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，科尔盖特大学的Anthony Chianese和Jason Keith正在研究催化剂如何在分子水平上起作用，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，尽量减少有害废物的产生，并在节能的条件下运作。联合首席研究员（co- pi），博士。中国和基思，正在使用一种结合实验和计算机建模的方法来阐明环氧化物氢解反应的催化剂机制。虽然这是制药和化学工业中的一个重要反应，但目前这种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著降低反应的成本和对环境的影响。在微观层面上理解反应是如何进行的，将有助于提供基本的科学知识，并促进下一代改进催化剂的设计。这个项目的研究是由本科生在科尔盖特大学的pi实验室进行的。参与本科生研究，特别是在学生职业生涯的早期，因其对学生的积极影响和扩大对科学的参与而日益受到认可。每年夏天，中国学生和他研究小组的学生都会抽出一天时间，为参加“第五营”（Camp five）的高中生开展拓展活动。“第五营”是一个住宿夏令营，接待一群来自纽约市和纽约州北部农村地区的高危学生。在之前由nsf资助的研究中，PIs china和Keith采用实验/计算相结合的方法确定了广泛使用的配合物Milstein催化剂催化酯加氢的机理，并展示了催化剂如何从原始形式转化为催化加氢反应中活跃的形式。在目前的项目中，中国和基思正在将这些知识应用到一个新的转化中，即钌催化环氧化物的氢解。该项目旨在开发对产物醇的一种异构体具有选择性的环氧化物氢解高活性催化剂，并了解这些催化剂在分子水平上是如何运作的。在另一项研究中，中国-基思研究小组将重新审视先前提出的由米尔斯坦催化剂促进的相关氢化反应机制，基于他们最近的发现，米尔斯坦的催化剂在加热时不可逆地转变为与催化相关的氢与氮原子结合的不同形式。这个项目有可能产生新的、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。该奖项反映了美国国家科学基金会的法定使命，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。

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.