Extended π-Conjugated Structures via Dehydrative C-C Coupling.

We describe a methodology for the synthesis of extended aromatic structures through dehydrative C-C coupling from readily accessible diols. Treatment of the diols with a Brønsted acid ( para-toluenesulfonic acid) induces the nucleophilic addition of an arene or heteroarene, yielding fully aromatic products in high to quantitative yields with thiophenes, furan, indole, and N, N-dimethylaniline as coupling partners. The C-C coupling reactions proceed under mild, open flask conditions and offer high atom economy, while providing an attractive alternative approach to metal-catalyzed cross-coupling.