全氟烷基芳烃的位点选择性和直接 C-F 键转化是通过铱光氧化还原催化剂系统用烯丙基锡烷实现的。本脱氟烯丙基化反应仅在苄基位置通过全氟烷基自由基进行,全氟烷基自由基是从受激光氧化还原催化剂到全氟烷基芳烃的单电子转移产生的。各种全氟烷基都适用:线性全氟烷基取代的芳烃,例如 Ar– n C 4 F 9和 Ar– n C 6 F 13和七氟异丙基芳烃(Ar–CF(CF 3 ) 2)进行了位点选择性脱氟烯丙基化。DFT 计算研究表明,原位生成的 Bu 3 SnF 捕获 F -以防止不稳定的全氟烷基自由基中间体发生逆反应,并且自由基中间体有利于与烯丙基锡烷反应。含双(三氟甲基)亚甲基单元的化合物是一种类似物,可用作预防或治疗糖尿病和炎症性疾病的药物,其合成证明了该反应的实用性。
Reduction of perfluoroalkylphenylcyanides and perfluorodecalin was investigated by cyclic voltammetry and interpreted by intramolecular dissociative electron-transfer models, taking into account the dependence of the diffusion coefficient on the molecular volume of the substrate. In both cases, reduction is governed by the first electron transfer and the following chemical reaction corresponding to F- expulsion. In the case of perfluoroalkylphenylcyanides, at the first reduction stage, one electron is exchanged for each fluorinated carbon atom. For perfluorodecalin, the first stage involves a transfer of four electrons, leading to the formation of a diene, in agreement with literature data on the electrochemical behavior of fluorinated olefins. Comparison of the different parameters obtained (standard reduction potentials and cleavage rate constants) with existing thermodynamic values allows us to observe the effect of lowering the C-F bond dissociation energy on the cleavage rate constant when going from primary to tertiary fluorinated carbon atoms. Moreover, deviations from the existing model become more important when the number of electron-withdrawing groups increases, indicating interactions between the radical and fluoride ion fragments. In the special case of perfluorodecalin, the slowness of the electron transfer could be attributed to the nature of the sigma* orbital that receives the extra electron.
Andrieux, Claude P.; Gélis, Laurence; Medebielle, Maurice, Journal of the American Chemical Society, 1990, vol. 112, # 9, p. 3509 - 3520
作者:Andrieux, Claude P.、Gélis, Laurence、Medebielle, Maurice、Pinson, Jean、Savéant, Jean-Michel
DOI:——
日期:——
Photoredox-Catalyzed C–F Bond Allylation of Perfluoroalkylarenes at the Benzylic Position
Ar–nC6F13 and heptafluoroisopropylarenes (Ar–CF(CF3)2) underwent site-selective defluoroallylation. DFT calculation studies revealed that the in situ generated Bu3SnF traps F– to prevent a retroreaction from the unstable perfluoroalkyl radical intermediate, and the radical intermediate favorably reacts with allylic stannanes. The synthesis of a bis(trifluoromethyl)methylene unit containing compound
全氟烷基芳烃的位点选择性和直接 C-F 键转化是通过铱光氧化还原催化剂系统用烯丙基锡烷实现的。本脱氟烯丙基化反应仅在苄基位置通过全氟烷基自由基进行,全氟烷基自由基是从受激光氧化还原催化剂到全氟烷基芳烃的单电子转移产生的。各种全氟烷基都适用:线性全氟烷基取代的芳烃,例如 Ar– n C 4 F 9和 Ar– n C 6 F 13和七氟异丙基芳烃(Ar–CF(CF 3 ) 2)进行了位点选择性脱氟烯丙基化。DFT 计算研究表明,原位生成的 Bu 3 SnF 捕获 F -以防止不稳定的全氟烷基自由基中间体发生逆反应,并且自由基中间体有利于与烯丙基锡烷反应。含双(三氟甲基)亚甲基单元的化合物是一种类似物,可用作预防或治疗糖尿病和炎症性疾病的药物,其合成证明了该反应的实用性。
Single-stage synthetic route to perfluoroalkylated arenes via electrocatalytic cross-coupling of organic halides using Co and Ni complexes
A new method of single-stage synthesis of perfluoroalkylated arenes via cross-coupling of bromo (in some cases, chloro) arenes and heteroarenes (derivatives of benzene, pyridine and furan) and organic perfluoroalkyl halides involving complexes of nickel and cobalt in low oxidation state with α-diimines under mild conditions was proposed. Perfluoroalkylated products are obtained in good yields in the