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 Bronsted 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.