Department of Chemistry, Georgetown University , Box 571227-1227, Washington, D.C. 20057, United States.
J Am Chem Soc. 2014 Aug 6;136(31):10930-40. doi: 10.1021/ja5026547. Epub 2014 Jul 24.
We report a series of novel β-diketiminato copper(II) anilides [Cl2NN]Cu-NHAr that participate in C-H amination. Reaction of H2NAr (Ar = 2,4,6-Cl3C6H2 (Ar(Cl3)), 3,5-(CF3)2C6H3 (Ar(F6)), or 2-py) with the copper(II) t-butoxide complex [Cl2NN]Cu-(t)OBu yields the corresponding copper(II) anilides [Cl2NN]Cu-NHAr. X-ray diffraction of these species reveal three different bonding modes for the anilido moiety: κ(1)-N in the trigonal [Cl2NN]Cu-NHAr(Cl3) to dinuclear bridging in {[Cl2NN]Cu}2(μ-NHAr(F6))2 and κ(2)-N,N in the square planar [Cl2NN]Cu(κ(2)-NH-2-py). Magnetic data reveal a weak antiferromagnetic interaction through a π-stacking arrangement of [Cl2NN]Cu-NHAr(Cl3); solution EPR data are consistent with monomeric species. Reaction of [Cl2NN]Cu-NHAr with hydrocarbons R-H (R-H = ethylbenzene and cyclohexane) reveals inefficient stoichiometric C-H amination with these copper(II) anilides. More rapid C-H amination takes place, however, when (t)BuOO(t)Bu is used, which allows for HAA of R-H to occur from the (t)BuO(•) radical generated by reaction of [Cl2NN]Cu and (t)BuOO(t)Bu. The principal role of these copper(II) anilides [Cl2NN]Cu-NHAr is to capture the radical R(•) generated from HAA by (t)BuO(•) to give functionalized aniline R-NHAr, resulting in a novel amino variant of the Kharasch-Sosnovsky reaction.
我们报道了一系列新型β-二酮亚胺铜（II）苯胺[Cl2NN]Cu-NHAr，它们参与 C-H 氨化反应。H2NAr（Ar = 2,4,6-Cl3C6H2（Ar(Cl3)）、3,5-(CF3)2C6H3（Ar(F6)）或 2-吡）与铜（II）叔丁氧化物配合物[Cl2NN]Cu-(t)OBu 反应生成相应的铜（II）苯胺[Cl2NN]Cu-NHAr。这些物种的 X 射线衍射揭示了苯胺部分的三种不同键合模式：κ(1)-N 在三角[Cl2NN]Cu-NHAr(Cl3)中到双核桥联{[Cl2NN]Cu}2(μ-NHAr(F6))2 和 κ(2)-N，N 在平面四方[Cl2NN]Cu(κ(2)-NH-2-py)中。磁数据显示通过[Cl2NN]Cu-NHAr(Cl3)的π-堆积排列存在弱反铁磁相互作用；溶液 EPR 数据与单体物种一致。[Cl2NN]Cu-NHAr 与烃 R-H（R-H = 乙苯和环己烷）反应显示这些铜（II）苯胺的 C-H 氨化效率低。然而，当使用(t)BuOO(t)Bu 时，C-H 氨化更快，这允许由[Cl2NN]Cu 和(t)BuOO(t)Bu 反应生成的(t)BuO(•)自由基引发 R-H 的 HAA。这些铜（II）苯胺[Cl2NN]Cu-NHAr 的主要作用是捕获由(t)BuO(•)产生的自由基 R(•)，从而生成功能化苯胺 R-NHAr，这是 Kharasch-Sosnovsky 反应的新型氨基变体。
