末端炔烃的催化环异构化引发的级联环化引起了人们的极大兴趣,并已广泛用于各种有价值的复杂杂环的简便合成中。然而,这些串联反应已经主要限于贵金属催化,并且由被启动外-cyclization通路。本文报道的是一种前所未有的铜-催化内切-cyclization发起的吲哚基高炔丙基酰胺,其中铜催化两个氢胺化和的Friedel-Crafts烷基化过程的串联反应。这种方法可以实现实用的,原子经济的有价值的桥连氮杂[ n .2.1]骨架(n= 3-6),具有广泛的底物范围,并且通过手性转移策略具有出色的非对映选择性和对映选择性。此外,这种新颖的级联环化的机理原理也得到了控制实验的有力支持,并且与相关的金催化作用明显不同。
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。
Palladium‐Catalyzed Synthesis of Carbazoles by Perester
作者:Li He、Yongjun Xu
DOI:10.1002/adsc.202200419
日期:2022.7.19
An intramolecular C−H amination for the synthesis of carbazoles with a Pd(II)/TBPB system has been developed. This catalytic amination process forms the carbazole products in good to excellent yields. It is noteworthy that this method implied the advantages of the catalytic mode involving perester with transition metal catalyst in the activation of inert C−H bonds. In addition, the transformation performs
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
Efficient Carbazole Synthesis via Pd/Cu-Cocatalyzed Cross-Coupling/Isomerization of 2-Allyl-3-iodoindoles and Terminal Alkynes
作者:Can Zhu、Shengming Ma
DOI:10.1021/ol500119r
日期:2014.3.21
The Pd/Cu-cocatalyzed one-pot reaction of 2-allyl-3-iodo-1-tosyl-1H-indoles and terminal alkynes afforded carbazoles highly efficiently via sequential carbon carbon coupling, isomerization, cyclization, and aromatization forming a benzene ring. Both Pd and Cu are responsible for the coupling step, while K2CO3 was observed to be critical for the subsequent cyclization.