针对有价值的甲基化过程,在这项工作中首次将易于获得且价格低廉的N , N , N' , N' -四甲基乙二胺(TMEDA) 确定为一种新的甲基化来源。凭借这种简单的甲基化试剂,开发了一种简便实用的N-杂芳烃直接 C-H 甲基化方案,具有反应条件温和、底物范围广和可扩展性等特点。机理研究表明,基本上涉及顺序光氧化还原、碱基辅助质子转移、碎裂和互变异构化过程。
Visible Light-Promoted Radical Relay Cyclization/C–C Bond Formation of <i>N</i>-Allylbromodifluoroacetamides with Quinoxalin-2(1<i>H</i>)-ones
作者:Zhi-Peng Ye、Fang Liu、Xin-Yu Duan、Jie Gao、Jian-Ping Guan、Jun-An Xiao、Hao-Yue Xiang、Kai Chen、Hua Yang
DOI:10.1021/acs.joc.1c02285
日期:2021.12.3
A visible light-promoted radical relay of N-allylbromodifluoroacetamide with quinoxalin-2(1H)-ones was developed in which 5-exo-trig cyclization and C–C bond formation were involved. This protocol was performed under mild conditions to facilely offer a variety of hybrid molecules bearing both quinoxalin-2(1H)-one and 3,3-difluoro-γ-lactam motifs. These prepared novel skeletons would expand the accessible
<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
A green synthesis strategy of 2-arylquinoxalines and 3-arylquinoxalin-2(1H)-ones via ball milling, which could avoid copious solvent waste, was accomplished in this work. Aryl radicals were produced from aryldiazoniumsalts by using a solvent-free or catalyst-free single electron transfer process induced by mechanical force, affording a series of 2-arylquinoxalines and 3-arylquinoxalin-2(1H)-ones with
本工作通过球磨实现了一种避免大量溶剂浪费的2-芳基喹喔啉和3-芳基喹喔啉-2(1 H )-酮的绿色合成策略。通过使用由机械力诱导的无溶剂或无催化剂的单电子转移过程从芳基重氮盐产生芳基自由基,得到一系列 2-arylquinoxaline 和 3-arylquinoxalin-2(1 H )-ones,其含量为 28%–85屈服。
Unusual C<sub>3</sub>-acetylation of quinoxalin-2(1<i>H</i>)-one <i>via</i> oxidative C–C and C–O bond cleavages of PEG-400
作者:Vishal Suresh Kudale、Mohana Reddy Mutra、Ching-Piao Chu、Jeh-Jeng Wang
DOI:10.1039/d1ob00769f
日期:——
Aerobic oxidative tandem conversion of PEG-400 to acetyl radical via C–C and C–O bond cleavages followed by silver-catalyzed menisci-type addition to the C3 position of quinoxalin-2(1H)-one is described. This reaction involves the in situ formation of the acetyl radical from PEG-400 via a sequence of acetaldehyde, 2-oxopropanal and, 2-oxopropanoic acid formation and successive oxidative cleavage to
Palladium-catalyzed oxidative amidation of quinoxalin-2(1<i>H</i>)-ones with acetonitrile: a highly efficient strategy toward 3-amidated quinoxalin-2(1<i>H</i>)-ones
palladium-catalyzed direct oxidative amidation of quinoxalin-2(1H)-ones with acetonitrile was developed to synthesize 3-amidated quinoxalin-2(1H)-ones. A series of 3-acetamino quinoxalin-2(1H)-one derivatives were constructed with good to excellent yields. This methodology provided a practical approach to various 3-acetamino quinoxalin-2(1H)-ones from the readily available starting material acetonitrile