Cp*Co(III)-Catalyzed Ketone-Directed ortho-C-H Activation for the Synthesis of Indene Derivatives.

A weakly coordinating, carbonyl-assisted C-H activation of aromatic systems with α,β-unsaturated ketone and subsequent aldol condensation has been developed using a Cp*Co(CO)I2 catalyst. The developed method is the first example of indene synthesis by cobalt-catalyzed C-H activation. In addition, the reaction requires mild reaction conditions and easily accessible starting materials, and it shows excellent functional group compatibility.