InBr3-Catalyzed Synthesis of Aryl 1,2-trans-Thio(seleno)glycosides

InBr3 is demonstrated to be an efficient catalyst for reactions of fully acetated aldoses with aryl mercaptans or selenophenol at room temperature, rapidly furnishing the corresponding thioglycosides or selenoglycosides with exclusively 1,2-trans-stereoselectivity. This bromide is an air- and moisture-stable Lewis acid and therefore the reactions can be performed in air atmosphere making the procedure simple to perform.