Visible-Light-Driven Oxidation of N-Alkylamides to Imides Using Oxone/H2O and Catalytic KBr

Imides are prepared conveniently by visible-light-driven oxidations of various N-alkylamides under mild conditions. The majority of the reactions proceed efficiently by using Oxone as the oxidant in the presence of a catalytic amount of KBr in H2O/CH2Cl2 under irradiation by an 8 W white LED at room temperature. Experimental studies suggest that an imine, obtained from the substrate amide via a radical process, is the key intermediate.