Palladium-catalyzed perarylation of 3-thiophene- and 3-furancarboxylic acids accompanied by C-H bond cleavage and decarboxylation

3-Thiophene- and 3-furancarboxylic acids efficiently undergo perarylation accompanied by cleavage of the three C-H bonds and decarboxylation upon treatment with excess aryl bromides in the presence of a palladium catalyst to give the corresponding tetraarylated products in good yields.