ortho-C-H Amidation of Phenols through Intramolecular Rearrangement of N-Phenoxyarylamides

This study presents an efficient and concise methodology devised for effectuating the ortho-C-H amidation of phenols through the rearrangement of N-phenoxybenzamide derivatives. A variety of substrates, equipped with different electron-withdrawing and electron-donating functional groups, react smoothly under mild basic conditions or even without a base, eliminating the need for excessive use of strong acids, Lewis acids, or costly transition-metal catalysts (e.g., [Cp*RhCl₂]₂ or [Cp*Co(MeCN)₃](SbF₆)₂) as previously delineated. Notably, the observed regioselectivity predominantly favors the ortho-position of the phenol rings. Mechanistic investigations suggest that C-H bond cleavage is likely not the rate-determining step and that an intramolecular rearrangement might be involved.