Solvent‐Dependent C(sp3)‐CF3 Reductive Elimination from Neutral Four‐Coordinate Cu(III) Complexes

A solvent dependent C(sp3)‐CF3 bond‐forming reductive elimination from neutral four‐coordinate Cu(III) complexes [(L)Cu(CF3)2(CH2CO2tBu)] (L = pyridine or its derivatives) is described. Reactions in less polar solvent ClCH2CH2Cl proceed via a concerted bond breaking/bond forming process along with the reorientation of the ligand, while reaction in polar solvent DMF occurs via a rate limiting ligand‐dissociation, followed by C(sp3)‐CF3 reductive elimination from the resulting three‐coordinate intermediate. These mechanistic proposals are supported by kinetic studies that included ligand and temperature effects, as well as DFT calculations.