O,O-Dimethylthiophosphonosulfenyl bromide-silver triflate: a new powerful promoter system for the preactivation of thioglycosides

O,O-Dimethylthiophosphonosulfenyl bromide (DMTPSB) in combination with silver triflate provides a powerful thiophilic promoter system. Both armed and disarmed thioglycoside glycosyl donors can be activated to form glycosidic linkages efficiently by the pre-activation protocol. The usefulness of this new promoter is illustrated by a successful iterative one-pot oligosaccharide assembly.