Sulfur hexafluoride (SF6) is a potent greenhouse gas widely used in industry, but its chemical inertness has limited its use as a source of pentafluorosulfanyl (SF5) groups. We report herein a visible-light-driven photocatalytic transformation that enables SF6 to function as an SF5 radical source for the synthesis of SF5 enamides under ambient pressure. Using ynamides as radical acceptors, a range of β-SF5-substituted enamides were obtained under mild conditions in moderate to good yields. Mechanistic studies support the involvement of SF5 radical intermediates and a hydrogen atom transfer process rather than a radical chain pathway. The resulting SF5 enamides could be further transformed into diverse functionalized products, demonstrating their synthetic utility. This work highlights the potential of SF6 as a practical SF5 radical source for constructing valuable SF5-containing organic molecules under photocatalytic conditions. This work provides a new strategy for the direct utilization of SF6 in synthetic organic chemistry.
Uchikura et al. (Sat,) studied this question.