Wu Xuesong, Zhao Yan, Ge Haibo
Department of Chemistry and Chemical Biology , Indiana University-Purdue University Indianapolis , Indianapolis , Indiana 46202 , USA . Email:
Chem Sci. 2015 Oct 1;6(10):5978-5983. doi: 10.1039/c5sc02143j. Epub 2015 Jul 20.
The pyridine-enabled cross dehydrogenative coupling of sp C-H bonds of polyfluoroarenes and unactivated sp C-H bonds of amides was achieved a copper-promoted process with good functional group compatibility. This reaction showed great site-selectivity by favoring the sp C-H bonds to two fluoro atoms of arenes and the sp C-H bonds of α-methyl groups over those of the α-methylene, β- or γ-methyl groups of the aliphatic amides. Mechanistic studies revealed that sp C-H bond cleavage is an irreversible but not the rate-determining step, and the sp C-H functionalization of arenes appears precedent to the sp C-H functionalization of amides in this process.
通过铜促进的过程实现了多氟芳烃的sp C-H键与酰胺未活化的sp C-H键的吡啶介导的交叉脱氢偶联，该过程具有良好的官能团兼容性。该反应通过优先选择芳烃两个氟原子邻位的sp C-H键以及脂肪族酰胺α-甲基的sp C-H键而非α-亚甲基、β-或γ-甲基的sp C-H键，表现出了很高的位点选择性。机理研究表明，sp C-H键的断裂是不可逆的，但不是速率决定步骤，并且在此过程中芳烃的sp C-H官能化先于酰胺的sp C-H官能化。
