A Versatile and Fast Photocatalyzed Deoxygenation of Organic N-oxides with a Rhenium Complex in the Presence of H2O

The oxidation of N-heterocycles is key to their functionalization since it enhances their reactivity in the ortho position. How-ever, an efficient post-reduction is often required to access the targeted compound. Here, a rhenium-based photocatalyst enables the versatile and fast deoxygenation of N-heterocyclic and alkyl N-oxides, avoiding sacrificial oxophilic reagents. The strong influence of the reaction conditions (solvent, H2O as additive, irradiation set-up) is demonstrated. The system shows a high functional group tolerance towards other reducible functions (free alcohol, carboxylic acid, ester, nitrile, halo-gen,…) and light-sensitive N-heterocycles.