- 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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- 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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- 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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- 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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- 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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- 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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- 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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- 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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- 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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- 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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- 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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- Alkylation of phenol with tertiary butyl alcohol over zeolites
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Alkylation of phenol was carried out with tert-butyl alcohol (TBA) producing p-tert-butyl phenol over a variety of zeolite catalysts, namely, zeolite Beta, 13X zeolite, Ce-exchanged 13X zeolite, and zeolite prepared from fly ash. Zeolite Beta showed the highest activity for the reaction under otherwise identical conditions. The activity of 13X zeolite was found to increase with an increase in cerium content in the catalyst, which was accomplished through ion exchange. The activity of zeolite (obtained from fly ash by hydrothermal treatment) in catalyzing the reaction was tested with highly encouraging results. The effects of various parameters such as reaction temperature, reactant ratio (mole ratio of phenol to that of tert-butyl alcohol), and catalyst loading on the rate of reaction were also studied. The alkylation reaction was found to be surface-reaction controlled with negligible interparticle mass-transfer resistance.
- Krishnan,Ojha, Keka,Pradhan, Narayan C.
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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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- 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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- A mild and practical method for deprotection of aryl methyl/benzyl/allyl ethers with HPPh2andtBuOK
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A general method for the demethylation, debenzylation, and deallylation of aryl ethers using HPPh2andtBuOK is reported. The reaction features mild and metal-free reaction conditions, broad substrate scope, good functional group compatibility, and high chemical selectivity towards aryl ethers over aliphatic structures. Notably, this approach is competent to selectively deprotect the allyl or benzyl group, making it a general and practical method in organic synthesis.
- Pan, Wenjing,Li, Chenchen,Zhu, Haoyin,Li, Fangfang,Li, Tao,Zhao, Wanxiang
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p. 7633 - 7640
(2021/09/22)
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- 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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- Aryl phenol compound as well as synthesis method and application thereof
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The invention discloses a synthesis method of an aryl phenol compound shown as a formula (3). All systems are carried out in an air or nitrogen atmosphere, and visible light is utilized to excite a photosensitizer for catalyzation. In a reaction solvent, ArNR1R2 as shown in a formula (1) and water as shown in a formula (2) are used as reaction raw materials and react under the auxiliary action of acid to obtain the aryl phenol compound as shown in a formula (3). The ArNR1R2 in the formula (1) can be primary amine and tertiary amine, can also be steroid and amino acid derivatives, and can also be drugs or derivatives of propofol, paracetamol, ibuprofen, oxaprozin, indomethacin and the like. The synthesis method has the advantages of cheap and easily available raw materials, simple reaction operation, mild reaction conditions, high reaction yield and good compatibility of substrate functional groups. The fluid reaction not only can realize amplification of basic chemicals, but also can realize amplification of fine chemicals, such as synthesis of drugs propofol and paracetamol. The invention has wide application prospect and use value.
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Paragraph 0054-0057
(2021/05/12)
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- Easy Synthesis of a Self-Assembled Imine-Based Iron(II) Complex Endowed with Crown-Ether Receptors
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Herein we report that an imine-based iron complex decorated with crown-ether moieties self-assembles in CH3CN solution from three building blocks (namely Fe(CH3CN)2(OTf)2, 2-picolylamine and aldehyde 6a) added in the proper molar ratio (1:2:2, respectively). Aldehyde 6a, endowed with a benzocrown-ether receptor, can be prepared in two steps from commercial materials with high yields (79 percent) and no need of chromatographic separations. The self-assembled complex is highly stable in CH3CN solution. The complex has been tested as catalyst for the oxidation of aromatic compounds endowed with primary ammonium anchoring group with H2O2. An unexpected yet moderate selectivity for remote meta over ortho hydroxylation was obtained, which is mainly due to the steric hindrance of the catalyst.
- Capocasa, Giorgio,Di Berto Mancini, Marika,Di Stefano, Stefano,Frateloreto, Federico,Lanzalunga, Osvaldo,Olivo, Giorgio
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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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- Aerobic C-C and C-O bond formation reactions mediated by high-valent nickel species
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Nickel complexes have been widely employed as catalysts in C-C and C-heteroatom bond formation reactions. While Ni(0), Ni(i), and Ni(ii) intermediates are most relevant in these transformations, recently Ni(iii) and Ni(iv) species have also been proposed to play a role in catalysis. Reported herein is the synthesis, detailed characterization, and reactivity of a series of Ni(ii) and Ni(iii) metallacycle complexes stabilized by tetradentate pyridinophane ligands with various N-substituents. Interestingly, while the oxidation of the Ni(ii) complexes with various other oxidants led to exclusive C-C bond formation in very good yields, the use of O2 or H2O2 as oxidants led to formation of appreciable amounts of C-O bond formation products, especially for the Ni(ii) complex supported by an asymmetric pyridinophane ligand containing one tosyl N-substituent. Moreover, cryo-ESI-MS studies support the formation of several high-valent Ni species as key intermediates in this uncommon Ni-mediated oxygenase-type chemistry.
- Gómez, Laura,Mirica, Liviu M.,Planas, Oriol,Rath, Nigam P.,Ribas, Xavi,Smith, Sofia M.
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p. 10366 - 10372
(2019/11/20)
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- Tetrafluoropyridyl (TFP): a general phenol protecting group readily cleaved under mild conditions
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Phenols are extremely valuable building blocks in the areas of pharmaceuticals, natural products, materials and catalysts. In order to carry out modifications on phenols, the phenolic oxygen is routinely protected to prevent unwanted side reactions. Presently many of the protecting groups available can require harsh conditions, specialist equipment, expensive or air/moisture-sensitive reagents to install and remove. Here we introduce the use of the tetrafluoropyridyl (TFP) group as a general protecting group for phenols. TFP can be installed in one step with no sensitivity to water or air, and it is stable under a range of commonly employed reaction conditions including acid and base. The TFP protecting group is readily cleaved under mild conditions with quantitative conversion to the parent phenol, observed in many cases in less than 1 hour.
- Brittain, William D. G.,Cobb, Steven L.
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supporting information
p. 2110 - 2115
(2019/02/27)
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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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- Synthesis method of tert-butyl cyclohexyl ethyl carbonate spice
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The invention discloses a synthesis method of tert-butyl cyclohexyl ethyl carbonate spice and relates to the technical field of fine chemical engineering. The synthesis method includes: using phenol and tert-butanol as starting raw materials for alkylation reaction, hydrogenating, being in acetylation reaction with diethyl carbonate to generate tert-butyl cyclohexyl ethyl carbonate. The synthesismethod is easy-to-get in raw material and high in yield, a ratio of o-tert-butyl phenol and p-tert-butyl phenol generated by reaction of phenol and tert-butanol reaches 7:3, and p-tert-butyl phenol which is a byproduct can generate iris ester for use after being hydrogenated and esterified; the spice is high in purity and pure and gentle in fragrance and meets flavoring requirements of essence andspice.
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Paragraph 0025; 0032-0034
(2018/03/26)
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- Production method of tertiary butyl cylcohexyl ethyl carbonate synthetic perfume
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The invention discloses a production method of a tertiary butyl cylcohexyl ethyl carbonate synthetic perfume and relates to the technical field of fine chemical production. The production method provided by the invention comprises the following steps of by taking phenol and tert-butyl alcohol as starting materials to perform alkylation reaction, then performing hydrogenation on a reactant, and performing acetylation reaction on the reactant and diethyl carbonate to produce tertiary butyl cylcohexyl ethyl carbonate, wherein the raw materials are available, the yield is high, the proportion of o-tert butylphenol produced by reaction of the phenol and the tert-butyl alcohol and p-tert-butylphenol reaches 7 to 3, an iris ester product can be obtained after performing hydrogenation and esterification on the p-tert-butylphenol as a by-product and is put to use. The production method is strong in controllability of technological parameters, good in repeatability and simplified in operation; and a product is high in purity, pure and gentle in fragrance and accords with the flavor blending requirements for an essence perfume.
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Paragraph 0041-0047
(2018/03/24)
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- METHOD FOR PREPARING P-HYDROXYMANDELIC COMPOUNDS IN STIRRED REACTORS
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The process allows the preparation of a p-hydroxymandelic compound, comprising at least one step of condensation of at least one aromatic compound bearing at least one hydroxyl group and whose para position is free, with glyoxylic acid, the condensation reaction being performed in at least one reactor equipped with at least one mixing means, the specific mixing power being between 0.1 kW/m3 and 15 kW/m3. In addition, the invention also relates to a process for preparing a 4-hydroxyaromatic aldehyde by oxidation of this p-hydroxymandelic compound.
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- Highly Selective and Efficient Ring Hydroxylation of Alkylbenzenes with Hydrogen Peroxide and an Osmium(VI) Nitrido Catalyst
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The OsVI nitrido complex, OsVI(N)(quin)2(OTs) (1, quin=2-quinaldinate, OTs=tosylate), is a highly selective and efficient catalyst for the ring hydroxylation of alkylbenzenes with H2O2 at room temperature. Oxidation of various alkylbenzenes occurs with ring/chain oxidation ratios ranging from 96.7/3.3 to 99.9/0.1, and total product yields from 93 % to 98 %. Moreover, turnover numbers up to 6360, 5670, and 3880 can be achieved for the oxidation of p-xylene, ethylbenzene, and mesitylene, respectively. Density functional theory calculations suggest that the active intermediate is an OsVIII nitrido oxo species.
- Kwong, Hoi-Ki,Lo, Po-Kam,Yiu, Shek-Man,Hirao, Hajime,Lau, Kai-Chung,Lau, Tai-Chu
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p. 12260 - 12263
(2017/09/06)
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- Oxidative C-C bond formation reactivity of organometallic Ni(II), Ni(III), and Ni(IV) complexes
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The use of the tridentate ligand 1,4,7-trimethyl-1,4,7-triazacyclononane (Me3tacn) and the cyclic alkyl/aryl C-donor ligand-CH2CMe2-o-C6H4-(cycloneophyl) allows for the synthesis of isolable organometallic NiII, NiIII, and NiIV complexes. Surprisingly, the fivecoordinate NiIII complex is stable both in solution and the solid state, and exhibits limited C-C bond formation reactivity. Oxidation by one electron of this NiIII species generates a six-coordinate NiIV complex, with an acetonitrile molecule bound to Ni. Interestingly, illumination of the NiIV complex with blue LEDs results in rapid formation of the cyclic C-C product at room temperature. This reactivity has important implications for the recently developed dual Ni/photoredox catalytic systems proposed to involve high-valent organometallic Ni intermediates. Additional reactivity studies show the corresponding NiII species undergoes oxidative addition with alkyl halides, as well as rapid oxidation by O2, to generate detectable NiIII and/or NiIV intermediates and followed by C-C bond formation.
- Watson, Michael B.,Rath, Nigam P.,Mirica, Liviu M.
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- Construction of Acid–Base Synergetic Sites on Mg-bearing BEA Zeolites Triggers the Unexpected Low-Temperature Alkylation of Phenol
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Novel Mg-bearing BEA zeolites are synthesized to simultaneously endow significantly enhanced basicity without compromising acidity over the zeolite framework. Serving as efficient solid acid–base bifunctional catalysts, they achieve the liquid-phase selective methylation of phenol with methanol to produce o- and p-cresol (o/p=2) under mild conditions. The method is readily extendable to the alkylation of phenols with various alcohols. Stereo- and regioselectivity (>95 % for p-product) was attained on the alkylation of phenol with bulky tert-butyl alcohol, rendering the first acid–base cooperative shape-selective catalysis relying on the basicity of zeolites. A preliminary mechanistic analysis reveals that the remarkable activity and shape-selectivity come from the superior special acidic–basic synergetic catalytic sites on the uniform microporous channels of the BEA zeolite.
- Xie, Jingyan,Zhuang, Wenxia,Zhang, Wei,Yan, Ning,Zhou, Yu,Wang, Jun
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p. 1076 - 1083
(2017/03/27)
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- Synthesis and catalytic reactivity of mononuclear substituted tetramethylcyclopentadienyl molybdenum carbonyl complexes
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The reactions of five dinuclear carbonyl complexes [(η 5-C5Me4R)Mo(CO)3]2 [R = allyl, n Bu, t Bu, Ph, Bz] with I2 in chloroform solution gave the corresponding mononuclear substituted tetramethylcyclopentadienyl molybdenum carbonyl complexes [(η 5-C5Me4R)MoI(CO)3] [R = allyl (1), n Bu (2), t Bu (3), Ph (4), Bz (5)]. The molecular structures of complexes 2, 3 and 5 were determined by X-ray diffraction analysis. The results show that the substituent in the ring can directly affect the Mo-I bond distances; the more sterically hindered the substituent, the longer the Mo-I bond. Friedel-Crafts reactions of aromatic compounds with a variety of alkylation reagents catalyzed by the complexes showed that all of these mononuclear molybdenum carbonyl complexes have catalytic activity in Friedel-Crafts alkylation reactions. Indeed, compared with traditional catalysts, these mononuclear metal carbonyl complexes have obvious advantages such as higher activities, mild reaction conditions, high selectivity, simple post-processing, and environmentally friendly chemistry.
- Ma, Zhi-Hong,Lv, Lin-Qian,Wang, Hong,Han, Zhan-Gang,Zheng, Xue-Zhong,Lin, Jin
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p. 225 - 233
(2016/02/20)
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- Hydrolysis of isobutylaluminum aryloxides studied by 1H NMR and quantum chemical methods
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The results of 1H NMR and quantum chemical studies of hydrolysis of isobutylaluminum aryloxides are presented. According to the data of 1H NMR spectroscopy, the hydrolysis of monomeric diisobutylaluminum aryloxides (2,6-Bu2 t—C6H3O)AlBu2 i and (2,6-Bu2 t,4-Me—C6H2O)AlBu2 i occurs selectively at the Al—OAr bond to form the corresponding sterically bulky phenol and polyisobutylaluminoxane. At the molar ratios Al: H2O = 2, the formed sterically bulky phenol reacts slowly with diisobutylaluminum monoaryloxide to form isobutylaluminum diaryloxide. Dimeric aryloxide [(2-But—C6H4O)AlBu2 i]2 is not hydrolyzed under similar conditions. The quantum chemical calculations confirmed the experimental results: the hydrolysis at the Al—OAr bond has a lower energy barrier than that at the Al—C bond because of the formation of HH2O…OO?Ar hydrogen bonds.
- Faingol’d,Zharkov,Bravaya,Chernyak
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p. 1958 - 1965
(2017/04/03)
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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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- Heterogeneous para-phenylamino sulfonic acid ligand functionalizedon MCM-41 derived from rice husk ash: Selective mono-alkylatedproducts of tert-butylation of phenol
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A new organo-inorganic hybrid material was prepared by immobilizing 3-(4-aminophenylamino)propane-1-sulfonic acid onto functionalized mesoporous MCM-41 via simplepost-synthesis method. The hybrid organo MCM-41 preserved its hexagonal honey-comb configurationafter both surface chemical modification and immobilization of sulfonic acid ligand. XRD analysisexhibited three well-resolved diffraction peaks corresponding to the highly ordered mesostructure. Thefive intense carbon peaks of solid-state CP-MAS 13CNMR spectroscopy confirmed the grafting of sulfonicacid ligand onto the well-structured MCM-41. Surface properties of the material revealed a pore size of 1.98 nm and surface area of 468 m2g-1. The catalytic performance of this hybrid material was tested inthe alkylation of phenol with tert-butanol (TBA) and showed a high catalytic activity leading to 99.5%conversion of tert-butyl alcohol and high selectivity to monoalkylated products.
- Adam, Farook,Kueh, Chien-Wen
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p. 162 - 170
(2015/05/05)
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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 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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- CYCLIC PEROXIDE OXIDATION OF AROMATIC COMPOUND PRODUCTION AND USE THEREOF
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The present invention provides a method for converting an aromatic hydrocarbon to a phenol by providing an aromatic hydrocarbon comprising one or more aromatic C-H bonds and one or more activated C-H bonds in a solvent; adding a phthaloyl peroxide to the solvent; converting the phthaloyl peroxide to a di-radical; contacting the di-radical with the one or more aromatic C-H bonds; oxidizing selectively one of the one or more aromatic C-H bonds in preference to the one or more activated C-H bonds; adding a hydroxyl group to the one of the one or more aromatic C-H bonds to form one or more phenols; and purifying the one or more phenols.
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Page/Page column 10
(2014/10/15)
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- Dioxygen activation by an organometallic Pd(II) precursor: Formation of a Pd(IV)-OH complex and its C-O bond formation reactivity
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The complex (Me3tacn)PdII(CH2CMe 2C6H4) is readily oxidized by O2 or H2O2 to yield the PdIV-OH complex [(Me 3tacn)PdIV(OH)(CH2CMe2C 6H4)]+. Thermolysis of this product leads to the selective C(sp2)-O reductive elimination of 2-tert-butylphenol, no C(sp3)-O elimination product being detected. This system represents a rare example of selective C(sp2)-O bond formation that is relevant to Pd-catalyzed aerobic C-H hydroxylation reactions. The Royal Society of Chemistry.
- Qu, Fengrui,Khusnutdinova, Julia R.,Rath, Nigam P.,Mirica, Liviu M.
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supporting information
p. 3036 - 3039
(2014/03/21)
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- Base-catalyzed dehydration of 3-substituted benzene cis -1,2-dihydrodiols: Stabilization of a cyclohexadienide anion intermediate by negative aromatic hyperconjugation
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Evidence that a 1,2-dihydroxycyclohexadienide anion is stabilized by aromatic "negative hyperconjugation" is described. It complements an earlier inference of "positive" hyperconjugative aromaticity for the cyclohexadienyl cation. The anion is a reactive intermediate in the dehydration of benzene cis-1,2-dihydrodiol to phenol. Rate constants for 3-substituted benzene cis-dihydrodiols are correlated by σ- values with = 3.2. Solvent isotope effects for the reactions are kH2O/kD 2O = 1.2-1.8. These measurements are consistent with reaction via a carbanion intermediate or a concerted reaction with a "carbanion-like" transition state. These and other experimental results confirm that the reaction proceeds by a stepwise mechanism, with a change in rate-determining step from proton transfer to the loss of hydroxide ion from the intermediate. Hydrogen isotope exchange accompanying dehydration of the parent benzene cis-1,2-dihydrodiol was not found, and thus, the proton transfer step is subject to internal return. A rate constant of ～1011 s-1, corresponding to rotational relaxation of the aqueous solvent, is assigned to loss of hydroxide ion from the intermediate. The rate constant for internal return therefore falls in the range 1011-1012 s -1. From these limiting values and the measured rate constant for hydroxide-catalyzed dehydration, a pKa of 30.8 ± 0.5 was determined for formation of the anion. Although loss of hydroxide ion is hugely exothermic, a concerted reaction is not enforced by the instability of the intermediate. Stabilization by negative hyperconjugation is proposed for 1,2-dihydroxycyclohexadienide and similar anions, and this proposal is supported by additional experimental evidence and by computational results, including evidence for a diatropic ("aromatic") ring current in 3,3-difluorocyclohexadienyl anion.
- Kudavalli, Jaya Satyanarayana,Rao, S. Nagaraja,More Oferrall, Rory A.,Bean, David E.,Fowler, Patrick W.,Sharma, Narain D.,Boyd, Derek R.,Kamerlin, Shina Caroline Lynn,Keeffe, James R.,Gronert, Scott
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supporting information
p. 14056 - 14069,14
(2020/08/31)
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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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- 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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- 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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- 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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- PROCESS FOR THE ALKYLATION OF PHENOLS
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The present invention relates to an improved process for the selective alkylation of phenols using heteropolyacid catalyst supported onto zirconia under mild conditions. The process is economically viable since the catalyst regenerated after the initial reaction on further use gives the product in high yield.
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Page/Page column 3-4
(2008/12/05)
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- Zirconia-modified superacid UDCaT-5: An efficient and versatile catalyst for alkylation reactions under solvent-free conditions
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UDCaT-5, a modified version of zirconia, efficiently catalyzes alkylation of phenols with alcohols under environmentally safe, heterogeneous reaction conditions with high selectivity and in excellent yields. The high content present in UDCaT-5 with preservation of tetragonal phase of zirconia was responsible for the superactivity. Several phenolic compounds carrying either electron-sulfer releasing or electron-withdrawing substituents in the ortho, meta, and para positions afforded high yields of the products. Copyright Taylor & Francis Group, LLC.
- Yadav, Ganapati D.,Pathre, Ganesh S.
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p. 2684 - 2691
(2008/12/22)
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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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- 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 17-18
(2008/06/13)
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- Non-catalytic anti-Markovnikov phenol alkylation with supercritical water
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The anti-Markovnikov alkylation of phenol with tert-butyl alcohol could be achieved without catalyst in supercritical water at 673 K. The dehydration of tert-butyl alcohol gave isobutene and was followed by the reaction with phenol to form 2-isobutylphenol as an anti-Markovnikov product, 2-tert-butylphenol and 4-tert-butylphenol. The hydroxy group probably participated in the anti-Markovnikov alkylation and the increase in water density enhanced the formation of 2-isobutylphenol as well as 4-tert-butylphenol. Copyright
- Sato, Takafumi,Ishiyama, Yasuyoshi,Itoh, Naotsugu
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p. 716 - 717
(2007/10/03)
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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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- 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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- Direct hydroxylation of substituted benzenes to phenols with air and CO using molybdovanadophosphates as a key catalyst
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A direct synthetic method of cresols from toluene by hydroxylation with air using CO as a reducing agent was developed. The reaction of toluene with air (15 atm) and CO (5 atm) in the presence of catalytic amounts of H 4PMo11VO40·31H2O and Pd/C in aqueous acetic acid at 120°C for 2 h afforded a mixture of o-, m-, and p-cresols in 9.9% yield at 83% selectivity. Cresols were obtained in 19% yield by recharging air and CO under these conditions. A variety of substituted benzenes were hydroxylated by this method to give the corresponding phenol derivatives in higher selectivity.
- Mita, Shuichi,Sakamoto, Takao,Yamada, Shingo,Sakaguchi, Satoshi,Ishii, Yasutaka
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p. 7729 - 7732
(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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