CAREER: Direct Radical Functionalization of Alcohols using Cobalt Photocatalysis

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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.