Product Control in Alkene Trifluoromethylation: Hydrotrifluoromethylation, Vinylic Trifluoromethylation, and Iodotrifluoromethylation using Togni Reagent
作者:Hiromichi Egami、Yoshihiko Usui、Shintaro Kawamura、Sayoko Nagashima、Mikiko Sodeoka
DOI:10.1002/asia.201500359
日期:2015.10
achieved by using Togni reagent in the absence of any transition metal catalyst. These reactions were readily controllable by selection of appropriate salts and solvents. The addition of K2CO3 afforded the hydrotrifluoromethylation product, with DMF acting not only as a solvent, but also as the hydrogen source. In contrast, the use of tetra‐n‐butylammonium iodide (TBAI) in 1,4‐dioxane resulted in vinylic
在没有任何过渡金属催化剂的情况下,使用 Togni 试剂实现了简单烯烃的氢三氟甲基化、乙烯基三氟甲基化和碘三氟甲基化。通过选择适当的盐和溶剂,这些反应很容易控制。添加K 2 CO 3得到氢三氟甲基化产物,其中DMF不仅充当溶剂,而且充当氢源。相比之下,在 1,4-二恶烷中使用四正丁基碘化铵 (TBAI) 会导致乙烯基三氟甲基化,而使用 KI 则会产生碘三氟甲基化产物。乙烯基三氟甲基化产物是通过用2-碘苯甲酸铵处理碘三氟甲基化产物得到的,这表明它是通过原位生成的碘三氟甲基化产物的消除反应形成的,并且所得2-碘苯甲酸盐的溶解度起着关键作用产品转换中的作用。自由基时钟实验表明这些反应通过自由基中间体进行。