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
研究了Cu(II)盐催化吲哚合成的有效方法的开发及其应用。已经证明,Cu(OAc)2是合成各种1-对甲苯磺酰基或1-甲基磺酰吲哚的最佳催化剂,这些1-对甲苯磺酰基或1-甲基磺酰吲哚在吲哚的芳环和C2位置均具有吸电子和供电子基团。对于初级苯胺衍生物,Cu(OCOCF 3)2表现出良好的活性,而Cu(OAc)2是仲苯胺环化的良好催化剂。该方法可用于在同一分子中具有亲电子部分的化合物的顺序环化反应。通过用KH预先处理,实现了顺序环化以提供三环系统,但第二个环化仅限于五元和六元环。最后,完成了以Cu(II)促进的吲哚合成为关键步骤的马匹的正式和全合成。