Synthesis of Diaryl Ethers, Diaryl Thioethers, and Diarylamines Mediated by Potassium Fluoride−Alumina and 18-Crown-6: Expansion of Scope and Utility1
摘要:
An efficient alternative to the Ullmann ether synthesis of diaryl ethers, diaryl thioethers, and diarylamines involving the SNAr addition of a phenol, thiophenol, or aniline to an appropriate aryl halide, mediated by potassium-fluoride alumina and 18-crown-6 in acetonitrile or DMSO, is described. Expansion of the reaction conditions to include DMSO as solvent has resulted in a far greater range of substitution patterns permitted on the electrophile. For example, it was found that electronically unfavorable S-chlorobenzonitrile could be condensed with 3-methoxyphenol to form the corresponding diaryl ether in 66% yield, a combination not normally amenable to Ullmann coupling. Electron-withdrawing groups present on the electrophile may be as diverse as nitro, cyano, formyl, acetyl, ester, amide, and even aryl. The method features a simple reaction procedure that provides products in generally good to excellent purified yields.
Room‐Temperature Arylation of Thiols: Breakthrough with Aryl Chlorides
作者:Min Jiang、Haifang Li、Haijun Yang、Hua Fu
DOI:10.1002/anie.201610414
日期:2017.1.16
catalyst loadings, specially designed ligands, high temperatures, and/or strong bases, thus leading to high costs and the incompatibility of some functional groups. Herein, we describe a simple and efficient visible‐light photoredox arylation of thiols with aryl halides at roomtemperature. More importantly, various aryl chlorides are also effective arylation reagents under the present conditions.
Mechanistic Study of a Photocatalyzed CS Bond Formation Involving Alkyl/Aryl Thiosulfate
作者:Yiming Li、Weisi Xie、Xuefeng Jiang
DOI:10.1002/chem.201502951
日期:2015.11.2
This study presents thioether construction involving alkyl/aryl thiosulfates and diazonium salt catalyzed by visible‐light‐excited [Ru(bpy)3Cl2] at room temperature in 44–86 % yield. Electron paramagnetic resonance studies found that thiosulfate radical formation was promoted by K2CO3. Conversely, radicals generated from BnSH or BnSSBn (Bn=benzyl) were clearly suppressed, demonstrating the special
这项研究提出了在室温下可见光激发[Ru(bpy)3 Cl 2 ]催化的含烷基/芳基硫代硫酸盐和重氮盐的硫醚结构,产率为44-86%。电子顺磁共振研究发现,K 2 CO 3促进了硫代硫酸根的形成。相反,从BnSH或BnSSBn(Bn =苄基)生成的自由基被明显抑制,证明了该系统中硫代硫酸盐的特殊性质。瞬态吸收光谱证实了[Ru(bpy)3 Cl 2 ]与4-MeO-苯基重氮盐之间的电子转移过程,其速率常数为1.69×10 9 M -1 s -1。通过X射线衍射确认了相应的自由基捕获产物。确定了完整的反应机理以及发射猝灭数据。此外,该系统有效地避免了在含有Ru 2+的光激发体系中H 2 O引起的硫化物过氧化。研究了具有各种电子性质的芳基和杂芳基重氮盐的合成兼容性。烷基和芳基取代的硫代硫酸盐都可用作底物。值得注意的是,药物衍生物在温和的条件下能够平稳地进行后期硫化。
A template free protocol for fabrication of a Ni(<scp>ii</scp>)-loaded magnetically separable nanoreactor scaffold for confined synthesis of unsymmetrical diaryl sulfides in water
An environmentally benign nickel(ii)-based magnetic nanoreactor has been developed for oxidative coupling of arenethiols with arylhydrazines to form unsymmetrical diaryl sulfides in water at room temperature.
COMPOSITION FOR AGRICULTURAL USE FOR CONTROLLING OR PREVENTING PLANT DISEASES CAUSED BY PLANT PATHOGENS
申请人:Matsuzaki Yuichi
公开号:US20110009454A1
公开(公告)日:2011-01-13
Disclosed is a composition for agricultural use, which is used for controlling or preventing plant diseases caused by plant pathogens. The composition for agricultural use contains a compound represented by formula (1), a salt thereof or a hydrate of the compound or the salt. (1) [In the formula, Z represents an oxygen atom, a sulfur atom or NR
Z
; and E represents a furyl group, a thienyl group, a pyrrolyl group, a tetrazolyl group, a thiazolyl group, a pyrazolyl group, a phenyl group or the like.]