Cobalt(III)-Catalyzed C–H Activation/Annulation Cascade Reaction of N-Chlorobenzamides with 2-Acetylenic Ketones at Room Temperature

Abstract A mild cascade annulation of Co(III)-catalyzed N -chlorobenz­amides with 2-acetylenic ketones at room temperature is reported. This reaction sets N–Cl bond of N -chlorobenzamide as an internal oxidant, displaying broad functional group tolerance and excellent reverse selectivity of alkyne insertion under mild and safe conditions. The cascade reaction offers a straightforward and mild protocol to construct isoquinolones in high yields at room temperature.