Ruthenium(II) Catalysis/Noncovalent Interaction Synergy for Cross-Dehydrogenative Coupling of Arene Carboxylic Acids

A ruthenium-catalyzed cross-dehydrogenative coupling is developed with the aid of a weakly coordinating carboxylic acid group toward the dimerization of arene carboxylic acids. The protocol is operationally simple and suitable to fabricate diverse homodimerized as well as cross-dimerized products in high yields. Computational insights have also been unveiled to comprehend the plausible reaction mechanism. The critical innovation of the synthetic strategy hinges on the soluble basic additive DBU, which constitutes a synergy of Ru­(II)-catalysis with noncovalent interaction and, thus, stabilizes pivotal intermediates to promote the challenging dimerization process.