- Synthesis of CNTs@POP-Salen Core-Shell Nanostructures for Catalytic Epoxides Hydration
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Microporous polymers have been considered as promising heterogeneous catalysts for versatile chemical transformations. However, the mass diffusion barriers through the microporous network still remains a big hindrance. Herein, an efficient and versatile strategy for shortening the mass diffusion pathway through microporous polymer was reported by constructing a CNTs@POP-salen core-shell nanostructure. CNTs@POP-Co(salen) could efficiently catalyze the epoxide hydration reaction at H2O/epoxides ratio as low as 2, demonstrating the efficient cooperation of Co(salen) integrated in the polymer network. CNTs@POP-Co(salen) showed much higher activity than bulk polymer in propylene oxide (PO) hydration reaction (TOF: 3150 versus 1470 h?1) due to the shortened diffusion pathway, which was further confirmed by adsorption experiment using phenol as probe molecule. Our primary results demonstrated the advantages of core-shell nanostructures to improve the catalytic activity of microporous polymers by enhancing the mass diffusion during the catalytic process.
- Li, He,Zhong, Mingmei,Li, Chunzhi,Ren, Yiqi,Chen, Jian,Yang, Qihua
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Read Online
- Nanotitania catalyzes the chemoselective hydration and alkoxylation of epoxides
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Glycols and ethoxy– and propoxy–alcohols are fundamental chemicals in industry, with annual productions of millions of tons, still manufactured in many cases with corrosive and unrecoverable catalysts such as KOH, amines and BF3?OEt2. Here we show that commercially available, inexpensive, non–toxic, solid and recyclable nanotitania catalyzes the hydration and alkoxylation of epoxides, with water and primary and secondary alcohols but not with phenols, carboxylic acids and tertiary alcohols. In this way, the chemoselective synthesis of different glycols and 1,4–dioxanones, and the implementation of nanotitania for the production in–flow of glycols and alkoxylated alcohols, has been achieved. Mechanistic studies support the key role of vacancies in the nano–oxide catalyst.
- Ballesteros–Soberanas, Jordi,Leyva–Pérez, Antonio,Martínez–Castelló, Aarón,Oliver–Meseguer, Judit,Tejeda–Serrano, María
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- CO2atmosphere enables efficient catalytic hydration of ethylene oxide by ionic liquids/organic bases at low water/epoxide ratios
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The development of an efficient and low-cost strategy for the production of monoethylene glycol (MEG) through hydration of ethylene oxide (EO) at low H2O/EO molar ratios is an important industrial challenge. We have established that by using CO2as the reaction atmosphere, hydration of EO can be achieved at a low H2O/EO ratio of 1.5?:?1 along with high yields (88-94%) and selectivities (91-97%) of MEG catalyzed by binary catalysts of ionic liquids and organic bases. The results are significantly better than those of experiments conducted under an atmosphere of N2. Isotope labeling experiments revealed that CO2had altered the reaction pathway and participated in the reaction, in which cycloaddition of EO with CO2occurred first followed by the hydrolysis of ethylene carbonate (EC) to generate MEG and recover CO2. The ionic liquids and organic bases synergistically catalyzed the one-pot two-step reaction. DFT calculations confirmed that this route is more kinetically favorable compared to the pathway of direct epoxide hydration.
- Ding, Tong,Gao, Guohua,Xia, Fei,Yuan, Huixia,Zha, Jinyin,Zhang, Dawei,Zhang, Jingshun
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supporting information
p. 3386 - 3391
(2021/05/25)
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- Catalysis, kinetic and mechanistical studies for the transformation of ethylene glycol by alumina and silica gel under autogenous pressure and solvent-free conditions
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A kinetic and mechanistical studies of the new pathway for competitive transformation of ethylene glycol by alumina and silica gel have been described. Commercial alumina (Al com), synthetic alumina (Al syn), commercial silica gel (Si com) and synthetic silica gel (Si syn) were used for the transformation of ethylene glycol to a mixture of diethylene glycol, 1,4-dioxane and 2-methyl-1,3-dioxolane via acetaldehyde by heating at 150 °C under autogenous pressure without solvent. The results show that the yield of these three products strongly depends on the nature of the used catalyst and the reaction time.
- Rohand, Taoufik,Tanemura, Kiyoshi
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p. 387 - 394
(2021/06/25)
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- Chromium-Catalyzed Production of Diols From Olefins
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Processes for converting an olefin reactant into a diol compound are disclosed, and these processes include the steps of contacting the olefin reactant and a supported chromium catalyst comprising chromium in a hexavalent oxidation state to reduce at least a portion of the supported chromium catalyst to form a reduced chromium catalyst, and hydrolyzing the reduced chromium catalyst to form a reaction product comprising the diol compound. While being contacted, the olefin reactant and the supported chromium catalyst can be irradiated with a light beam at a wavelength in the UV-visible spectrum. Optionally, these processes can further comprise a step of calcining at least a portion of the reduced chromium catalyst to regenerate the supported chromium catalyst.
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Paragraph 0111
(2021/03/19)
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- AEROBIC ELECTROCATALYTIC OXIDATION OF HYDROCARBONS
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This invention is directed to a method of oxygenating hydrocarbons with molecular oxygen, O2, as oxidant under electrochemical reducing conditions, using polyoxometalate compounds containing copper such as Q10 [Gu4(H2O)2(B-α-PW9O)2] or Q12{ [Cu(H2O)]3[(A-α- PW9O34)2(NO3)-] } or solvates thereof as catalysts, wherein Q are each independently selected from alkali metal cations, alkaline earth metal cations, transition metal cations, NH4+,H+ or any combination thereof.
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Paragraph 0074
(2022/01/04)
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- CATALYTIC CONVERSION OF CARBON DIOXIDE TO METHANOL
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The present disclosure relates to a new catalytic process for the production of methanol from carbon dioxide, comprising: (1) the conversion of carbon dioxide and hydrogen to formic acid or formate salts; (2) converting the formic acid or formate salts to diformate esters of diols; (3) hydrogenating the diformate esters to methanol and diols. The diols produced from the hydrogenation reaction can be recovered and re-used to prepare the diformate esters.
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Page/Page column 23; 24
(2019/10/29)
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- Ketalization of ketones to 1,3-dioxolanes and concurring self-aldolization catalyzed by an amorphous, hydrophilic SiO2-SO3H catalyst under microwave irradiation
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The amorphous, mesoporous SiO2-SO3H catalyst with a surface area of 115 m2 g-1 and 1.32 mmol H+ per g was very efficient for the protonation of ketones on a 10percent (m/m) basis, and the catalyst-bound intermediates can be trapped by polyalcohols to produce ketals in high yields or suffer aldol condensations within minutes under low-power microwave irradiation. The same catalyst can easily reverse the ketalization reaction. Printed in Brazil-
- Barbosa, Sandro L.,Ottone, Myrlene,De Almeida, Mainara T.,Lage, Guilherme L.C.,Almeida, Melina A.R.,Nelson, David Lee,Dos Santos, Wallans T.P.,Clososki, Giuliano C.,Lopes, Norberto P.,Klein, Stanlei I.,Zanatta, Lucas D.
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p. 1663 - 1671
(2018/06/29)
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- Lewis Base Catalyzed Selective Chlorination of Monosilanes
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A preparatively facile, highly selective synthesis of bifunctional monosilanes R2SiHCl, RSiHCl2 and RSiH2Cl is reported. By chlorination of R2SiH2 and RSiH3 with concentrated HCl/ether solutions, the stepwise introduction of Si?Cl bonds is readily controlled by temperature and reaction time for a broad range of substrates. In a combined experimental and computational study, we establish a new mode of Si?H bond activation assisted by Lewis bases such as ethers, amines, phosphines, and chloride ions. Elucidation of the underlying reaction mechanisms shows that alcohol assistance through hydrogen-bond networks is equally efficient and selective. Remarkably, formation of alkoxysilanes or siloxanes is not observed under moderate reaction conditions.
- Sturm, Alexander G.,Schweizer, Julia I.,Meyer, Lioba,Santowski, Tobias,Auner, Norbert,Holthausen, Max C.
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supporting information
p. 17796 - 17801
(2018/11/23)
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- Self-assembled orthoester cryptands: Orthoester scope, post-functionalization, kinetic locking and tunable degradation kinetics
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Dynamic adaptability and biodegradability are key features of functional, 21st century host-guest systems. We have recently discovered a class of tripodal supramolecular hosts, in which two orthoesters act as constitutionally dynamic bridgeheads. Having previously demonstrated the adaptive nature of these hosts, we now report the synthesis and characterization-including eight solid state structures-of a diverse set of orthoester cages, which provides evidence for the broad scope of this new host class. With the same set of compounds, we demonstrated that the rates of orthoester exchange and hydrolysis can be tuned over a remarkably wide range, from rapid hydrolysis at pH 8 to nearly inert at pH 1, and that the Taft parameter of the orthoester substituent allows an adequate prediction of the reaction kinetics. Moreover, the synthesis of an alkyne-capped cryptand enabled the post-functionalization of orthoester cryptands by Sonogashira and CuAAC "click" reactions. The methylation of the resulting triazole furnished a cryptate that was kinetically inert towards orthoester exchange and hydrolysis at pH > 1, which is equivalent to the "turnoff" of constitutionally dynamic imines by means of reduction. These findings indicate that orthoester cages may be more broadly useful than anticipated, e.g. as drug delivery agents with precisely tunable biodegradability or, thanks to the kinetic locking strategy, as ion sensors.
- L?w, Henrik,Mena-Osteritz, Elena,Von Delius, Max
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p. 4785 - 4793
(2018/06/07)
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- Synthesis of dioxolanes and oxazolidines by silica gel catalysis
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Abstract: Ethylene glycol condensed with carbonyl compounds in the presence of silica gel or alumina, without solvent and under pressure, affords 1,3-dioxolanes. 2-Amino-2-methylpropanol also condensed with carbonyl compounds in the presence of silica gel or an acid-activated clay, without solvent and under pressure, produces oxazolidines. To explain these results, we propose that the glycol and the aminopropanol react with Br?nsted (H+) and Lewis acid sites (Si and Al) located on the surface of the catalysts, leading to the products via various ionic intermediates.
- Rohand, Taoufik,Savary, Jér?me,Markó, István E.
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p. 1429 - 1436
(2018/06/25)
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- Photocatalytic Degradation of Hexaethylene Glycol
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Abstract: Polyethylene glycol (PEG) photodegradation was studied in water under UV irradiation in the presence of catalytic amount of TiO2 using hexaethylene glycol as a model compound. Full conversion was achieved in 7 h with an average quantum yield around 1%. Formic acid was found to be the main intermediate and was slower to oxidize into CO2 (traces remains after 24 h). The other intermediates [lower PEG, oxidized PEG (formates, aldehydes and acids, acetic acid)] of the photodegradation have also been identified and quantified. A mechanism based on previous literature but also taking into account these new observations is proposed. Graphical Abstract: [Figure not available: see fulltext.].
- Simangoye Ngobissi, Drocilia Ednah,Soufi, Jihène,Vanoye, Laurent,Richard, Dominique
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p. 1608 - 1614
(2017/08/29)
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- Catalytic hydration process for production of ethylene glycol
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The invention relates to a method for producing glycol by catalytic hydration, which solves the problems of high equipment investment and high energy consumption existed in the direct hydration production of glycol in prior art. The method comprises the following steps: a) a material flow 1 containing ethylene oxide and water is introduced in a catalytic hydration reaction unit R, a material flow 6 containing glycol can be obtained after the reaction; b) the material flow 6 is introduced in a feed preheater of an evaporation tower D3, and preheating is carried out to obtain a material flow 7; c) the material flow 7 is introduced in the center part of the evaporation tower, after being separated, a glycol aqueous solution 8 is obtained at the bottom of the evaporation tower, and a steam material flow 9 is obtained at the top of the tower; and d) the material flow 9 is divided into a material flow 10 and a material flow 11; the material flow 10 is introduced in the feed preheater of the evaporation tower D3; and the material flow 11 is introduced into a subsequent flow. The technical scheme can better solve the problems, and the method of the invention can be used in an industrial production for producing glycol by ethylene oxide catalytic hydration.
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Paragraph 0035-0042
(2017/02/24)
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- Production of aldehydes from 1,2-alkanediols over silica-supported WO3 catalyst
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Vapor-phase dehydration of several 1,2-alkanediols, such as 1,2-ethanediol, 1,2-propanediol, 1,2-butanediol and 1,2-pentanediol, to produce corresponding aldehydes was investigated over silica-supported WO3 catalyst, which was prepared by impregnation method and then calcined at 320?°C. Higher than 90% yield of aldehydes could be achieved over WO3/SiO2 catalyst at 250?°C with a feed of 20% aqueous 1,2-alkanediol solution. Both Br?nsted and Lewis acid sites exist on WO3/SiO2 catalyst, while Br?nsted acid sites are proposed to be the active species for the formation of aldehyde. High concentrations of H2O were effective for inhibiting the intermolecular reaction and improving the selectivity to aldehydes. The dehydration of different 1,2-alkanediols was compared under different reaction conditions. The reactivity of 1,2-ethanediol was low and the product distribution was several comparing with those of the other 1,2-alkanediols. Cyclic acetal, which was generated by the cyclodehydration of the produced aldehyde with another 1,2-alkanediol, was a main by-product, and the formation of acetal was affected by both the temperature and the carbon-chain length of the 1,2-alkanediols.
- Sun, Daolai,Yamada, Yasuhiro,Sato, Satoshi,Suganuma, Satoshi,Katada, Naonobu
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p. 164 - 171
(2016/09/09)
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- The effect of a unique halide-stabilizing residue on the catalytic properties of haloalkane dehalogenase DatA from Agrobacterium tumefaciens C58
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Haloalkane dehalogenases catalyze the hydrolysis of carbon-halogen bonds in various chlorinated, brominated and iodinated compounds. These enzymes have a conserved pair of halide-stabilizing residues that are important in substrate binding and stabilization of the transition state and the halide ion product via hydrogen bonding. In all previously known haloalkane dehalogenases, these residues are either a pair of tryptophans or a tryptophan-asparagine pair. The newly-isolated haloalkane dehalogenase DatA from Agrobacterium tumefaciens C58 (EC 3.8.1.5) possesses a unique halide-stabilizing tyrosine residue, Y109, in place of the conventional tryptophan. A variant of DatA with the Y109W mutation was created and the effects of this mutation on the structure and catalytic properties of the enzyme were studied using spectroscopy and pre-steady-state kinetic experiments. Quantum mechanical and molecular dynamics calculations were used to obtain a detailed analysis of the hydrogen-bonding patterns within the active sites of the wild-type and the mutant, as well as of the stabilization of the ligands as the reaction proceeds. Fluorescence quenching experiments suggested that replacing the tyrosine with tryptophan improves halide binding by 3.7-fold, presumably as a result of the introduction of an additional hydrogen bond. Kinetic analysis revealed that the mutation affected the substrate specificity of the enzyme and reduced its K0.5 for selected halogenated substrates by a factor of 2-4, without impacting the rate-determining hydrolytic step. We conclude that DatA is the first natural haloalkane dehalogenase that stabilizes its substrate in the active site using only a single hydrogen bond, which is a new paradigm in catalysis by this enzyme family. The newly-isolated haloalkane dehalogenase DatA from Agrobacterium tumefaciens C58 possesses a unique halide-stabilising tyrosine residue, Y109, in place of the conventional tryptophan. This is the first natural haloalkane dehalogenase that stabilises its substrate in the active site using only a single hydrogen bond, which is a new paradigm in catalysis by this enzyme family.
- Hasan, Khomaini,Gora, Artur,Brezovsky, Jan,Chaloupkova, Radka,Moskalikova, Hana,Fortova, Andrea,Nagata, Yuji,Damborsky, Jiri,Prokop, Zbynek
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p. 3149 - 3159
(2013/07/26)
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- A mild, efficient, and selective deprotection of tert-butyldimethylsilyl (TBDMS) ethers using dicationic ionic liquid as a catalyst
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Selective deprotection of alkyl TBDMS ether in the presence of phenolic TBDMS ether using dicationic ionic liquid [tetraEG(mim)2][OMs] 2 as a homogeneous catalyst showed significant catalytic activity in methanol at ambient temperature to produce respective alcohol in excellent yield. The present environmentally benign catalytic system is found to be very convenient, fast, high yielding, and clean method for selective desilylation of alkyl silyl ethers even in the existence of other sensitive organic functional groups such as aldehyde, methoxy, and acetate were also achieved.
- Jadhav, Arvind H.,Kim, Hern
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p. 5338 - 5342
(2012/11/07)
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- Two-Stage, Gas Phase Process for the Manufacture of Alkylene Glycol
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A two-stage, gas phase process for manufacturing alkylene glycol (e.g., ethylene glycol) from an alkene (e.g., ethylene), oxygen and water, the process comprising the steps of: (A) Contacting under gas phase, oxidation conditions gaseous alkene and oxygen over a heterogeneous oxidation catalyst to produce a gaseous oxidation product comprising alkylene oxide, water and unreacted alkene;(B) Contacting under gas phase, hydrolysis conditions the gaseous oxidation product of (A) with added water over a heterogeneous hydrolysis catalyst to produce a gaseous alkylene glycol and unreacted alkene; and(C) Recycling the unreacted alkene of (B) to (A). The hydrolysis catalyst is selected from the group consisting of hydrotalcites, metal-loaded zeolites, phosphates, and metal-loaded ion-exchanged molecular sieves. The process improves over the conventional two-stage process by the elimination of steps and equipment to recover and refine alkylene oxide, the use of less water in the hydrolysis reaction, and the elimination of the entire evaporation train used in the recovery of alkylene glycol.
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Page/Page column 8
(2010/03/02)
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- PROCESS FOR PRODUCTION OF DIALKYL CARBONATE AND DIOL
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Disclosed is a process for production of a dialkyl carbonate and a diol from a cyclic carboante and an univalent aliphatic alcohol, in which the cyclic carbonate can be converted at a high conversion rate, the dialkyl carboante and the diol can be produced with a high selectivity, any complicated treatment (e.g., addition of water during the diol distillation/purification process) is not required, and a highly pure diol having a high UV ray transmittance and a low aldehyde content can be produced. A process for production of a dialkyl carbonate and a diol comprising the step of reacting a cyclic carbonate with an univalent aliphatic alcohol in the presence of a catalyst in a transesterification reactor equipped with a tray-type continuous multistage distillation column, wherein the reaction in the distillation column is performed under predetermined conditions (retention time, temperature).
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Page/Page column 21-23; 1/1
(2008/06/13)
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- Photochemical Crosslinkers for Polymer Coatings and Substrate Tie-Layer
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The invention describes novel crosslinking compounds that include photoactivatable moieties. Several families of compounds are disclosed that can include one or more hydrophilic moieties that help to solubilize the compounds in aqueous environments.
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- Process for the preparation of alkylene glycols
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Disclosed is a process for the preparation of alkylene glycols from the corresponding alkylene oxide, such as ethylene glycol from ethylene oxide, in the presence of water, a catalyst and, optionally, carbon dioxide. The catalyst contains an amphoteric compound, such as such as (ethylenedinitrilo) tetraacetic acid (EDTA). These befunctional compounds have both acid and base moieties. Preferably, a compound useful in the present invention forms a buffered solution in water, i.e., the acid and base moieties do not completely disassociate. The pH of the buffered solution should be 2-10, preferably 5-10, more preferably 4-9. A compound useful in the present invention is preferably organic with the base moiety and the acid moiety being separated by one to four carbon atoms.
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Page/Page column 3-4
(2008/06/13)
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- Process for preparing alkylene glycols
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The invention relates to a process for preparing alkylene glycols by hydration of alkylene oxides in the presence of polyalkylene glycol dialkyl ethers of the formula [in-line-formulae]R1—O—[—(CH2CH2O)m(CH(CH3)CH2)—O]n—R2 [/in-line-formulae] in which m=0-100, n=0-100, where n+m is at least equal to 1, R1 is a C1- to C6-alkyl radical, R2 is a C1- to C6-alkyl radical, where R2 may be different from R1, with the proviso that for at least 50 mol % of the polyalkylene glycol dialkyl ether m+n is greater than or equal to 11.
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Page/Page column 2
(2008/06/13)
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- Synthesis of hydroxylated hydrocarbons
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Ethylene glycol, other diols, triols, and polyols are made in an efficient manner by reacting dibromides with water in the presence of a metal oxide. An integrated process of dibromide formation, alcohol synthesis, metal oxide regeneration, and bromine recycling is also provided.
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Page/Page column 5
(2008/06/13)
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- WATER AND SOLVENT FREE PROCESS FOR ALKOXYLATION
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A water and solvent free process for alkoxylation of mixed polyhydric compounds comprising at least two different polyhydric compounds each having at least 3 hydroxyl groups is disclosed. The process comprises that at least one polyhydric compound (I) has a melting point exceeding applied alkoxylation temperature and that at least one polyhydric compound (II) has a melting point below said alkoxylation temperature. Compound (II) is used as solution medium and/or as carrier for said compound (I). Yielded mixed polyhydric alkoxylate has a combined monoalkylene, dialkylene and trialkylene glycol content of less than 0.5% by weight.
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Page/Page column 9
(2008/06/13)
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- Process of preparing an alkylene glycol
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A process of preparing an alkylene glycol which process involves: i) reacting a respective alkylene oxide and water in a first reactor, ii) removing from the first reactor a reactor output mixture comprising an alkylene glycol and unreacted water, iii) transferring a proportion of the reactor output mixture to a distillation unit and a proportion of the reaction output mixture to a second reactor containing a catalyst, iv) reacting the reaction output mixture in the second reactor with a further amount of the respective alkylene oxide, and v) transferring a reactor output mixture from the second reactor to a distillation unit.
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Page/Page column 3-4
(2008/06/13)
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- PROCESS FOR PRODUCING DIALKYL CARBONATE AND DIOL
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A process for producing a dialkyl carbonate and a diol, comprising (a) subjecting a cyclic carbonate and an aliphatic monohydric alcohol to transesterification in the presence of a transesterification catalyst to produce a reaction solution containing a dialkyl carbonate and a diol, (b) extracting a dialkyl carbonate-containing reaction solution from the reaction solution and then separating a dialkyl carbonate from the dialkyl carbonate-containing reaction solution, and (c) extracting a diol-containing reaction solution from the reaction solution and then separating a diol from the diol-containing reaction solution. This process is characterized in that the content of a cyclic ether in the cyclic carbonate is 0.1 to 3,000 ppm and the content of carbonate ether in the dialkyl carbonate thus obtained is not more than 10,000 ppm.
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Page/Page column 26-29
(2010/02/15)
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- PROCESSES FOR THE PURIFICATION OF BIS(2-HYDROXYETHYL) TEREPHTHALATE
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An object of the present invention is to provide a method of obtaining BHET of high purity efficiently from an EG (ethylene glycol) solution containing crude BHET (bis(2-hydroxyethyl)terephthalate), especially a decomposition product solution obtained by decomposing a polyester containing PET (polyethylene terephthalate) as a main component, by use of EG, while minimizing by-production of impurity components such as DEG (diethylene glycol), DEG ester and oligomers. The present invention is a method of purifying BHET by subjecting the decomposition product solution to crystallization and solid-liquid separation under specific temperature conditions. Further, the present invention is a method of purifying BHET which comprises evaporation steps of evaporating low-boiling-point components from the decomposition product solution under specific conditions so as to obtain a melt solution and a molecular distillation step of distilling the obtained melt solution under specific conditions so as to obtain a specific fraction.
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Page/Page column 29-31
(2010/02/10)
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- Aminopropylation of alcohols in the presence of amide or ether solvents
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This invention relates to an improved hydrogenation process for the preparation of etheramines. In the process, cyanoethylated alcohols, i.e., the reaction product of an alcohol with (meth)acrylonitrile, are contacted with hydrogen in the presence of a sponge cobalt catalyst. The improvement in the process resides in effecting the hydrogenation process utilizing a cyanoethylated alcohol feedstock contaminated with byproduct acrylonitrile and utilizing a solvent that solubilizes byproduct (meth)acrylonitrile present in the feedstock. Specific classes of solvents employed are ethers and amides.
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Page/Page column 3; 6
(2008/06/13)
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- Process for the production of alkylene glycols using homogeneous catalysts
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A process for the manufacture of alkylene glycol by the hydration of alkylene oxide using a soluble catalyst that permits the separation of the reaction product into an alkylene glycol product stream and a recycle stream without the significant precipitation of the soluble catalyst from the recycle stream.
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- Continuous chemoselective methylation of functionalized amines and diols with supercritical methanol over solid acid and acid-base bifunctional catalysts
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The selective N-methylation of bifunctionalized amines with supercritical methanol (scCH3OH) promoted by the conventional solid acids (H-mordenite, β-zeolite, amorphous silica-alumina) and acid-base bifunctional catalysts (Cs-P-Si mixed oxide and γ-alumina) was investigated in a continuous-flow, fixed-bed reactor. The use of scCH 3OH in the reaction of 2-aminoethanol with methanol (amine/CH 3OH = 1/10.8) over the solid catalysts led to a significant improvement in the chemoselectivity of the N-methylation. Among the catalysts examined, the Cs-P-Si mixed oxide provided the most efficient catalyst performance in terms of selectivity and reactivity at 300 °C and 8.2 MPa; the N-methylation selectivity in the products reaching up to 94% at 86% conversion. The present selective methylation was successfully applied to the synthesis of N-methylated amino alcohols and diamines as well as O-methylated ethylene glycol. Noticeably, ethoxyethylamine was less reactive, suggesting that the hydroxy group of the amino alcohols is a crucial structural factor in determining high reactivity and selectivity, possibly because of the tethering effect of another terminus, a hydroxo group, to the catalyst surface. The magic-angle-spinning NMR spectroscopy and X-ray diffraction analysis of the Cs-P-Si mixed oxide catalyst revealed that the acidic and basic sites originate from P2O5/SiO2 and Cs/SiO2, respectively, and the weak acid-base paired sites are attributed to three kinds of cesium phosphates on SiO2. The weak acid-base sites on the catalyst surface might be responsible for the selective dehydrative methylation.
- Oku, Tomoharu,Arita, Yoshitaka,Tsuneki, Hideaki,Ikariya, Takao
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p. 7368 - 7377
(2007/10/03)
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- PROCESS FOR SPLITTING WATER-SOLUBLE ETHERS
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A process for production of 1,3-propanediol including the steps: (a) hydrating acrolein in the presence of an acid hydration catalyst; (b) catalytically hydrogenating the reaction mixture of step (a), which reaction mixture comprises 3-hydroxypropionaldehyde and is freed of unreacted acrolein; (c) refining the reaction mixture of step (b) containing water, 1,3-propanediol and the by-products boiling higher than 1,3-propanediol; and (d) treating 4-oxa-1,7-heptanediol to form 1,3-propanediol by (1) removing a boiler sump comprising 4-oxa-1,7-heptanediol from the refining step (c), (2) treating the boiler sump in an aqueous solution in the presence of an acid catalyst at about 200 to about 300° C. to form a solution comprising 1,3-propanediol, (3) neutralizing the solution obtained is step (2), and returning the neutralized solution from step (3) to the refining step (c). In addition, a process for splitting oligomeric water-soluble ether comprising: (a) treating an aqueous solution comprising oligomeric water-soluble ether in the presence of homogeneous acid catalyst at a temperature of from about 200 to about 300 ° C. to form the monomer of the oligomeric water-soluble ether; and (b) neutralizing the solution obtained in step (a),
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- Process for continuous production of dialkyl carbonate and diol
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A method for continuously producing a (A) dialkyl carbonate and a (B) diol, comprising continuously feeding a cyclic carbonate and an aliphatic monohydric alcohol to a continuous multi-stage distillation column to thereby effect a transesterification therebetween, thereby continuously producing a dialkyl carbonate and a diol, while continuously withdrawing a low boiling point mixture containing the produced dialkyl carbonate (A) in a gaseous form from an upper portion of the distillation column and continuously withdrawing a high boiling point mixture containing the produced diol (B) in a liquid form from a lower portion of the distillation column, wherein the transesterification is performed under conditions wherein: (a) the reaction pressure of the column bottom is 5×104Pa or less; (b) the reaction temperature of the column bottom is in the range of from ?20° C. to less than 60° C.; and (c) the distillation column has an F-factor in the range of from 0.2 to 5.0, the F-factor being represented by the following formula (1): F-factor=ug(ρg)???(1) wherein ugrepresents the gas velocity (m/s) in the distillation column and ρgrepresents the gas density (kg/m3) in the distillation column.
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Page column 25-32
(2008/06/13)
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- Single-step method for producing glycol monoethers from olefins
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A process for preparing glycol monoethers from olefins comprises reacting the olefins with an epoxidizing reagent in the simultaneous presence of hydroxyl-containing organic compounds over a mixture of epoxidation catalysts and alkoxylation catalysts.
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- Process for the purification of water-soluble cyclodextrin derivatives
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A process for the purification of water-soluble cyclodextrin derivatives utilizes a reverse osmosis (RO) using at least one hydrophilic, asymmetric solution-diffusion membrane with a nominal molecular weight cut-off of 200-800 D.
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- Process for producing hydroxyalkyl glucosides
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A process is disclosed for producing particular hydroxyalkyl glucosides in the presence of a binary catalyst.
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- Synthesis and pharmacological evaluation of oligoethylene ester derivatives as indomethacin oral prodrugs
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Five indomethacin oligoethylene ester derivatives (3-7) were synthesized and evaluated for their anti-inflammatory, analgesic, and ulcerogenic activity after oral administration. The molecular weight of the oligoethylene glycols used for synthesizing esters 3-7 ranged from 106 to 282. The chemical and enzymatic stabilities of esters 3-7 were evaluated in pH 7.4 and 2.0 buffers and in human plasma, respectively. All the prodrugs showed a good stability both in pH 7.4 phosphate buffer and in pH 2.0 buffer, and they were readily hydrolyzed by human plasma. Esters 3-7 showed an anti-inflammatory activity, determined as the percent inhibition of carrageenan-induced edema, similar to that of indomethacin, although at higher doses. From writhing test results, we observed that all the prodrugs exhibited better or similar analgesic activity compared to indomethacin. Esters 3-7 were significantly less irritating to the gastric mucosa than indomethacin, after oral administration, and esters 3-5 did not show any ulcerogenic activity, although they were administered at higher doses than indomethacin.
- De Caprariis,Palagiano,Bonina,Montenegro,D'Amico,Rossi
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p. 1578 - 1581
(2007/10/02)
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- Process for producing hydroxyalkyl glucosides
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A process is disclosed for producing particular hydroxyalkyl glucosides in the presence of a binary catalyst.
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- Process for the production of organosilicon compounds
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Organosilicon compounds of the formula STR1 wherein R1 and R2 are each independently straight or branched alkyl of 1 to 4 carbon atoms or --OR3, R3 is R4 --(OR5)m --, R6 is straight or branched alkyl of 1 to 4 carbon atoms, m is an integer from 0 to 6, inclusive, R5 is straight or branched alkylene of 2 to 4 carbon atoms, which may be identical or different when m is an integer from 2 to 6, and R6 is straight or branched alkylene of 2 to 6 carbon atoms, are prepared by reacting hydrogensilanes of the formula STR2 wherein R7 are identical or different groups R4 or the group OR4, and R4 has the previously indicated meaning, with terminally unsaturated ethers of the formula wherein m, R4 and R5 have the previously indicated meanings, and R8 is terminally unsaturated straight or branched alkenyl or 2 to 6 carbon atoms, in the presence of a catalyst at controlled temperatures to form addition products of the formula STR3 wherein m and R4, R5, R6 and R7 have the previously indicated meanings, and the R4 's are identical or different which are converted into the desired end products by thermal and/or catalytic transesterification with monofunctional hydroxy compounds of the formula wherein m, R4 and R5 have the previously indicated meanings.
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- Kinetics of the Esterification of Triethylene Glycol by Methacrylic Acid
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In order to model catalysis by sulphonic acid cadion-exchange resins, the esterification of triethylene glycol by methacrylic acid has been studied experimentally in the presence of a large amount of catalyst (toluene-p-sulphonic acid).A mathematical model of the process is proposed.
- Onishchenko, V. V.,Gantman, A. I.
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p. 1132 - 1134
(2007/10/02)
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- Carbonylation of diols and their ethers and esters with ruthenium catalysts: synthesis of lactones and hydroxyacids ethers and esters
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Diols and their formic or acetic esters can be carbonylated to give lactones or the corresponding hydroxyacid ester or ethers in the presence of carbonylruthenium iodide systems. -/alkyl or metal iodide, at a temperature of 200 deg C and CO pressure of 10-20 MPa.The reaction in the case of 1,3-propanediol gives γ-butyrolactone, with a selectivity of 60-70 percent.Side reactions of homologation to 1,4-butanediol derivatives and hydrogenolysis to n-propyl derivatives by H2 produced by the water gas shift reaction (WGSR) also occur, together with acid-catalyzed dehydration to give linear polypropylene glycols, α,ω-diols with more than 3 carbon atoms in the chain preferentially give hydroxyacid esters and ethers.The cyclic ether by-products and linear polyether by-products can be further activated and carbonylated under the reaction conditions to give lactones or hydroxy-acid derivatives thus increasing the total yield of carbonylation products.The formation of H2 by WGSR involving water produced by the acid-catalyzed dehydration reactions, and the subsequent hydrogenolysis and homologation reactions cannot be avoided.
- Braca, G.,Sbrana, G.,Galletti, A. M. Raspolli,Berti, S.
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p. 245 - 258
(2007/10/02)
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- CATALYTIC HYDROGENATION OF DIBENZO-18-CROWN-6 AT METALS OF THE PLATINUM GROUP
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The hydrogenation of the aromatic rings in dibenzo-18-crown-6 is accompanied by hydrogenolysis of the carbon-oxygen bonds of the polyether ring.The selectivity of hydrogenation depends on composition of the solvent, the nature of the catalyst, the temperature, the hydrogen pressure, and other factors.Rhodium and ruthenium catalysts exhibit the highest activity in the reaction: in water, Ru > Rh > Pt, Pd; in 2-propanol, Rh >> Ru > Pt > Pd.The hydrogenation and hydrogenolysis are concurrent reactions, and the former is favored by high pressure.
- Gurskii, R. N.,Istratova, R. V.,Kirova, A. V.,Kotlyar, S. A.,Ivanov, O. V.,Luk'yanenko, N. G.
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p. 543 - 547
(2007/10/02)
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- REACTIONS OF AROMATIC NITRO-COMPOUNDS. LV. ANIONIC ?-COMPLEXES OF sym-TRINITROBENZENE WITH THE ALKOXIDES OF DIHYDRIC ALCOHOLS
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The reactions of alkoxides of dihydric alcohols with 2,4,6-trinitroanisole and picryl chloride have been studied.The reaction between 2,4,6-trinitroanisole and sodium 2-hydroxyethoxide, 3-hydroxypropoxide, 4-hydroxybutoxide, and 2-methoxyethoxide gives the unsymmetrical 1-methoxy-1-hydroxyalkoxy-2,4,6-trinitrocyclohexa-2,5-dienate ?-complexes, which are converted on heating into the 1,1-dihydroxyalkoxy-2,4,6-trinitrocyclohexa-2,5-dienate ?-complexes.In the case of sodium 1-methoxy-1-(β-hydroxyethoxy)-2,4,6-trinitrocyclohexa-2,5-dienate, heating results in intramolecular spirocyclization of the β-hydroxyethoxy grouping to give sodium 6,8,10-trinitro-1,4-dioxaspirodeca-6,9-dienate.The reaction of sodium 3-hydroxypropoxide, 4-hydroxybutoxide, 2-methoxyethoxide, and diethyleneglycolate with picryl chloride gives the symmetrical 1,1-dihydroxyalkoxy ?-complexes, while sodium 2-hydroxyethoxide forms a ?-complex with a 1,3-dioxolane spiro-ring.The composition and structures of the ?-complexes, isolated as their sodium salts, were established by their elemental analyses and PMR and IR spectroscopy.
- Mel'nikov, A. I.,Gitis, S. S.,Kaminskii, A. Ya.
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p. 1358 - 1366
(2007/10/02)
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- Organotin-containing composition for the stabilization of polymers of vinyl chloride
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An organotin-containing composition for the stabilization of polymers or copolymers of vinyl chloride in which there is incorporated a stabilizing amount of an organotin compound containing at least two tin atoms and which is a mercapto, hydroxy or alkoxy substituted ester of a mercapto acid substituted organotin mercapto acid diester.
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- Heteroylidene indolone compounds
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Certain substituted 1-phenyl-3-(aminoalkylidene)-2(1H,3H)-indolones are highly potent gabaergic agents, valuable in the treatment of individuals suffering from schizophrenia or reversing the side effects of a previously or concurrently administered neuroleptic agent; or in the treatment of epilepsy. A wider class of substituted 1-phenyl-3-(aminoalkylidene)-2(1H,3H)-indolones, together with 1-phenyl-3-(2-pyrrolidinylidene)-2(1H,3H)-indolones, and homologs thereof, are valuable in the treatment of anxiety.
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- The Influence of Cation Binding on the Kinetics of the Hydrolysis of Crown Ether Acetals
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The rate of hydrogen ion-catalysed hydrolysis of crown ether acetals in 60:40 (v/v) dioxan-water is found to be strongly decreased by the addition of alkali and alkaline earth metal chlorides having cations of appropriate size to be complexed by the substrate ring.The compounds studied are the monoacetals CH3CH(OCH2CH2)xO with x=1-8.The dependence of the initial rate of formation of acetaldehyde on metal-ion concentration is expressed in terms of (i) the equilibrium constant for complex formation, (ii) the influence of the bound cation on the rate constant, and (iii) an electrolyte effect.A curve-fitting procedure is used to derive the parameters governing the first two of these effects.The equilibrium constants are large and cannot be evaluated with any precision, but a fair estimate of the influence of the guest cation on the rate can be obtained.This effect is explicable by the electrostatic repulsion between the cationic charges of the metal ion and the proton added to the acetal in the first step of the hydrolysis.The size of the effect requires the values of the effective relative permittivity of the space between the charges to be close to that of the bulk solvent.
- Baker, David S.,Gold, Victor,Sghibartz, Cristian M.
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p. 1121 - 1128
(2007/10/02)
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- UNSATURATED CROWN ETHERS: STILBENO-CROWN ETHERS
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Stilbenocrown ethers 3a,c and 4a,b were synthesized in a cyclization reaction of benzoin with oligoethylene glycol ditosylates (2a-c) under a phase-transfer condition.Extractions of aqueous alkali picrates (Na+-Cs+) were examined with the distilbenocrown ethers 4a,b, the partially-hydrogenated tetraphenylcrown ethers 6a,b, and the fully-hydrogenated tetracyclohexylcrown ethers 7a,b.
- Inoue, Yoshihisa,Ouchi, Mikio,Nakazato, Toshiyo,Matsuda, Takashi,Hakushi, Tadao
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p. 781 - 784
(2007/10/02)
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- Manufacture of ethylene glycol from synthesis gas
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This invention concerns a process of making ethylene glycol which comprises the steps of contacting a mixture of CO and H2 with a catalyst system comprising a ruthenium-containing compound dispersed in a low melting quaternary phosphonium or ammonium base or salt, and heating said resultant reaction mixture under a pressure of 500 psi or greater at a temperature of at least 150° C. for a sufficient time to provide said ethylene glycol.
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