Copper-mediated tetrafluoroethylation of unsaturated organotrifluoroborates via generation of the HCF2CF2-radical from zinc 1,1,2,2-tetrafluoroethanesulfinate

Abstract

A copper-mediated synthetic method for the incorporation of the 1,1,2,2-tetrafluoroethyl (CF₂CF₂H) group into unsaturated potassium organotrifluoroborate systems using the zinc 1,1,2,2-tetrafluoroethanesulfinate reagent has been developed. The HCF₂CF₂-radical, derived in situ from (HCF₂CF₂SO₂)₂Zn using TBHP as an oxidant, combines with a copper-catalyst to promote the replacement of the BF₃K group on alkenes and alkynes. The reactions are carried out under ambient air, using mild and practical conditions. The method provides access to tetrafluoroethylated alkene and alkyne products in moderate to good yields.