A visible-light-promoted O-glycosylation with a thioglycoside donor
© 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. Visible-light irradiation of 4-p-methoxyphenyl-3-butenylthioglucoside donors in the presence of Umemoto's reagent and alcohol acceptors serves as a mild approach to O-glycosylation. Visible-light photocatalysts are not required for activation, and alkyl- and arylthioglycosides not bearing the p-methoxystyrene are inert to these conditions. Experimental and computational evidence for an intervening electron donor-acceptor complex, which is necessary for reactivity, is provided. Yields with primary, secondary, and tertiary alcohol acceptors range from moderate to high. Complete β-selectivity can be attained through neighboring-group participation. Visible-light irradiation of 4-p-methoxyphenyl-3-butenylthioglucoside donors in the presence of Umemoto's reagent serves as an exceptionally mild and orthogonal approach to O-glycosylation. Alkyl- and arylthioglycosides not containing the p-methoxystyrene moiety are inert under these conditions, and evidence suggests that an intervening electron donor-acceptor complex is necessary for reactivity.
Publication Source (Journal or Book title)
Angewandte Chemie - International Edition
Spell, M., Deveaux, K., Bresnahan, C., Bernard, B., Sheffield, W., Kumar, R., & Ragains, J. (2016). A visible-light-promoted O-glycosylation with a thioglycoside donor. Angewandte Chemie - International Edition, 55 (22), 6515-6519. https://doi.org/10.1002/anie.201601566