Transition-metal-free oxidative carboazidation of acrylamides via cascade C-N and C-C bond-forming reactions

A novel transition-metal-free oxidative carboazidation of acrylamides using inexpensive NaN3 and K2S2O8 was achieved, which not only provided an efficient method to prepare various N-3-substituted oxindoles, but also represented a novel strategy for C-N and C-C bond formation via a free-radical cascade process. This transformation exhibits excellent functional group tolerance, affording the desired oxindoles in good to excellent yields.