An efficient protocol toward fully substitutedthiophenes and thieno[2,3-b]thiophenes has been developed through CuCl2-catalyzed annulative coupling of S,S-disubstituted enones with diazo compounds under mild conditions. Tetrasubstituted thiophenes and thieno[2,3-b]thiophenes were efficiently accessed by variation of the feed ratio of the reactants in good to excellent yields, respectively. The synthetic