Although the transition metal-catalyzed radical fluorine atom transfer (FAT) strategy has emerged as a powerful tool for the construction of C–F bonds, to our knowledge, this approach has rarely been applied to the formation of S–F bonds. Here, we report that 4-methoxypyridine 1-oxide can serve as an inexpensive and simple yet effective ligand and thus promote the transformation of the copper-mediated challengeable radical FAT to sulfonyl radicals, paving the way for the assembly of an FSO₂ group. Based on this concept, three Cu(I)-catalyzed protocols involving site-selective intra- and intermolecular fluorosulfonylation of inert C(sp³)–H bonds and 1,2-aminofluorosulfonylation of inactivated alkenes have been developed, enabling the preparation of C(sp³)-rich aliphatic sulfonyl fluorides that cannot be easily synthesized by known methods. These practical and operationally simple methods result in high functional group tolerance under mild conditions and can be applied to the modification of bioactive derivatives and preparation of highly valued molecules. Detailed mechanistic studies indicate the unique role of the 4-methoxypyridine 1-oxide ligand in facilitating the formation of such rare radical FATs via an outer-sphere pathway.

中文翻译：

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铜介导的自由基氟原子转移至磺酰自由基：显着的 4-甲氧基吡啶 1-氧化物配体效应

尽管过渡金属催化的自由基氟原子转移（FAT）策略已成为构建C-F键的有力工具，但据我们所知，这种方法很少应用于S-F键的形成。_{在这里，我们报道4-甲氧基吡啶1-氧化物可以作为一种廉价、简单而有效的配体，从而促进铜介导的挑战自由基FAT向磺酰自由基的转化，为FSO 2}基团的组装铺平道路。基于这一概念，开发了三种 Cu(I) 催化方案，涉及惰性 C(sp ³ )–H 键的位点选择性分子内和分子间氟磺酰化和失活烯烃的 1,2-氨基氟磺酰化，从而能够制备 C富含(sp ³ )的脂肪族磺酰氟不能通过已知方法轻易合成。这些实用且操作简单的方法在温和条件下具有较高的官能团耐受性，可应用于生物活性衍生物的修饰和高价值分子的制备。详细的机理研究表明，4-甲氧基吡啶 1-氧化物配体在通过外球途径促进此类罕见自由基 FAT 的形成方面具有独特的作用。