Base-assisted, copper-catalyzed N-arylation of (benz)imidazoles and amines with diarylborinic acids
作者:Changwei Guan、Yuanyuan Feng、Gang Zou、Jie Tang
DOI:10.1016/j.tet.2017.10.043
日期:2017.12
cost-effective aryl source has been efficiently effected via Cu(OAc)2-catalyzed Chan-Lam coupling in assistance of tetramethylethylenediamine (TMEDA) in methanol and pyridine (Py) in dichloromethane, respectively, in air at room temperature. The diarylborinic acids could be well accommodated by the Chan-Lam coupling oxidative conditions containing a proper combination of bases and solvents. The steric
Electrochemical Reductive Arylation of Nitroarenes with Arylboronic Acids
作者:Dan Wang、Zhaohua Wan、Heng Zhang、Hesham Alhumade、Hong Yi、Aiwen Lei
DOI:10.1002/cssc.202101924
日期:2021.12.17
Reductive arylation: The synthesis of diarylamine is extremely important in organic chemistry. Herein, a novel electrochemical reductive arylation of arylboronicacids with nitroarenes is developed. A variety of diarylamines is synthesized without the need for transition-metal catalysts. The reaction can be scaled up efficiently in a flow cell and several derivatization reactions are carried out smoothly
An efficient palladium-catalyzed amination, including polyaminations of aromatic bromides mediated on a surface of KF-alumina, is reported. The solvent-free one-pot protocol avoids the use of a strong base (sodium tert-butoxide) making it applicable to substrates containing a base-sensitive functional group. It proceeds without concomitant reductive bromination and provides access to selective amination of polyhaloaromatics.
Copper immobilized at a covalent organic framework: an efficient and recyclable heterogeneous catalyst for the Chan–Lam coupling reaction of aryl boronic acids and amines
作者:Yi Han、Mo Zhang、Ya-Qing Zhang、Zhan-Hui Zhang
DOI:10.1039/c8gc02611d
日期:——
inexpensive reagents and was employed as an effective support for heterogeneous copper. It was demonstrated that the obtained Cu@PI-COF is a highly active heterogeneous catalyst which can effectively promote the Chan–Lamcouplingreaction of aryl boronic acids and amines in an open flask without the aid of any base or additive. In addition, the catalyst could be readily recovered from the reaction mixture
‐1,1’‐biaryls. Various 9‐(arylamino)aryl‐9H‐carbazoles could be synthesized from aryl(haloaryl)amines and 9H‐carbazole derivatives in high yields by the use of tBu‐XPhos. The amination of 4‐bromotoluene with a mixture of diphenylamine and 9H‐carbazole gave only 9‐o‐tolyl‐9H‐carbazole with tBu‐XPhos, while the use of PtBu3 or XPhos afforded the mixture of 9‐o‐tolyl‐9H‐carbazole and diphenyl(o‐tolyl)amine
研究了钯与9 H-咔唑衍生物的芳基(卤代芳基)胺的胺化反应。在使用Pd 2(dba)3 / P t Bu 3 / NaO t Bu催化剂与9 H-咔唑胺化(4-溴苯基)苯胺中,主要产物为9- [4-(苯基氨基)苯基] -9 H-咔唑,收率60%,其中(4-溴苯基)苯胺转化率> 99%,并伴随形成9- [4- [苯基[4- [苯基[4-(苯基氨基)苯基]氨基]苯基] -9 H观察到连续产生的副产物咔唑(产率为15%)。使用XPhos代替P t Bu 3时,以81%的收率提供所需的产品,并将连续的副产品抑制到7.7%。通过使用t Bu‐XPhos ,所需产品的收率达到98%。用其他2-二叔丁基或2-二(1-金刚烷基)膦基-1,1'-联芳基也获得了如此优异的所需产品收率。可以通过使用t Bu-XPhos从芳基(卤代芳基)胺和9 H-咔唑衍生物高产率合成各种9-(芳基氨基)芳基-9 H-咔唑。用二苯胺和9