Abstract
This paper describes the synthesis of C- and N-glucopyranosides via trimethylsilyl trifluoromethanesulfonate catalyzed nucleophilic substitution of glucopyranosides, derived from d-glucopyranose, with methyl, ethyl, n-butyl, allyl, benzyl, and phenyl groups at the anomeric carbon centers. Generally, the reactions using allyltrimethylsilane, trimethylsilyl azide, trimethylsilyl cyanide, and 1-phenyl-1-(trimethylsiloxy)ethene as the nucleophiles in the presence of 20 mol% trimethylsilyl trifluoromethanesulfonate in acetonitrile at -40 °C smoothly proceeded with α-stereoselectivity to afford various C- and N-glucopyranosides in 78-99% yield. Although a decrease in the synthetic yields was observed for some reactions using glucopyranoses with allyl and benzyl groups at the anomeric carbon, the yields could be improved using glucopyranosyl acetates in the presence of 20 mol% trimethylsilyl trifluoromethanesulfonate in acetonitrile-dichloromethane (1:1) at -78 °C.
Key words
glycosides - nucleophilic substitutions -
d-glucopyranose - trifluoromethanesulfonate catalysis - trimethylsilylated nucleophiles
