Copper( <scp>ii</scp> )-mediated deoxychlorination synthesis of glycosyl chlorides from glycosyl hemiacetals

Herein, we report a highly efficient and mild methodology for the deoxychlorination synthesis of glycosyl chlorides directly from readily available glycosyl hemiacetal precursors, by using diphenylchlorophosphate in combination with copper(II) chloride salt. This strategy utilizes bench-stable substrates with remarkable functional group tolerance and high stereoselectivity, effectively accommodating both disarmed and armed sugars with 70-90% yields. The synthesized chloroglycosides directly demonstrated broad utility in <i>O</i>- and <i>N</i>-glycosylations with saccharin, amino acids, and flavonoids, offering a general route to diverse glycoconjugates.