Non-symmetrical diarylcarboxylic acids via rhodium(I)-catalyzed regiospecific cross-dehydrogenation coupling of aromatic acids: twofold direct C-H bond activations in water

A rhodium-catalyzed direct cross-dehydrogenative coupling reaction between two different aromatic acids to generate non-symmetrical diaryl acids was developed for the first time. This reaction is operationally simple, tolerant to air, compatible with water, and it can be easily scaled up to gram level by using 0.2 mol% of the catalyst.