Cu-Catalyzed Electrochemical Activation of Nitromethane to Access Aldoxime-Substituted Nitrile Oxide for Huisgen Reaction

Here, we report an electrochemical approach to generate an aldoxime-substituted nitrile oxide via the activation of nitromethane. The Cu-catalyzed Huisgen reaction of this 1,3-dipole with alkynes enables successful preparation of 48 new isoxazole aldoximes, which are typically challenging to synthesize by other methods, in 52 to 97% yields with excellent regioselectivity and chemoselectivity in a single step. Moreover, 20 3,3′-bisisoxazoles are prepared from the isoxazole aldoxime products in good yields via a two-step sequence.