Investigations to mechanism and applications of the glycosylation protocol employing 8-methyltosylaminoethynyl-1-naphthyl (MTEAN) glycoside donors

Abstract

Based on the capability of silyl ethers for efficient glycosylation, the new MTEAN glycosylation protocol utilizing 8-methyltosylaminoethynyl-1-naphthyl (MTEAN) glycosides as donors were extended to one-pot synthesis of nucleosides, late-stage modification of bioactive molecules, and stereoselective construction of 1,2-cis-glucosidic linkages using silyl ethers of the acceptors. Moreover, the reaction mechanism was systematically investigated by control reactions and side product characterizations, leading to the determination of a TfOH-catalyzed ynamide functionality-initiated process, which was further corroborated by identifications of the departure form of leaving group and the real catalyst.