Radical dehydroxylative C-glycosylation of 1-hydroxycarbohydrates enabled by photoredox catalysis

C -Glycosides, known for their superior in vivo stability compared to their O - and N -glycoside counterparts, have been widely explored as drug candidates and utilized in biological research. Traditional radical C-glycosidation techniques relied on precursors such as glycosyl halides and glycosyl sulfones. These methods, however, face several challenges, including the instability of glycosyl precursors, the requirement for multi-step synthesis, and limited practicality. Herein, we present a straightforward, metal-free method to synthesize both sp 2 and sp 3 C -glycosides with high stereoselectivity via direct deoxy-glycosidation of readily available and stable 1-hydroxycarbohydrates. Mechanistic investigations indicate the involvement of glycosyl radicals in the reaction. Cellular assays reveal the antitumor activity of the synthesized products, which underscores the potential of this strategy in medicinal chemistry. Glycosyl radicals were generated via NHC-mediated in situ deoxygenation of 1-hydroxycarbohydrates. We exploit this Glycosyl radical to prepare a broad selection of C(sp 2 ) and C(sp 3 )–glycosides from structurally diverse and readily available feedstocks.