Synthesis of functionalized long-chain perfluoroalkanes from methyl halodifluoroacetates: a process of difluorocarbene insertion intocopper-carbon bonds

Treatment of XCF2CO2Me (X=Cl, Br) with organic halides in the presence of KF and catalytic amounts of CuI at 80–120 °C for 3–8 h in DMF gave long-chain perfluoroalkylated compounds which are considered to be former by the insertion of CF:2into carbon-copper bonds.