Electronically Ambivalent Hydrodefluorination of Aryl-CF3 groups enabled by Electrochemical Deep-Reduction on a Ni Cathode

Angew Chem Int Ed Engl. 2023 Jan 27;62(12):e202218195. doi: 10.1002/anie.202218195. Online ahead of print.

Abstract

We report a general procedure for the direct mono- and di-hydrodefluorination of ArCF3 compounds. Exploiting the tunability of electrochemistry and the selectivity enabled by a Ni cathode, the deep reduction garners high selectivity with good to excellent yields up to gram scale. The late-stage peripheral editing of CF3 feedstocks to construct fluoromethyl moieties will aid the rapid diversification of lead-compounds and compound libraries.

The Ar-CF2 H moiety is featured in an increasing number of bioactive compounds due to its unique combination of properties. The hydrodefluorination of Ar-CF3 compounds is a direct and efficient route toward this motif. As reported methods for this transformation have focused on specific substrate families, herein we describe a general-electronically ambivalent-procedure for the single-step direct mono-hydrodefluorination of a variety of feedstock and functionalized Ar-CF3 compounds. Exploiting the inherent tunability of electrochemistry and the selectivity enabled by a Ni cathode, the deep reduction garners high selectivity for ArCF2 H products, with good to excellent yields up to gram scale. The protocol has been extended to a single-step di-hydrodefluorination yielding benzyl fluorides. The late-stage peripheral editing of a single CF3 feedstock to construct fluoromethyl (CF2 H, CFH2 ) moieties will aid the rapid diversification of lead-compounds and compound libraries.

Keywords: Defluorination; Electrochemistry; Fluorine; Nickel; Reduction.