The highly stereoselective synthesis of diverse medicinally valuable alkynyl C-glycosides under mild and green reaction conditions remains a great challenge. Herein, we wish to report a visible-light induced photocatalytic decarboxylative alkynylation approach. By utilizing an iridium photocatalyst in the presence of visible light, glycosyl radicals are in-situ generated via the decarboxylation of anomeric acids and efficiently coupled with a variety of ethynylbenziodoxolones (EBXs), which allows the facile synthesis of a variety of alkynyl C-glycosides in moderate to high yields and with excellent diastereoselectivity..

Visible‐light‐induced heterogeneous photocatalysis for decarboxylative alkynylation has been performed. The using of cheap, metal‐free and recyclable graphitic carbon nitride (g‐C3N4) as the photoredox catalyst in the process enables the facile transformation of a variety of carboxylic acids into structurally diverse alkyne‐containing molecular architectures under mild and environmentally‐benign conditions. Notably, the heterogeneous nature of the reaction system allows for the recovery and reuse of the catalyst in multiple runs without loss of reactivity. The photocatalytic reactions could also be performed in a continuous flow fashion and scaled up to gram‐scale. Furthermore, the preparative power of this strategy is further highlighted by its application in the 1, 2‐amido alkynylation of unactivated alkenes.