CAREER: Direct Radical Functionalization of Alcohols using Cobalt Photocatalysis

职业：使用钴光催化对醇进行直接自由基官能化

• 批准号: 1952860
• 负责人: David Martin
• 金额: $ 50.57万
• 依托单位: University of Iowa
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-09-01 至 2024-04-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1952860&HistoricalAwards=false
• 关键词: CAREER; Direct; Radical; Functionalization; Alcohols

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.

近年来，在设计利用光能为其提供动力的新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。需要作出重大改进，以减少成本和浪费。利用廉价和广泛获得的金属、简单的底物和试剂以及产生良性副产物的催化反应和工艺将满足这一需求。在这个项目中，戴夫·马丁博士正在开发一种新型的钴基催化剂，将简单的化学物质转化为许多有用的产品。这种方法是利用廉价，丰富的原料，如生物质。对这些反应机制的新见解也正在学习中。与加州大学滨江分校的本科生分享这些新的发展，促进了绿色化学价值观，作为提高研究参与和科学参与的更大努力的一部分。通过化学演示以及当地学校的K-12学生与他的研究小组成员之间的互动，马丁博士培养了对科学的兴奋感和好奇心，并鼓励来自各种背景的年轻学生追求高等教育和科学职业。在化学部化学催化项目的资助下，加州大学滨江分校的Dave Martin博士正在开发一种钴基催化剂系统，该系统利用光能通过酰基和烷基自由基中间体进行醇的直接官能化。目前的方法通常需要预官能化步骤并产生必须分离的不期望的、通常有毒的副产物。使用丰富的钴基催化剂的灵感来自维生素B12的生物化学提供了一种替代机制，原位活化，并产生多功能的自由基中间体，可以参与各种各样的化学转化，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来自常规来源的容易获得的原料化学品，并且还提供用于可再生来源（例如糖和木质素生物质）的稳定化的有力手段。化学计量和催化途径的机制正在研究中，以提供更深入的了解在光化学条件下的自由基中间体的Co（II）配合物的相互作用。马丁博士还参与外展活动，以提高加州大学滨江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演示。该奖项反映了NSF的法定使命，并被认为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来支持。

项目成果

C–O Bond Cleavage of Alcohols via Visible Light Activation of Cobalt Alkoxycarbonyls

通过可见光活化烷氧基羰基钴来裂解醇的 C–O 键

• DOI: 10.1021/acs.organomet.9b00552
• 发表时间: 2019
• 期刊: Organometallics
• 影响因子: 2.8
• 作者: Chambers, Dana R.;Juneau, Antoine;Ludwig, Cory T.;Frenette, Mathieu;Martin, David B.
• 通讯作者: Martin, David B.