A sequential one-pot strategy for the synthesis of triterpenoid saponins in ionic liquid [emim][OTf].

1-Ethyl-3-methylimidazolium trifluoromethanesulfonate ([emim][OTf]) is an efficient co-solvent and co-promoter for one-pot sequential glycosylation with the combined use of thioglycosides and trichloroacetimidates (or N-phenyltrifluoroacetimidates) donors at room temperature. One-pot glycosylation is efficient for the synthesis of triterpenoid saponins with the combined use of N-phenyltrifluoroacetimidate donors and 2-methyl-5-tert-butylphenyl (Mbp) thioglycoside donors in [emim][OTf]. [ABSTRACT FROM AUTHOR]