在此,通过利用氟酰胺的不同活化模式,我们实现了具有可切换区域选择性的硝基烷烃的α-和δ-C(sp 3 )–H烷基化。Cu 催化作用使得以 N 为中心的自由基拦截远端以 C 为中心的自由基,从而偶联硝基烷烃和未活化的 δ-C-H 键。此外,氟酰胺原位生成的亚胺被硝基烷烃捕获,实现酰胺的α-C-H烷基化。这两种可扩展的协议都具有广泛的底物范围和良好的官能团耐受性。
The <i>ortho</i>-substituent on 2,4-bis(trifluoromethyl)phenylboronic acid catalyzed dehydrative condensation between carboxylic acids and amines
作者:Ke Wang、Yanhui Lu、Kazuaki Ishihara
DOI:10.1039/c8cc02558d
日期:——
2,4-Bis(trifluoromethyl)phenylboronic acid is a highly effective catalyst for dehydrative amidation between carboxylic acids and amines. Mechanistic studies suggest that a 2 : 2 mixed anhydride is expected to be the only active species, and the ortho-substituent of boronic acid plays a key role in preventing the coordination of amines to the boron atom of the active species, thus accelerating the amidation