- Green synthesis of 1-phenyl-1-ortho-xylene ethane in IL and reaction mechanism
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1-Phenyl-1-ortho-xylene ethane (PXE) in IL was synthesized, and the catalysts used were AlCl3 in 1-butyl-3-methylimidazolium bromide ([BMIM][Br]) or 1-butyl-3-methylimidazolium chloride ([BMIM][Cl]), and H2SO4. When the concentrations of AlCl3 in IL, ortho-xylene and styrene were 0.35, 0.03 and 0.005?mol, respectively, it could be discovered that ([BMIM][Br]) was the best catalyst. When the mole fraction concentration of AlCl3/[BMIM][Br] was more than 0.40%, the reaction was able to achieve 100% conversion. When the reaction time was longer than 60 minutes, the percentage conversion of ortho-xylene attained was 100%. The mechanisms of the reaction were investigated by the DFT method at the B3LYP/6-311++G(d, p) level. The potential energy surface (PES) profile indicated that the energy of transition state was 22.59 kcal mol?1. This indicated that the activation energy of reaction was 28.24 kcal mol?1, which illustrated that the reaction occurred easily. Vibrational frequencies were observed in FT-IR spectra, the corresponding vibrational modes νs(H4-C3Al-H5) and νas(H4-C3Al-H5) indicated that an Al3+ ion was combined with a C3 atom. In addition, the repeated use of the catalysts was studied; the ionic liquids could still catalyze the reaction and the percentage yield of PXE was larger than 91% after 6 runs.
- Sun, Xuejun,Zhou, Xinming,Cao, Bobo,Cao, Ziping,Fu, Hui
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- The catalytic performance study of polymerized ionic liquid synthesized in different conditions on alkylation of o-Xylene with styrene
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In this work, a series of novel acidic polymerized ionic liquids were used as heterogeneous catalyst for alkylation of o-Xylene with styrene. And the effect of the amount of initiator and the type of acid used for ion exchange on catalyst structure and the catalytic performance of catalysts for alkylation were studied thoroughly. The experiment results show: when the percentage of the amount of initiator in the total material is 3%, the polymerized ionic liquid catalyst MPM-SO3H-[C3V][SO3CF3] has the most uniform with a specific surface area of 97.30?m2/g and a pore volume of 0.35?cm3/g. Benefiting from the unique structure features, MPM-SO3H-[C3V][SO3CF3] manifested an excellent catalytic performance for alkylation of o-Xylene with styrene, along with the conversion of styrene was 96.8% and the yield of 1-Phenyl-1-ortho-xylene ethane was 94.7%. Therefore, this work provides a novel reference to the synthesis of polymerized ionic liquids and clearly explains the advantage of novel acidic polymerized ionic liquids on alkylation.
- Liu, Yonghui,Gao, Huaying,Sheng, Xiaoli,Zhou, Yuming,Wang, Beibei,Sha, Xiao,Jin, Maolu,Zhao, Jie,Liu, Wenqi
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- Alkylation of O-xylene and styrene catalyzed by cross-linked poly acidic ionic liquids catalyst with novel mesoporous-macroporous structure
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Cross-linked poly acidic ionic liquids (MPM-C6V-SO3CF3-IL) with mesoporous and macroporous network structure have been synthesized in different solvents. The novel solid acid catalyst with special network structure has a large surface area (103.83 m2/g), large pore volume (0.72 cm3/g) and abundant mesopores and macropores, which help to improve the contact between active site and reactants. Catalytic performance of catalyst was investigated through alkylation of o-xylene and styrene. Different reaction parameters specifically solvent on obtained catalyst and production of PXE were systematically investigated. Under optimal reaction conditions (reaction time was 3 h, reaction temperature was 120 °C, catalyst amount was 0.17 g (0.5 wt%), and o-xylene/styrene mass ratio was 7.5:1), a high conversion of styrene (100%) and 1,2-diphenylethane (PXE) yield of 99.67% was obtained, which is superior to commercial acid in liquid and even previous acids synthesized by our own group. Moreover, catalyst could keep relatively high thermostability under reaction and are easy to be separated and recycled from the solution, which are critical for heterogeneous solid catalysts. Thus, this novel catalyst can be potentially applied in other acidic reactions.
- Gao, Huaying,Zhou, Yuming,Sheng, Xiaoli,Zhao, Shuo,Zhang, Chao,Fang, Jiasheng,Wang, Beibei
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- Synthesis of P123-Templated and DVB-Cross-linked Meso-macroporous Poly (ionic liquids) with High-Performance Alkylation
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Meso-macroporous poly (ionic liquids) (MPILs) were successfully synthesized through a novel strategy with P123 (PEO20PPO70PEO20) as the pore-forming agent and divinylbenzene as crosslinker. Then effects of reaction temperature and the molar ratio of ionic liquid to divinylbenzene (IL to DVB) were systematically investigated together with the morphology and structure of MPILs. It was found the MPILs owned a meso-macroporous channel-like structure, large surface area (up to 732 m2/g), large pore volume (1.42 cm3/g) and high thermal stability. Meanwhile, the Brunauer–Emmett–Teller surface of MPILs could be fabricated by adjusting the reaction temperature and especially the IL to DVB molar ratio. In the probe reaction of alkylation of styrene and o-xylene, a 100% conversion of styrene and 96.4% PXE yield was acquired, and this is more expert than common commercial liquid acid catalyst. This work might develop a novel way for synthesizing porous heterogeneous polymer catalysts in the future and owning a promising future applied in other acidic catalytic reactions.
- Liao, Qiang,Liu, Yonghui,Sha, Xiao,Sheng, Xiaoli,Wang, Beibei,Zhou, Yuming,Zhu, Zhiying
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- Highly active and green aminopropyl-immobilized phosphotungstic acid on mesoporous LaSBA-15 for alkylation of o-xylene with styrene
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The Keggin phosphotungstic acid, H3PW12O40 (HPW), was successfully immobilized on the surface of mesostructured LaSBA-15 by means of chemical bonding to aminosilane groups. The catalysts were characterized by elemental analysis, N2 adsoption, TEM, DRS-UV, and FTIR spectroscopy. Characterization results suggest that the surface area decreased after grafting amino groups to silica and the structures of heteropolyanions on amine-modified LaSBA-15 was maintained. Their catalytic behaviors were investigated in the alkylation of o-xylene with styrene. Among the functionalized catalysts, when the content of amino-groups was suitable, it had the best catalytic performances in terms of yield and stability. It is worth mentioning that the catalysts could be used repeatedly without loss of the activity and selectivity during several catalytic cycles. The good stability can be attributed to the strong interaction between the amino groups on the surface of LaSBA-15 and HPW anions.
- Sheng, Xiaoli,Zhou, Yuming,Zhang, Yiwei,Duan, Yongzheng,Xue, Mengwei
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- H3PW12O40/mpg-C3N4 as an efficient and reusable catalyst in the alkylation of o-xylene and styrene
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A heterogeneous catalyst (HPW/mpg-C3N4) for the alkylation of o-xylene and styrene reaction was acquired by the immobilization of phosphotungstic acid (HPW) on mesoporous graphitic carbon nitride (mpg-C3N4) through electrostatic interaction. The results of Fourier transform infrared spectroscopy (FT-IR), X-ray powder diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and thermogravimetric analysis (TGA) proved that HPW was successfully immobilized on the protonated mpg-C3N4 by electrostatic interaction. The textural properties and morphology of HPW/mpg-C3N4 were characterized by N2 adsorption–desorption, scanning electron microscopy (SEM). Among them, 40% HPW/mpg-C3N4 displays the best catalytic performance in the alkylation reaction with 91.8% yield and 96.5% selectivity to 1, 2-diphenylethylane. Moreover, protonated mpg-C3N4 not only displays as a support to facilitate great dispersion of HPW but also promotes the alkylation product diffusion effectively. Besides, the HPW/mpg-C3N4 catalyst could be recycled easily without significant loss of catalytic activity, which is demonstrate by the recyclability of HPW/mpg-C3N4 catalyst test.
- Zhu, Zhiying,Wang, Beibei,Yao, Qingzhao,Zhou, Yuming,Yang, Haiyong,Liu, Yonghui
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- One-step synthesis of hierarchical aluminosilicates using alkoxy-functionalized ionic liquid as a novel template
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Hierarchical zeolites have bridged the gap between conventional zeolite and mesoporous materials, which not only maintain the excellent advantages of microporous sieves, but also effectively resolve the diffusion limitations. Herein, a novel alkoxy-functionalized ionic liquid was employed as a mesoporous structure-directing agent to synthesize hierarchical aluminosilicates with dual micro-mesoporous channels. X-ray diffraction (XRD), N2 adsorption-desorption isotherms (BET), scanning electron microscopy (SEM), transmission electron microscopy (TEM), temperature-programmed desorption (TPD), thermogravimetric analysis (TGA) and 27Al magic-angle spinning nuclear magnetic resonance (27Al MAS NMR) were used to characterize the structural and textural features of the hierarchical aluminosilicates. The results showed that the ionic liquid (MTPI) employed played the role of a mesoporous structure-directing agent which was trapped within the pores of a faujasite structure through -Si-O-Al- and -Si-O-Si- linkages. The mesoporous diameters and structures of the final hierarchical materials could be uniformly tailored by tuning the added amount of template. Hierarchical aluminosilicates with the combined advantages of both mesoporous properties and the microporous crystalline structure of zeolites exhibited high catalytic activity and resistance to deactivation in the alkylation of o-xylene with styrene, as compared to the conventional zeolite with the sole presence of micropores. The distinct catalytic performance of hierarchical aluminosilicates could be attributed to the short diffusion routes and abundant exposed acidic sites on the external surface.
- Fu, Xiaoqin,Sheng, Xiaoli,Zhou, Yuming,Fu, Zhiwei,Zhao, Shuo,Zhang, Zewu,Zhang, Yiwei
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- Design of micro-mesoporous zeolite catalysts for alkylation
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Hierarchical zeolite Y was hydrothermally synthesized using ionic liquid 1-methyl-3-[3′-(trimethoxysilyl)propyl]imidazolium chloride, which was added into the conventional synthesis composition for crystalline microporous aluminosilicate as a mesopore-directing agent. An extremely short diffusion path length and abundant exposed acid sites in the hierarchical zeolite Y made it suitable for the catalytic transformation of bulky molecules. Then the catalytic performance of hierarchical zeolites Y was investigated using the alkylation of o-xylene with styrene. The ionic liquid directed hierarchical zeolite Y exhibited a remarkably high catalytic activity and long catalytic lifetime for the production of 1-phenyl-1-xylylethane via alkylation reaction, as compared with that of solely microporous zeolite Y. The distinct catalytic performances of the novel hierarchical zeolite Y could be attributed to the enhancement of medium strong acid amount and its micro-mesoporous structural properties which are favorable for the fast diffusion of products.
- Fu, Xiaoqin,Sheng, Xiaoli,Zhou, Yuming,Fu, Zhiwei,Zhao, Shuo,Bu, Xiaohai,Zhang, Chao
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- Deep compositional understanding of TBA: AlCl3 ionic liquid for its applications
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Chloroaluminate ionic liquids (ILs) have been immensely used as homogeneous catalyst in Friedel-Crafts reaction. We have recently synthesized chloroaluminate ILs by reacting aluminium chloride with a hydrophobic neutral ligand i.e. tributylamine (TBA:AlCl3). The current study elaborates on the investigations of the composition of the ionic liquids at various stages of their formation. The ionic liquids were synthesized using various mole ratios of tributyl amine and aluminium chloride in range of 1:1 to 1:2.3, in presence of an aromatic solvent in a one pot reaction. Various characterization techniques like Mass spectrometry, 27Al Nuclear Magnetic Resonance, 31P Nuclear Magnetic Resonance and Fourier Transform Infrared spectroscopy were used to elucidate the formation of various moieties of the TBA:AlCl3 Ionic Liquid. This study also elaborates on the investigations of the cationic and anionic moieties and their structure-property relationship for various applications. Various Friedel-Crafts reaction of industrial importance were performed using the ionic liquid having (Al2Cl7)?moiety to assess its performance and compared with conventional processes. The synthesized products were characterised by sophisticated analytical techniques like 1H NMR, 13C NMR, FTIR, GC–MS, GC-FID, to name a few. This class of ionic liquids also have importance in various electrochemical applications like aluminium deposition and aluminium batteries.
- Bhakthavatsalam, Vishnupriya,Chandra, Sudeshna,Choudhury, Rudra Prosad,Lande, Sharad V.,Pradhan, Jeevan,Sakhalkar, Mangesh
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- Room Temperature Catalyst System for the Hydroarylation of Olefins
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A simple protocol for the hydroarylation of olefins to yield diarylmethine products is described. A Friedel-Crafts-type synthetic strategy allows direct access to biorelevant products in high atom efficiency. A combination of substoichiometric amounts of TMSCl and ZnBr2 promotes a rapid hydroarylation process at ambient temperature. The method is high yielding and is amenable to scale-up protocols.
- Lee, Siu Yin,Villani-Gale, Alexander,Eichman, Chad C.
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supporting information
p. 5034 - 5037
(2016/10/14)
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- A surprising substituent effect provides a superior boronic acid catalyst for mild and metal-free direct Friedel-Crafts alkylations and prenylations of neutral arenes
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The development of more general and efficient catalytic processes for Friedel-Crafts alkylations is an important objective of interest toward the production of pharmaceuticals and commodity chemicals. Herein, 2,3,4,5-tetrafluorophenylboronic acid was identified as a potent air- and moisture-tolerant metal-free catalyst that significantly improves the scope of direct Friedel-Crafts alkylations of a variety of slightly activated and neutral arenes, including polyarenes, with allylic and benzylic alcohols. This method also provides a simple alternative for the direct installation of prenyl units commonly found in naturally occurring arenes. Alkylations with benzylic alcohols occur under exceptionally mild conditions.
- Ricardo, Carolynne L.,Mo, Xiaobin,McCubbin, J. Adam,Hall, Dennis G.
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supporting information
p. 4218 - 4223
(2015/03/14)
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- Synthesis of micro/mesoporous silica material by duallate method as a heterogeneous catalyst support for alkylation
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A series of micro/mesoporous composites were synthesized using non-ionic block copolymer Pluronic P123 and protic ionic liquid (triethylamine acetate) as the colates. The structures of all the composites were characterized by using small angle X-ray scattering, N2 gas sorption, dynamic laser light scattering (DLS), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The results reflected that the structure of the final silica materials changes along with the content of protic ionic liquid (PIL) and hydrothermal temperature. It was found that the sample whose mass ratio of PIL to (P123 + PIL) was 40% had a t-plot micropore area of 404 m2 g-1 at the hydrothermal temperature of 373 K, without destroying the ordered mesoporous structure. The formation mechanism of the micro/mesoporous silica which is based on the interaction between PIL and P123 is tentatively elucidated. 12-Tungstophosphoric acid (HPW) catalysts supported on these micro/mesoporous materials were prepared by impregnation, and their catalytic performances were investigated in the alkylation of o-xylene with styrene. Alkylation results showed that all the catalysts showed high catalytic performance in terms of propane conversion and selectivity to propene.
- Zhao, Shuo,He, Man,Zhou, Yuming,Sheng, Xiaoli,Fu, Xiaoqin,Zhang, Yiwei
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p. 28124 - 28132
(2015/04/14)
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- Electrophilic Fluorophosphonium Cations in Frustrated Lewis Pair Hydrogen Activation and Catalytic Hydrogenation of Olefins
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The combination of phosphorus(V)-based Lewis acids with diaryl amines and diaryl silylamines promotes reversible activation of dihydrogen and can be further exploited in metal-free catalytic olefin hydrogenation. Combined experimental and density functional theory (DFT) studies suggest a frustrated Lewis pair type activation mechanism. FLP hydrogenation: The combination of a phosphorus(V)-based Lewis acid with diaryl amines or diaryl silylamines promotes reversible activation of dihydrogen and can be further exploited in metal-free catalytic olefin hydrogenation. Combined experimental and density functional theory (DFT) studies suggest a frustrated Lewis pair (FLP)-type activation mechanism.
- Vom Stein, Thorsten,Perz, Manuel,Dobrovetsky, Roman,Winkelhaus, Daniel,Caputo, Christopher B.,Stephan, Douglas W.
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supporting information
p. 10178 - 10182
(2015/09/01)
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- Iron-catalyzed friedel-crafts benzylation with benzyl TMS ethers at room temperature
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Friedel-Crafts benzylations between unactivated arenes and benzyl alcohol derivatives are clean and straightforward processes to construct biologically useful di- and triarylmethanes. We have established an efficient iron-catalyzed Friedel-Crafts benzylation method at room temperature that uses benzyl TMS ethers as substrates, which are poorly reactive under common nucleophilic substitution conditions. The reaction seems to progress through iron-catalyzed self-condensation of the benzyl TMS ether to the corresponding dibenzylic ether. The use of excess arene relative to benzyl TMS ether produced mono-benzylated arene (diand tri-arylmethane products), whereas the use of excess benzyl TMS ether versus arene provided bis-benzylated arene (polyarylated products) in high yields and regioselectivities. In previous methods, the latter double Friedel-Crafts benzylations hardly proceed.
- Sawama, Yoshinari,Shishido, Yuko,Kawajiri, Takahiro,Goto, Ryota,Monguchi, Yasunari,Sajiki, Hironao
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supporting information
p. 510 - 516
(2014/04/03)
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- Synthesis of immobilized heteropolyanion-based ionic liquids on mesoporous silica SBA-15 as a heterogeneous catalyst for alkylation
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Phosphotungstic acid (H3PW12O40) has been successfully loaded onto sulfonate-functionalized ionic liquid-modified mesoporous silica SBA-15 by total anion-exchange. The immobilized catalysts were characterized by XRD, N2 adsorption, TEM, and FTIR spectroscopy. Characterization results show that the mesopore structure of SBA-15 was maintained well even after surface modification and the subsequent anion-exchange step of [PW12O40]3- (PW). In comparison with the task-specific basic ionic liquid (1-(propyl-3-sulfonate) 3-methyl-imidazolium phosphotungstate), the obtained catalyst showed much higher efficiency in alkylation of o-xylene with styrene. More importantly, such an immobilized task-specific basic ionic liquid could be reused without significant loss of catalytic activity even after recycling six times. This journal is the Partner Organisations 2014.
- Sheng, Xiaoli,Zhou, Yuming,Yang, Yongle,Zhang, Yiwei,Zhang, Zewu,Zhou, Shijian,Fu, Xiaoqin,Zhao, Shuo
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p. 30697 - 30703
(2014/08/05)
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- Synthesis of diarylmethanes via a Friedel-Crafts benzylation using arenes and benzyl alcohols in the presence of triphenylphosphine ditriflate
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Triphenylphosphine ditriflate (TPPD) was found to be an efficient promoter for the Friedel-Crafts benzylation of arenes with benzyl alcohols in CH 2Cl2 at room temperature. The good yields, the 1:1 molar ratio of arene and benzyl alcohol, the benzylation of chlorobenzene as a nonactivated aromatic compound at room temperature, and no by-product formation are the main advantages of this procedure.
- Khodaei, Mohammad Mehdi,Nazari, Ehsan
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experimental part
p. 5131 - 5135
(2012/09/22)
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- Iron(iii)-based ionic liquid-catalyzed regioselective benzylation of arenes and heteroarenes
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An easily prepared Fe(iii)-derived Lewis acid ionic liquid ([C 4mim][FeCl4]), being comprised of 1-butyl-3-methyl imidazolium cation and tetrachloroferrate anion, was found to be an efficient, recyclable catalyst for benzylation of various arenes/heteroarenes into the diarylmethanes derivatives under mild reaction conditions without utilization of additional organic solvent. Interestingly, the acidity of [C 4mim][FeCl4] could account for its catalytic activity in promoting the Lewis acid-catalyzed alkylation. Notably, this type of Fe(iii)-based ionic liquid (IL) shows excellent stability, and could be easily recovered, and reused for five times without significant loss of its catalytic activity.
- Gao, Jian,Wang, Jin-Quan,Song, Qing-Wen,He, Liang-Nian
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p. 1182 - 1186
(2011/06/25)
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- Efficient and general continuous-flow hydroarylation and hydroalkylation of styrenes
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A simple and efficient continuous-flow hydroarylation of arenes and heteroarenes using various styrenes in conjunction with a heterogeneous catalyst has been developed. Additionally, this method has been successfully extended to the hydroalkylation of styrenes by employing 1,3-dicarbonyl compounds as the nucleophile. Multigram quantities of diarylmethanes have been prepared using this new flow method. Copyright
- Rueping, Magnus,Bootwicha, Teerawut,Sugiono, Erli
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experimental part
p. 2961 - 2965
(2011/02/22)
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- Highly efficient gold(III)-catalyzed intermolecular hydroarylation of unactivated alkenes with arenes under mild conditions
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A simple and efficient method for functionalization of electron-rich arenes and heteroarenes with unactivated alkenes by Au(III)-catalyzed intermolecular hydroarylation under mild reaction conditions was developed. This method features a short reaction time (5 h) under mild conditions and has a broad substrate scope, including electron-rich arenes and heteroarenes, terminal and internal substituted aryl alkenes, and unactivated aliphatic alkenes.
- Xiao, Ya-Ping,Liu, Xin-Yuan,Che, Chi-Ming
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experimental part
p. 494 - 501
(2009/06/06)
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- A novel InCl3/SiO2-catalyzed hydroarylation of arenes with styrenes under solvent-free conditions
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A novel InCl3/SiO2-catalyzed hydroarylation of various styrenes with arenes has been developed. The reaction can be carried out under solvent-free conditions to afford a series of 1,1-diarylalkanes in high yields and with good regioselectivities. The catalyst can be reused six times without obvious loss of catalytic activity. Georg Thieme Verlag Stuttgart.
- Sun, Gaojun,Sun, Huayin,Wang, Zhiyong,Zhou, Ming-Ming
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experimental part
p. 1096 - 1100
(2009/04/04)
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- Process for the preparation of substituted phenols
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A substituted phenolic compound is prepared by oxidizing a substituted diarylethane compound with oxygen in the presence of a nitrogen-containing cyclic compound, and treating the oxidized product with an acid. The nitrogen-containing cyclic compound includes, as a constituent of its ring, a skeleton represented by following Formula (I): wherein X is oxygen atom or an -OR group, where R is hydrogen atom or a hydroxyl-protecting group. The substituted diarylethane compound is represented by following Formula (1): wherein each of Ring Ar1 and Ring Ar2 is independently a monocyclic or polycyclic aromatic carbocyclic ring; Y1 is an electron-donating group; Y2 is an electron-withdrawing group; "p" is an integer of 1 or more; and "q" is an integer of 0 or more. The substituted phenolic compound is represented by following Formula (2): wherein Ring Ar1, Y1, and "p" are as defined above.
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Page/Page column 13
(2008/12/08)
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- Selective one-pot synthesis of various phenols from diarylethanes
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Various substituted phenols were selectively synthesized by a one-pot reaction through the NHPI-catalyzed aerobic oxidation of 1,1-diarylethanes followed by treatment with dilute sulfuric acid. The Royal Society of Chemistry.
- Nakamura, Ryota,Obora, Yasushi,Ishii, Yasutaka
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supporting information; experimental part
p. 3417 - 3419
(2009/02/05)
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- Highly efficient iodine-catalyzed hydroarylation of arenes with styrenes
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Iodine mediates the hydroarylation of styrenes with arenes and heteroarenes to afford 1,1-diarylalkanes in good to high yields. Details regarding the substrate scope and selectivity of this hydroarylation reaction are discussed.
- Chu, Cheng-Ming,Huang, Wan-Ju,Liu, Ju-Tsung,Yao, Ching-Fa
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p. 6881 - 6885
(2008/02/12)
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- Secondary benzylation with benzyl alcohols catalyzed by a high-valent heterobimetallic Ir-Sn complex
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(Chemical Equation Presented) A highly efficient secondary benzylation procedure has been demonstrated using a high-valent heterobimetallic complex [Ir2(COD)2(SnCls)2(Cl)2(μ-Cl) 2] 1 as the catalyst in 1,2-dichloroethane to afford the corresponding benzylated products in moderate to excellent yields. The reaction was performed not only with carbon nucleophiles (arenes and heteroarenes) but also with oxygen (alcohol), nitrogen (amide and sulfonamide), and sulfur (thiol) nucleophiles. Mechanistic investigation showed the intermediacy of the ether in this reaction. An electrophilic mechanism is proposed from Hammett correlation.
- Podder, Susmita,Choudhury, Joyanta,Roy, Sujit
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p. 3129 - 3132
(2008/02/07)
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- An effective bismuth-catalyzed benzylation of arenes and heteroarenes
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A highly efficient Bi(OTf)3-catalyzed benzylation of arenes and heteroarenes has been developed. The mild reaction conditions, high yields, operational simplicity and practicability, broad scope, and remarkably low catalyst loading render this environment friendly process an attractive approach to diarylmethane derivatives. The extension to an intramolecular variant of this procedure provides a valuable route to substituted fluorenes.
- Rueping, Magnus,Nachtsheim, Boris J.,Ieawsuwan, Winai
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p. 1033 - 1037
(2007/10/03)
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- Gold-catalyzed benzylation of arenes and heteroarenes
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Friedel-Crafts type benzylation of arenes and heteroarenes with benzylic acetates, alcohols, and carbonates is effectively promoted under mild reaction conditions using catalytic amounts of gold salts. The resulting 1,1-diarylalkanes and 1-aryl-1-heteroarylalkanes are obtained in high yields and with high selectivity. The utility of the method is demonstrated by a short synthesis of beclobrate {ethyl 2-[4-(4-chlorobenzyl)-phenoxy]-2-methylbutyrate (3)}, a fibric acid derivative.
- Mertins, Kristin,Iovel, Irina,Kischel, Jette,Zapf, Alexander,Beller, Matthias
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p. 691 - 695
(2007/10/03)
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- A convenient FeCl3-catalyzed hydroarylation of styrenes
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(Chemical Equation Presented) 1,1-Diarylalkanes are easily synthesized by CH-functionalization reactions of electron-rich arenes and heteroarenes with styrenes in the presence of FeCl3 as catalyst.
- Kischel, Jette,Jovel, Irina,Mertins, Kristin,Zapf, Alexander,Beller, Matthias
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- Efficient metal-catalyzed hydroarylation of styrenes
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A highly efficient metal-catalyzed hydroarylation of various styrenes has been developed. This new bismuth-catalyzed C-H functionalization provides straightforward access to a series of valuable 1,1-diarylalkane products.
- Rueping, Magnus,Nachtsheim, Boris J.,Scheidt, Thomas
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p. 3717 - 3719
(2007/10/03)
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- An efficient and general iron-catalyzed arylation of benzyl alcohols and benzyl carboxylates
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(Chemical Equation Presented) Green grow the diarylmethanes: Substituted arenes and heteroarenes can be easily benzylated in the presence of inexpensive and relatively nontoxic metal salts such as FeCl3 (see scheme). This arylation method with benzyl alcohols is a state-of-the-art green route to diarylmethanes as water is the only by-product.
- Iovel, Irina,Mertins, Kristin,Kischel, Jette,Zapf, Alexander,Beller, Matthias
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p. 3913 - 3917
(2007/10/03)
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- Transition-metal-catalyzed benzylation of arenes and heteroarenes
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Friedel-Crafts-type benzylation of various aromatic and heteroaromatic compounds with benzylic acetates, alcohols, and carbonates was promoted under mild reaction conditions by a series of Rh, Ir, Pd, and Pt catalysts (see scheme; R1 = H, Me; R2 = H, Cl, MeO; R3 = H, Ac, CO2Me). The desired products were obtained in high yields and with high selectivities.
- Mertins, Kristin,Iovel, Irina,Kischel, Jette,Zapf, Alexander,Beller, Matthias
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p. 238 - 242
(2007/10/03)
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- ACID-CATALYZED DIMERIZATION AND ARALKYLATION IN DIVINYLAROMATIC COMPOUND-AROMATIC SOLVENT SYSTEMS
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On heating styrene and bis(4-vinylphenyl) ether or a linear unsaturated aromatic oligomer with terminal vinyl groups in aromatic solvents, depending on the temperature and concentration of toluene-p-sulfonic acid, there are obtained predominantly dimers and linear oligomers, and/or products of the alkylation of the aromatic solvent by the unsaturated monomers, dimers, and oligomers.
- Zaitsev, B. A.,Kiseleva, R. F.,Denisov, V. M.,Kol'tsov, A. I.
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p. 2323 - 2330
(2007/10/02)
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- REACTION OF DISUBSTITUTED AROMATIC COMPOUNDS WITH STYRENE
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Hydrocarbons of the 1,1-diphenylethane typr vere obtained by the reaction of styrene with various disubstituted derivatives of benzene in the presence of titanium tetrachloride.It was found that the yield of the desired compound depends on the strength of the electron-donating substituents and on steric factors in the aromatic ring.
- Grushin, A. I.,Grigor'ev, V. V.,Prokof'ev, K. V.,Kozlova, N. M.
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p. 1939 - 1941
(2007/10/02)
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- Lewis Acid-induced Nucleophilic Substitution Reactions of Aliphatic Nitro Compounds with Carbon Nucleophiles
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Tertiary, benzyl, and allylic nitro compounds undergo nucleophilic substitution reactions with carbon nucleophiles such as electron rich aromatic compounds, allylsilanes, or silyl enol ethers in the presence of SnCl4.
- Ono, Noboru,Yanai, Tetsuya,Kamimura, Akio,Kaji, Aritsune
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p. 1285 - 1287
(2007/10/02)
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