Yb(OTf)3‑Mediated Access to Furans from β‑Ketothioamides via Eschenmoser Sulfide Contraction Reaction

A mild and straightforward synthetic protocol for construction of a furan skeleton promoted by Yb­(OTf)3 from β-ketothioamides and arylglyoxals has been developed at room temperature. Importantly, this protocol involves a tandem sequence that includes aldol condensation, N-cyclization, ring opening, O-cyclization, S-cyclization, and Eschenmoser sulfide contraction.

本研究开发了一种温和简便的合成方案，可在室温下以三氟甲磺酸镱（Yb(OTf)3）为促进剂，由β-酮硫代酰胺与芳基乙二醛构建呋喃骨架。值得注意的是，该方案涉及包含羟醛缩合、N-环化、开环、O-环化、S-环化以及埃申莫瑟硫化物收缩反应的串联序列。