An efficient and general palladium-catalyzedcoupling of 3-chloro-quinoxalinones with a variety of nitrogen-containingnucleophiles such as (hetero)aromatic and aliphatic amides as well as some challenging weakly nucleophilic nitrogen compounds including lactams, carbamates and NH-containing azoles is described. In all cases, the reactions take place rapidly and cleanly in dioxane using Pd(OAc)2 as
3-氯喹喔啉酮与各种含氮亲核试剂(如(杂)芳族和脂族酰胺)以及一些具有挑战性的弱亲核氮化合物(包括内酰胺,氨基甲酸酯和含NH的吡咯)的有效且通用的钯催化偶联是描述。在所有情况下,反应都会在二恶烷使用Pd(OAc)2作为催化剂,使用Xantphos作为配体,使用K 2 CO 3作为碱,可以很好地实现3- N-取代的喹喔啉酮类产品的偶联。
Visible‐Light Photoredox Catalyzed C−N Coupling of Quinoxaline‐2(1
<i>H</i>
)‐ones with Azoles without External Photosensitizer
作者:Mingli Sun、Lei Wang、Lulu Zhao、Zhiming Wang、Pinhua Li
DOI:10.1002/cctc.202000459
日期:2020.10.20
A visible‐lightphotoredoxcatalyzedC−Ncoupling of quinoxaline‐2(1H)‐ones with azoles in the absence of externalphotosensitizer has been developed. The protocol employs commercially available pyrazoles and triazoles as amination reagents and shows wide substrate scope, providing the corresponding C3‐position amination products in good yields and high regioselectivity under ambient conditions. Investigations
在没有外部光敏剂的情况下,已经开发了可见光的光氧化还原催化喹喔啉-2(1 H)-one与唑类的C-N偶联。该方案使用了市售的吡唑和三唑作为胺化试剂,并显示了较宽的底物范围,可在环境条件下以高收率和高区域选择性提供相应的C3位胺化产物。研究表明,原料和产物可以用作光敏剂,避免以自催化方式使用其他光催化剂。另外,1 O 2与分子氧中的O 2 .-共存(3 O 2)通过反应过程中的能量转移(ET)和单电子转移(SET)过程。
Copper-catalyzed C3-amination of quinoxalin-2(1H)-ones: Using Selectfluor as a mild oxidant
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。