Synthesis of π-Extended Heterocycles via Rh(III)-Catalyzed Oxidative Annulation of 5-Aryl Pyrazinones with Alkynes
作者:Harin Oh、Hee Won Byun、Kyeongwon Moon、Saegun Kim、Prithwish Ghosh、Won An、Jong Hwan Kwak、Jung Su Park、Neeraj Kumar Mishra、In Su Kim
DOI:10.1021/acs.joc.1c01752
日期:2021.12.3
The Rh(III)-catalyzed C–H functionalization and subsequent oxidative annulation between 5-aryl pyrazinones and internalalkynes are reported. This protocol provides facile access to a wide range of pyrazinone-linked naphthalenes via the C(sp2)–H alkenylation and subsequent annulation. This transformation is characterized by mild conditions, simplicity, and excellent functional group compatibility.
<i>N</i>,<i>N</i>,<i>N</i>’,<i>N</i>’-Tetramethylethylenediamine-Enabled Photoredox-Catalyzed C–H Methylation of <i>N</i>-Heteroarenes
作者:Fang Liu、Zhi-Peng Ye、Yuan-Zhuo Hu、Jie Gao、Lan Zheng、Kai Chen、Hao-Yue Xiang、Xiao-Qing Chen、Hua Yang
DOI:10.1021/acs.joc.1c01325
日期:2021.9.3
Aiming at the valuable methylation process, readily available and inexpensive N,N,N′,N′-tetramethylethylenediamine (TMEDA) was first identified as a new methyl source in photoredox-catalyzed transformation in this work. By virtue of this simple methylating reagent, a facile and practical protocol for the direct C–H methylation of N-heteroarenes was developed, featuring mild reaction conditions, broad
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。
Alkylation of quinoxalin-2(1<i>H</i>)-ones using phosphonium ylides as alkylating reagents
作者:Sha Peng、Jun-Jia Liu、Luo Yang
DOI:10.1039/d1ob01858b
日期:——
through base promoted direct alkylation of quinoxalin-2(1H)-ones with phosphonium ylides as alkylating reagents under metal- and oxidant-free conditions was developed. Various 3-alkylquinoxalin-2(1H)-ones were easily obtained in good to excellent yields. Tentative mechanistic studies suggest that this reaction is likely to involve a nucleophilic addition–elimination process.
开发了一种实用且有效的方法,用于通过碱促进 quinoxalin-2(1 H )-ones 在无金属和无氧化剂条件下作为烷基化试剂直接烷基化 quinoxalin-2(1 H )-ones。各种 3-烷基喹喔啉-2(1 H )-酮很容易以良好至优异的产率获得。初步的机理研究表明,该反应可能涉及亲核加成 - 消除过程。
[4+2] Cycloaddition of 2(1<i>H</i>)-pyrazinones and 1,2,4-triazoline-3,5-diones
作者:Takehiko Nishio
DOI:10.1002/jhet.5570350326
日期:1998.5
The reaction of 2(1H)-pyrazinones 1 and 1,2,4-triazoline-3,5-diones 3 was investigated by comparing that of 1 with singlet oxygen. 2(1H)-Pyrazinones 1 reacted in Diels-Alder fashion with 1,2,4-triazoline-3,5-diones 3 to afford [4+2]-adducts 4–17 in high yields.