Nickel-catalyzed fluoroethylation of arylboronic acids via Suzuki-type coupling

Abstract

A mild method for efficient access to fluoroethylated (hetero)arenes via Suzuki-type coupling has been developed. This base metal Ni-catalyzed method features selective transformation of the more susceptible C–X bond of 1-fluoro-2-haloethanes (FCH₂CH₂X, X = I or Br) and leaves the vicinal fluorine intact. Preliminary mechanistic studies illustrate the intermediacy of fluoroethyl radicals in the radical-rebound oxidative addition and Ni–B transmetalation as the rate-limiting step within the catalytic cycle. The practical value of this protocol is further demonstrated by late-stage modification of several complex bioactive molecules.