RUI: Improving Activity and Selectivity in Ruthenium-Catalyzed Hydrogenation Reactions Through Mechanistic Understanding

在化学系化学催化项目的支持下，Colgate大学的Anthony Chianese和Jason基思正在研究催化剂如何在分子水平上运作，以提高其效率和可持续性。化学的一个主要目标是发展可持续的化学反应，最大限度地减少危险废物的产生，并在节能条件下运行。共同主要研究者（co-PI）Chianese和基思博士正在使用一种基于实验和计算机建模的方法来阐明环氧化物氢解反应催化剂的机理。虽然这是制药和化学工业中的一个重要反应，但目前用于该反应的方法产生大量危险废物，这限制了该过程的可持续性。用氢气取代传统的化学试剂有可能显着降低反应成本和环境影响。了解反应如何在微观水平上工作将有助于基础科学知识，并促进下一代改进催化剂的设计。该项目的研究由本科生在高露洁大学的PI实验室进行。参与本科研究，特别是在学生职业生涯的早期，越来越多地认识到其对学生的积极影响，并扩大参与科学。Chianese和他的研究小组的学生每年夏天都会花一天的时间为参加Camp Fiver的高中生开展一项外展活动，Camp Fiver是一个寄宿夏令营，接待一群纽约市和纽约州北部农村的高危学生。在之前的NSF资助的研究中，PI Chianese和基思使用实验/计算相结合的方法来确定一种广泛使用的络合物催化酯氢化的机制，Milstein的催化剂，并显示了催化剂如何从其原始形式转化为催化氢化反应中的活性形式。在目前的项目中，Chianese和基思正在将这些知识应用于一种新的转化，即环氧化物的铼催化氢解。该项目旨在开发高活性的环氧化物氢解催化剂，对产品醇的一种异构体具有选择性，并了解这些催化剂如何在分子水平上运作。在另一个推力中，中国-基思研究团队将重新审视先前提出的由Milstein催化剂促进的相关氢化反应的机制，以他们最近的发现为基础，即Milstein的催化剂在加热时不可逆地转化为不同的形式，催化相关的氢与氮原子结合。这个项目有可能导致新的，更可持续的化学转化，并提高我们对这些反应如何在分子水平上进行的理解。这个奖项反映了NSF的法定使命，并已被认为是值得通过使用基金会的智力价值和更广泛的影响审查标准进行评估的支持。

With support from the Chemical Catalysis Program in the Division of Chemistry, Anthony Chianese and Jason Keith of Colgate University are studying how catalysts operate at a molecular level to improve their efficiency and sustainability. A major goal in chemistry is the development of sustainable chemical reactions that minimize the production of hazardous waste and operate under energy-efficient conditions. The co-principal investigators (co-PIs), Drs. Chianese and Keith, are using a combined experimental- and computer-modeling-based approach to elucidate the mechanisms of catalysts for the epoxide hydrogenolysis reaction. While this is an important reaction in the pharmaceutical and chemical industries, current methods for this reaction produce significant amounts of hazardous waste, which limits the sustainability of the process. Replacing traditional chemical reagents with hydrogen gas has the potential to significantly reduce the reaction’s cost and environmental impact. Understanding how the reaction works at a microscopic level would contribute basic scientific knowledge and facilitate the design of the next generation of improved catalysts. The research for this project is being conducted by undergraduate students in the laboratories of the PIs at Colgate University. Participation in undergraduate research, especially early in a student’s career, is increasingly recognized for its positive impacts on students and for broadening participation in the sciences. Chianese and the students working in his research group devote a day each summer to an outreach activity for high school students attending Camp Fiver, a residential summer camp that hosts a group of at-risk students New York City and rural upstate New York.In previous NSF-funded research, PIs Chianese and Keith used a combined experimental/computational approach to determine the mechanism of ester hydrogenation catalyzed by a widely used complex, Milstein’s catalyst, and showed how the catalyst converts from its original form to the form active in catalytic hydrogenation reactions. In the current project, Chianese and Keith are applying this knowledge to a new transformation, the ruthenium-catalyzed hydrogenolysis of epoxides. The project aims to develop highly active catalysts for epoxide hydrogenolysis that are selective for one isomer of the product alcohol, and to understand how these catalysts operate at the molecular level. In another thrust, the Chinese-Keith research team will revisit the previously proposed mechanisms of related hydrogenation reactions promoted by Milstein’s catalyst, building on their recent discovery that Milstein’s catalyst irreversibly transforms upon heating to a different form with a catalytically relevant hydrogen bound to a nitrogen atom. This project has the potential to result in new, more sustainable chemical transformations, and to improve our understanding of how these reactions proceed at a molecular level.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.