Résumé
This research account describes part of the work that has been carried out in our laboratory over the last three years on the use of two classical free‐radical reactions in modern glycochemistry, namely the photoinduced coupling of thiols with alkenes (thiol‐ene coupling, TEC) and alkynes (thiol‐yne coupling, TYC). These reactions are endowed with all the essential attributes of a click process, including high level of atom economy, chemo‐ and regioselectivity, tolerance to water and oxygen, and rapid formation of a single product in high yield. The first part of the account reports on the validation of these metal‐free reactions in the synthesis of S‐disaccharides, S‐glycosyl amino acids, S‐glycodendrimers, and S‐glycoclusters on calix[4]arene and silsesquioxane scaffolds. The second part deals with the glycosylation of various peptides and the natural protein bovine serum albumin. In all cases, the key role of TEC and TYC is discussed and highlighted.