Abstract The first examples are reported of an efficient regioselective direct C–H arylation of thieno [3, 4-b] pyrazine (TP) and its 2, 3-dimethyl derivative with bromoalkylthiophenes (BATs), under Heck experimental conditions using Pd (OAc) 2/Bu 4 NBr as the catalytic system, giving rise to a variety of valuable aryl-substituted thienopyrazines. The obtained results suggested that the 2-position of the TP moiety is less reactive towards C–H ...