Metal-Free Fluorination of C(sp³)-H Bonds using a Catalytic N-Oxyl Radical

Inoue et al. have reported the metal-free fluorination of C(sp³)—H bonds using NDHPI and F-TEDA-BF₄. According to their results, a catalytic N-oxyl radical generated from NDHPI extracts hydrogen from the C(sp³)—H bond, and the resulting carbon radical is trapped by F-TEDA-BF₄ to form the C(sp³)—F bond. This protocol is useful for the synthesis of various fluorinated compounds because it enables the chemoselective introduction of a fluorine atom into various aromatic and aliphatic compounds.