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.
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。
Microwave-assisted reactions of nitroheterocycles with dienes. Diels–Alder and tandem hetero Diels–Alder/[3,3] sigmatropic shift
作者:M. Victoria Gómez、Ana I. Aranda、Andrés Moreno、Fernando P. Cossío、Abel de Cózar、Ángel Díaz-Ortiz、Antonio de la Hoz、Pilar Prieto
DOI:10.1016/j.tet.2009.04.065
日期:2009.7
the pyrazolate ion, as elucidated by computational studies. Reaction of nitroindole 1 with cyclohexadiene 2 afforded exclusively the endo stereoisomer (10endo) in a tandem hetero Diels–Alder/[3,3] sigmatropicshift, as determined by computational calculations.
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
Pd-Catalyzed Intramolecular Oxidative C–H Amination: Synthesis of Carbazoles
作者:So Won Youn、Joon Hyung Bihn、Byung Seok Kim
DOI:10.1021/ol201416u
日期:2011.7.15
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.