A conceptually new and straightforward introduction of sulfonyl groups at the C-7 position of an indole ring has been achieved via AlCl3 mediated unexpected regioselective sulfonyl group migration for N-alkyl/aryl/heteroarylsulfonyl indoles affording potential inhibitors of Mycobacterium tuberculosis H37Rv chorismate mutase.
terminal alkynes under mild conditions, namely in the presence of cuprous iodide (10 mol%) and a base in ethanol or 1,4‐dioxane. Further investigation reveals that palladium contaminants as low as 100 ppb are responsible for these successful couplings. It is worth noting that simple aliphatic substituted terminal alkynes could be tolerated to smoothly produce indole and benzo[b]furan derivatives.
在温和的条件下,即在碘化亚铜(10摩尔%)和乙醇碱存在下,通过2-碘苯胺衍生物和2-碘酚与末端炔烃的反应,可以高产率获得吲哚和苯并[ b ]呋喃。或1,4-二恶烷。进一步的研究表明,低至100 ppb的钯污染物是这些成功偶联的原因。值得注意的是,可以容忍简单的脂族取代的末端炔烃,以平稳地生产吲哚和苯并[ b ]呋喃衍生物。
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.
Mild and efficient cyclization reaction of 2-ethynylaniline derivatives to indoles in aqueous medium
作者:Kou Hiroya、Shin Itoh、Takao Sakamoto
DOI:10.1016/j.tet.2005.08.098
日期:2005.11
Results of the optimized cyclization reaction of 2-ethynyl aniline derivatives to indoles catalyzed by copper(II) salts are described. The reactions can be carried out in a mixture of H2O and MeOH in the presence of 1-ethylpiperidine at room temperature. These conditions can be applied to a bulky substrate, which is difficult to be cyclized efficiently by existing reaction conditions. Furthermore, this reaction condition was applied to a catalyst recycling reaction system. (c) 2005 Elsevier Ltd. All rights reserved.