Biomimetic activation enables direct functionalization with native sugars

We report a metal- and protecting-group-free strategy that enables the direct anomeric functionalization of unprotected monosaccharides and oligosaccharides in their native forms via glycosyl radical-based cross-coupling with various electrophiles under mild photoirradiation conditions. This approach eliminates the need for pre-installation and removal of protecting groups, solving an enduring problem in the field and providing a general platform to accelerate the preparation of robust carbo-, thio- and selenoglycosyl compounds in high regio- and stereo-selectivity. We also show that the protocol is amenable to the chemical synthesis of unprotected C-glycosylproteins in a post-translational manner that is complementary to the analogous biological O- and N-glycosylation processes. This dataset contains LCMS data of tryptic or LysC digests of PstS, PanC, histone, and SSβG proteins selectively modified by either Mannose, Galactose, or N-Acetylgalactosamine. In total, 7 LCMS files are presented along with the results of the identification by MSFragger, corresponding to the variants of the proteins with different modifications.