Generation of benzyne from aryl benziodoxaborole triflate under aqueous conditions and its reactions with alkyl aryl sulfides

Mesityl benziodoxaborole triflate is a unique benzyne precursor under aqueous conditions in the presence of NaHCO3 3 at room temperature. Reactions of alkyl aryl sulfides with benzyne generated under these conditions selectively afford the corresponding sulfonium salts. In contrast, the previously reported reactions of alkyl aryl sulfides with common benzyne precursors under strongly basic anhydrous conditions lead to various products of cyclization, rearrangement, or elimination but not to sulfonium salts. This very mild procedure can be further extended to the preparation of sulfonium salts from diaryl sulfides, dialkyl sulfides, cyclic alkyl and arylsulfides, as well as a selenonium salt from diphenyl selenide.