CAREER: Direct Radical Functionalization of Alcohols using Cobalt Photocatalysis

近年来，在利用光能驱动的新化学反应的设计方面取得了重大进展。通常，这些反应需要以贵金属为基础的催化剂。需要进行重大改进，以降低成本和浪费。用廉价和广泛可获得的金属、简单的底物和试剂以及产生良性副产品的催化反应和过程将满足这一需求。在这个项目中，戴夫·马丁博士正在利用一种新型的钴基催化剂开发新的光驱动反应，这种催化剂可以将简单的化学物质转化为一系列有用的产品。这种方法利用了廉价、丰富的原料，如生物质。对这些反应的机制的新见解也正在被了解。与加州大学河滨分校的本科生分享这些新的发展，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学生与他的研究小组成员之间的互动，马丁博士培养了人们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高等教育和科学事业。在化学部化学催化计划的资助下，加州大学的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中间体执行醇的直接官能化。目前的方法通常需要预功能化步骤，并产生必须分离的不良的、通常是有毒的副产品。受维生素B12生物化学启发，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，这些中间体可以参与各种化学转化，包括催化脱氧、自由基环化和分子间交叉偶联。直接酒精偶联工艺利用从传统来源获得的原料化学品，也为糖和木质素生物质等可再生来源的价态提供了一种强有力的手段。人们正在研究化学计量学和催化途径的机理，以便更深入地理解Co(II)配合物在光化学条件下与自由基中间体的相互作用。Martin博士还致力于扩大加州大学河滨分校的研究参与和科学参与，特别是在少数族裔学生中，包括研究小组讨论和当地演示。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势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.