The Difluoromethylated Organogold(III) Complex cis-[Au(PCy₃)(4-F-C₆H₄)(CF₂H)(Cl)]: Preparation, Characterization, and Its C(sp²)-CF₂H Reductive Elimination

The preparation of the difluoromethylated organogold(III) complex cis-[Au(PCy₃)(4-F-C₆H₄)(CF₂H)(Cl)] (3) and its Ar-CF₂H reductive elimination are described. In the presence of 1.0 equiv of AgSbF₆ or AgPF₆, compound 3 underwent a quantitative Ar-CF₂H reductive elimination in less than 1.0 min at 25 °C, while the lack of silver salt resulted in Ar-CF₂H reductive elimination from complex 3 in 1,1,2,2-tetrachloroethane (CCl₂HCCl₂H) after 80 min at 115 °C to afford the elimination product p-F-PhCF₂H (4) and (Cy₃P)Au(Cl) in quantitative yields. On the basis of the mechanistic studies of the kinetics of the reaction and DFT calculation, a concerted Ar-CF₂H bond-forming pathway for the Ar-CF₂H reductive elimination from organogold(III) complex 3 is proposed.