We report herein, a very simple catalytic system for the direct arylation of benzoxazole and benzothiazole derivatives at C7 position, namely, phosphine-free PdCl2 associated with PivOK in NMP at 150 °C. (Thio)­phenoxy chelation-assisted Pd-catalyzed C–H bond cleavage, from an opened intermediate, was proposed to explain this unique regioselectivity. This reaction allows the synthesis of 2-amino-6-arylphenols through the ring opening of the benzoxazole.

International audienceWe report, herein, on palladium-catalyzed direct arylation of difluorobenzenes and dichlorobenzenes bearing benzoxazole or benzothiazole moieties, which don't act as directing groups. With moderate electron-withdrawing substituents on the aryl bromides as coupling partners, the reaction proceeds nicely using phosphine-free PdCl2 catalyst, and potassium pivalate/dimethylacetamide (PivOK/DMA) as catalytic system. The reaction was regioselective and occurred at the less hindered ortho-positions of fluorine or chlorine atom