The selective activation and controlled transformation of C(sp3)−F bonds in trifluoromethyl groups (CF3) represent a long-standing challenge in organofluorine chemistry due to their exceptionally high bond dissociation energies. In this work, we report on the catalytic C(sp3)–F bond activation of trifluoromethyl alkenes at the low-valent germanium and tin redox platforms. Reactions of organogermanium(II) and tin(II) species with trifluoromethyl alkenes proceed via an SN2'-type oxidative addition, resulting in a series of well-defined structurally rearranged Ge(IV) and Sn(IV) adducts. Remarkably, the Sn(II)/Sn(IV) redox system enables both stoichiometric and catalytic hydrodefluorination of trifluoromethyl alkenes in the presence of PhSiH3. By modulating the reaction conditions, α-fluorinated methylalkenes, monofluoroalkenes and gem‑difluoroalkenes can be obtained selectively and efficiently. Notably, combined experimental and theoretical mechanistic studies reveal two divergent pathways for the C–F bond transformation.
This work was published in J. Am. Chem. Soc. entitled “Catalytic C(sp3)–F Bond Activation at Low-Valent Germanium and Tin Redox Platforms” (https://doi.org/10.1021/jacs.5c22945). Prof. Zhaowen Dong and Prof. Xiaoming Zeng are the corresponding authors of the paper, and Ph.D. candidates Zhuchunguang Liu and Ru-De Lin are the co-first authors. This work was financially supported by National Natural Science Foundation of China, the National Key R&D Program of China, and Natural Science Foundation of Sichuan, China and the Fundamental Research Funds for the Central Universities.
