19F nuclear magnetic resonance studies of aromatic compounds. Part III. The transmission of substituent effects across bridged ring systems
作者:I. R. Ager、L. Phillips、S. J. Roberts
DOI:10.1039/p29720001988
日期:——
bridged dinuclear aromatic compounds of the type p-F·C6H4·Z·C6H4·X-p[Z = all-trans-·CHCH–CHCH·, CCH2, CH2, CH(OH), CMe(OH), –O–, or –S–; X = NH2, OMe, H, F, Cl, or NO2] is described. The 19F n.m.r. spectra of these compounds are used to examine the ‘transmission’ of electronic effects, due to the group X, across the bridge Z. A distinction is drawn between ‘transmission effects’ in which electron density
几个系列的类型的双核桥接的芳族化合物的合成中p -F·C 6 H ^ 4 ·Z·C 6 H ^ 4 ·X- p [Z =清一色反式- ·CH CH-CH CH·,C CH 2,CH 2,CH(OH),CMe(OH),– O–或–S–;描述了X = NH 2,OMe,H,F,Cl或NO 2 ]。在19这些化合物的F nmr光谱用于检查由于基团X跨桥Z引起的电子效应的“透射”。在“透射效应”之间进行了区分,其中电子密度可以认为是从一个相互影响和“继电器效应”,其中可能没有电子密度的净转移。
Electro-oxidative C(sp<sup>2</sup>)–H/O–H cross-dehydrogenative coupling of phenols and tertiary anilines for diaryl ether formation
作者:Hongyang Tang、Simon Smolders、Yun Li、Dirk De Vos、Jannick Vercammen
DOI:10.1039/d1cy00186h
日期:——
substrates at elevated temperatures. Herein, we report a protocol for electrochemical C(sp2)–H/O–H cross-dehydrogenativecoupling of phenols and tertiary anilines to synthesize diaryl ethers. The C(sp2) H/O–H coupling product can be obtained under metal- and oxidant-free conditions at roomtemperature in moderate to excellent yield (up to 83% yield) with high regioselectivity (>99% for para-substitution)
Ullmann Diaryl Ether Synthesis: Rate Acceleration by 2,2,6,6-Tetramethylheptane-3,5-dione
作者:Elizabeth Buck、Zhiguo Jake Song、David Tschaen、Peter G. Dormer、R. P. Volante、Paul J. Reider
DOI:10.1021/ol025839t
日期:2002.5.1
[reaction: see text]. In the copper salt catalyzed ether formation from aryl bromides or iodides and phenols, 2,2,6,6-tetramethylheptane-3,5-dione (TMHD) was found to greatly accelerate the ordinarily difficult reaction, making it occur under more moderate temperatures and reaction times. A series of aryl halides and phenols were shown to form ethers in NMP as the solvent, cesium carbonate as the base