Fischer Lukas, Lee Michael H, Kim Isaac, Wiesner Anja, Hoffmann Kurt F, Riedel Sebastian
Fachbereich Biologie, Chemie, Pharmazie Institut für Chemie und Biochemie-Anorganische Chemie, Freie Universität Berlin, Fabeckstraße 34/36, 14195, Berlin, Germany.
Angew Chem Int Ed Engl. 2024 Oct 7;63(41):e202407497. doi: 10.1002/anie.202407497. Epub 2024 Sep 9.
A new concept for the synthesis of dialkyl chloronium cations [R-Cl-R] is described (R=CH, CHCF), that allows the formation of fluorinated derivatives. By utilizing the xenonium salt [XeOTeF][M(OTeF)] (M=Sb, n=6; M=Al, n=4) chlorine atoms of chloroalkanes or the deactivated chlorofluoroalkane CHClCF are oxidized and removed as ClOTeF leading to the isolation of the corresponding chloronium salt. Since the resulting highly electrophilic cation [Cl(CHCF)] is able to alkylate weak nucleophiles, this compound can be utilized for the introduction of a fluorinated alkyl group to those. In addition, the fluorinated alkyl chloronium cation displays a high hydride ion affinity, enabling the activation of linear hydrocarbons by hydride abstraction even at low temperatures ultimately leading to the formation of branched carbocations.
描述了一种合成二烷基氯鎓阳离子[R-Cl-R]（R = CH₃、CH₂CF₃）的新概念，该概念允许形成氟化衍生物。通过使用氙盐[XeOTeF₅][M(OTeF₆)]（M = Sb，n = 6；M = Al，n = 4），氯代烷烃或钝化的氯氟烷烃CH₂ClCF₃中的氯原子被氧化并以ClOTeF₅的形式除去，从而分离出相应的氯鎓盐。由于生成的高亲电阳离子[Cl(CH₂CF₃)₂]能够使弱亲核试剂烷基化，因此该化合物可用于将氟化烷基引入其中。此外，氟化烷基氯鎓阳离子表现出高的氢离子亲和力，即使在低温下也能通过氢化物提取激活直链烃，最终导致支链碳正离子的形成。
