catalyst for the directarylation of 3-substituted thiophene derivatives. The regioselectivity of the arylation strongly depends on the thiophene substituent and also on the nature of the arylbromide. When using 3-formyl, 3-cyano, 3-methyl, 3-hydroxymethyl or 3-bromothiophene, the 2-arylated thiophenes were obtained with 76-95% regioselectivity; whereas, the arylation of 3-formylthiophene diethylacetal