Stereocontrolled <i>O</i>-Glycosylation with Palladium-Catalyzed Decarboxylative Allylation

Abstract

The Pd-π-allyl intermediate in an electron-rich glycal system with poor reactivity is employed as an efficient glycosyl donor. Starting from glucal derived carbonate, various O-glycosides were formed via a palladium-catalyzed reaction through a tandem decarboxylation, proton abstraction, and nucleophilic addition, in good yields with excellent selectivity. Iterative glycosylation with the same strategy may provide an access to complex oligosaccharides.