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..

Ethanol is typically used in organic synthesis as an environmentally benign solvent. Herein, we report a mild and efficient cross-dehydrogenative coupling (CDC) reaction of N-heteroarenes with cyclic ethers by uncovering the new reactivity of ethanol as an efficient promoter in PIFA-mediated radical process. The reaction proceeds smoothly under the irradiation of visible light and features excellent functional group compatibility, which allows the expedite synthesis of a variety of medicinally valuable Cα-heteroarylated cyclic ethers in moderate to high yields.