On the Importance of an Acid Additive in the Synthesis of Pyrido[1,2-a]benzimidazoles by Direct Copper-Catalyzed Amination

被引：130
作者：
Masters, Kye-Simeon [1 ]
Rauws, Tom R. M. [1 ]
Yadav, Ashok K. [1 ]
Herrebout, Wouter A. [1 ]
Van der Veken, Benjamin [1 ]
Maes, Bert U. W. [1 ]
机构：
[1] Univ Antwerp, B-2020 Antwerp, Belgium
来源：
CHEMISTRY-A EUROPEAN JOURNAL | 2011年 / 17卷 / 23期
关键词：
catalysis; C-H activation; C-H amination; C-H functionalization; copper; N BOND FORMATION; PROTON-ABSTRACTION MECHANISM; BETA-HYDRIDE ELIMINATION; C-H FUNCTIONALIZATION; DIRECT ARYLATION; ARYL BROMIDES; EFFICIENT; ACTIVATION; NITROGEN; DERIVATIVES;
D O I：
10.1002/chem.201100574
中图分类号：
O6 [化学];
学科分类号：
0703 ;
摘要：
Not just an acid! An expedient and highly modular synthesis of 6-, 7-, and 8-substituted pyrido[1,2-a]benzimidazoles (4) has been developed by a direct intramolecular C-H amination of N-phenylpyridin-2-amines (3). Efficient C-H amination of 3 could only be achieved in the presence of catalytic copper and an acid additive. The type of acid (pKa) proved to be crucial for the catalysis. C-Cl aminations in N-(2-chloroaryl)pyridin-2-amines allow access to 9-substituted pyrido[1,2-a]benzimidazoles. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
引用
收藏
页码：6315 / 6320
页数：6
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