Recent advances in anomeric C-S bond activation: Emerging opportunities for stereoselective glycosides

Carbohydrates are essential biomolecules in nature for their numerous biological functions. To advance in-depth understanding of complex biochemical processes, obtaining pure, structurally well-defined carbohydrates is crucial. Despite extensive progress, achieving high yields with precise anomeric stereocontrol through chemical glycosylation remains a long-standing challenge. In the last few years, redox-catalyzed C-S bond activation strategies have opened new opportunities in glycosylation chemistry by enabling catalytic activation of thio-glycosyl donors. In particular, photoredox, electrochemical, and radical-mediated approaches have emerged as versatile tools, offering efficient and highly stereoselective glycosylation pathways. These methods expand the scope of thio-donor activation and provide practical routes to challenging glycosidic linkages under mild conditions. This review summarizes recent progress in the stereoselective synthesis of C-, N-, and O-glycosides via anomeric C-S bond activation, showing significant potential for synthesizing biologically relevant glycoconjugates and carbohydrate-based scaffolds.