Cp*CoIII‐Catalyzed C—H Alkenylation/Annulation to Afford Spiro Indenyl Benzosultam.

Cp*CoIII-catalyzed tandem inert C–H alkenylation/annulation of N-sulfonyl ketimines with alkynes is revealed. A series of spiro indenyl benzosultams were facilely prepared in good yields under mild reaction conditions.