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.
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.