Rhodium-Catalyzed Selective Olefination of Arene Esters via C−H Bond Activation

A new catalytic procedure of ortho-olefination of benzoates and benzaldehydes has been developed. Ester and carboxaldehyde units were revealed to be effective chelating groups in focusing the activation of aryl C-H bonds ortho to the directing moieties under the Rh-catalyzed oxidative conditions. The reaction is highly regioselective with a range of benzoates and benzaldehydes enabling the efficient olefination with acrylates, acrylic acid, and styrenes.