Pd-Catalyzed Intramolecular Oxidative C–H Amination: Synthesis of Carbazoles
摘要:
A Pd-catalyzed oxidative C-H amination of N-Ts-2-arylanilines under ambient temperature using Ozone as an inexpensive, safe, and easy-to-handle oxidant has been developed. This process represents a green and practical method for the facile construction of carbazoles with a broad substrate scope and wide functional group tolerance.
Electrochemical
<scp>Palladium‐Catalyzed</scp>
Intramolecular C—H Amination of
<scp>2‐Amidobiaryls</scp>
for Synthesis of Carbazoles
作者:Qingqing Wang、Xiaojing Zhang、Pan Wang、Xinlong Gao、Heng Zhang、Aiwen Lei
DOI:10.1002/cjoc.202000407
日期:2021.1
The synthesis of carbazoles based on the electrochemical Pd‐catalyzed intramolecularC—H amination of 2‐amidobiaryls through oxidative cross coupling has been achieved under mild reaction conditions. The reaction can be carried out in undivided cell without the addition of external chemical oxidant. Besides good functional group compatibility, the desired carbazoles can be scaled up and modified easily
Transition metal-catalyzed diamination by hydroxylamines is a common approach for making three-membered aziridines, while its use for building the larger N-heterocycles is still underdeveloped. Herein, we report an efficient Pd(0)-catalyzed inter-molecular [4+1] annulation of o-bromo(or chloro)-biaryls with bifunctional secondary hydroxylamines for the one-step assembly of synthetically useful carbazoles
羟胺的过渡金属催化二化是制备三元氮丙啶的常用方法,而其用于构建较大的N-杂环的用途仍未开发。在此,我们报告了一种有效的 Pd(0) 催化的分子间 [4+1] 环化邻溴(或氯)-联芳基与双功能仲羟胺,用于一步组装合成有用的咔唑。值得注意的是,这种多米诺骨牌反应的关键是明智地选择氨基源和 Pd(0)-催化剂,以便在具有不稳定 NO 的羟胺存在下将芳基卤化物氧化加成到 Pd(0)-物种中。键。
involving sequential nucleophilic and electrophilic C–Nbondformations. Herein, we report a novel Suzuki reaction/C–Hactivation/amination sequence for building a myriad of carbazoles in a single transformation using bifunctional secondary hydroxylamines. It is noteworthy that the synthetic utility of this methodology is highlighted by the total synthesis of clausine V and glycoborine by incorporating