Revisiting Glycosylations Using Glycosyl Fluoride by BF<sub>3</sub>·Et<sub>2</sub>O: Activation of Disarmed Glycosyl Fluorides with High Catalytic Turnover
Catalytic glycosylations with glycosylfluorides using BF3·Et2O are presented. Glycosylations with both armed and disarmed donors were efficiently catalyzed by 1 mol% of BF3·Et2O in a nitrogen-filled glovebox without the use of dehydrating agents. Our finding is in sharp contrast with conventional BF3·Et2O-mediated glycosylations, where excess Lewis acid and additives are required. Mechanistic studies