2-Aminopyrimidine-4,6-diol as an Efficient Ligand for Solvent-Free Copper-Catalyzed N-Arylations of Imidazoles with Aryl and Heteroaryl Halides
作者:Ye-Xiang Xie、Shao-Feng Pi、Jian Wang、Du-Lin Yin、Jin-Heng Li
DOI:10.1021/jo061572q
日期:2006.10.1
Efficient and solvent-free copper-catalyzed N-arylations of imidazoles with aryl and heteroaryl halides have been demonstrated. In the presence of CuBr, 2-aminopyrimidine-4,6-diol, and TBAF (n-Bu4NF), a variety of imidazoles underwent the N-arylation reaction with aryl and heteroaryl halides smoothly in moderate to excellent yields. Noteworthy is that the reaction is conducted under solvent-free conditions
It was determined that diaryliodonium(III) triflates bearing a trimethoxybenzene (TMP) auxiliary are more reactive than the reported selective aryl-transfer iodonium salts in the N-arylation of benzimidazoles and other types of azole compounds under catalytic conditions. The TMP-iodonium(III) salts can thus effectively facilitate the reaction at 50 °C or below, producing the corresponding N-arylated
Open-air N-arylation of N–H heterocycles with arylboronic acids catalyzed by copper(II) Schiff base complexes
作者:S. M. Islam、Ram Chandra Dey、Anupam Singha Roy、Sumantra Paul、Sanchita Mondal
DOI:10.1007/s11243-014-9881-2
日期:2014.11
Two copper Schiff base complexes, in both homogeneous and heterogeneous forms, were prepared and characterized by using elemental analysis, FTIR, UV–Vis spectroscopy and scanning electron microscopy. The catalytic performances of these complexes were studied in the N-arylation of N–H heterocycles with arylboronic acids in methanol without any added base at 40 °C under open air. The effects of various parameters such as solvent and temperature on the reaction system were studied. The reaction is applicable to a wide variety of N–H heterocycles and arylboronic acids. The heterogeneous catalyst was recovered by simple filtration, and reusability experiments showed that this catalyst can be used five times without much loss in the catalytic activity.
Nickel-Catalyzed Heteroarenes Cross Coupling via Tandem C–H/C–O Activation
作者:Ting-Hsuan Wang、Ram Ambre、Qing Wang、Wei-Chih Lee、Pen-Cheng Wang、Yuhua Liu、Lili Zhao、Tiow-Gan Ong
DOI:10.1021/acscatal.8b03436
日期:2018.12.7
Inert aryl methyl ethers as coupling components via C–O activation have been established with a Ni catalyst for C–H activation of heteroarene. The key to simultaneous C–H/C–O bond activation is the use of sterically demanding o-tolylMgBr. The protocol is effective for a wide scope of substrates including naphthyl methyl ethers, anisoles, and a variety of other heteroarene derivatives. Detailed mechanistic
Bergman cycloaromatization of imidazole-fused enediynes: the remarkable effect of N-aryl substitution
作者:Zhengrong Zhao、Yunshan Peng、N.Kent Dalley、John F Cannon、Matt A Peterson
DOI:10.1016/j.tetlet.2004.02.152
日期:2004.4
A series of N-arylsubstituted `imidazole-fused' (Z) 3-ene-1,5-diynes was prepared and kinetic parameters for their Bergman cycloaromatization reactivities were determined. N-Arylation enhanced rates relative to N-alkyl derivatives by up to sevenfold (ANOVA p<0.0001). The greatest enhancement was exhibited by the N-phenyl derivative (sevenfold at 145 °C).
制备了一系列的N-芳基取代的“咪唑稠合的”(Z)3-烯-1,5-二炔,并确定了其Bergman环芳化反应活性的动力学参数。N-芳基化相对于N-烷基衍生物的速率提高了七倍(ANOVA p <0.0001)。N-苯基衍生物表现出最大的增强作用(在145°C时为七倍)。