Methanedisulfonyl fluoride, CH₂(SO₂F)₂, transforms aromatic aldehydes into β-arylethenesulfonyl fluorides, useful substrates for the SuFEx “click”-type transformations. The reaction mimics mechanism of the Horner–Wadsworth–Emmons olefination, which runs via addition of the carbanion, followed by cyclization–fragmentation of the four-membered ring intermediate. In the absence of base, electron-rich aldehydes follow an alternative pathway of the Knoevenagel condensation to provide unsaturated 1,1-disulfonyl fluorides. We demonstrate also trapping of elusive ethene-1,1-disulfonyl fluoride, CH₂═C(SO₂F)₂, with 4-(dimethylamino)pyridine (DMAP) that forms zwitterionic adduct, characterized with X-ray studies.

中文翻译：

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磺酰卤和酯的烯烃化：不饱和磺酰氟的合成

甲二磺酰氟 CH ₂ (SO ₂ F) ₂将芳香醛转化为 β-芳基乙烯磺酰氟，是 SuFEx“点击”型转化的有用底物。该反应模拟了 Horner-Wadsworth-Emmons 烯化的机理，该反应通过添加碳负离子进行，然后是四元环中间体的环化-断裂。在没有碱的情况下，富电子醛遵循 Knoevenagel 缩合的替代途径以提供不饱和的 1,1-二磺酰氟。我们还展示了捕获难以捉摸的乙烯-1,1-二磺酰氟，CH ₂ =C(SO ₂ F) ₂, 与 4-(二甲氨基) 吡啶 (DMAP) 形成两性离子加合物，通过 X 射线研究进行表征。