The interest in organic compounds bearing the pentafluorosulfanyl (SF5) group has increased significantly. The photocatalytic utilization of the cheap and nontoxic sulfur hexafluoride (SF6) as a SF5 donating motif is an extremely valuable and still underdeveloped pathway in comparison to the well-established methodology employing the highly toxic SF5Cl gas. However, due to the high stability and associated low redox potential of SF6, paired with the high electrophilic nature of the instable SF5 radical species, renders the development of catalytic systems to gain SF5 bearing organic molecules from SF6 particularly challenging. We hereby present the first photocatalytic hydropentafluorosulfanylation of aryl acetylenes by SF6 using Ir(ppy)3 as visible-light photoredox catalyst and Hantzsch’s ester as a sacrificial reductant as well as hydrogen atom transfer (HAT) transfer reagent. The method delivers the corresponding pentafluorosulfanylated alkenes in good to excellent yields.
Klehenz et al. (Tue,) studied this question.