Photocatalytic Benzylic Oxidation Promoted by Eosin Y in Water

The oxidation of the C–H bond received wide attention in organic synthesis and pharmaceutical chemistry due to its potential as one of the most straightforward and powerful methods to construct molecular scaffolds. The development of a green and efficient catalytic protocol for the oxidation of the sp3 C–H bond is highly desirable. We described a light-induced synthetic strategy for benzyl oxidation. This approach featured characteristics of the use of Eosin Y as a photocatalyst, water as a solvent, and O2 as an oxidant. A range of substrates with different functional groups were converted to aromatic ketones in moderate to high yields. The control experiments suggested that this reaction undergoes a single electron-transfer (SET) mechanism.