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

Abstract

AbstractThe Ar‐CF2H 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 ArCF2H 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 (CF2H, CFH2) moieties will aid the rapid diversification of lead‐compounds and compound libraries.