Copper-Catalyzed Photocatalyst-Free Radical <i>N</i> -Glycosylation

N-Glycosides widely exist in nature and have very important biological activities. Although the traditional ionic N-glycosylation strategy has many advances, the challenges remain, including water sensitivity, stoichiometric/excess promoters, precious metal catalysts, and unsatisfactory efficiency. Herein, we describe a copper-catalyzed radical N-glycosylation method using ortho-(1-acyloxyimino)ethylphenyl thioglycoside donors. This N-glycosylation protocol features photocatalyst-free, oxidant-free, mild and practical conditions, high stereoselectivity, broad substrate scope, and earth-abundant metal copper catalysis, and is applicable to the late-stage modification and synthesis of marketed drugs and natural products.