In the recent years, it has been shown that polyhalogenated heterocycles can be regioselectively functionalized in palladium(0)-catalyzed cross-coupling reactions by selective activation of a single halogen atom. The regioselectivity is controlled by electronic and steric parameters. 6 Recently, we have reported the synthesis of aryl-substituted thiophenes, 7 pyrroles, 8 and selenophenes 9 based on regioselective Suzuki reactions of tetrabromothiophene, tetrabromo-N- ...