Access to CyclicN-Trifluoromethyl Ureas through PhotocatalyticActivation of Carbamoyl Azides br

We report the mild activation of carbamoyl azidesto the corresponding nitrenes using a blue light/[Ir]-catalyzedstrategy, which enables stereospecific access toN-trifluoromethylimidazolidinones and benzimidazolones. These novel structuralmotifs proved to be highly robust, allowing their downstreamdiversification. On the basis of our combined computational andexperimental studies, we propose that an electron rebound with theexcited metal catalyst is undergone, involving a reduction-triggered nitrogen loss, followed by oxidation to the correspondingcarbamoyl nitrene and subsequent C-H insertion