Site‐Selective S‐Arylation of 1‐Thiosugars with Aryl Thianthrenium Salts through Copper(I)‐Mediated, Photoredox‐ Catalyzed Reactions

Abstract A process for the synthesis of aryl thioglycosides from the aryl thianthrenium salts and 1‐thiosugars is achieved by copper(I)‐mediated, photoredox‐catalyzed reactions. The desired products could be obtained in 32% to 78% yield after irradiation with 34 W blue light at room temperature. Various functional groups, especially including halogen groups, were well tolerated under standard reaction conditions. This strategy differs conceptually from all previous S ‐glycosylations in that thiosugar functionality could be incorporated into complex natural products or drugs at a late stage site‐selectively, which has not been shown via aryl halides and aryldiazonium salts.