A Visible-Light-Promoted O-Glycosylation with a Thioglycoside Donor

Mark L Spell; Kristina Deveaux; Caitlin G Bresnahan; Bradley L Bernard; William Sheffield; Revati Kumar; Justin R Ragains

doi:10.1002/anie.201601566

A Visible-Light-Promoted O-Glycosylation with a Thioglycoside Donor

Angew Chem Int Ed Engl. 2016 May 23;55(22):6515-9. doi: 10.1002/anie.201601566. Epub 2016 Apr 18.

Authors

Mark L Spell¹, Kristina Deveaux¹, Caitlin G Bresnahan¹, Bradley L Bernard¹, William Sheffield¹, Revati Kumar¹, Justin R Ragains²

Affiliations

¹ Department of Chemistry, Louisiana State University, 232 Choppin Hall, Baton Rouge, LA, 70803, USA.
² Department of Chemistry, Louisiana State University, 232 Choppin Hall, Baton Rouge, LA, 70803, USA. jragains@lsu.edu.

PMID: 27086646
DOI: 10.1002/anie.201601566

Abstract

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.

Keywords: glycosylation; photochemistry; reaction mechanisms; sulfur.

Publication types

Research Support, Non-U.S. Gov't