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

Abstract

A solvent dependent C(sp³)-CF₃ bond-forming reductive elimination from neutral four-coordinate Cu(III) complexes [(L)Cu^III(CF₃)₂(CH₂CO₂ ^tBu)] (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.

Keywords: Cu(III); concerted; dissociation; mechanism; reductive elimination.