An efficient Heck-type C-glycosylation of glycals via the C-N bond cleavage of aryl hydrazines has been developed. The flexibility of the reaction was tested by the substrate scope, consisting of glycals from different carbohydrate origins as well as aryl hydrazines with various substituents. Pure α-C-glycosides were obtained when (3R)-glycals were employed, whereas α,β mixtures were observed with (3S)-glycals.

Oxidation Heck Reaction of Glycals and Aryl Hydrazines: A Palladium--Catalyzed C-Glycosylation. -Depending on the C3 stereochemistry of the glycal substrate this method yields either diastereomerically pure products or mixtures of diastereomers. (3R)-Glycals (I) are converted exclusively to the α-glycosides (III), while (3S)-glycals (IV) give α/β mixtures. -(BAI, Y.; KIM, L. M. H.; LIAO, H.; LIU*, X.-W.; J. Org. Chem. 78 (2013) 17, 8821-8825, http://dx.