Oxidative (Cross‐)Coupling Reactions Mediated by C–H Activation of Thiophene Derivatives by Using Molybdenum(V) Reagents

Oxidative coupling by using molybdenum pentachloride provides fast and modular access to sophisticated thienoacenes in excellent yields. The coupling process can be accomplished with thiophene and benzothiophene derivatives and provides various complex skeletons such as spirocyclic compounds. In this approach, the first cross-coupling reactions with the use of MoCl5 were established and important motifs for semiconducting materials were synthesized.