A transition-metal-free method for the selective hydroxylation of o-fluorobenzamides has been developed, providing efficient access to salicylamides under basic conditions. The reaction proceeds with KOt-Bu and H2O in DMSO, affording the desired products in good to excellent yields with broad functional group tolerance and high ortho selectivity. Mechanistic studies indicate that the reaction critically depends on the hydrogen-bond donor ability and conformational flexibility of the amide. This work provides a practical approach to salicylamides and related derivatives and highlights hydrogen-bond-controlled reactivity in nucleophilic aromatic substitution.
Chen et al. (Mon,) studied this question.