Copper(I)-catalyzed temperature- and oxidant-induced selective synthesis of pentathiepinoindoles and diindole tetrasulfides is demonstrated. Among them, unsymmetric tetrathiadiindole compounds were synthesized for the first time. In this strategy, the key intermediate biindolyls were in situ generated through Cu-catalyzed direct C–H transformations of indoles. The biindolyls could be selectively converted into the corresponding products by fine-tuning reaction conditions. More than 50 polythioindole products were synthesized with excellent regioselectivity and broad functional group tolerance.