Photochemically Generated Sulfenylnitrene Unlocks Chemoselective Activation of Conventional Thioglycosides for Stereocontrolled Furanosylations

2-type pathways, enabling Lewis-acid-free and highly stereoselective furanosylations across ribose, arabinose, xylose, and the particularly challenging 2-deoxyribose systems. Mechanistic investigations reveal that the steric and electronic effects of the C5-protecting group induce the stereoselectivity. The synthetic utility of this platform is demonstrated by the efficient construction of glycosylated bioactive molecules and a 1,2-cis ribopentasaccharide. Overall, this work introduces sulfenylnitrene-mediated activation as a sustainable and broadly applicable strategy for stereocontrolled furanosylation, expanding the conceptual scope of sulfur-based nitrene chemistry in selective bond construction.