Tetrafluoroethylation of Electron‐Rich Alkenyl Iodides Enabled by in situ Generation of Solvent‐Stabilized “Ligandless” CuCF₂CF₂H

Abstract

In this study, we have developed a metal‐mediated synthetic method for incorporating the 1,1,2,2‐tetrafluoroethyl (CF2CF2H) motif into unactivated, electron‐rich alkenyl iodides using cross‐coupling reactions. We discovered that the stable Cu(CF2CF2H)(PPh2Me)3 complex, while unreactive with these substrates, serves as a valuable P‐ligated reservoir for the formation of solvent‐stabilized "ligandless" and reactive CuCF2CF2H species. This transformation occurs upon addition of CuBr, which partially scavenges the P‐ligand in the form of CuBr(PPh2Me)3. The resulting in situ generated solvent stabilized "ligandless" system significantly enhances the reactivity of the complex, particularly towards challenging electron‐rich substrates. This advancement enables the synthesis of HCF2CF2‐glycals, as well as nucleosides/nucleobases and arenes.