Cobalt-catalyzed ortho-alkylation of secondary benzamide with alkyl chloride through directed C-H bond activation.

Coupling of an alkyl chloride with a secondary benzamide derivative at the ortho-position can be achieved in good to excellent yield in the presence of a cobalt catalyst and cyclohexylmagnesium chloride in diethyl ether at room temperature. Cyclohexylmagnesium chloride formally acts to remove hydrogen atoms from the amide nitrogen and from the ortho-position and to generate the active cobalt species.