Institute of Organic Chemistry, Karlsruhe Institute of Technology (KIT), Campus South, Fritz-Haber-Weg 6, 76131 Karlsruhe, Germany.
J Org Chem. 2013 Aug 16;78(16):7938-48. doi: 10.1021/jo401145g. Epub 2013 Jul 25.
A robust protocol for perfluoroalkylation and ethoxycarbonyldifluoromethylation of functionalized aromatic triazenes is described. Using silver(I)-fluoride and different fluorinated (trimethyl)silyl substituted species, it was possible to synthesize various ortho-fluorinated triazenes in good yields via simple CH-substitution. Initial reactions under solvent-free (neat) conditions indicate a stabilizing interaction between "AgRf" and the triazene moiety, which may be responsible for the good yields and regioselectivity. The transformation possibilities of the triazene moiety make these reactions interesting for the synthesis of fluorinated building blocks. In addition, quantum chemical calculations suggest that the stabilization of the radical intermediate in the ortho-position is distinctly more favored for aromatic triazenes than for other aromatic substrates.
描述了一种功能化芳香三氮烯的全氟烷基化和乙氧基羰二氟甲基化的稳健方案。使用银（I）-氟化物和不同的全氟取代的（三甲基）硅基取代物，可以通过简单的 CH 取代以良好的收率合成各种邻氟取代的三氮烯。无溶剂（纯）条件下的初始反应表明“AgRf”和三氮烯部分之间存在稳定相互作用，这可能是高产率和区域选择性的原因。三氮烯部分的转化可能性使这些反应成为合成氟化构建块的有趣选择。此外，量子化学计算表明，与其他芳香族底物相比，芳基三氮烯中自由基中间体在邻位的稳定明显更为有利。
