Ag<sup>+</sup>-Mediated Synthesis of Substituted Furo[2,3-<i>b</i>]pyrazines
作者:Erik Van der Eycken、Denis Ermolat’ev、Vaibhav Mehta
DOI:10.1055/s-2007-992358
日期:——
A highly efficient method for the preparation of trisubstituted furo[2,3-b]pyrazines has been developed. Sonogashira coupling reaction with the readily available 1-(4-methoxybenzyl)-3,5-dichloropyrazin-2(1H)-ones was followed by silver-catalyzed heteroannulation to provide the corresponding 2-chlorofuro[2,3-b]pyrazines in excellent yields. The latter were subjected to Suzuki or Buchwald-Hartwig coupling reaction for further decoration.
The First Palladium-Catalyzed Desulfitative Sonogashira-Type Cross-Coupling of (Hetero)aryl Thioethers with Terminal Alkynes
作者:Vaibhav Pravinchandra Mehta、Anuj Sharma、Erik Van der Eycken
DOI:10.1021/ol800054b
日期:2008.3.1
An unprecedented desulfitative Sonogashira-type cross-coupling protocol is exemplified by the synthesis of substituted 5-chloro-3-alkynylpyrazinones from the corresponding 5-chloro-3-(phenylsulfanyl) pyrazin-2(1H)-ones. The applicability of the method is extended to solid-phase linked pyrazin-2(1H)-ones as well as to some oxazinones, pyrazines, and phenyl thioesters.
Diversity-Oriented Synthesis of Substituted Furo[2,3-b]pyrazines
作者:Vaibhav P. Mehta、Sachin G. Modha、Denis Ermolat'ev、Kristof Van Hecke、Luc Van Meervelt、Erik V. Van der Eycken
DOI:10.1071/ch08376
日期:——
the synthesis of diversely substituted furo[2,3-b]pyrazines has been elaborated. The Ag+- or iodine-mediated electrophilic cyclization of readily generated 5-chloro-3-substituted ethynyl-1-(4-methoxybenzyl)-pyrazin-2(1H)-ones affords substituted furo[2,3-b]pyrazines, which undergo various palladium catalyzed reactions to generate a library of difficult to attain diversely substituted furo[2,3-b]pyrazines
精心设计了一种高效的合成不同取代的呋喃并[2,3- b ]吡嗪的方法。易产生的5-氯-3-取代的乙炔基-1-(4-甲氧基苄基)-吡嗪-2(1 H)-酮的Ag +或碘介导的亲电环化反应提供了取代的呋喃[2,3- b ]吡嗪,它们经历各种钯催化的反应以生成难以获得不同取代的呋喃并[2,3- b ]吡嗪的文库。