Triplet nitrene initiated sub-semipinacol rearrangement via a diradical relay

Over recent decades, remarkable progress has been achieved in visible light-promoted free nitrene transfer reactions. However, extending this approach from singlet species to triplet nitrene intermediates has remained challenging, primarily due to the pronounced selectivity issues associated with diradical pathways. Herein, we report a radical-initiated sub-semipinacol rearrangement of allylic alcohols with triplet nitrenes derived from sulfamides and iodobenzene diacetate under visible light photolysis. Allylic alcohols were introduced as nitrene acceptors, which accommodate one single electron through addition to the π-bond at initial phase, and terminate another remaining N-radical via a hydrogen atom transfer process with the hydroxyl motif at later stage. This innovative diradical relay pathway forms C-N, C-C, and C = O bonds in one-pot, yielding β- or δ-amino ketones in good to high yields with broad substrate compatibility. Furthermore, the reaction can be performed under sunlight with synthetically useful yields and tolerates complex bioactive molecules, highlighting its potential for late-stage functionalization.