An Efficient Synthesis of Phenol via CuI/8-Hydroxyquinoline-Catalyzed Hydroxylation of Aryl Halides and Potassium Hydroxide

The CuI/8-hydroxyquinoline-catalyzed direct hydroxylation of aryl iodides with KOH takes place at 100 ˚C in a mixed solvent system (t-BuOH-DMSO-H2O), providing the corresponding phenols in great diversity. Aryl bromides are found to be rather less reactive under these reaction conditions.