C(sp3)‑CF3 Reductive Elimination from a Five-Coordinate Neutral Copper(III) Complex

The reductive elimination from a high-valent late-transition-metal complex for the formation of a carbon–carbon or carbon–heteroatom bond represents a fundamental product-forming step in a number of catalytic processes. While reductive eliminations from well-defined Pt­(IV), Pd­(IV), Ni­(III)/Ni­(IV), and Au­(III) complexes have been studied, the analogous reactions from neutral Cu­(III) complexes remain largely unexplored. Herein, we report the isolation of a stable, five-coordinate, neutral square pyramidal Cu­(III) complex that gives CH3-CF3 in quantitative yield via reductive elimination. Mechanistic studies suggest that the reaction occurs through a synchronous bond-breaking/bond-forming process via a three-membered ring transition state.