Iron(III)-triflate-catalyzed multiple glycosylations with peracetylated beta-D-glucosamine
Résumé
Direct multiple glycosylations of thioaryl and propargyl mannopyranosides with peracetylated beta-D-glucosamine have been carried out using catalytic iron(III) triflate as a promoter in the presence of 2,4,6-tri-tert-butylpyrimidine under microwave irradiation. This has led to the one-step formation of various oligosaccharides with mannose at the branching point. Subsequent direct introduction of a linker through copper-catalyzed azide-alkyne cycloaddition with the propargyl branched glycan and final deprotection gave rapid access to N-glycan mimetics.