1667-02-3Relevant articles and documents
Tuning of the textural features and acidic properties of sulfated mesoporous lanthana-zirconia solid acid catalysts for alkenylation of diverse aromatics to their corresponding α-arylstyrenes
Zhao, Zhongkui,Ran, Jinfeng,Guo, Yongle,Miao, Boyuan,Wang, Guiru
, p. 1303 - 1313 (2016)
The textural features and acidic properties of sulfated mesoporous lanthana-zirconia solid acids (SO42?/meso-La0.1Zr0.9Oδ) were efficiently tuned by modifying the conditions used to prepare the meso-La0.1Zr0.9Oδ composites, such as the molar ratio of the template to La and Zr metal ions (Nt/m), molar ratio of ammonia to La and Zr metal ions (Na/m), hydrothermal temperature (Thydro), and hydrothermal time (thydro). The effect of the textural features and acidic properties on the catalytic performance of solid acid catalysts for alkenylation of p-xylene with phenylacetylene was investigated. Various characterization techniques such as N2 physisorption, X-ray diffraction, NH3 temperature-programmed desorption, and thermogravimetric analysis were employed to reveal the relationship between the nature of catalyst and its catalytic performance. It was found that the catalytic performance significantly depended on the textural features and acidic properties, which were strongly affected by preparation conditions of the meso-La0.1Zr0.9Oδ composite. Appropriate acidic sites and high accessibility were required to obtain satisfactory catalytic reactions for this reaction. It was also found that the average crystallite size of t-ZrO2 affected by the preparation conditions had significant influence on the ultrastrong acidic sites of the catalysts. The optimized SO42?/meso-La0.1Zr0.9Oδ catalyst exhibited much superior catalytic activity and coke-resistant stability. Moreover, the developed SO42?/meso-La0.1Zr0.9Oδ catalyst demonstrated excellent catalytic performance for alkenylation of diverse aromatics with phenylacetylene to their corresponding α-arylstyrenes. Combining the previously established complete regeneration of used catalysts by a facile calcination process with the improved catalytic properties, the developed SO42?/meso-La0.1Zr0.9Oδ solid acid could be a potential catalyst for industrial production of α-arylstyrenes through clean and atom efficient solid-acid-mediated Friedel-Crafts alkenylation of diverse aromatics with phenylacetylene.
Extended lifetimes of gold(III) chloride catalysts using copper(II) chloride and 2,2,6,6-tetramethylpiperidine 1-oxyl (TEMPO)
Graf, Tyler A.,Anderson, Thomas K.,Bowden, Ned B.
, p. 1033 - 1038 (2011)
The turnovers of a gold(III) chloride catalyst were increased by 3,300% with the addition of several equivalents of 2,2,6,6-tetramethylpiperidine 1-oxyl (TEMPO) and catalytic amounts of copper(II) chloride. A three-component coupling reaction between pipe
Palladacycles bearing COOH-/ester-functionalized N-heterocyclic carbenes: Divergent syntheses and catalytic applications
Hu, Yanyan,Guo, Shuai
, (2019)
Two new [C^N]-type palladacyclic dinuclear complexes bearing carboxylate-containing N-heterocyclic carbenes (NHCs) were synthesized, and in both cases the carboxylato-NHC ligand adopts a bridging mode. Both complexes proved to be suitable precursors, whic
Supported phosphotungstic acid catalyst on modified activated carbon for Friedel-Crafts alkenylation of diverse aromatics to their corresponding α-arylstyrenes
Zhao, Zhongkui,Wang, Xianhui
, p. 103 - 110 (2015)
Abstract The supported phosphotungstic acid catalysts on modified activated carbon (PTA/AC) prepared by a facile wet impregnation method were employed for Friedel-Crafts alkenylation of diverse aromatics with phenylacetylene to synthesize their corresponding α-arylstyrenes. Reaction results demonstrate that the fabricated PTA/AC catalyst with 30 wt.% PTA loading exhibits outstanding catalytic performance. The 100% conversion of phenylacetylene with 95.7% selectivity towards α-(2,5-dimethylphenyl) styrene can be achieved over the developed 30 wt.% PTA/AC catalyst under optimized reaction conditions, and no visible loss in catalytic performance can be observed after it suffers from several times recycling. The various characterization techniques including X-ray diffraction, N2 adsorption-desorption, Fourier transform infrared spectroscopy, and NH3 temperature-programmed desorption were employed to reveal the relationship between the catalysts nature and catalytic properties. Moreover, the results on the scope of aromatics for the Friedel-Crafts alkenylation illustrate that the developed PTA/AC alkenylation catalyst can be efficiently catalyze the diverse aromatics and even for the electron deficient chlorobenzene. The developed PTA/AC catalyst, using the modified low-cost and sustainable AC as support, may be a robust and promising candidate for highly-efficient and clean α-arylstyrenes production through Friedel-Crafts alkenylation of diverse aromatics including electron-donating and electron-withdrawing groups substituted benzene derivatives as well as heterocyclic and polypolycyclic arenes with phenylacetylene.
Spherical hollow mesoporous silica supported phosphotungstic acid as a promising catalyst for α-arylstyrenes synthesis via Friedel-Crafts alkenylation
Wang, Xianhui,Zhao, Zhongkui
, p. 729 - 734 (2019)
In this work, a spherical hollow mesoporous silica (SHMS) with high surface area (902 m2/g) and large mesopore volume (1.31 cm3/g) was prepared via a facile and scalable two-step soft-hard dual template-assisted sol-gel approach (OSD
Understanding the effect of α-cationic phosphines and group 15 analogues on &phi-acid catalysis
García-Rodeja, Yago,Fernández, Israel
, p. 460 - 466 (2017)
The factors responsible for the experimentally observed acceleration of ?-Acid-catalyzed reactions induced by ?-cationic phosphines and group 15 analogues have been computationally explored within the density functional theory framework. To this end, the
Electrophilic Alkenylation of Arometics with Phenylacetylene over Zeolite HSZ-360
Sartori, Giovanni,Bigi, Franca,Pastorio, Andrea,Porta, Cecilia,Arienti, Attilio,et al.
, p. 9177 - 9180 (1995)
Aromatic compounds react with phenylacetylene in the presence of zeolite HSZ-360 affording 1,1-diarylethylenes 3 in good to excellent yields and selectivities.
[Mes-B-TMP]+borinium cation initiated cyanosilylation and catalysed hydrosilylation of ketones and aldehydes
Chen, Po-Han,Chiu, Ching-Wen,Hsu, Ching-Pei,Liu, Yi-Hung,Tseng, Hsi-Ching
supporting information, p. 13732 - 13735 (2021/12/27)
Two aryl amino borinium cations derived from Cl(Mes)B-NR2(NR2= TMP, HMDS) faced divergent outcomes. As the HMDS-substituted one underwent methyl migration from silicon to boron transforming the putative borinium ion to a silylium ion, [Mes-B-TMP]+can initiate cyanosilylation and catalyse hydrosilylation of ketones and aldehydes.
Bimolecular vinylation of arenes by vinyl cations
Bour, Christophe,Gandon, Vincent,Li, Zhilong
supporting information, p. 6507 - 6510 (2020/07/02)
Styrene derivatives can be easily synthesized from vinyl triflates and arenes under mild reaction conditions, using [Li][Al(OC(CF3)3)4] as a catalyst and LiHMDS as a base. This transformation is likely to involve a vinyl cation intermediate as an electrophile, which is corroborated by DFT calculations, deuterium-labeling and other control experiments. The use of an inert weakly coordinating anion is a decisive factor in this bimolecular vinylation process. This journal is
(P,C) Cyclometalated Gold(III) Complexes: Highly Active Catalysts for the Hydroarylation of Alkynes
Blons, Charlie,Mallet-Ladeira, Sonia,Amgoune, Abderrahmane,Bourissou, Didier
supporting information, p. 11732 - 11736 (2018/09/10)
The first catalytic application of well-defined (P,C) cyclometalated gold(III) complexes is reported. The bench-stable bis(trifluoroacetyl) complexes 2 a,b perform very well in the intermolecular hydroarylation of alkynes. The reaction is broad in scope, it proceeds within few hours at 25 °C at catalytic loadings of 0.1–5 mol %. The electron-rich arene adds across the C≡C bond with complete regio- and stereo-selectivity. The significance of well-defined gold(III) complexes and ligand design are highlighted in a powerful but challenging catalytic transformation.
