<p>Despite
the growing interest in the synthesis of fluorinated organic compounds, few
methods are able to incorporate fluoride ion directly into alkyl C-H bonds. Here,
we report the C(sp<sup>3</sup>)-H fluorination reactivity of a formally
copper(III) fluoride complex. The C-H fluorination intermediate, <b>L</b>CuF,
along with its chloride and bromide analogs, <b>L</b>CuCl and <b>L</b>CuBr,
were prepared directly from halide sources with a chemical oxidant and fully
characterized. While all three copper(III) halide complexes capture carbon radicals
efficiently to afford C(sp<sup>3</sup>)-halogen bonds, <b>L</b>CuF is two
orders of magnitude more efficient at hydrogen atom abstraction (HAA) than <b>L</b>CuCl
and <b>L</b>CuBr. Alongside reported kinetic data for other <b>L</b>Cu(III)
species, we established a positive correlation between ligand basicity and the rate
of HAA. The capability of <b>L</b>CuF to perform both hydrogen atom abstraction and radical capture was
leveraged to enable fluorination of allylic and benzylic C-H bonds and α-C-H
bonds of ethers at room temperature.</p>
C(sp3)-H Fluorination with a Copper(II)/(III) Redox Couple
