Direct benzothiophene formation via oxygen-triggered intermolecular cyclization of thiophenols and alkynes assisted by manganese/PhCOOH.

An intermolecular oxidative cyclization between thiophenols and alkynes for benzothiophene formation has been established. A variety of multifunctional benzothiophenes are synthesized. In addition, we demonstrated that the obtained benzothiophenes can be used for further transformation to give diverse benzothiophene derivatives efficiently and selectively.