“…In 1988, Fraser-Reid and co-workers introduced the so-called armed-disarmed chemoselective glycosylation strategy; that is, a C(2)-ether-protected pentenyl glyco- side was chemoselectively coupled with a benzoylated pentenyl glycoside [22]. Chemoselective glycosylations have also been developed for other types of glycosides, for example, thioglycosides, selenoglycosides, glycals, and 2,6-anhydro-2-thiosugars; as concerns glycosyl fluorides, it was firstly reported by Castillon and co-workers a chemoselective glycosylation with glycosyl fluorides by using [HfCl 2 (Cp) 2 ]/AgX (X OTf, ClO 4 ) promoter system [23] to give the corresponding disaccharide in a good yield, and later, Ley and co-workers reported a successful chemoselective glycosylation based on their cyclic acetal protecting-group strategy [24]. We decided to study the application of the TrB(C 6 F 5 ) 4 -catalyzed glycosylation reaction to the ordinary armed-disarmed glycosylation strategy.…”