Cobalt(II)-Catalyzed C–H and N–H Functionalization of 1‑Arylpyrazolidinones with Dioxazolones as Bifunctional Synthons

Dioxazolone has been attractive as an important synthon for a direct C–H amidation through a nitrene intermediate or Curtius rearrangement to form the isocyanate. However, the combination of two reaction models of dioxazolone has not been reported. Herein, a cobalt-catalyzed C–H and N–H functionalization of 1-arylpyrazolidinones with dioxazolones was developed. The dioxazolones acted as an amidated and carboxamidated reagent. Three C–N bonds were formed in a “one-pot” manner, which promoted the requirement of synthetic diversity.