Singh A, Kubik J J, Weaver J D
107 Physical Science , Department of Chemistry , Oklahoma State University , USA . Email:
Chem Sci. 2015 Dec 1;6(12):7206-7212. doi: 10.1039/c5sc03013g. Epub 2015 Sep 29.
C-F functionalizations that provide C-C bonds are challenging synthetic transformations, due in part to the large C-F bond strength, short bond length, nonpolarizable nature, the production of fluoride, and the regioselectivity-in the case of multifluorinated substrates. However, commercially available highly fluorinated arenes possess great synthetic potential because they already possess the C-F bonds in the desired locations that would be difficult to selectively fluorinate. In order to take advantage of this potential, selective C-F functionalizations must be developed. Herein, we disclose conditions for the photocatalytic reductive alkylation of highly fluorinated arenes with ubiquitous and unactivated alkenes. The mild reaction conditions provide for a broad functional group scope, and the reaction is remarkably efficient using just 0.25 mol% catalyst. Finally, we demonstrate the utility of the strategy by converting highly fluorinated arenes to elaborate (hetero)arenes that contain 2-5 C-F bonds synergistic use of photocatalysis and SAr chemistry.
构建碳-碳键的碳-氟官能化反应是具有挑战性的合成转化反应，部分原因在于碳-氟键强度大、键长短、不可极化的性质、氟化物的生成以及在多氟代底物情况下的区域选择性。然而，市售的高度氟化芳烃具有巨大的合成潜力，因为它们已经在难以选择性氟化的所需位置拥有碳-氟键。为了利用这一潜力，必须开发选择性碳-氟官能化反应。在此，我们公开了用常见的未活化烯烃对高度氟化芳烃进行光催化还原烷基化的条件。温和的反应条件适用于广泛的官能团范围，并且仅使用0.25 mol%的催化剂，反应就非常高效。最后，我们通过光催化和亲核芳香取代化学的协同使用，将高度氟化芳烃转化为含有2至5个碳-氟键的复杂（杂）芳烃，证明了该策略的实用性。
