620-83-7Relevant academic research and scientific papers
REACTIVE FORM OF 12-MOLYBDOSILICATE CATALYST ON FRIEDEL-CRAFTS-TYPE REACTION
Nomiya, Kenji,Sasa, Sadayoshi,Miwa, Makoto
, p. 1075 - 1076 (1980)
Stepwise replacement of protons in H4 by tetrabutylammonium cation and catalysis by the replaced compounds for alkylation of toluene with benzyl chloride have been investigated.Only threeprotonated compound showed comparable activity with that of parent one.
Selective Friedel-Crafts Alkylation on a Vermiculite, a Highly Active Natural Clay Mineral with Lewis Acid Sites
Okada, Shin-ichi,Tanaka, Katsumi,Nakadaira, Yasuhiro,Nakagawa, Naoya
, p. 2833 - 2835 (1992)
Acid-catalyzed Friedel-Crafts alkylation reactions of p-methylbenzyl chloride with benzene were carried out on four unmodified natural clay minerals.Phenyl-p-tolylmethane was quickly and selectively formed in the presence of vermiculite.Although the speci
High alkylation activities of ball-milled synthesized low-load supported iron oxide nanoparticles on mesoporous aluminosilicates
Pineda, Antonio,Balu, Alina M.,Campelo, Juan Manuel,Luque, Rafael,Romero, Antonio Angel,Serrano-Ruiz, Juan Carlos
, p. 65 - 69 (2012)
Low-load iron oxide nanoparticles on Al-SBA-15 prepared using a novel dry milling approach exhibited excelling activities in the microwave-assisted akylation of toluene with benzyl chloride (Lewis acids promoted reaction) and benzyl alcohol (Br?nsted acids promoted reaction) as compared to the parent Al-SBA-15 and similar iron oxide nanoparticles supported on Al-MCM-41 materials. Materials prepared using the milling protocol possessed remarkably low iron loadings (0.1 wt%) but featured highly accessible sites and small nanoparticle sizes that seemed to be related to the observed differences in activities in the systems.
Sulfated and phosphated mesoporous Nb oxide in the benzylation of anisole and toluene by benzyl alcohol
Rao, Yuxiang,Trudeau, Michel,Antonelli, David
, p. 13996 - 13997 (2006)
Materials possessing the high acidities of sulfated zirconia and the diffusion properties of mesoporous oxides are predicted to have numerous applications in the petrochemical industry. Because of surface deactivation and loss of structure under highly acidic conditions, there are few examples of materials which meet these specifications. In this work, mesoporous Nb oxide was treated with 1 M sulfuric acid or phosphoric acid and evaluated for their catalytic activities in the benzylation of toluene or anisole with benzyl alcohol. Characterization by XRD, nitrogen adsorption/desorption, and TEM demonstrated that the mesostructure was surprisingly stable to acid treatment. Pyridine adsorption and infrared spectroscopy (IR) showed a mixture of Lewis and Bronsted sites before and after acid treatment. Titration with a series of indicators demonstrated that sulfated mesoporous Nb oxide possesses a pKa of -8.2 and 31.784 mmol/g acid sites, roughly 100 times stronger than either bulk phosphated or sulfated niobia, which both possess pKa values in the range of -3.0. The best catalytic results in this study were achieved when using mesoporous Nb oxide treated with sulfuric acid; the conversion of benzyl alcohol with anisole to the benzylation product was 100% in 30 min, which is 200 times faster than the bulk catalyst. The extremely high activity was rationalized by the high number of strong Bronsted sites on the surface coupled with the superior diffusion properties of the mesoporous system. Copyright
One-pot synthesis of phenylmethanes using Al3+ doped and natural clays
Miranda,Aceves,Corona-Cortes,Dominguez,Cabrera,Salmon
, p. 727 - 732 (1994)
New simple alternatives to produce phenylmethanes using toluene and toluene derivatives are reported; such processes are catalyzed by a natural and a doped Al3+ Mexican bentonitic earth. The clays show a dual catalytic effect, as inductors of free radicals and as catalysts of electrophilic aromatic substitution. The catalytic effect as well as some physical and chemical properties of the clays are also reported.
Hydrothermal etching assisted crystallization: A facile route to functional yolk-shell titanate microspheres with ultrathin nanosheets-assembled double shells
Li, Wei,Deng, Yonghui,Wu, Zhangxiong,Qian, Xufang,Yang, Jianping,Wang, Yao,Gu, Dong,Zhang, Fan,Tu, Bo,Zhao, Dongyuan
, p. 15830 - 15833 (2011)
We report a facile "hydrothermal etching assisted crystallization" route to synthesize Fe3O4@titanate yolk-shell microspheres with ultrathin nanosheets-assembled double-shell structure. The as-prepared microspheres possess a uniform size, tailored shell structure, good structural stability, versatile ion-exchange capability, high surface area, large magnetization, and exhibit a remarkable catalytic performance.
Mixed Alkyl/Aryl Diphos Ligands for Iron-Catalyzed Negishi and Kumada Cross Coupling Towards the Synthesis of Diarylmethane
Ma, Xufeng,Wang, Han,Liu, Yao,Zhao, Xing,Zhang, Jun
, p. 5134 - 5140 (2021/11/16)
Mixed alkyl/aryl diphos ligands have been prepared and their application in iron-catalyzed cross coupling of benzylic chlorides with diaryl zinc (Negishi) or aryl Grignard reagents (Kumada) towards the synthesis of diarylmethane has been evaluated. The iron?diphos catalytic system exhibited the enhanced activity and selectivity in the two coupling reactions. The electron-rich mixed PPh2/PCy2 ligands outperformed their symmetrical PPh2 congeners, and led to decreased homocoupling byproduct formation. It indicates that the electronic effect of the ligands plays an important role in the catalytic performance. The Fe catalyst supported by L8 bearing an electron-rich PCy2 substituent and a sterically demanding tert-butyl on ethene backbone exhibited the best catalytic performance and good functional group tolerance in the two cross coupling reactions.
Conversion of Aryl Aldehydes to Benzyl Iodides and Diarylmethanes by H3PO3/I2
Lv, Fang,Xiao, Jing,Xiang, Junchun,Guo, Fengzhe,Tang, Zi-Long,Han, Li-Biao
, p. 3081 - 3088 (2021/02/01)
For the first time, H3PO3 was used as both the reducing reagent and the promotor in the reductive benzylation reactions with aryl aldehydes. By using a H3PO3/I2 combination, various aromatic aldehydes underwent iodination reactions and Friedel-Crafts type reactions with arenes via benzyl iodide intermediates, readily producing benzyl iodides and diarylmethanes in good yields. Intramolecular cyclization reactions also took place, giving the corresponding cyclic compounds. This new strategy features easy-handling, low-cost, and metal-free conditions.
Development of highly efficient Friedel-Crafts alkylations with alcohols using heterogeneous catalysts under continuous-flow conditions
Kobayashi, Shū,Koumura, Nagatoshi,Masuda, Koichiro,Okamoto, Yukiko,Onozawa, Shun-Ya
, p. 24424 - 24428 (2021/07/29)
The development of Friedel-Crafts alkylations with alcohols under continuous-flow conditions using heterogeneous catalysts is reported. The reactivities and durabilities of the examined catalysts were systematically investigated, which showed that montmorillonite clay is the best catalyst for these reactions. A high turnover frequency of 9.0 × 102h?1was recorded under continuous-flow conditions, and the continuous operation was successfully maintained over one week.
Multifunctional oxygen vacancies in WO3–x for catalytic alkylation of C–H by alcohols under red-light
Gu, Xianmo,Sun, Xichen,Wang, Yunwei,Zhang, Jin,Zheng, Zhanfeng,Zhu, Pengqi
, p. 208 - 217 (2021/09/06)
Surface reaction kinetics and light absorption properties of a photocatalyst are essential demands for efficiently solar to chemical energy converting. In this study, plasmonic WO3–x was firstly applied to photocatalytic alkylation of arenes under red light irradiation. The oxygen vacancies, both on the surface and in the bulk of WO3–x, allow abundant free electrons to increase carrier densities and support its LSPR using low energy photons. The surface oxygen vacancies have more functions: they not only release surface tungsten sites which ensure the chemisorption of alcohols due to the coordianation ability but also promote the activation of alcohols via an efficient transport of the holes on the neighbouring O sites to chemisorption alcohol species. In brief, the bulk oxygen vacancies provide abundant charges and the surface vacancies promote the bond adsorption and activation abilities, which ensure the high efficiency of photocatalytic alkylation of C–H.
