Iridium(III)-Catalyzed Cyclization of Oximes with Iodonium Ylides: Synthesis of Multisubstituted Heterocyclic N-Oxides

Iridium(III)-catalyzed regioselective cyclization of substituted oximes with iodonium ylides has been described. This methodology offered multisubstituted heterocyclic N-oxides under mild reaction conditions in a redox-neutral manner. The cyclization reaction was also compatible with vinyl oximes. Additionally, substrate diversification was carried out to illustrate the synthetic application of protocol. A possible reaction mechanism involving the C-H bond activation was also proposed as well as supported by the isolation of the key five-membered iridacycle intermediate.