Photoinduced Nitroarenes as Versatile Anaerobic Oxidants for Accessing Carbonyl and Imine Derivatives

Herein, we report a protocol for the anaerobic oxidation of alcohols, amines, aldehydes, and imines promoted by photoexcited nitroarenes. Mechanistic studies support the idea that photoexcited nitroarenes undergo double hydrogen atom transfer (HAT) steps with alcohols and amines to provide the respective ketone and imine products. In the presence of aldehydes and imines, successive HAT and oxygen atom transfer (OAT) events occur to yield carboxylic acids and amides, respectively. This transformation is amenable to a continuous-photoflow setup, which led to reduced reaction times.

Automated summary

Here, a protocol for anaerobic oxidation of alcohols, amines, aldehydes, and imines is reported using photoexcited nitroarenes. Mechanistic studies show that photoexcited nitroarenes undergo double hydrogen atom transfer (HAT) steps with alcohols and amines, leading to ketone and imine products. In the presence of aldehydes and imines, successive HAT and oxygen atom transfer (OAT) events occur, yielding carboxylic acids and amides, respectively. The use of a continuous-photoflow setup reduces reaction times.