Nickel-Catalyzed Reductive Coupling for the C-Alkyl Glycosylation of Saccharides with Alkenes.

C-Glycosides are recognized as ideal surrogates for natural O-glycosides owing to their excellent stability against acid-catalyzed and enzymatic hydrolysis, thus holding great application potential in drug discovery and glycochemical research. Nevertheless, the stereoselective assembly of fully saturated C-alkyl glycosides remains a formidable synthetic challenge. Herein, we disclose a one-pot reductive coupling strategy between saccharides and alkenes. This protocol integrates in situ anomeric bromination with nickel-catalyzed reductive coupling, allowing the direct C-glycosylation of partially protected saccharides that bear merely a free anomeric hydroxyl group with activated alkenes represented by ethyl acrylate.