Streamlined Ruthenium(II) Catalysis for One-Pot 2-fold Unsymmetrical C-H Olefination of (Hetero)Arenes.

The potential of carboxylate-directed Ru(II)-catalyzed C-H bond activation has been exploited in the first example of challenging 2-fold unsymmetrical cross-dehydrogenative olefination of (hetero)aromatic carboxylic acids. This highly regioselective protocol operates in one pot under a single catalytic system and tolerates a wide spectrum of carboxylic acids as well as activated olefins. A rare example of an unsymmetrical meta-bis-olefination approach has also been successfully engineered via a tailored unsymmetrical double C-H functionalization and concomitant decarboxylation process.