Direct Synthesis of Diaryl Sulfoxides from Arylboronic Acids

, we report an acid-promoted strategy for the synthesis of valuable symmetrical and unsymmetrical diaryl sulfoxides in good to excellent yields (>35 examples, up to 90%) under mild conditions, directly from commercially available arylboronic acids, trifluoroacetic acid, and diethylaminosulfur trifluoride (DAST). The method shows good functional group tolerance, and proceeds without a base and external oxidants, offering a simple approach to diaryl sulfoxide synthesis. Control experiments and mechanistic investigation are also presented to elucidate the reaction pathway.