CAREER: Catalytic Activation of Alkenyl C-H Bonds

The Scripps Research Institute, La Jolla CA

Investigators

Abstract

With support from the Chemical Catalysis (CAT) Program in the Division of Chemistry, Keary Engle of the Scripps Research Institute is developing new catalytic processes to upgrade chemical feedstocks containing alkenes (molecules that contain a carbon–carbon double bond (C=C)) to more complex value-added molecules for materials, agrochemical, and chemical biology/medicinal chemistry applications. Palladium-based catalysts that are capable of selecting specific alkene carbon-hydrogen bonds (C-H) bonds and activating these for C-X bond formation are being studied. Insight into how these catalysts work is also being investigated to differentiate key features from related catalytic transformations. In parallel, Dr. Engle and his research team are leading synergistic activities to expand access to cutting-edge educational experiences for underserved students and to enhance the diversity and global competitiveness of the science, technology, engineering, and mathematics (STEM) workforce. These efforts include developing open-access graduate courses and learning resources, expanding programming offered through a STEM pipeline consortium that serves diverse undergraduate students from local two- and four-year colleges in San Diego, and involving undergraduate and high school interns from historically underserved groups in research activities. Overall, this research program is helping to improve the efficiency and sustainability of industrially relevant chemical processes, while bolstering the future STEM workforce of the United States. Catalytic reactions that convert carbon–hydrogen bonds into new carbon–carbon and carbon–heteroatom bonds enable the rapid synthesis of valuable target compounds with reduced waste generation compared to traditional approaches. Keary Engle and his team at the Scripps Research Institute are developing palladium-catalyzed C(alkenyl)–H activation reactions and studying the factors that promote C(alkenyl)–H activation versus other reaction manifolds that typically emerge from alkene–palladium(II) species. These catalytic transformations are simultaneously being optimized to convert readily accessible mono- and disubstituted alkene starting materials into more highly-substituted alkene products that are otherwise difficult to prepare with defined regio- and stereochemistry. Activities further include mechanistic studies, directing group investigations, and the use of alkene isomerization strategies to understand the catalytic process and to broaden the reactivity to include a significant variety of alkene substrates for these catalytic systems. This multidisciplinary project will integrate insights from mechanistic organometallic chemistry, and organic synthesis, providing a holistic and innovative training experience for a diverse group of high school students, undergraduates, Ph.D. students, and postdoctoral fellows. 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.