Catalytic C-C Sigma-Bond Functionalization via Metal-Metal Cooperativity

About This Grant

With the support of the Chemical Catalysis program in the Division of Chemistry, Professor Neil C. Tomson of the University of Pennsylvania is studying how to break and rearrange the bonds that hold carbon atoms together. This research will first explore how tailor-made iron complexes can split strong carbon–carbon bonds under mild conditions, rather than relying on costly and energy-intensive approaches. His team will then use this knowledge to design highly effective catalysts for rearranging carbon-carbon bonds at will. If successful, this project will lay the groundwork for future technologies that can produce pharmaceuticals, plastics, and electronic materials more efficiently and with improved control. The project will also foster the training of graduate and undergraduate students in advanced techniques of synthetic chemistry and chemical analysis. As part of the broader outreach plan, the team will create engaging educational videos designed to help high school students connect real-world energy and catalysis challenges with chemistry concepts they are learning in school. With the support of the Chemical Catalysis program in the Division of Chemistry, Professor Neil C. Tomson of the University of Pennsylvania is studying the selective activation and functionalization of carbon–carbon sigma bonds using base metal catalysts. Building on preliminary results demonstrating that a diiron complex supported by a macrocyclic ligand framework can cleave C–C sigma bonds adjacent to alkynyl units at room temperature, the project will initially investigate the steric and electronic factors that govern bond activation selectivity. A central goal is then to use this knowledge to establish the first catalytic cycle for direct C–C sigma-bond metathesis through a sequence involving oxidative addition, metal–carbon bond exchange, and reductive elimination. Both redox-switching and thermally driven pathways for closing the catalytic cycle will be explored. The final phase of the project will pursue cross-coupling strategies for functionalizing the cleaved C–C bonds, focusing on borylation, silylation, alkylation, and amination of the acetylide products. This research is expected to expand the synthetic toolbox for C–C bond activation and provide fundamental insights into reactivity patterns at base metal centers. 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.