- Unusual C-C bond cleavage in the formation of amine-bis(phenoxy) group 4 benzyl complexes: Mechanism of formation and application to stereospecific polymerization
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Group 4 tetrabenzyl compounds MBn4 (M = Zr, Ti), upon protonolysis with an equimolar amount of the tetradentate amine-tris(phenol) ligand N[(2,4-tBu2C6H2(CH 2)OH]3 in toluene from -30 to 25 °C, unexpectedly lead to amine-bis(phenoxy) dibenzyl complexes, BnCH2N[(2,4- tBu2C6H2(CH2)O] 2MBn2 (M = Zr (1), Ti (2)) in 80% (1) and 75% (2) yields. This reaction involves an apparent cleavage of the >NCH2-ArOH bond (loss of the phenol in the ligand) and formation of the >NCH 2-CH2Bn bond (gain of the benzyl group in the ligand). Structural characterization of 1 by X-ray diffraction analysis confirms that the complex formed is a bis(benzyl) complex of Zr coordinated by a newly derived tridentate amine-bis(phenoxy) ligand arranged in a mer configuration in the solid state. The abstractive activation of 1 and 2 with B(C6F 5)3·THF in CD2Cl2 at room temperature generates the corresponding benzyl cations {BnCH2N[(2,4- tBu2C6H2(CH2)O] 2MBn(THF)}+[BnB(C6F5) 3]- (M = Zr (3), Ti, (4)). These cationic complexes, along with their analogues derived from (imino)phenoxy tri- and dibenzyl complexes, [(2,6-iPr2C6H3)N=C(3,5- tBu2C6H2)O]ZrBn3 (5) and [2,4-Br2C6H2(O)(6-CH2(NC 5H9))CH2N=CH(2-adamantyl-4-MeC 6H2O)]ZrBn2 (6), have been found to effectively polymerize the biomass-derived renewable β-methyl-α-methylene- γ-butyrolactone (βMMBL) at room temperature into the highly stereoregular polymer PβMMBL with an isotacticity up to 99% mm. A combined experimental and DFT study has yielded a mechanistic pathway for the observed unusual C-C bond cleavage in the present protonolysis reaction between ZrBn4 and N[(2,4-tBu2C 6H2(CH2)OH]3 for the formation of complex 1, which involves the benzyl radical and the Zr(III) species, resulting from thermal and photochemical decomposition of ZrBn4, followed by a series of reaction sequences consisting of protonolysis, tautomerization, H-transfer, oxidation, elimination, and radical coupling.
- Gowda, Ravikumar R.,Caporaso, Lucia,Cavallo, Luigi,Chen, Eugene Y.-X.
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Read Online
- Alkylation of Phenol with tert-Butanol in a Draining-Film Reactor
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The alkylation of phenol with tert-butanol in a displacement draining-film reactor on a heterogeneous catalyst, Beta zeolite, was evaluated. Optimum process conditions ensuring the maximal p-tert-butylphenol yield were determined: phenol:tert-butanol molar ratio (3–3.5):1, superficial liquid velocity 1.0–1.5 m3 m–2 h–1, and temperature 100°C–110°C. A procedure ensuring 100% conversion of tert-butanol and isobutylene (a by-product formed from tert-butanol) was observed.
- Maksimov, A. L.,Mel’chakov, I. S.,Terekhov, A. V.,Zanaveskin, L. N.
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p. 569 - 575
(2021/07/26)
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- Increasing the steric hindrance around the catalytic core of a self-assembled imine-based non-heme iron catalyst for C-H oxidation
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Sterically hindered imine-based non-heme complexes4and5rapidly self-assemble in acetonitrile at 25 °C, when the corresponding building blocks are added in solution in the proper ratios. Such complexes are investigated as catalysts for the H2O2oxidation of a series of substrates in order to ascertain the role and the importance of the ligand steric hindrance on the action of the catalytic core1, previously shown to be an efficient catalyst for aliphatic and aromatic C-H bond oxidation. The study reveals a modest dependence of the output of the oxidation reactions on the presence of bulky substituents in the backbone of the catalyst, both in terms of activity and selectivity. This result supports a previously hypothesized catalytic mechanism, which is based on the hemi-lability of the metal complex. In the active form of the catalyst, one of the pyridine arms temporarily leaves the iron centre, freeing up a lot of room for the access of the substrate.
- Frateloreto, Federico,Capocasa, Giorgio,Olivo, Giorgio,Abdel Hady, Karim,Sappino, Carla,Di Berto Mancini, Marika,Levi Mortera, Stefano,Lanzalunga, Osvaldo,Di Stefano, Stefano
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p. 537 - 542
(2021/02/09)
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- Alkylation of Phenols with tert-Butanol Catalyzed by H-Form of Y Zeolites with a Hierarchical Porous Structure
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tert-Butyl-substituted phenols have been synthesized via the reaction of phenol, o-, m-, and p-cresols with tert-butanol under the action of CBr4-promoted Y-zeolites in the H-form with a hierarchical porous structure.
- Bayguzina,Makhiyanova,Khazipova,Khusnutdinov
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p. 1554 - 1559
(2019/10/14)
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- Hierarchical ZSM-5 nanocrystal aggregates: Seed-induced green synthesis and its application in alkylation of phenol with: Tert -butanol
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Hierarchical ZSM-5 zeolite aggregates were synthesized in an organic-template-free system via seed-induced crystallization. The obtained samples were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron mi
- Chen, Li,Xue, Teng,Wu, Haihong,Wu, Peng
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p. 2751 - 2758
(2018/02/06)
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- A PROCESS FOR THE PREPARATION OF TERTIARY BUTYL PHENOL
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The present invention disclosed a process for the preparation of tertiary butyl phenol by reaction of phenol with tertiary butanol using phosphorus pentoxide as catalyst.
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Page/Page column 7-8
(2018/05/16)
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- 2, 4-di-tert-butylphenol preparation method
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The invention relates to the field of organic synthesis, in particular to a 2, 4-di-tert-butylphenol preparation method which includes the steps: 1) adding and stirring catalysts and methyl tertiary butyl ether in the presence of a certain pressure and organic solvents; 2) dropwise adding phenol into the step 1), and heating and stirring reaction liquid; 3) cooling the reaction liquid in the step2) to room temperature, filtering the reaction liquid, washing filtrate and vaporizing solvents; 4) rectifying and drying 2, 4-di-tert-butylphenol crude products in the step 3) to obtain 2, 4-di-tert-butylphenol products. The preparation method is mild in reaction condition and high in product selectivity, and the catalysts can be recycled.
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Paragraph 0030-0034; 0036-0040; 0042-0046; 0048-0053
(2019/01/14)
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- Method for preparing hydrocarbyl phenol by catalytic conversion of phenolic compound in presence of molybdenum-based catalyst
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The invention discloses a method for preparing hydrocarbyl phenol by catalytic conversion of a phenolic compound in the presence of a molybdenum-based catalyst. The method comprises mixing a phenoliccompound, a molybdenum-based catalyst and a reaction solvent, adding the mixture into a sealed reactor, feeding gas into the reactor, heating the mixture to 150-350 DEG C, carrying out stirring for areaction for 0.5-2h, then filtering to remove a solid catalyst and carrying out rotary evaporateion to obtain a liquid product. The phenolic compound has a wide source, a cost is low, product alkyl phenol selectivity is high, an added value is high, alcohol or an alcohol-water mixture is used as a reaction solvent, environmental friendliness is realized, pollution is avoided, any inorganic acids and alkalis are avoided in the reaction process, the common environmental pollution problems in the biomass processing technology are solved, the reaction conditions are mild, the process can be carried out at a low temperature, high-efficiency conversion of the reactants can be realized without consuming hydrogen gas and the method is suitable for large-scale industrial trial production.
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Paragraph 0040-0041; 0070; 0073; 0079; 0084; 0089; 0100-0107
(2018/04/02)
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- Synthesis and catalytic activity of rhenium carbonyl complexes containing alkyl-substituted tetramethylcyclopentadienyl ligands
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A series of six alkyl-substituted tetramethylcyclopentadienyl mononuclear metal carbonyl complexes [(η5-C5Me4R)Re(CO)3] [R?=?allyl (1), i-Pr (2), n-butyl (3), t-butyl (4), benzyl (5), CH(CH2)4 (6)] have been synthesized by treating the corresponding ligands (C5Me4R) [R?=?allyl, i-Pr, n-butyl, t-butyl, benzyl, CH(CH2)4] with Re2(CO)10 in refluxing xylene. The six new complexes were characterized by elemental analysis, IR, 1H NMR and 13C NMR spectroscopy. The crystal structures of all six complexes were determined by X-ray crystal diffraction analysis, showing that they have similar molecular structures, being mononuclear carbonyl complexes. In each of these complexes, the Re atom is η5-coordinated to the cyclopentadienyl ring. Complexes 1–5 have significant catalytic activity in Friedel–Crafts reactions of aromatic compounds with alkylation reagents. Compared with traditional catalysts, these mononuclear rhenium carbonyl complexes have obvious advantages such as lower amounts of catalyst, mild reaction conditions and environmentally friendly chemistry.
- Li, Zhan-Wei,Ma, Zhi-Hong,Li, Su-Zhen,Han, Zhan-Gang,Zheng, Xue-Zhong,Lin, Jin
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p. 137 - 144
(2017/02/23)
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- Syntheses, structures and catalytic activity for Friedel-Crafts reactions of substituted indenyl rhenium carbonyl complexes
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The complexes [(η5-C9H6R)Re(CO)3] [R?=?nBu (8), tBu (9), CH(CH2)4 (10), Ph (11), Bz (12), 4-methoxyphenyl (13), 4-chlorophenyl (14)] were synthesized by refluxing substituted indenyl ligands [C9H7R] [R?=?nBu (1), tBu (2), CH(CH2)4 (3), Ph (4), Bz (5), 4-methoxyphenyl (6), 4-chlorophenyl (7)], and Re2(CO)10 in decalin. The molecular structures of 9, 10, 12, and 13 were determined by X-ray diffraction analysis. These four crystals have similar molecular structures of the mononuclear carbonyl complex. In each of these molecules, Re is η5-coordinated to the five-membered ring of the indenyl group. Complexes 8–14 have catalytic activity for Friedel-Crafts reactions of aromatic compounds with a variety of alkylation and acylation reagents. Compared with traditional catalysts, these mononuclear metal carbonyl complexes have obvious advantages such as high activities, mild reaction conditions, high selectivity, and environmentally friendly chemistry.
- Ma, Zhihong,Zhang, Xinli,Wang, Hong,Han, Zhangang,Zheng, Xuezhong,Lin, Jin
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p. 709 - 721
(2017/02/05)
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- Designing ordered mesoporous aluminosilicates under acidic conditions via an intrinsic hydrolysis method
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Acid-mediated synthesis of ordered mesoporous aluminosilicates (OMAS) with medium-to-strong Br?nsted acid sites and trivalent aluminium exclusively in a tetrahedral framework structure is realized by a newly devised intrinsic hydrolysis method. In this way, we have synthesized a series of well-ordered OMAS, e.g., H-AlSBA-15 and H-AlIITM-56, which are otherwise difficult to distinguish under acidic conditions owing to very different hydrolysis rates of both silicon and aluminium sources used for preparation as well as easy dissociation of thus formed Al-O-Si bonds. This novel intrinsic hydrolysis approach, however, relies mainly on similar hydrolysis rates of constituent inorganic species leading to efficient condensation. Thus, the innovative methodology using tetraethyl orthosilicate and aluminium citrate, respectively, as tetravalent silicon and trivalent aluminium as precursors facilitates the formation of high quality OMAS with a narrow pore size distribution, thicker walls, and trivalent aluminium in a tetrahedral framework structure with a high aluminium content, as evidenced by a battery of characterization techniques, viz., XRD, XRF, SEM, TEM and BET. The resulting materials, in turn, generate Br?nsted acid sites in the aluminosilicate matrix, with the absence of the usually encountered Lewis acid sites, viz., extra-framework and/or non-framework species, as confirmed by both 27Al MAS-NMR and NH3-TPD studies. All the prepared catalysts exhibit excellent activity towards the tertiary butylation of phenol, and the high activity of the catalysts is attributed to the unique and exclusive presence of medium-to-strong acid sites in the OMAS matrix.
- Krishna, Nunna V.,Selvam, Parasuraman
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p. 770 - 779
(2017/02/05)
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- Selecting an optimum catalyst for producing para-tert-butylphenol by phenol alkylation with tert-butanol
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Results of testing various heterogeneous catalysts in the synthesis of p-tert-butylphenol via phenol alkylation with tert-butyl alcohol are presented. It has been shown that all other conditions being equal, zeolite beta produced by the Angarsk catalyst and organic synthesis plant possesses the highest catalytic activity and selectivity for the desired product.
- Terekhov,Zanaveskin,Khadzhiev
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p. 714 - 717
(2017/07/26)
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- Highly active and spherical natured mesoporous aluminosilicate nanoparticles materialized for: T -butylation of phenol
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Aluminium-containing spherical mesoporous silica nanoparticle (AlSMSN) materials were synthesized for the first time using cetyltrimethylammonium bromide (CTMABr) as a structure-directing agent under nonhydrothermal conditions at room temperature. The effect of the nature of the Al source on the synthesis of the AlSMSN materials was investigated using a variety of Al sources. The effect of higher Al ion incorporation on the structural and textural properties of the AlSMSN materials was evaluated by varying the nSi/nAl ratios, and an efficient chemical treatment method was developed for the removal of superficial octahedral Al ions from the surface of the AlSMSN materials. The synthesized AlSMSN materials were characterized using ICP-AES, XRD, N2 adsorption, 27Al & 29Si MAS NMR, FTIR, TEM, and FE-SEM techniques. ICP-AES results revealed incorporation of a high Al ion content (nSi/nAl = 24) into the spherical mesoporous silica nanoparticle materials. For all of the calcined AlSMSN materials, the XRD reflection peaks shifted to lower angle with increasing Al ion content, resulting in an increase of the unit cell parameter. The textural parameters of the AlSMSN materials, except for the surface area, found from nitrogen adsorption measurements, increase with an increase in the amount of aluminium isopropoxide in the synthesis gel. The location and coordination of Al ions on the walls of the AlSMSN materials and the amount of Al ions incorporation were determined from the 27Al MAS NMR measurements. TEM and FE-SEM images demonstrated that the AlSMSN materials comprise spherical particles with hexagonally packed uniform mesoporous channels. Furthermore, the AlSMSN(20) with a higher Al content exhibits better hydrothermal stability than the AlSMSN(100) congener with a lower Al content. Catalyst recyclability studies showed that the washed catalyst (W-AlSMSN(20)) exhibited exceptional catalytic activity during t-butylation of phenol with 95.4% 4-t-butylphenol (4-TBP) selectivity due to removal of superficial octahedrally coordinated Al ions on the surface of active sites.
- Selvaraj
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p. 60983 - 60995
(2016/07/07)
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- Synthesis and catalytic activity of monobridged bis(cyclopentadienyl)rhenium carbonyl complexes
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Thermal treatment of three monobridged biscyclopentadienes (C5H5)R(C5H5) [R?=?C(CH3)2 (1), C(CH2)5 (2), Si(CH3)2 (3)] with Re2(CO)10 in refluxing mesitylene gave the corresponding complexes [(η5-C5H4)2R][Re(CO)3]2 [R?=?C(CH3)2 (4), C(C5H10) (5), Si(CH3)2 (6)], which were separated by chromatography, and characterized by elemental analysis, IR, and 1H NMR spectroscopy. The molecular structures of complexes 5 and 6 were characterized by X-ray crystal diffraction analysis and show that both are monobridged bis(cyclopentadienyl)rhenium carbonyl complexes in which the molecule consists of two [(η5-C5H4)Re(CO)3] moieties linked by a single bridge, in which each of the two Re(CO)3 units is coordinated to the cyclopentadienyl ring in an η5 mode. All three of these monobridged bis(cyclopentadienyl)rhenium carbonyl complexes have good catalytic activities in Friedel–Crafts alkylation reactions.
- Li, Zhen,Ma, Zhi-Hong,Wang, Hong,Han, Zhan-Gang,Zheng, Xue-Zhong,Lin, Jin
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p. 647 - 653
(2016/07/29)
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- Process for the production of tertiary butyl phenols
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The present invention relates to an improved process for the selective alkylation of phenols by reacting it with methyl tertiary butyl ether (MTBE) using polymer supported carbon composite acidic catalyst under mild to moderate conditions at atmospheric pressure. The process is economically viable since the catalyst regenerated after the initial reaction on further use gives the para tertiary butyl phenol (PTBP) in high yield.
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Page/Page column 6-7
(2016/09/26)
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- Highly efficient alkylation of phenol with tert-butyl alcohol using environmentally benign Bronsted acidic ionic liquids
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A series of SO3-H functionalized environmentally benign Bronsted acidic ionic liquids were prepared using triethylamine, 1-methyl imidazole, pyridine, diethanolamine, 1,4-butane sultone and methane sulfonic acid as the starting materials. These synthesized ionic liquid catalysts were characterized using spectroscopic tools like 1H NMR, 13C NMR. The catalytic activity of the synthesized ionic liquids was investigated in tert-butylation of phenol with tert-butyl alcohol. The effect of kinetic parameters like reaction time, reaction temperature, reactant mole ratio, reactant to catalyst mole ratio, on the conversion of phenol and selectivity to 2-tert-butyl-phenol and 2,4-di-tert-butyl-phenol were investigated. Phenol conversion upto 94.2% was achieved at temperature as low as 80 °C and low alcohol to phenol molar ratio of 2:1, ionic liquid to phenol ratio of 1:1 and reaction time of 2 h. The catalyst was found to retain its activity even after 8 recycles and was completely recoverable. The plausible reaction mechanism was formulated based on product distribution. The kinetic data was found to agree well with classical phenomenological models and the kinetic parameters were estimated. The experimental results were further validated by Density Functional Theory (DFT) optimizations of the ionic liquid structures performed at the B3LYP/6-311G??level using Gaussian 09 package.
- Patra, Tanmoy,Ahamad, Salahuddin,Upadhyayula, Sreedevi
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p. 228 - 236
(2015/10/20)
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- Polymer impregnated sulfonated carbon composite solid acid catalyst for alkylation of phenol with methyl-tert-butyl ether
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A polymer impregnated sulfonated carbon composite solid acid (P-C-SO3H) catalyst was synthesized via sulfonation of a composite material formed through incomplete carbonization of hydrolyzed glucose supported on a polymer matrix (co-polymer of styrene and chloromethylstyrene i.e. Merrifield's peptide resin) and used for the alkylation of phenol using methyl-tert-butyl ether (MTBE) as an alkylating agent in a pressure reactor under autogenous pressure. The developed catalyst exhibited excellent catalytic activity and provided para-tert-butyl phenol (PTBP) exclusively with the added benefits of facile recovery and reusability for several runs without loss of catalytic activity.
- Khatri, Praveen K.,Manchanda, Manvi,Ghosh, Indrajit K.,Jain, Suman L.
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p. 3286 - 3290
(2015/02/18)
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- Synthesis of hierarchical ZSM-5 using glucose as a templating precursor
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Various hierarchical ZSM-5 materials have been synthesized by adopting a novel concept using glucose as a precursor for the structure directing agent through a steam-assisted crystallization (SAC) process. The effect of the glucose/TEOS weight ratio was studied, and materials exhibiting different properties such as surface area, porosity and acidity were obtained by varying the concentration of glucose in the initial synthesis mixture. All the samples were characterized by XRD, SEM, TPD, and N2 adsorption-desorption and were studied for their performance towards the tertiary butylation of phenol reaction. The activities of all the hierarchical ZSM-5 materials synthesized by the present method were observed to be higher than that of the conventional ZSM-5. The optimal production of 2,4-di-tertiary butyl phenol over hierarchical ZSM-5 occurred at a reaction temperature of 150 °C after 7 h reaction time under solvent free conditions.
- Nandan, Devaki,Saxena, Sandeep K.,Viswanadham, Nagabhatla
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p. 1054 - 1059
(2014/01/06)
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- Sulfuric acid functional zirconium (or aluminum) incorporated mesoporous MCM-48 solid acid catalysts for alkylation of phenol with tert-butyl alcohol
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Several zirconium (or aluminum) incorporated mesoporous MCM-48 solid acid catalysts (SO42-/Zr-MCM-48 and SO4 2-/Al-MCM-48) were prepared by the impregnation method and their physicochemical properties were characterized by means of XRD, FT-IR, TEM, NH3-TPD and N2 physical adsorption. Also, the catalytic activities of these solid acid catalysts were evaluated by the alkylation of phenol with tert-butyl alcohol. The effect of weight hour space velocity (WHSV), reaction time and reaction temperature on catalytic properties was also studied. The results show that the SO42-/Zr-MCM-48 and SO42-/Al-MCM-48 still have good mesoporous structure and long range ordering. Compared with the Zr (or Al)-MCM-48 samples, SO 42-/Zr-MCM-48 and SO42-/Al-MCM-48 solid acid catalysts have strong acidity and exhibit high activities in alkylation reaction of phenol with tert-butyl alcohol. The SO4 2-/Zr-MCM-48-25 (molar ratio of Si/Zr=0.04) catalyst was found to be the most promising and gave the highest phenol conversion among all catalysts. A maximum phenol conversion of 91.6% with 4-tert-butyl phenol (4-TBP) selectivity of 81.8% was achieved when the molar ratio of tert-butyl alcohol:phenol is 2:1, reaction time is 2 h, the WHSV is 2 h-1 and the reaction temperature is 140 °C.
- Jiang, Tingshun,Cheng, Jinlian,Liu, Wangping,Fu, Lie,Zhou, Xuping,Zhao, Qian,Yin, Hengbo
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- Facile in situ syntheses of highly water-stable acidic sulfonated mesoporous silica without surfactant or template
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A new simple method to prepare acidic mesoporous sulfonated silica in situ without any surfactant is reported. The prepared catalysts were characterized by XRD, nitrogen adsorption, thermogravimetric analysis (TGA), and elemental analysis. The concentration of -SO3H groups was measured by titration, and FTIR was applied to confirm the successful incorporation of the strong acid sites. The in situ sulfonated silica (ISS) has a large surface area with a narrow range of mesoporosity and good thermal stability. Moreover, the preparation method has the advantage of easy control of the acid concentration and versatile synthesis. The ISS was used in catalytic hydrolysis and showed remarkable reusability even under very harsh conditions. The butylation of phenol was conducted over ISS to utilize the mesoporosity of the catalysts. Finally, the ISS catalysts might be used in various acid catalyses owing to the advantages of their simple/inexpensive preparation, reusability, and mesoporosity. New facile syntheses of acidic mesoporous catalysts and their catalytic applications are reported. The catalysts are extremely stable in water and at high temperature and can be used many times even under very harsh conditions Copyright
- Hasan, Zubair,Jhung, Sung Hwa
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supporting information
p. 3420 - 3426
(2014/08/05)
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- Facile in situ syntheses of highly water-stable acidic sulfonated mesoporous silica without surfactant or template
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A new simple method to prepare acidic mesoporous sulfonated silica in situ without any surfactant is reported. The prepared catalysts were characterized by XRD, nitrogen adsorption, thermogravimetric analysis (TGA), and elemental analysis. The concentration of -SO3H groups was measured by titration, and FTIR was applied to confirm the successful incorporation of the strong acid sites. The in situ sulfonated silica (ISS) has a large surface area with a narrow range of mesoporosity and good thermal stability. Moreover, the preparation method has the advantage of easy control of the acid concentration and versatile synthesis. The ISS was used in catalytic hydrolysis and showed remarkable reusability even under very harsh conditions. The butylation of phenol was conducted over ISS to utilize the mesoporosity of the catalysts. Finally, the ISS catalysts might be used in various acid catalyses owing to the advantages of their simple/inexpensive preparation, reusability, and mesoporosity. New facile syntheses of acidic mesoporous catalysts and their catalytic applications are reported. The catalysts are extremely stable in water and at high temperature and can be used many times even under very harsh conditions
- Hasan, Zubair,Jhung, Sung Hwa
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supporting information
p. 3420 - 3426
(2015/04/27)
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- Facile single step synthesis of an acid functionalized nano porous carbon composite as an efficient catalyst for tertiary butylation of phenol
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Here we report a simple synthesis method for the preparation of an acid functionalized nano porous nanocomposite of carbon for the first time from petroleum waste by a simultaneous carbonisation and sulfonation method. The material exhibited the highest ever reported catalytic activity towards liquid phase tertiary butylation of phenol up to several reaction cycles.
- Nandan, Devaki,Viswanadham, Nagabhatla
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p. 57223 - 57226
(2015/02/05)
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- Solvent free liquid-phase alkylation of phenol over solid sulfanilic acid catalyst
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Sulfanilic acid was immobilized onto rice husk ash via 3-(chloropropyl) triethoxy-silane to form an acidic solid catalyst denoted as RHAPhSO 3H. The BET surface area was found to be 308 m2 g -1. Pyridine adsorption study revealed the presence of Br?nsted acid sites. The EDX analysis showed the presence of S (10.88%) and N (10.37%). The 29Si MAS NMR showed the presence of T 2, T3, Q3 and Q4 silicon centres. The three carbon atoms of the propyl group were evident from the 13C MAS NMR together with a series of chemical shifts consistent with the presence of the benzene ring. In the alkylation of phenol using RHAPhSO3H as the catalyst resulted in 95% conversion of tert-butyl alcohol at 120 °C with 52% selectivity towards 4-tert-butylphenol. The catalyst was reused several times without significant loss of catalytic activity.
- Adam, Farook,Hello, Kasim Mohammed,Ali, Tammar Hussein
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experimental part
p. 42 - 49
(2012/02/01)
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- Facile synthesis of a sulfonated carbon-silica-meso composite and mesoporous silica
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In this study we report a novel and simple method for preparing a sulfonated carbon-silica-meso composite showing high acidity and porosity useful for transformation of bulky molecules, where glucose was used as a carbon source as well as a non-surfactant templating precursor and the resultant composite upon calcination yielded the mesoporous silica.
- Nandan, Devaki,Sreenivasulu, Peta,Saxena, Sandeep K.,Viswanadham, Nagbhatla
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supporting information; experimental part
p. 11537 - 11539
(2011/11/07)
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- PROCESS FOR PRODUCING A T-BUTYL PHENOL FROM A C4 RAFFINATE STREAM
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This invention relates to processes for producing various t-butyl phenols, such as 2,6-di-tert-butyl phenol and ortho-tert-butyl phenol, by selectively reacting phenol or a substituted phenol with an isobutylene-containing C4 raffinate stream. The 2,6-di-tert-butyl phenol and ortho-tert-butyl phenol can be transalkylated to form other tert-butyl phenols, such as para-tert-butyl phenol, 2,4-di-tert-butyl phenol.
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Page/Page column 11
(2011/06/25)
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- SOLID ALKYLARYL PHOSPHITE COMPOSITIONS AND METHODS FOR MANUFACTURING SAME
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The invention is directed to various alkylaryl phosphite compositions that ideally are suitable for use as secondary antioxidants in polymers. In one aspect, the phosphite composition comprises a tris(dialkylaryl)phosphite in an amount from 20 to 93 weight percent; and at least one of: a bis(dialkylaryl)monoalkylaryl phosphite; a bis(monoalkylaryl)dialkylaryl phosphite; and a tris(monoalkylaryl) phosphite. The inventive phosphite composition is a solid at ambient conditions. The invention also relates to alkylate compositions and processes for forming such alkylate compositions and such phosphite compositions.
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Page/Page column 39
(2011/02/24)
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- LIQUID ALKYLATED TRISARYL PHOSPHITE COMPOSITIONS HAVING TWO ALKYL GROUPS WITH DIFFERENT CARBON NUMBER
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A composition comprising at least two different alkylaryl phosphites, wherein some alkyl groups have a different number of carbon atoms than other alkyl groups and wherein the composition is a liquid at ambient conditions.
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Page/Page column 42
(2011/02/24)
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- LIQUID BUTYLARYL PHOSPHITE COMPOSITIONS
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A phosphite composition comprising at least two of a tris(dibutylaryl) phosphite, a tris(monobutylaryl) phosphite, a bis(dibutylaryl)monobutylaryl phosphite, and a bis(monobutylaryl)dibutylaryl phosphite. The inventive phosphite composition is a liquid at ambient conditions. The inventive phosphite is a reaction product of a phorsphous trihalide with an alkylate composition having a molar ratio of monobutylaryl alkylate to dibutylaryl alkylate that is higher than 2:1 and equal to or lower than 5:1.
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Page/Page column 41
(2011/02/24)
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- SOLID ALKYLARYL PHOSPHITE COMPOSITIONS AND METHODS FOR MANUFACTURING SAME
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The invention is directed to various alkylaryl phosphite compositions that ideally are suitable for use as secondary antioxidants in polymers. In one aspect, the phosphite composition comprises a tris(monoalkylaryl)phosphite in an amount from 51 to 95 weight percent; and at least one of: a bis(monoalkylaryl)dialkylaryl phosphite; a bis(dialkylaryl)monoalkylaryl phosphite; and a tris(dialkylaryl) phosphite. The inventive phosphite composition is a solid at ambient conditions. The invention also relates to alkylate compositions and processes for forming such alkylate compositions and such phosphite compositions.
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Page/Page column 35
(2011/02/24)
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- Chloroindate(iii) ionic liquids as catalysts for alkylation of phenols and catechol with alkenes
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Chloroindate(iii) ionic liquids are shown to be versatile catalysts for the alkylation of phenols with alkenes, giving high conversions to alkylated phenols with high selectivities.
- Gunaratne, H. Q. Nimal,Lotz, Tobias J.,Seddon, Kenneth R.
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scheme or table
p. 1821 - 1824
(2011/01/07)
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- Vapor-phase alkylation of phenol with tert-butyl alcohol catalyzed by H3PO4/MCM-41
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The catalytic performance of Al-MCM-41 containing 5-35 wt H 3PO4 was studied for the vapor-phase alkylation of phenol with tert-butyl alcohol (TBA) from 383 to 493 K. 4-Tert-butyl phenol was produced as the main product with moderate selectivity. The product distribution depends on the reaction temperature, number of acid sites, and the Broensted to Lewis sites ratios. A lower molar ratio of reactants (TBA/phenol = 2) and a higher space velocity facilitated the production of 4-tert-butyl phenol. The influence of various parameters such as temperature, reactant feed molar ratio, feed rate, and time on stream were investigated for conversion yield and product selectivity.
- Ghiaci, Mehran,Aghabarari, Behzad
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experimental part
p. 759 - 764
(2010/12/24)
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- The effect of pH on the formation of aroma compounds produced by heating a model system containing l-ascorbic acid with l-threonine/l-serine
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The identification of aroma compounds, formed from the reactions of l-ascorbic acid with l-threonine/l-serine at five different pH values (5.00, 6.00, 7.00, 8.00, or 9.55) and 143 ± 2 °C for 2 h, was performed using a SPME-GC-MS technique, and further use
- Yu, Ai-Nong,Zhang, Ai-Dong
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experimental part
p. 214 - 219
(2011/12/14)
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- Phenol alkylation with isobutene - influence of heterogeneous Lewis and/or Bronsted acid sites
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Acidic solid catalysts with different types of acidity were used to study the liquid-phase alkylation of phenol with isobutene. A phosphonium ionic liquid immobilized on silica type carrier exhibiting pure Lewis acidity, Amberlyst 15 with pure Bronsted acidity as well as WO3/ZrO2 with both types of acid sites were used for this study. The active sites are postulated based on pyridine-FT-IR and NH3-TPD studies, BET analyses, MAS NMR and XRD measurements. The different properties of the chosen catalysts are mirrored in the product distribution of the reaction mixture. It was found that WO3/ZrO2 is a very active and selective catalyst for the production of 2,4-di-tert-butylphenol under mild reaction conditions.
- Modrogan, Elena,Valkenberg, Michael H.,Hoelderich, Wolfgang F.
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experimental part
p. 177 - 187
(2009/06/05)
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- Development of a one-stage synthesis of 2,6-di-tert-4-ethylbutylphenol from 2,6-di-tert-butylphenol
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Investigation of the catalyzed reaction of 2,6-di-tert-butylphenol with ethanol, ethylene glycol, oligomeric glycols, and paraldehyde in a strongly basic medium permitted to develop a technologically suitable procedure for manufacture of 2,6-di-tert-4-ethyl-butylphenol, used in the synthesis of Antioxidant-425.
- Krysin,Pokrovskii
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experimental part
p. 1728 - 1733
(2009/02/06)
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- ALKYLATION OF HYDROXYARENES WITH OLEFINS, ALCOHOLS AND ETHERS IN IONIC LIQUIDS
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Hydroxyarenes are alkylated using an ionic liquid catalyst system with olefins, alcohols, or ethers as alkylating agents. The ionic liquid catalyst system comprises chloroindate (III) anions. The reactions may be conducted at moderate temperatures and pressures to yield commercially relevant alkylated hydroxyarene compounds.
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Page/Page column 19-20
(2008/06/13)
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- Alcohols and di-tert-butyl dicarbonate: How the nature of the Lewis acid catalyst may address the reaction to the synthesis of tert-butyl ethers
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The reaction between alcohols and Boc2O leads to the formation of ferf-butyl ethers and/or Boc-alcohols, depending on the nature of the Lewis acid catalyst. Product distribution is mainly tuned by the anionic part of the salt. Perchlorates and Inflates, anions with highly delocalized negative charge, give prevalent or exclusive ether formation. On the other hand, Boc alcohols are the main or exclusive products with un-delocalized isopropoxide or low-delocalized acetate ions. The metal ion influences only the reaction rate, roughly following standard parameters for calculating Lewis acidity. A reaction mechanism is supposed, and a series of experimental evidences is reported to support it. These studies allowed us to conclude that, to synthesize tert-butyl ethers, in reactions involving aliphatic alcohols, Mg(ClO4) 2 or Al(ClO4)3 represents the best compromise between costs and efficiency of the reaction, while, in reactions involving phenols, Sc(OTf)3 is the best choice, since aromatic tert-butyl ethers are not stable in the presence of perchlorates.
- Bartoli, Giuseppe,Bosco, Marcella,Carlone, Armando,Dalpozzo, Renato,Locatelli, Manuela,Melchiorre, Paolo,Sambri, Letizia
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p. 9580 - 9588
(2007/10/03)
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- Alkylation of phenol with tert-butyl alcohol catalysed by some sulphated titania systems
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Titania sulphated titania and transition metal loaded (9%) sulphated titania have been prepared by sol gel method and characterized by XRD, FTIR, BET surface area, EDX and UV-vis DRS. Surface acidity of these catalysts is determined by temperature programmed desorption of ammonia. Alkylation of phenol with tert-butanol in the vapour phase over the prepared systems has been studied at 1 atm and 160-220°C. The reaction provides high selectivity of alkylation at the para position. The product selectivity has been correlated with the surface acidity of the systems.
- Sunajadevi,Sugunan
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p. 1131 - 1138
(2007/10/03)
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- Efficient t-butylation of phenol using the Wells-Dawson-type molybdovanadophosphoric heteropolyacid, H7P2Mo 17VO62, as catalyst
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Wells-Dawson heteropolyacid H7P2Mo 17VO62 proved to be an efficient catalyst for the alkylation of phenol with t-butyl alcohol. Under optimized conditions, 80°C and 4 h, H7P2Mo17VO62 loads as low as 0.15 mol % can be used leading to high phenol conversion. The main product, 2, 4-di-t-butylphenol, could be obtained in moderate selectivity.
- Li, Guixian,Wang, Bo,Wang, Jianming,Yan, Liang,Suo, Jishuan
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p. 173 - 176
(2007/10/03)
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- The t-butylation of phenol in supercritical carbon dioxide over H-Y zeolite. Remarkable enhancement of catalytic performance for the formation of 2,4-di-t-butylphenol
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Remarkable enhancement of the formation of 2,4-di-t-butyl-phenol was observed in the t-butylation of phenol over H-Y zeolite under supercritical CO2 medium. Supercritical CO2 renders active sites free for the catalysis by fast remova
- Kamalakar, Gunda,Komura, Kenichi,Sugi, Yoshihiro
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p. 1446 - 1447
(2007/10/03)
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- Tertiary butylation of phenol on Cu1-xCoxFe 2O4: Catalysis and structure-activity correlation
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A systematic study of catalytic tertiary butylation of phenol was carried out with isobutene as a function of temperature, feed composition, time on stream, space velocity, and catalyst composition on Cu1-xCo xFe2O4 (x=0 to 1) system. Tertiary butylation of phenol gives three products, namely, 2-tert-butyl phenol, 4-tert-butyl phenol, and 2,4-di-tert-butyl phenol. The phenol conversion and selectivity of these products depend on the reaction parameters. A good correlation was found between the activity, in terms of phenol conversion and various product selectivities for this reaction, and the acid-base properties of the catalysts. High activity is achieved with x=0.5 composition, illustrating the importance of a 1:1 combination of Cu and Co and the necessity for optimum concentrations of acid-base centers for this reaction. A reaction mechanism involving the interaction of phenoxide from phenol and the tert-butyl cation from isobutene on Cu1-xCoxFe2O4 is proposed. X-ray photoelectron spectroscopy and X-ray induced Auger electron spectroscopic analysis of fresh and spent catalysts revealed a partial reduction of metal ions due to reaction. Valence band studies clearly revealed an increase in the overlap of metal ion 3d bands from fresh to spent catalysts as reflected from a large decrease in the energy gap between them. The better catalytic results observed with x=0.5 are attributed to an optimum distribution of Cu species with heteroatom neighbors, maximum overlap between the Cu and Co 3d bands, and intermediate acid-base character.
- Mathew, Thomas,Rao, Bollapragada S.,Gopinath, Chinnakonda S.
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p. 107 - 116
(2007/10/03)
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- Selective alkylation of phenol with tert-butyl alcohol catalyzed by [bmim]PF6
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Alkylation of phenol with tert-butyl alcohol (TBA) in a room temperature ionic liquid, 1-butyl-3-methylimidazoliumhexafluorophosphate ([bmim]PF6), has been investigated. The effects of various parameters such as reaction temperature, reaction time, reactant ratio (mol ratio of phenol to that of TBA), and the amount of the ionic liquid used were studied. The [bmim]PF6 ionic liquid was found to catalyze the reaction with high conversion and good selectivity.
- Shen, Hao-Yu,Judeh, Zaher M. A.,Ching, Chi Bun
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p. 981 - 983
(2007/10/03)
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- On the Mechanism of the Oxidation of Toluenes in Artificial P450 Model Systems: Formation of Benzyl Alcohols, Benzaldehydes and Phenols
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Systems with pentafluoroiodosylbenzene (PFIB) and hemin (FeTPPCl8Cl) in dichloromethane were adopted to study the activities of the model system using toluenes as substrates for P450 enzymes. The oxidation products were mainly corresponding benzyl alcohols and benzaldehydes. Previously reported suspension systems were extended to homogeneous mixed solution systems of CH2Cl2/CH3OH/H2O to study the oxidation of benzyl alcohols to the corresponding benzaldehydes: the Hammett relation with ρ = -0.86 against ?+. As benzaldehydes were scarcely observed in natural P450 systems, the formation of benzaldehyde seemed characteristic only of the "open" model systems. In suspension systems, the product ratios between corresponding benzaldehydes and benzyl alcohols (ald/alc) were about 0.1-0.4, specific to the substituents and conditions applied. Curiously, the ratios (ald/alc) increased with the electronegativity of the substituents on the phenyl rings of the toluene derivatives. Time course experiments in suspension systems indicated that benzyl alcohols and benzaldehydes were formed not stepwise, but simultaneously from toluene. Separate experiments indicated that the reaction of benzyl alcohol to benzaldehyde was four-fold faster than that of toluene to benzyl alcohol. The rate was not enough to elucidate the amount of benzaldehyde. We suggest that the benzyl radical is formed by hydrogen abstraction and is attacked by the second oxidant, PFIB. Rebounding of the hydroxyl radical and the reaction with the oxidant were competitive depending on the conditions. Additionally, small amounts of phenols were formed from toluenes with electron-donating substituents. This was a minor reaction on which the aromatic hydroxylation occurred via epoxidation under the present conditions.
- Nakano, Taku,Kawabata, Sally,Sugihara, Tamami,Agatsuma, Noriko,Kakuda, Hiroko,Mori, Yoshihiro
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p. 2353 - 2360
(2007/10/03)
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- Iron-containing graphite as a Friedel-Crafts alkylation catalyst
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The activity of iron-containing graphites for the Friedel-Crafts reaction of phenol with tert-butyl halides was studied. The reaction of phenol with either different tert-butyl halides or tert-butyl alcohol on iron-containing graphite was conducted in a benzene solvent for 4 hr at 50°C. The Friedel-Crafts reaction of phenol with tert-butyl halides on graphite was in the following order: iodide > bromide > chloride. tert-Butyl iodide was the most active in the Friedel-Crafts of phenol in the presence of graphite, whereas it was the least reactive in the presence of AlCl3. AlCl3 was very highly active in phenol, while graphite was mildly reactive in phenol. The presence of iron accelerated the reaction of phenol with the tert-butyl halide on graphite to produced p-tert-butylphenol as the main product. The distance between the layers of graphite increased in the presence of both tert-butyl bromide and iron, but not in the presence of either the iron or tert-butyl bromide. tert-Butyl halide was first adsorbed on graphite and then dissociated to form tert-butyl and halogen ions. The Friedel-Crafts alkylation of phenol on graphite was accompanied by isomerization and dealkylation.
- Nagai,Kodomari,Omi,Yoda
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p. 105 - 112
(2007/10/03)
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- Mechanism of dimerization-rearrangement of organosilicon aroxyls
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Organosilicon aroxyls form disiloxyhiaryls via C-C dimerization with simultaneous (or subsequent) isomerization of the dimeric intermediate, involving migration of the ortho-organosilyl substituents from carbon to oxygen.
- Muslin,Lyapina,Tyulina,Khorshev,Vavilina
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p. 1248 - 1251
(2007/10/03)
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- Rhenium complexes-catalyzed alkylation of arenes with alkyl halides
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Rhenium complexes have been shown to catalyze the alkylation of arenes with alkyl halides. When arenes were reacted with an alkyl chloride in the presence of a catalytic amount of rhenium complexes, such as bromopentacarbonylrhenium(I) [ReBr(CO)5], tricarbonylcyclopentadienylrhenium(I) [Re(C5H5)(CO)3] and decacarbonyldirhenium [Re2(CO)10], alkylation of the arenes proceeded under mild conditions to give a mixture of mono- and dialkyl substituted arenes in moderate-to-good yields.
- Nishiyama,Kakushou,Sonoda
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p. 2779 - 2782
(2007/10/03)
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- Substituent effects on the benzene ring. Determination of the intramolecular interactions of substituents in tert-alkyl-substituted catechols from thermochemical measurements
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Chemical equilibria of reactions of transalkylation among tert-butylphenols and tert-butylcatechols in the liquid phase were investigated in the temperature range 373-483 K. The molar enthalpies of fusion ΔcrlH°m of the catechol, 4-tert-butylcatechol, and 3,5-di-tert-butylcatechol were measured by DSC. The standard (p° = 0.1 MPa) molar enthalpies of formation ΔfH°m (cr) at the temperature T = 298.15 K were measured by means of combustion calorimetry for 4-tert-butylcatechol and 3,5-di-tert-butylcatechol. The standard molar enthalpies of sublimation of these compounds, and also the enthalpy of vaporization of 3-tert-butylcatechol, were obtained from the temperature dependence of the vapor pressure measured by the transpiration method. The measured reaction enthalpies were utilized for reconciliation of calorimetrically derived standard molar enthalpies of formation of tert-butyl-substituted phenols and catechols, as a stringent test of thermodynamic consistency of results derived from the diverse techniques employed in this work. Resulting values of ΔfH°m(g) of tert-butylcatechols were obtained at the temperature T = 298.15 K and used to derive their strain enthalpies. The intramolecular interactions of the substituents were discussed in terms of deviations of ΔfH°m(g) from the group additivity rules. No peculiarities in the interaction energy among alkyl groups and the hydroxyl groups in the ortho-, para-, and meta-positions of alkylcatechols in comparison with those of alkyl-substituted phenols were detected. Thus, no new parameters are needed for the prediction of the ΔfH°m(g) values of alkylcatechols by using the group-additive procedure.
- Verevkin, Sergey P.,Schick, Christoph
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p. 946 - 952
(2007/10/03)
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- Color-stabilized basic monomers, process for producing the same and method for handling the same
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Color-stabilized basic monomers are provided. Said basic monomers are obtained by adding, to a basic monomer ?e.g. an N,N-dialkylaminoalkyl (meth)acrylate or an N,N-dialkylaminoalkyl (meth)acrylamide!, at least one member selected from the group consisting of amido group-containing compounds, phosphorous acid esters, phosphoric acid esters and phosphines and at least one phenol compound represented by the general formula: STR1 wherein R5, R6, R8 and R9 are each independently a hydrogen atom or an alkyl group having 1 to 4 carbon atoms; and R7 is a hydrogen atom, an alkyl group having 1 to 4 carbon atoms or an alkoxy group having 1 to 4 carbon atoms. The color-stabilized basic monomers are more resistant to coloration when they are handled under such conditions that the oxygen concentration in the gas phase contacting therewith is 0.01 to 10% by volume.
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- Bis-phosphepines and processses for their preparation
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The invention relates to bis-phosphepines of the formula (I): STR1 where: Ar--Ar is biphenyl, 1,1'-binaphthyl or 1-phenylnaphthyl, R1 independently of one another are F, (C1 -C8)-alkyl or (C1 -C8)-alkoxy, m is 0, 1, 2, 3 or 4, R2 and R3 independently of one another are H, (C1 -C20)-alkyl, (C6 -C20)-aryl, (C7 -C20)-aralkyl, (C7 -C20)-alkaryl or (C3 -C20)-cycloalkyl and R4 is (C1 -C10)-alkylene, it also being possible for the alkylene chain to contain oxygen atoms and N-alkyl groups, (C3 -C10)-cycloalkylene, (C8 -C22)-arylene-bisalkyl or (C6 -C10)-arylene, the group CR2 R3 always being adjacent to the Ar--Ar bond. The invention further relates to processes for the preparation of compounds of the formula (I).
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- Clathrate compound including water-soluble microbicide
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A clathrate compound composed of a water-soluble microbicide and a phenolic compound of formula (1) or (2): STR1
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- Reactions gaz/solide organique. Alkylation du 4-tert-butylphenol solide par l'isobutene gaz en presence de catalyseurs solides ou liquides. Etude des parametres de la reaction.
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Organic solid/gas reactions.Alkylation of 4-tert-butylphenol by isobutene gas in the presence of solid or liquid catalysts.Study of the reaction parameters.Alkylation of phenols was studied in the solid phase in the presence of acid catalysts.The solid 4-tert-butylphenol was alkylated by gaseous isobutene under mild conditions in a batch reactor, tubular reactor and fixed-bed reactor.The solid 4-tert-butylphenol can be used in three ways: directly in its initial solid state; supported on silica or alumina; or deposited on a solid catalyst.The reaction arises from three reactive phases, each of which was characterized.The effect of followed parameters was studied: temperature; pressure; flow-rate; proportion and nature of the catalyst; contact area and size of reactants and catalysts; and reactor geometry.The modification of the conversion ratio with these parameters allowed us to define the optimum conditions for the gas/solid reactions.The nature and the number of contacts between solid phases are specified; the reaction and the interface are localized.The O- and C-alkylation ratio was studied; O-alkylation predominated at low temperature. - Keywords: solid state; alkylation; 4-tert-butylphenol; 2,4-di-tert-butylphenol; tert-butyl-4-tert-butylphenyl ether; catalyst.
- Selatnia, Ammar,Bassus, Jacques,Lamartine, Roger
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p. 360 - 368
(2007/10/02)
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