Preparation of Difluoromethylated Benzothiophene by Visible-Light-Mediated Alkyne Difunctionalization Reaction.

An efficient method for the preparation of difluoromethylated benzothiophenes via visible-light-mediated alkyne difunctionalization was developed. In this method, inexpensive sodium difluoromethanesulfinate (HCF2SO2Na) was used as the fluorine source, and a variety of benzothiophene derivatives were obtained in moderate to excellent yield under mild reaction conditions. Moreover, the reaction operation is simple and easy to scale up.