General Copper-Catalyzed Transformations of Functional Groups from Arylboronic Acids in Water

A simple and general copper-catalyzed method has been developed for transformations of various functional groups (-I, -N-3, -SO2R, -OH, -NH2, and -NO2) on aromatic rings from arylboronic acids in water under air. The protocol uses cheap and readily available inorganic salts (KI, NaN3, NaSO2R, NaOH, NaNO2) and aqueous ammonia as the functionalgroup sources, simple Cu2O/NH3 as the catalyst system, environmentally friendly water as the solvent, and oxygen in air as the oxidant. Importantly, the copper catalyst system in water was recyclable. This study should provide a useful strategy for interconversions of the functional groups on aromatic rings.