Demyan Prokopchuk

Abstract:

The selective, efficient, and sustainable activation of carbon-hydrogen bonds continues to be a critical area of research. Current synthetic methodologies heavily rely on transition metal catalysts to mediate the reactivity of C-H bonds for making medicines, fuels, agrochemicals, and materials. Broadly speaking, we are interested in leveraging C-H bonds housed within chelating ligand frameworks to understand the fundamentals of C-H activation and discover new (electro)catalytic transformations. We have used an amine-rich cyclopentadienyl ligand (CpN3) coordinated to iron, which facilitates electrocatalytic H2 production in the presence of exogenous acid. Although Cp ligands are classically viewed as ancillary ligands, the H2 production mechanism involves a crucial stereoselective endo-CpN3 protonation step followed by ligand-to-metal proton transfer. In a separate endeavor, we have coordinated diamondoid pincer-type ligands to nickel, which provide unique insights into understanding the magnitude of C(sp3)-H bond weakening when an alkane moiety interacts with a transition metal (i.e., agostic interactions). Recent work in these two areas will be presented.