Palladium-Catalyzed Chemoselective Oxygenation of C(sp)-H and C(sp)-H Bonds in Isatins.

The palladium-catalyzed chemoselective C(sp)-H and C(sp)-H bond oxygenation of substituted isatin derivatives is reported. This mild protocol exhibits the C5 C(sp)-H oxygenation of isatins through electrophilic intermolecular C-H palladation in concentrated solutions using PhI(OAc) or Selectfluor as an oxidant, whereas it exhibits-N-CH C(sp)-H oxygenation in dilute solutions via carbonyl-assisted intramolecular palladation in the presence of KSO. This oxygenation reaction provides a direct and unified approach for synthesizing diverse oxygenated isatins with sensitive functionalities, including biorelevant compounds.