Photoinduced C–S Bond Cleavage of Thioglycosidesand Glycosylation.

A glycosylcoupling reaction via photoinduced direct activationof thioglycosides and subsequent O-glycosylationin the absence of photosensitizer was developed for the first time.This reaction underwent a selectively homolytic cleavage of a C–Sbond to generate a glycosyl radical, which was oxidized to an oxacarbeniumion by Cu(OTf)2, and a sequential O-glycosylation.A wide range of glycosides were synthesized in moderate to excellentyield using sugars, amino acids, or cholesterol as the acceptors. [ABSTRACT FROM AUTHOR]