Ni-Catalyzed and Pentafluorobenzoate-Leaving-Group-Enabled Stereoselective -Aryl Glycosylation.

Inspired by the excellent stereoinduction of palladium catalytic glycosylation with glycals via an inner-sphere pathway, a nickel-catalyzed, stereoselective -aryl glycosylation has been developed for glucals bearing a pentafluorobenzoate (PFB) group at the C3 position. The extremely electron-deficient nature of PFB not only endows stronger activity compared to the traditional leaving groups but also functions as an orientation group, presumably through the strong π-π interactions with the bipyridine ligand coordinated to the nickel center, thereby enabling the β-selective formation of a -aryl glycosidic bond with aryl iodides as glycosyl acceptors under mild conditions. This method features a broad substrate scope, high efficiency, and scalability, providing a general solution to the synthesis of challenging β--glycosides.