Collaborative Research: Electrochemical Ni-Catalyzed Reductive Biaryl Coupling: Mechanistic Studies to Enable Chemical Synthesis

With the support of the Chemical Catalysis program in the Division of Chemistry, Professors Daniel Weix and Shannon Stahl of the University of Wisconsin-Madison, Professor Mohammad Rafiee of the University of Missouri-Kansas City, and Professor Robert Paton of Colorado State University are studying new approaches to catalysis and electrochemistry for the synthesis of biaryl molecules useful in polymers and agriculture. Building upon their recent advances, this team will continue to develop analytical and computational tools that will be used to illuminate fundamental principles that are important for success of these catalytic reactions. The lessons learned will enable lower-cost, higher-efficiency synthesis of important molecules using electricity in place of metal reductants. The research team will also work to train the next generation of chemists via several established programs and to educate the broader chemistry community about organic electrochemistry via courses and lectures. This project focuses on electrochemistry-driven and nickel-catalyzed reductive biaryl synthesis from a variety of aryl electrophiles. The research team will use a combination of stoichiometric organonickel studies, theory, and electroanalytical techniques to understand how each step in the biaryl synthesis (oxidative addition, transmetalation, reduction, and reductive elimination) is influenced by catalyst identity, conditions, and applied potential. This understanding will be used to make electrochemical biaryl synthesis suitable for commercial scale-up by conducting additional studies to improve catalyst turnover number, turnover frequency, and selectivity, including the development of cross-selective reactions. More broadly, these studies will contribute to an improved understanding of nickel catalysis and electrosynthesis; the resulting reactions will be lower-cost, more efficient alternatives to the state-of-the-art biaryl syntheses, which may utilize less selective oxidation reactions, more expensive precious metal catalysts, and/or more reactive aryl nucleophiles. 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.