Synthesis of oxindole from acetanilide via Ir(III)-catalyzed C-H carbenoid functionalization

Herein we disclose the first report on the synthesis of oxindole derivatives from acetanilide via Ir(III)-catalyzed intermolecular C-H functionalization with diazotized Meldrum's acid. A broad range of substituted anilides were found to react smoothly under the Ir(III)-catalytic system to afford the corresponding N-protected oxindoles. The N-protecting groups, such as Ac, Bz or Piv, can be easily removed to furnish the oxindole. Various synthetic applications of the synthesized oxindole were also demonstrated.