A novel iron-mediated direct C–H arylation of quinones and pyridine analogues with arylboronic acids has been developed using dichloromethane and water as solvents at ambient temperature. FeS is employed and serves as an efficient catalyst. A detailed reaction mechanism is speculated and expounded.
L'ARYLATION DES QUINONES PAR LES SELS DE DIAZONIUM : II. SUR LA SYNTHÈSE DES 2,5-BISARYL-<i>p</i>-BENZOQUINONES
作者:P. Brassard、P. L'Écuyer
DOI:10.1139/v58-100
日期:1958.4.1
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Iron-catalyzed cross-coupling of arylboronic acids with unactivated <i>N</i>-heterocycles and quinones under microwave heating
作者:Keegan P. Start、Mikhailey D. Wheeler、Christopher M. Kozak
DOI:10.1139/cjc-2020-0339
日期:2021.2
heating was first optimized. Ultimately, optimization led to similar product yields, but reactions that previously required 12 — 48 h could be conducted in 25 min. The reactionscope was then examined. The scope of arylboronic acids when reacted with pyrazine was somewhat limited, as strong electron-withdrawing and electron-donating groups were not tolerated. Examination of the reaction mixtures revealed
FeSO4-promoted direct arylation of benzoquinones with ArB(OH)2 or ArBF3K
作者:Kimihiro Komeyama、Tetsuya Kashihara、Ken Takaki
DOI:10.1016/j.tetlet.2012.12.031
日期:2013.2
FeSO4 center dot 7H(2)O was proven to work as effective promoter for the direct arylation of benzoquinones with aryl boronic acids in the presence of K2S2O8. In the arylation, slow addition of iron solution was crucial to efficiently proceed with the reaction. Interestingly, the Fe-mediated arylation could be converted into a catalytic reaction by using hydroquinones, instead of benzoquinones, or addition of ascorbic acid. (C) 2012 Elsevier Ltd. All rights reserved.
Seismic attenuation tomography in frequency domain and its application to engineering
作者:Yonggui Zhao、Qin Li、Hong Guo、Hongxiao Jin、Chaofan Wang
DOI:10.1007/bf02959454
日期:2000.8
Seismic tomography is a new geophysical technique being developed to meet the needs of mining and engineering projects. Attenuation tomography, as one kind of seismic tomography technique, is a powerful prospecting tool for determining structure defaults such as fault, broken zone, and hidden voids, but it has been little discussed up to now. Its principle and applications are presented in detail. Attenuation tomography technology includes the following main points. First, on the basis of spectrum analysis to each seismic record, geometric correction is conducted, then common source parameters are introduced into common shot records in order to keep absorption effect of the geological media separate from source spectrum influence. Finally, an equation set is obtained which consists of absorption coefficients, common source parameters and energy field data observed. This technique can tie employed together with velocity tomography to provide more evidence for engineering and geological diagnosis. Its applications to exploration of mineral and engineering have led to satisfactory results.