Highly chemo- and stereoselective glycosidation of permethacrylated O-glycosyl trichloroacetimidate reagents promoted by TMSNTf2

TMSNTf2 has been used efficiently as a promoter in glycosidation reaction involving permethacrylated Schmidt reagents. While TMSNTf2 is known to be a powerful activator for Cdouble bond; length as m-dashO double bonds, we have discovered that this reagent can activate Cdouble bond; length as m-dashN double bond selectively, even in the presence of excess Cdouble bond; length as m-dashO groups of permethacrylated O-glycosyl trichloroacetimidate substrates. Glycosides are synthesized in moderate to reasonable yields with an excellent overall β-stereoselectivity.