Self‐Promoted N‐Glycosylation: Extended Substrate Scope and Substituent Effects

Abstract

AbstractA self‐promoted glycosylation method for the stereoselective formation of β‐glucosides from a substrate library of glycosyl trichloroacetimidate glycosyl donors and glycosyl acceptors is presented. The simple two‐component reaction takes place at elevated temperatures, without the addition of any additives or catalysts. After a simple basic workup, N‐glycosides were obtained in good yields and with high β‐selectivity and hence this method allows for easy access to glycoconjugates under very mild conditions. The influences of neighboring group participation and substituents, in both the glycosyl donor and acceptor, were studied. Kinetic data were obtained from in situ IR and these were used for a Hammett study. A connection between the pKa of the acceptor and reaction rate was found and new mechanistic insight in self‐promoted glycosylations gained.