Deprotection of N-sulfonyl nitrogen-heteroaromatics with tetrabutylammonium fluoride
摘要:
The deprotection of N-methylsulfonyl, N-(p-toluenesufonyl), and N-phenylsulfonyl nitrogen-heteroaromatic compounds proceeds easily in excellent yields by refluxing with tetrabutylammonium fluoride (TBAF) in THF. (C) 1998 Elsevier Science Ltd. All rights reserved.
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
paper describes the preparation of indoles, azaindoles and benzofurans in pure water by using a new heterogeneous Pd-Cu/C catalyst through a cascade Sonogashira alkynylation-cyclization sequence. Details of the optimization studies and the substrate scope are discussed. This procedure allows the preparation of heterocycles with good yields and is tolerant to a wide variety of functional groups.
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。
Convenient Indole Synthesis from 2-Iodoanilines and Terminal Alkynes by the Sequential Sonogashira Reaction and the Cyclization Reaction Promoted by Tetrabutylammonium Fluoride (TBAF)
The sequential Sonogashira reaction and the cyclization reaction of various 2-iodoanilines and terminal alkynes in the presence of a palladium catalyst and tetrabutylammonium fluoride (TBAF) gave the corresponding 2-substituted indoles in good yields.
Cupric Halide-Mediated Intramolecular Halocyclization of N-Electron-Withdrawing Group-Substituted 2-Alkynylanilines for the Synthesis of 3-Haloindoles
作者:Zengming Shen、Xiyan Lu
DOI:10.1002/adsc.200900609
日期:2009.12
efficient method for the synthesis of 3-haloindoles has been developed. Both 3-chloro- and 3-bromoindole derivatives can be obtained in high yields by the reaction of N-electron-withdrawinggroup-substituted2-alkynylanilines with cupric halide in dimethyl sulfoxide (DMSO) within a short period of time. Investigation of the reaction mechanism reveals that two equivalents of cupric halide are necessary