Proton-Coupled Electron Transfer-Driven Fragmentation and Functionalization Strategies for Carbohydrate Diversification.

We present a proton-coupled electron transfer (PCET)-mediated strategy for the direct activation of glycosyl alcohols, providing a unified platform for three key transformations: fragmentative hydrogenation, radical conjugate addition, and dual nickel/photoredox-catalyzed cross-coupling. This approach enables efficient access to C(sp3)-H, C(sp3)-C(sp3), and C(sp3)-C(sp2) bonds from conveniently accessible monohydroxy glycosyl donors. The broad substrate scope and functional group tolerance underscore its versatility, offering streamlined routes to structurally complex and pharmaceutically important C-glycosides while expanding the synthetic repertoire of modern carbohydrate chemistry.