CAREER: Direct Radical Functionalization of Alcohols using Cobalt Photocatalysis

近年来，在设计利用光能驱动的新型化学反应方面取得了重大进展。通常，这些反应需要基于贵金属的催化剂。需要进行重大改进以减少成本和浪费。用廉价和广泛可用的金属、简单的底物和试剂以及产生良性副产物进行催化反应和处理将满足这一需要。在这个项目中，戴夫·马丁博士正在用一种新型的钴基催化剂开发新的光驱动反应，将简单的化学物质转化为大量有用的产品。这种方法是利用廉价、丰富的原料，如生物质。人们对这些反应的机制也有了新的认识。与加州大学河滨分校的本科生分享这些新发展，以促进绿色化学价值观，作为增加研究参与和科学参与的更大努力的一部分。通过化学演示和当地学校的K-12学生和他的研究小组成员之间的互动，马丁博士培养了对科学的兴奋和好奇心，并鼓励来自各种背景的年轻学生追求科学的高等教育和职业。在化学部化学催化项目的资助下，加州大学河滨分校的Dave Martin博士正在开发一种基于钴的催化剂系统，该系统利用光能通过酰基和烷基自由基中间体直接实现醇的功能化。目前的方法通常需要一个预功能化步骤，并产生不需要的，通常是有毒的副产品，必须分离。受维生素B12生物化学的启发，大量钴基催化剂的使用为原位活化提供了一种替代机制，并产生了多种自由基中间体，可以参与多种化学转化，包括催化脱氧、自由基环化和分子间交叉偶联。直接醇偶联工艺利用了传统来源的现成原料化学品，也为糖和木质素生物质等可再生资源的增值提供了有力的手段。为了更深入地了解Co（II）配合物与自由基中间体在光化学条件下的相互作用，人们正在研究其化学计量学和催化途径的机制。马丁博士还致力于提高加州大学河滨分校的研究参与度和科学参与度，特别是在少数民族学生中，包括研究小组讨论和当地示范。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。

In recent years, significant progress has been made in the design of new chemical reactions that use light energy to power them. Often, these reactions need catalysts based on precious metals. Significant improvements need to be made to reduce costs and waste. Catalytic reactions and processes with inexpensive and widely-available metals metals, simple substrates and reagents, and generation of benign by-products will serve this need. In this project, Dr. Dave Martin is developing new light-driven reactions with a novel cobalt-based catalyst that converts simple chemicals into a host of useful products. This approach is leveraging cheap, abundant feedstocks such as biomass. New insights into the mechanism of these reactions are also being learned. Sharing these new developments with undergraduate students at UC Riverside promotes green chemistry values as a part of a larger effort to increase research participation and scientific engagement. Through chemistry demonstrations and interactions between K-12 students from local schools and members of his research group, Dr. Martin fosters excitement and curiosity for the sciences and encourages young students from all backgrounds to pursue higher education and careers in science. With funding from the Chemical Catalysis Program of the Chemistry Division, Dr. Dave Martin of the University of California, Riverside is developing a cobalt-based catalyst system that harnesses light energy to perform the direct functionalization of alcohols via acyl and alkyl radical intermediates. Current methods typically require a pre-functionalization step and produce undesirable, often toxic by-products that must be separated. The use of abundant cobalt-based catalysts inspired by the biochemistry of vitamin B12 provides an alternative mechanism for in situ activation and generates versatile radical intermediates that can participate in a wide variety of chemical transformations including catalytic deoxygenation, radical cyclizations and intermolecular cross-coupling. Direct alcohol coupling processes leverage readily available feedstock chemicals from conventional sources and also provide a powerful means for the valorization of renewable sources such as sugars and lignin biomass. The mechanisms of stoichiometric and catalytic pathways are being studied to provide a deeper understanding of the interaction of Co(II) complexes with radical intermediates under photochemical conditions. Dr. Martin is also engaged in outreach to increase research participation and scientific engagement at UC Riverside, especially among minority students, including research panel discussions and local demonstrations.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.