Cobalt-Catalyzed Olefinic C-H Alkenylation/Alkylation Switched by Carbonyl Groups.

The first cobalt-catalyzed cross-couplings between olefins has been demonstrated to provide C(alkenyl)-H alkenylation and alkylation products, using complex [Cp*Co(CO)I2]. While coupling partner acrylates afforded conjugated dienoates, α,β-unsaturated ketones led to γ-alkenyl ketones completely, representing a switchable C-H functionalization controlled by different carbonyl groups.