Highly Stereoselective C-Glycosylation by Photocatalytic Decarboxylative Alkynylation on Anomeric Position: A Facile Access to Alkynyl C-Glycosides

Comprehensive Summary 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.