Rhodium-Catalyzed Annulation of Tertiary Aniline N-Oxides to N-Alkylindoles: Regioselective C-H Activation, Oxygen-Atom Transfer, and N-Dealkylative Cyclization

[Cp*Rh-III]-catalyzed annulation of tertiary aniline N-oxides with alkynes was reported to achieve the challenging ortho C-H functionalization of tertiary anilines via N-O bond acting as a traceless directing group. More significantly, this system represents the first example which integrates C-H activation, oxygen-atom transfer, and N-dealkylative cyclization in one reaction. This unprecedented coupling reaction has allowed the construction of N-alkylindole derivatives in high efficiency with broad substrate scope and good functional group tolerance.