Base-Catalyzed Bifunctionalization of Phenacyl Bromide with Glycosyl Thiosulfonates to Access Stereoselective Synthesis of Diverse Glycosylthio β-Keto Sulfones

A simple and high-yielding strategy to synthesize glycosylthio β-keto sulfones using easily accessible glycosyl thiosulfonates with phenacyl bromide derivatives under metal-free conditions is developed. This method enables the straightforward formation of two new C-S bonds (C-S and C-SO₂) simultaneously. Meanwhile, five different sugar thiosulfonates were well tolerated in this reaction, exhibiting high efficiency and broad applicability (up to 94%, 36 examples). The synthetic process was reliable at the gram-scale, thus demonstrating their efficiency and practicality. In addition, a plausible reaction mechanism underlying this method is proposed.