Catalytic and Chemoselective Glycosylation between “Armed” and “Disarmed” Glycosyl p-Trifluoromethylbenzylthio-p-trifluoromethylphenyl Formimidates

Catalytic and chemoselective glycosylation between novel “armed” and “disarmed” glycosyl p-trifluoromethylbenzylthio-p-trifluoromethylphenyl formimidates was effectively performed in the presence of a catalytic amount of TfOH and MS 4A in CH2Cl2 at -78 °C. In addition, it was noted that highly 1,2-cis or 1,2-trans stereoselective synthesis was established when the above glycosylation was carried out at -78 °C in tBuOMe or EtCN, respectively.