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Novel heteroleptic Ni (II) complexes bearing a highly hindered yet flexible IPr* ligand, Ni (IPr*)(PPh3)Br2 ( 1 ) and Ni (IPr*)(PCy3)Br2 ( 2 ) (IPr* = 1,3-bis(2,6-bis (diphenylmethyl)-4-methylphenyl)imidazol-2-ylidene), were easily prepared in 78% and 89% yield, respectively. Both were characterized by elemental analysis and NMR spectroscopy, and 1 was subjected to X-ray crystallography. Compared with 2 and its analogue bearing a less sterically demanding IPr ligand (IPr = 1,3-bis(2,6-diisopropylphenyl)imidazol-2-ylidene), complex 1 exhibited superior catalytic activity in the magnesium-mediated reductive coupling of benzyl chlorides with aryl chlorides, featuring outstanding tolerance of both coupling partners with steric demand. This study discloses a ligand-facilitated reductive coupling of benzyl chlorides with aryl chlorides, which provides a new and practical synthetic tool for the synthesis of diarylmethanes. 相似文献
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In the presence of a catalytic amount of silica – supported phosphine palladium(0) complex, sodium tetraphenylborate (NaBPh4) reacts with acid chlorides under mild conditions to give the corresponding phenyl ketones in 57 – 80% yields; it also reacts with aryl iodides to afford the corresponding biaryls in 75 – 84% yields. 相似文献
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二氧化硅负载胂钯(0)配合物催化酰氯和芳基碘与四苯硼化钠的苯基化反应 总被引:1,自引:0,他引:1
氯丙基三乙氧基硅烷依次与气相法二氧化硅、二苯胂钾、氯化钯作用, 再用水合肼还原, 合成了二氧化硅负载的胂钯(0)配合物. 该配合物是酰氯及芳基碘化物与四苯硼化钠苯基化反应的有效催化剂, 为苯基酮及不对称联苯的合成提供了简便且实用的新方法. 相似文献
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The palladium-catalyzed amidation of electron-deficient aryl chlorides proceeds readily in the presence of low CO pressures and a slight excess of an iodide salt. The rates of amidation are accelerated over those without added salt, and iodide is preferred over bromide or chloride. More electron-rich aryl chlorides were not effectively amidated, either with or without added iodide. We postulate that an intermediate anionic palladium(0) iodide complex is responsible for the enhanced reactivity. 相似文献
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A General Palladium‐Catalyzed Hiyama Cross‐Coupling Reaction of Aryl and Heteroaryl Chlorides 下载免费PDF全文
Dr. On Ying Yuen Dr. Chau Ming So Ho Wing Man Prof. Fuk Yee Kwong 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(19):6471-6476
A general palladium‐catalyzed Hiyama cross‐coupling reaction of aryl and heteroaryl chlorides with aryl and heteroaryl trialkoxysilanes by a Pd(OAc)2/ L2 catalytic system is presented. A newly developed water addition protocol can dramatically improve the product yields. The conjugation of the Pd/ L2 system and the water addition protocol can efficiently catalyze a broad range of electron‐rich, ‐neutral, ‐deficient, and sterically hindered aryl chlorides and heteroaryl chlorides with excellent yields within three hours and the catalyst loading can be down to 0.05 mol % Pd for the first time. Hiyama coupling of heteroaryl chlorides with heteroaryl silanes is also reported for the first time. The reaction can be easily scaled up 200 times (100 mmol) without any degasification and purification of reactants; this facilitates the practical application in routine synthesis. 相似文献
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Dr. Takanori Iwasaki Ryo Akimoto Prof. Dr. Hitoshi Kuniyasu Prof. Dr. Nobuaki Kambe 《化学:亚洲杂志》2016,11(20):2834-2837
Iron‐catalyzed cross‐coupling reaction of vinylic ethers with aryl Grignard reagents is described. The reaction proceeded at room temperature with catalytic amounts of an iron salt without the aid of costly ligands and additives. In this catalytic system, vinylic C?O bonds were preferentially cleaved over aromatic C?O bonds of aryl ethers or aryl sulfonates. 相似文献
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Guanghui Sun Lirong Zhang Guanlin Zhang Yuehui Fan Yuhong Wang Guanzhong Lu 《中国化学会会志》2013,60(11):1365-1370
The hydrodechlorination performance of nickel complex catalysts, Ni[phen]2(PF6)2 and Ni[bpy]3(PF6)2, were investigated with [Bmim]Br as the ionic liquid solvent. It is proved that Ni[phen]2(PF6)2 is efficient for the hydrodechlorination of aryl chlorides under mild conditions with water as the hydrogen source. The hydrogen source of reaction is from the water which was confirmed by the deuterium incorporation experiments. Recycling experiments showed a decreasing activity of this catalyst due to a small leaching of nickel complex from the ionic liquid phase during the recycling process where n‐heptane was used as the extractant. A plausible reaction route has been suggested. 相似文献
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Dr. Thorsten Scherpf M. Sc. Henning Steinert M. Sc. Angela Großjohann Dr. Katharina Dilchert M. Sc. Jens Tappen M. Sc. Ilja Rodstein Prof. Dr. Viktoria H. Gessner 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(46):20777-20784
Organolithium compounds are amongst the most important organometallic reagents and frequently used in difficult metallation reactions. However, their direct use in the formation of C−C bonds is less established. Although remarkable advances in the coupling of aryllithium compounds have been achieved, Csp2−Csp3 coupling reactions are very limited. Herein, we report the first general protocol for the coupling or aryl chlorides with alkyllithium reagents. Palladium catalysts based on ylide-substituted phosphines (YPhos) were found to be excellently suited for this transformation giving high selectivities at room temperature with a variety of aryl chlorides without the need for an additional transmetallation reagent. This is demonstrated in gram-scale synthesis including building blocks for materials chemistry and pharmaceutical industry. Furthermore, the direct coupling of aryllithiums as well as Grignard reagents with aryl chlorides was also easily accomplished at room temperature. 相似文献
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《中国化学》2017,35(11):1749-1754
Triphenylphosphine and salicylaldimine could be used as a mixed ligand system to obtain a high catalytic activity for palladium catalyzed diarylation of primary anilines with unactivated aryl chlorides by the synergistic effect of ligands. The activity and selectivity of the catalytic system could be improved by modifying the structure of salicylaldimine. In refluxing o ‐xylene, PdCl2(Ph3P)2 with 2,5‐ditrifluoromethyl N ‐phenylsalicylaldimine as a coligand shows high efficiency for the diarylation of various anilines. The catalytic system shows good toleration for the steric hindrance of the substrates. The facile catalytic system works as well on the multiple arylation of 1,1′‐biphenyl‐ 4,4′‐diamine with aryl chlorides to afford N ,N ,N′ ,N′ ‐tetraaryl‐1,1′‐biphenyl‐4,4′‐diamines which are important intermediates of organic light emitting diode (OLED) hole transport materials. 相似文献