A general photoinduced oxidative strategy with molecular oxygen in water

We describe here an environmentally friendly and low-cost oxidative strategy with the use of water as a solvent and O2 as an oxidant for the oxidation of a broad array of substrates, which included 1 degrees, 2 degrees, or 3 degrees benzylic C-H compounds, alcohols, organic halides, alkenes, and alkynes, by using diacetyl as a photosensitizer under the irradiation of visible light. Mechanism studies indicate that diacetyl acts as the photosensitizer to activate oxygen to its singlet state or superoxide radical which participates in the mild synthesis of ketones, alcohols, carboxylic acids, or aldehydes. The photoinduced oxidation of a wide range of functional groups in water and O2 is achieved by using diacetyl as a photosensitizer.