A PdII-catalyzed ortho-C(sp²)−H hydroxylation of benzyl alcohols using oxime ether as a monodentate directing group was developed. The N-acetyl glycine ligand is crucial to the reactivity through facilitating the C−H cleavage. The reaction might involve the formation of hydroxyl radicals generated from oxone and a 6-membered exo-palladacycle intermediate was proposed. Various substituents on the phenyl ring were tolerated in the reaction. Gram-scale reaction and directing group removal were also demonstrated to show its applicability for the syntheses of salicyl alcohols.
