Trifluoroacetic Acid Mediated One-Pot Synthesis of Furo-Fused Quinoxalines/Pyrazines
作者:Kapil Mohan Saini、Sonu Kumar、Monika Patel、Rakesh K. Saunthwal、Akhilesh K. Verma
DOI:10.1002/ejoc.201700541
日期:2017.7.7
A trifluoroacetic acid promoted step-economical one-pot approach to the synthesis of furo-fused quinoxalines/pyrazines by the reaction of 2,3-dichloroquinoxalines/pyrazines with alkynes is described. The reaction involves a selective in-situ Sonogashiracoupling step and a hydroxylation followed by a metal-free 5-endo-dig cyclization. Preliminary experiments show that trifluoroacetic acid acts as a
efficient method is developed for the synthesis of furo[2,3-b]quinoxalines using novel Cu(OTf)2 loaded protonated trititanate nanotube catalysts via A3-coupling followed by 5-endo-dig cyclization from o-phenylenediamines, ethylglyoxalate and phenylacetylenes. This method is beneficial and advantageous as it facilitates high yield in conventional heating and a short reaction time besides offering reusable
开发了一种有效的方法,使用新型Cu(OTf)2负载的质子化三钛酸酯纳米管催化剂,通过A 3偶联,然后从邻位5-内挖式环化,合成呋喃并[2,3- b ]喹喔啉-苯二胺,乙二酸乙二酯和苯乙炔。该方法是有益和有利的,因为除了提供可重复使用的非均相催化剂之外,它还有助于常规加热中的高产率和短的反应时间。可以通过离心回收这些催化剂,并且它们的活性在连续五次运行中基本上保持不变。另一方面,这些催化剂是使用简单的水热和湿浸渍方法制备的,并使用XRD,HR-TEM和N 2吸附-解吸技术进行了表征。
Synthesis and photophysical properties of selenopheno[2,3-<i>b</i>]quinoxaline and selenopheno[2,3-<i>b</i>]pyrazine heteroacenes
作者:Amol D. Sonawane、Atsushi Shimozuma、Taro Udagawa、Masayuki Ninomiya、Mamoru Koketsu
DOI:10.1039/d0ob00718h
日期:——
In this paper, we report the novel synthesis of three different heterocycles, namely 2-arylselenopheno[2,3-b]quinoxaline, 3-(aryl/alkylselanyl)-2-arylselenopheno[2,3-b]quinoxaline and 6-phenyl-7-(arylselanyl)selenopheno[2,3-b]pyrazine derivatives, from the corresponding 2,3-dichloroquinoxaline and 2,3-dichloropyrazine derivatives. Furthermore, photophysical properties were investigated to study the
在本文中,我们报告了三种不同杂环的新颖合成,即2-芳基硒代苯并[2,3- b ]喹喔啉,3-(芳基/烷基硒基)-2-芳基硒代苯并[2,3- b ]喹喔啉和6-苯基来自相应的2,3-二氯喹喔啉和2,3-二氯吡嗪衍生物的-7-(芳基杂戊基)硒代苯并[2,3- b ]吡嗪衍生物。此外,研究了光物理性质以研究杂原子对紫外线吸收和荧光性质的影响。
Copper-Catalyzed Divergent C–H Functionalization Reaction of Quinoxalin-2(1<i>H</i>)-ones and Alkynes Controlled by N1-Substituents for the Synthesis of (<i>Z</i>)-Enaminones and Furo[2,3-<i>b</i>]quinoxalines
With control by N1-substituents, the switchable divergent C–H functionalization reaction of quinoxalin-2(1H)-ones is achieved for the synthesis of (Z)-enaminones and furo[2,3-b]quinoxalines using the combination of a copper catalyst and an oxidant. This new protocol features mild reaction conditions, readily available materials, and a broad substrate scope. Gram-scale and mechanistic studies were also