化学试剂

五氟硫基(SF₅)因亲脂性高、吸电子性强，被称为“超级三氟甲基”，在新药研发与先进材料创制领域逐渐备受关注。经典的五氟硫基试剂——五氟硫氯，在自由基五氟硫基化反应中，易发生卤素原子转移，生成氯代五氟硫基化产物，难以合成其他类型五氟硫基类化合物。为解决这一问题，本文以1,4-环己二烯为自由基调节剂，顺利实现了炔烃的五氟硫基化氢化反应，合成了一系列以顺式构型为主的五氟硫基烯烃化合物，目标产物产率高达89%，顺反异构比>20∶1。该方法还展现出良好的官能团兼容性，可兼容酯基、氰基、卤素等多种结构单元。以1,4-环己二烯为自由基调节剂，可有效抑制五氟硫氯的氯原子转移副反应，从而实现炔烃的五氟硫基化氢化，为顺式五氟硫基烯烃的构建提供了一种新策略。

The pentafluorosulfanyl(SF₅) group has emerged as an attractive fluorinated motif in medicinal chemistry,agrochemicals,and functional materials owing to its unique physicochemical properties,including high lipophilicity,strong electron-withdrawing ability,and exceptional metabolic stability. Among the available SF_5reagents,sulfur pentafluorochloride(SF_5Cl) is the most readily accessible and widely used SF_5source. However,its application in radical transformations remains challenging because the highly reactive chlorine atom readily undergoes competing chlorine atom transfer(XAT),leading to undesired chlorinated products and limiting the efficient synthesis of structurally diverse SF₅-containing molecules. Herein,we report a visible-light-mediated hydropentafluorosulfanylation of alkynes using SF_5Cl as the pentafluorosulfanylation reagent and 1,4-cyclohexadiene as a radical mediator. Under mild reaction conditions,a broad range of aryl-and alkyl-substituted alkynes undergo highly stereoselective hydropentafluorosulfanylation to afford cis-pentafluorosulfanylated alkenes in up to 89% isolated yield with excellent cis/trans selectivity( >20 ∶ 1). The protocol exhibits broad substrate scope and functional-group tolerance,accommodating esters,nitriles,halides,ethers,heterocycles,and other synthetically useful functionalities. Furthermore,the practicality of the method is demonstrated by the late-stage pentafluorosulfanylation of structurally complex bioactive molecules,including derivatives of(S)-(+)-ibuprofen,loxoprofen,and tigogenin,providing direct access to structurally diverse SF₅-containing analogues.Mechanistic studies support that 1,4-cyclohexadiene serves as an effective radical mediator that suppresses competing chlorine atom transfer from SF_5Cl while promoting selective hydrogen atom transfer,thereby enabling efficient and stereoselective hydropentafluorosulfanylation. This protocol provides a practical strategy for the synthesis of cispentafluorosulfanylated alkenes,expands the synthetic utility of SF_5Cl in radical chemistry,and offers a versatile platform for the preparation of SF₅-containing molecules of potential interest in medicinal chemistry and functional materials.