title: An improved method for the synthesis of protected glycosyl fluorides from thioglycosides using N,N-diethylaminosulfur trifluoride (DAST).
abstract: The direct conversion of thioglycosides to glycosyl fluorides frequently used in oligosaccharide synthesis was examined using N,N-diethylaminosulfur trifluoride (DAST). Although the reaction proceeded without N-bromosuccinimide (NBS), in some cases it was found that the electrophilicity of the Vilsmeier-type electrophilic sulfinium cation species was not sufficient for the activation of certain less-reactive thioglycosides. Here, we report the results of fluorination reactions of a series of monosaccharides using DAST in the absence of NBS, and also discuss the acceleration of the reaction in the presence of dimethyl(methylthio)sulfonium trifluoromethanesulfonate (DMTST) resulting in excellent product yields.
authors.affiliation: Japan Science and Technology Agency (JST), ERATO, Wako-shi, Saitama, Japan.
authors.forename: Katsuhiko
authors.initials: K
authors.lastname: Suzuki
authors.forename: Yukishige
authors.initials: Y
authors.lastname: Ito
authors.forename: Osamu
authors.initials: O
authors.lastname: Kanie
mesh_terms: D001974:Bromosuccinimide / Q000737:chemistry; D002384:Catalysis; D060326:Chemistry Techniques, Synthetic / Q000379:methods*; D004048:Diethylamines / Q000737:chemistry*; D005461:Fluorine / Q000737:chemistry*; D006031:Glycosylation; D054879:Halogenation; D007700:Kinetics; D013865:Thioglycosides / Q000138:chemical synthesis* / Q000737:chemistry*
chemical_list: D004048:Diethylamines; D013865:Thioglycosides; D005461:Fluorine; C040394:diethylaminosulfur trifluoride; D001974:Bromosuccinimide