开发了一种可持续且环境友好的方法,用于在水中对 1-甲基-3-苯基喹喔啉-2(1 H )-酮进行区域选择性酰化。本协议需要醋酸钯作为催化剂,并通过使用市售的无毒醛、苯甲醇和甲苯作为酰基替代物来展示广泛的底物范围。机理研究表明采用自由基途径进行这种转化。此外,已建立的协议表现出出色的区域选择性和高官能团耐受性,并且适用于克级。所建立的合成方法也为一些潜在候选药物的后期功能化提供了实用便捷的途径。
描述了使用二芳基碘鎓三氟甲磺酸盐作为方便、稳定和廉价的芳基来源的 quinoxalin-2-(1 H )-ones 的光氧化还原催化直接芳基化。多种 quinoxalin-2-(1 H )-ones 可与结构和电子不同的二芳基碘鎓三氟甲磺酸盐反应,从而可以有效地获得多种药学上重要的 3-arylquinoxalin-2-(1 H )-ones。所提出的方法在操作简单、条件温和、范围广、可扩展性和高官能团耐受性方面具有吸引力。
Rh(<scp>iii</scp>)-catalyzed spiroannulation of 3-arylquinoxalin-2(1<i>H</i>)-ones with alkynes: practical access to spiroquinoxalinones
作者:Yuanfei Zhang、Ting Huang、Xinghua Li、Min Zhang、Ying Song、Kelin Huang、Weiping Su
DOI:10.1039/d0ra03348k
日期:——
The use of imines as a H acceptor for Rh(iii)-catalyzed spirocyclization of 3-arylquinoxalinones and alkynes via a C–H functionalization/[3 + 2] annulation sequence has been achieved.
Electrochemical Cross‐Coupling of C(
<i>sp</i>
<sup>2</sup>
)−H with Aryldiazonium Salts via a Paired Electrolysis: an Alternative to Visible Light Photoredox‐Based Approach
作者:Yang‐ye Jiang、Gui‐yuan Dou、Luo‐sha Zhang、Kun Xu、R. Daniel Little、Cheng‐chu Zeng
DOI:10.1002/adsc.201901011
日期:2019.11.19
Photoredox‐based C−H bond functionalization constitutes one of the most powerful and atom‐economical approaches to organic syntheses. During this type of reaction, single electron transfer takes place between the photocatalyst (PC) and redox‐ active substrates. Electrosynthesis also involves electron transfer between substrates and electrodes. In this paper, we focus upon electrochemical cross‐coupling of C(sp2)−H
Two facile and effective C-3 arylation protocols of quinoxalin-2(1H)-ones with arylhydrazines and aryl boronic acids respectively via free radical cross-coupling reactions under metal-, photocatalyst- and light-free conditions have been unveiled. K2S2O8 has been used as an efficient oxidant to generate aryl radicals from arylhydrazines and aryl boronic acids under two different reaction conditions
已经揭示了喹喔啉-2( 1H )-酮分别与芳基肼和芳基硼酸通过自由基交叉偶联反应在金属、光催化剂和无光条件下进行的两种简便有效的C-3芳基化方案。 K 2 S 2 O 8已被用作有效的氧化剂,在两种不同的反应条件下由芳基肼和芳基硼酸生成芳基自由基。生成的芳基自由基在喹喔啉-2(1 H )-酮的C-3位发生自由基偶联反应,以良好至优异的产率产生3-芳基喹喔啉-2(1 H )-酮。 2,2,6,6-四甲基哌啶-1-氧基自由基捕获实验已证明自由基参与反应过程。
Transition-Metal-Free Direct C–H Arylation of Quinoxalin-2(1<i>H</i>)-ones with Diaryliodonium Salts at Room Temperature
作者:Kun Yin、Ronghua Zhang
DOI:10.1021/acs.orglett.7b00310
日期:2017.4.7
A method of synthesizing 3-arylquinoxalin-2(1H)-ones using diaryliodonium tetrafluoroborates under mild conditions is described. This protocol has a wide substrate scope and enables direct C–H functionalization. The synthetic potential of this coupling was explored using a range of readily accessible diaryliodonium salts and quinoxalin-2(1H)-ones.
Aryl acyl peroxides for visible-light induced decarboxylative arylation of quinoxalin-2(1<i>H</i>)-ones under additive-, metal catalyst-, and external photosensitizer-free and ambient conditions
作者:Long-Yong Xie、Sha Peng、Li-Hua Yang、Cun Peng、Ying-Wu Lin、Xianyong Yu、Zhong Cao、Yu-Yu Peng、Wei-Min He
DOI:10.1039/d0gc02844d
日期:——
Aryl radicals were generated for the first time from cheap and easily available aryl acyl peroxides in eco-friendly ethyl acetate underambientconditions and visible-light illumination in the absence of any additive, metal catalyst, or external photosensitizer. The present arylation of quinoxalin-2(1H)-ones was chemo- and regioselective, and provided good access to various 3-arylquinoxalin-2(1H)-ones