In the presence of 1/HBF4 propargylic thioethers undergo a novel intramolecular exo-endo-cyclisation. This sequence represents a novel domino reaction which involves an alkyne-alkyne coupling followed by an intramolecular Friedel-Crafts like cyclisation.7 Bis(pyridine)iodonium(I)tetrafluoroborate (1) Barluenga’s reagent is a powerful iodination agent which is the reagent of choice for highly selective electrophilic iodination under mild conditions. Examples include all kinds of unsaturated substrates such as isolated and conjugated olefins,1 acetylenes2 and aromatic compounds3 tolerating a variety of functional groups. Compound 1 also allows to control polyiodination reactions3b in a regioselective manner and has been reported to initiate iodination/cyclisation cascade-processes.4

中文翻译：

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双(吡啶)碘鎓(I)四氟硼酸盐

在 1/HBF4 炔丙基硫醚的存在下，会发生一种新型的分子内外-内-环化反应。该序列代表了一种新的多米诺反应，其中包括炔-炔偶联，然后是分子内弗里德尔-克拉夫茨，如环化。7 双（吡啶）碘鎓（I）四氟硼酸盐 (1) Barluenga 试剂是一种强大的碘化剂，是首选试剂在温和条件下用于高选择性亲电碘化。例子包括各种不饱和底物，例如分离的和共轭的烯烃、1 乙炔 2 和芳香族化合物 3，这些物质可以耐受各种官能团。化合物 1 还允许以区域选择性方式控制多碘化反应 3b，并且据报道可引发碘化/环化级联过程。 4