Linear Selective C-H Bond Alkylation with Activated Olefins Catalyzed by Cp*CoIII

A simple and efficient method for Cp*CoIII-catalyzed C–H bond alkylation using activated olefins was developed. Selective C–H monoalkylation was performed at ambient temperature. One-pot symmetrical dialkylation and sequential unsymmetrical C–H dialkylation were performed to give the desired products in excellent yields. The reaction was found to proceed through an M–alkyl intermediate after migratory insertion, and this intermediate undergoes protodemetalation to give the expected alkylated product along with the regenerated catalyst.