Efficient construction of indole rings from 2-ethynylaniline derivatives catalyzed by copper(II) salts and its application to the tandem cyclization reactions
The efficient cyclization reactions of the N-methanesulfonyl or N-ethoxycarbonyl derivatives of 2-ethynylanilines, functionalized on the benzene ring and/or the acetylene terminal into indoles catalyzed by either Cu(OTf)2 or Cu(OAc)2 are accomplished. The application of this reaction to the tandem cyclization reaction is also described.
Development of an Efficient Procedure for Indole Ring Synthesis from 2-Ethynylaniline Derivatives Catalyzed by Cu(II) Salts and Its Application to Natural Product Synthesis
作者:Kou Hiroya、Shin Itoh、Takao Sakamoto
DOI:10.1021/jo035528b
日期:2004.2.1
The development of efficient methods for the indole synthesis catalyzed by Cu(II) salts and its applications were investigated. Cu(OAc)2 has been proved to be the best catalyst for the synthesis of various 1-p-tolylsulfonyl or 1-methylsulfonylindoles, which have both electron-withdrawing and electron-donating groups on the aromatic ring and C2 position of indoles. For the primary aniline derivatives