Peroxide-mediated site-specific C–H methylation of imidazo[1,2-<i>a</i>]pyridines and quinoxalin-2(1<i>H</i>)-ones under metal-free conditions
作者:Shengzhou Jin、Hua Yao、Sen Lin、Xiaoqing You、Yao Yang、Zhaohua Yan
DOI:10.1039/c9ob02328c
日期:——
An effective approach to realize the direct methylation of imidazo[1,2-a]pyridines and quinoxalin-2(1H)-ones with peroxides under metal-free conditions is described.
Herein, a novel method for the gram-scale synthesis of (E)-quinoxalinone oximes through a multicomponent reaction undermildconditions is described. Such a transformation was performed under transition-metal-free conditions, affording (E)-oximes in a moderate-to-good yield through recrystallization. Our methodology demonstrates a successful combination of a Mannich-type reaction and radical coupling
<i>O</i>-Perhalopyridin-4-yl Hydroxylamines: Amidyl-Radical Generation Scaffolds in Photoinduced Direct Amination of Heterocycles
作者:Lan Zheng、Yu-En Qian、Yuan-Zhuo Hu、Jun-An Xiao、Zhi-Peng Ye、Kai Chen、Hao-Yue Xiang、Xiao-Qing Chen、Hua Yang
DOI:10.1021/acs.orglett.1c00064
日期:2021.3.5
O-perhalopyridin-4-yl hydroxylamines as shelf-stable and versatile amidyl-radical precursors. The novel amination reagents can be easily prepared via a single synthetic step from inexpensive commercially available starting materials using monoprotected HONH2 as amino source. The synthetic potency of the developed reagents was well demonstrated by direct amination of a series of quinoxalin-2(1H)-ones and their
α-Functionalization of ketones promoted by sunlight and heterogeneous catalysis in the aqueous phase
作者:Lei He、Chenfeng Liang、Yani Ouyang、Lin Li、Yirui Guo、Pengfei Zhang、Wanmei Li
DOI:10.1039/d1ob02249k
日期:——
Herein, a protocol that combines heterogeneous catalysis and solar photocatalysis for the regioselective α-substitution of asymmetricketones with quinoxalinones has been reported. The result indicates that the reaction is more likely to occur on the α-carbon. This strategy provides a green and efficient way for the α-functionalization of ketones. A singlet oxygen involved mechanism is suggested for
A practical and efficient route for copper-catalyzed C-3 amination of quinoxalin-2(1H)-ones with easily available azoles as nitrogen sources and Selectfluor as mild oxidant has been developed. The transformation features atomic economy, simple operation, broad substrate scope, and moderate to excellent yields.
已经开发了一种实用且有效的铜催化 C-3 胺化喹喔啉-2(1 H )-酮的路线,以容易获得的唑类作为氮源,Selectfluor 作为温和的氧化剂。该转化具有原子经济、操作简单、底物范围广、收率中等至优等特点。