Single C(sp3)–F Bond Activation in a CF3 Group: Ipso-Defluorooxylation of (Trifluoromethyl)alkenes with Oximes

The first defluorinative ipso-functionalization reaction of (trifluoromethyl)alkenes is reported. This exclusively regioselective ipso-defluorooxylation of (trifluoromethyl)alkenes with oximes affords various attractive O-(1,1-difluoroallyl)oxime ethers efficiently via a chemoselective single C(sp³)-F bond activation in the CF₃ group. Primary mechanism studies indicated an anionic S_N2-type substitution pathway might be involved in this transformation.