Oxidative Alkenylation of Aromatic Esters by Ruthenium-Catalyzed Twofold C-H Bond Cleavages

Cationic ruthenium(II) complexes enabled catalytic twofold C-H bond functionalizations with weakly coordinating aromatic esters in a highly chemo-, site- and diastereo-selective as well as site selective fashion. The oxidative Fujiwara-Moritani-type alkenylation provided step-economical access to diversely substituted styrenes and proved viable in an aerobic manner. Mechanistic studies were indicative of a reversible acetate-assisted cycloruthenation step.