A metal‐free, one‐potsynthesis of 1,2‐naphthoquinone was accomplished from 2‐naphthol by utilizing economically cheap NBS under open air conditions. Initial formation of 1,1‐dibromonaphthalen‐2‐one and subsequent transformation afforded the 1,2‐naphthoquinone. This oxidation was completed within 30 min and had broad substrate scope. Moreover, this system tolerated heterocyclic systems and was also
catalyzed controlled oxidation of terminal CC alkynes to α-keto esters and quinoxalines via formation of phenylglyoxals as stable intermediates, under mild conditions by using molecular O2 as a sustainable oxidant. The current copper catalysed photoredox method is simple, highly functional group compatible with a broad range of electron rich and electron poor aromatic alkynes as well as aliphatic alcohols
在此,我们报道了一种在温和条件下使用分子 O 2通过形成苯基乙二醛作为稳定的中间体,在可见光诱导的铜催化下,末端 C C 炔烃可控氧化为 α-酮酯和喹喔啉的方法。作为一种可持续的氧化剂。目前的铜催化光氧化还原方法简单、官能团高,与广泛的富电子和贫电子芳烃以及脂肪醇(1°、2°和3°醇)相容,为制备α-酮酯(43 个例子)、喹喔啉和萘醌的产率高于文献报道的热工艺。此外,该产品的合成效用已在两种生物活性分子的合成中得到证明,即大肠杆菌DHPS 抑制剂和 CFTR 活化剂,使用当前的光氧化还原过程。此外,我们将该方法应用于杂环化合物(喹喔啉,一种 FLT3 抑制剂)的一锅合成,方法是用邻苯二胺。也可以分离中间体苯乙二醛并进一步与内部炔烃反应以形成萘醌。这个过程可以很容易地放大到克级。
Copper-catalyzed divergent oxidative pathways of 2-naphthol derivatives: ortho-naphthoquinones versus 2-BINOLs
作者:H. Y. Kim、S. Takizawa、K. Oh
DOI:10.1039/c6ob01183g
日期:——
aerobic oxidation of 2-naphthol derivatives to ortho-naphthoquinones whereas switching the catalyst system to Cu(OAc)2–DBN under an argon atmosphere allows the oxidative coupling of 2-naphthols to 1,1′-bi-2-naphthols (BINOLs) in good to excellent yields.
A One-Pot Method to Prepare 4,5-Benzotropones and 2,3,4,5-Dibenzotropones
作者:Zili Chen、Fang-Qin Li、Xiao-Yu Liu
DOI:10.1055/a-2011-6969
日期:2023.4
An extremely simple method is developed to prepare 4,5-benzotropones and 2,3,4,5-dibenzotropones via one-pot cycloaddition reactions of alkynes with naphthoquinones and dibenzoquinones mediated by BF3·Et2O. Various mono- and disubstituted phenylacetylenes, multisubstituted 1,2-naphthoquinones and dibenzoquinone substrates are investigated. In addition, a scale-up synthesis of 7-phenyl-5H-dibenzo[a