过单电子转移引发自由基反应的新策略。 由于单电子反应（自由基反应）传统上被认为是高度反应性和难以控制的，本研究的目标是更好地了解自由基引发的基本性质，以设计温和和用户友好的实验方案。 在药物、维生素、材料和聚合物中发现了许多可以通过自由基化学获得的结构，因此自由基引发的新策略可能对许多直接造福社会的科学领域产生积极影响。 该项目涉及实时监测自由基反应，以了解化学行为。 由此产生的反应数据用于开发本科有机化学实验室和讲座课程的教材。此外，通过工业合作伙伴关系，收集和完善了大量真实的反应数据，以开发一个本科生/研究生教育材料库，供全国各地的教育工作者使用。 芳烃和杂芳烃是许多理想材料的常见结构。 需要制定战略，使其迅速多样化。自由基碳-氢官能化提供了通过亲核或亲电过程直接修饰芳族碳氢键的能力，尽管不受控制的反应性对于分子间过程是常见的。 该项目包括两个独立的目标，研究影响合成重要反应的自由基引发速率的基本物理性质。 第一个重点是开发催化剂系统，使用银离子，作为氧化剂，和外源性吡啶配体以一种新的方式来控制自由基引发杂芳烃的分子间亲核官能化的速率。催化剂的氧化还原性能进行了电化学研究，并将这些数据与全球反应速率相关，以告知最佳催化剂/氧化剂系统的发展。 第二个目标涉及铁催化还原氮氧键，以促进分子间自由基胺化芳烃通过亲电过程。 对各种氮自由基前体的电子性质进行检查，以制定将联合收割机温和引发与可靠引发率相结合的有效策略。该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响进行评估，被认为值得支持。审查标准。

In this CAREER project, funded by the Chemical Structure, Dynamics & Mechanisms B Program of the Chemistry Division, Professor Ryan Baxter of the Department of Chemistry & Chemical Biology at the University of California, Merced is developing new strategies for initiating radical reactions through single-electron transfers. Because one electron reactions (radical reactions) are traditionally viewed as highly reactive and difficult to control, the goal of this research is to better understand fundamental properties of radical initiations to engineer mild and user-friendly experimental protocols. Many structures that can be accessed via radical chemistry are found in drugs, vitamins, materials and polymers, and so new strategies for radical initiation may have a positive impact on many fields of science that directly benefit society. The project involves monitoring radical reactions in real-time to understand chemical behavior. The resulting reaction data is used to develop educational materials for undergraduate organic chemistry laboratory and lecture courses. In addition, through industrial partnerships, volumes of authentic reaction data is collected and refined to develop a repository of undergraduate/graduate educational materials that are made available to educators throughout the Nation. Arenes and heteroarenes are common structures with many desirable materials. Strategies for their rapid diversification are in demand. Radical carbon-hydrogen functionalization offers the ability to directly modify aromatic carbon hydrogen bonds via either nucleophilic or electrophilic processes, although uncontrolled reactivity is common to intermolecular processes. This project involves two discrete aims to study fundamental physical properties that affect rates of radical initiation for synthetically important reactions. The first focuses on developing catalyst systems that use silver ion, as an oxidant, and exogenous pyridine ligands in a novel way to control the rates of radical initiation for intermolecular nucleophilic functionalization of heteroarenes. Catalyst redox properties are studied electrochemically, and this data is correlated with global reaction rates to inform the development of optimum catalyst/oxidant systems. The second aim involves the iron-catalyzed reduction of nitrogen-oxygen bonds to promote intermolecular radical amination of arenes through an electrophilic process. The electronic properties of various nitrogen-radical precursors are examined to develop efficient strategies that combine mild initiation with reliable rates of initiation.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.