A catalytic Koenigs-Knorr glycosylation based on acceptor activation with In(NTf2)(3)

The development of efficient glycosylation methods is important for gaining better insight into biological processes of significance to medicinal chemistry. Herein, we describe an In(NTf2)(3)-catalyzed Koenigs-Knorr glycosylation based on the activation of an alcoholic hydroxyl group. A catalytic amount of In(NTf2)(3) enables effective glycosylation of diverse alcohols with peracylated aldosyl bromides as donors, leading to the stereoselective formation of a series of glycosides in satisfactory yields. The protocol is characterized by mild reaction conditions and good functional-group tolerance, while obviating any need for any additive. Moreover, the potential utility of this transformation is demonstrated by the convenient syntheses of key building blocks for biomolecules of medicinal relevance. (C) 2018 Published by Elsevier Ltd.