CAS: Iron-Catalyzed Three-Component Coupling Methods via Iron Azametallacyclobutene Complexes

CAS：铁氮杂金属环丁烯配合物的铁催化三组分偶联方法

• 批准号: 2247744
• 负责人: Jamie Neely
• 金额: $ 50万
• 依托单位: Saint Louis University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-07-01 至 2026-06-30
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2247744&HistoricalAwards=false
• 关键词: CAS; Iron; Catalyzed; Three; Component

With the support of the Chemical Synthesis Program in the Division of Chemistry, Jamie Neely of Saint Louis University is studying iron-catalyzed processes that join together three distinct chemical building blocks to generate products that are of value to medicine, agriculture, and materials science. The choice of iron complexes as the catalysts for these methods is rooted in their ability to interact with the three coupling partners in a controlled fashion, each at a specific stage of the reaction pathway. The catalysts of interest have the added benefit of being based on the most abundant transition metal in the Earth’s crust, as well as one of the least expensive and least toxic, accentuating the sustainability and potential practical utility of the processes under development. The broader impacts of the funded project will extend to providing evidence that the distinct behavior of Earth-abundant metals can complement the reactivity of the rare precious metals that are more commonly deployed in current transition metal-catalyzed technology. Students participating in the funded research will gain a comprehensive education encompassing all aspects of transition metal catalysis, providing them with the capacity to become knowledgeable and insightful contributors to the scientific community. The activities supported by the award include outreach efforts directed toward establishing an undergraduate summer research program for students from minority groups underrepresented in science, technology, engineering, and mathematics (STEM) from the Saint Louis area.The funded research is focused on the development of iron-catalyzed three-component coupling reactions of nitrene precursors (e.g., azides), alkynes, and nitrile or isonitrile substrates for the synthesis of value-added, nitrogen-containing compounds. The methods under investigation capitalize on [2+2] cycloaddition reactivity of sterically congested iron imide complexes that is highly sensitive to the nature of the alkyne substrate, allowing for the incorporation of unsymmetrical alkynes with high regioselectivity. Reactions of nitrile coupling partners will provide a general and modular route to imidazoles, a pervasive structural motif in biologically active compounds, with further application to the preparation of diversely substituted N-heterocyclic carbenes. Early efforts in imidazole formation will focus on translating the stoichiometric behavior observed in preliminary studies to catalytic reactivity, with later work aimed at optimizing reaction conditions and exploring the scope of the process with respect to each of the three substrates. Iron-catalyzed coupling using isonitriles will be explored to access imidoyl ketenimine products that have broad utility as synthetic intermediates. Initial stoichiometric studies will target conditions that favor three-component coupling over a competing process identified in preliminary experiments. These observations will inform later efforts to render the reaction catalytic in iron.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.

在化学系化学合成项目的支持下，圣刘易斯大学的Jamie Neely正在研究铁催化过程，该过程将三种不同的化学构建模块结合在一起，以产生对医学，农业和材料科学有价值的产品。选择铁络合物作为这些方法的催化剂是基于它们以受控方式与三种偶联配偶体相互作用的能力，每种偶联配偶体都处于反应途径的特定阶段。感兴趣的催化剂具有基于地壳中最丰富的过渡金属的额外好处，以及最便宜和毒性最小的催化剂之一，突出了正在开发的工艺的可持续性和潜在的实际效用。该资助项目的更广泛影响将扩展到提供证据，证明地球上丰富的金属的独特行为可以补充当前过渡金属催化技术中更常见的稀有贵金属的反应性。参与资助研究的学生将获得全面的教育，涵盖过渡金属催化的各个方面，为他们提供成为科学界知识渊博和有见地的贡献者的能力。该奖项支持的活动包括为来自圣刘易斯地区科学、技术、工程和数学（STEM）代表性不足的少数群体的学生建立本科夏季研究计划的外联工作。资助的研究重点是氮烯前体的铁催化三组分偶联反应（例如，叠氮化物）、炔和腈或异腈底物用于合成增值的含氮化合物。正在调查的方法利用[2+2]环加成反应的空间拥挤的铁酰亚胺络合物，是高度敏感的性质的炔底物，允许不对称炔的掺入具有高区域选择性。腈偶联伙伴的反应将提供一个通用的和模块化的路线，咪唑，一个普遍的结构基序在生物活性化合物，进一步应用于制备二取代的N-杂环卡宾。咪唑形成的早期努力将集中在将初步研究中观察到的化学计量行为转化为催化反应性，随后的工作旨在优化反应条件并探索三种底物中每一种的过程范围。将探索使用异腈的铁催化偶联以获得作为合成中间体具有广泛用途的亚氨酰基烯酮亚胺产物。初始化学计量研究的目标是有利于三组分偶联的条件，而不是初步实验中确定的竞争过程。这些观察结果将为后来的努力提供信息，使反应在铁中具有催化作用。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审查标准进行评估，被认为值得支持。