Synthetic models of enzyme intermediates play an important role in evaluating mechanistic hypotheses for critical biochemical reactions. In the first part of my talk, I will present the synthesis of dicopper coordination complexes as models to understand the reactivity of NO and NO2- at copper enzymes. We discovered that dicopper complex could activate NO or nitrite to generate a unique dicopper (II,III) oxo nitrosyl species [Cu2(μ-O)(μ-NO)]2+, which exhibits oxidative and nitrosative reactivity. This new mode of reactivity has important implications in how Nature employs NO and nitrite as electron acceptors for hydrocarbon oxidation. In the second part of my talk, I will discuss how synthetic models of monocopper oxygenases can be applied in the synthesis of pharmaceutically relevant organic molecules. Inspired by lytic polysaccharide monooxygenases, we develop a general Cu(II)/Cu(III) platform to activate simple nucleophiles (Nu) toward C-H functionalization. Oxidation of Cu(II)-Nu to Cu(III)-Nu endows the Nu moiety with hydrogen atom transfer and radical capture reactivity. Building on this platform, we have established a catalytic C-H fluorination method that selectively produces monofluorinated products in an undivided electrochemical cell at room temperature.

Shiyu Zhang (Ohio State University)