- Highly efficient conversion of aldehydes to carboxylic acid in the presence of platinum porphyrin sensitizers, air and sunlight
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A variety of aromatic and aliphatic aldehydes were oxidized to the corresponding carboxylic acids in the presence of platinum porphyrin, sunlight and air in acetonitrile solvent under mild conditions. Nitrobenzaldehydes were found to be very efficient 1O2 scavengers that quench the formation of acids from any aldehyde in the presence of free-base porphyrin sensitizers. However, nitrobenzaldehydes were converted to the corresponding acids in the presence of platinum porphyrins. The platinum porphyrins are very good and efficient catalysts for a wide range of applications in the aerobic conversion of aldehydes to acids.
- Hajimohammadi, Mahdi,Mofakham, Hamid,Safari, Nasser,Manesh, Anahita Mortazavi
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- N-hydroxyphthalimide-catalyzed oxidative production of phthalic acids from xylenes using O2/HNO3 in an ionic liquid
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A simple and mild process for oxidation of xylenes to phthalic acids using N-hydroxyphthalimide/O2/HNO3 in an ionic liquid, wherein the ionic liquid can be successfully recovered and reused, is described.
- Yavari, Issa,Karimi, Elham
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- Liquid-phase oxidation of p-xylene using N-hydroxyimides
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In this communication, we describe p-xylene oxidation with molecular oxygen at 373 K and atmospheric pressure using N-hydroxyimide catalysts. p-Xylene conversion was rather high over the first 2 h of reaction and complete by the end of the experiment. The
- Falcon,Campos-Martin,Al-Zahrani,Fierro
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- Efficient oxidation of p-xylene to terephthalic acid by using N,N-dihydroxypyromellitimide in conjunction with Co-benzenetricarboxylate
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The MOF Co-BTC (BTC = benzenetricarboxylate) has been synthesized by a hydrothermal method, and characterized by means of N2 physical adsorption, X-ray diffraction, scanning electron microscope, thermogravimetric analysis, and X-ray photoelectron spectroscopy. The material has multiple crevices, as opposed to a pore structure, and shows high thermal stability, with Co in the divalent state. It has been used in conjunction with N,N-dihydroxypyromellitimide to catalyze the oxidation of p-xylene to terephthalic acid, the reaction conditions for which have been investigated and optimized. At 150 °C, with acetonitrile as solvent instead of acetic acid and in the absence of corrosive bromine, the conversion of p-xylene reached 100 % and the selectivity for terephthalic acid exceeded 97 %. Under the optimized conditions, Co-BTC exhibits stronger catalytic activity than cobalt(II) acetate, and maintains excellent stability during the reaction. The reaction mechanism has been deduced, and the roles of N,N-dihydroxypyromellitimide and Co-BTC as synergistic catalysts in the reaction have been clarified.
- Chen, Dawei,Jiang, Haoran,Xu, Luo,Yuan, Xia
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- Novel oxidation of toluenes catalyzed by reusable vanadyl(IV) sulfate under mild conditions with molecular oxygen
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Efficient oxidation system using reusable vanadyl(IV) sulfate catalyst was established. Toluenes were easily oxidized under molecular oxygen (0.1 MPa) at 100 °C catalyzed by vanadyl(IV) sulfate to afford the corresponding benzoic acids in excellent yields. The recovered catalyst could be reused without loss of activity.
- Nakai, Takeo,Iwai, Toshiyuki,Mihara, Masatoshi,Ito, Takatoshi,Mizuno, Takumi
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- A new and efficient aerobic oxidation of aldehydes to carboxylic acids with singlet oxygen in the presence of porphyrin sensitizers and visible light
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A new aerobic route is introduced for the oxidation of a variety of aromatic and aliphatic aldehydes to the corresponding carboxylic acid derivatives using molecular oxygen in the presence of tetraphenylporphyrin (H2TPP), tetramesitylporphyrin (H2TMP), tetrakisdichlorophenylporphyrin (H2TDCPP), ZnTPP, and ZnTMP as sensitizers using visible light in an organic solvent. The method has a wide range of applications, does not involve cumbersome work-up, exhibits chemoselectivity, and proceeds under mild reaction conditions. The products are obtained with good conversions and in reasonable reaction times.
- Hajimohammadi, Mahdi,Safari, Nasser,Mofakham, Hamid,Shaabani, Ahmad
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- One-Pot Enzyme Cascade for Controlled Synthesis of Furancarboxylic Acids from 5-Hydroxymethylfurfural by H2O2 Internal Recycling
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Furancarboxylic acids are promising biobased building blocks in pharmaceutical and polymer industries. In this work, dual-enzyme cascade systems composed of galactose oxidase (GOase) and alcohol dehydrogenases (ADHs) are constructed for controlled synthesis of 5-formyl-2-furancarboxylic acid (FFCA) and 2,5-furandicarboxylic acid (FDCA) from 5-hydroxymethylfurfural (HMF), based on the catalytic promiscuity of ADHs. The byproduct H2O2, which is produced in GOase-catalyzed oxidation of HMF to 2,5-diformylfuran (DFF), is used for horseradish peroxidase (HRP)-mediated regeneration of the oxidized nicotinamide cofactors for subsequent oxidation of DFF promoted by an ADH, thus implementing H2O2 internal recycling. The desired products FFCA and FDCA are obtained with yields of more than 95 %.
- Jia, Hao-Yu,Zong, Min-Hua,Zheng, Gao-Wei,Li, Ning
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- Synthesis, characterization and catalytic activity of manganese(II)-cobalt(II) complexes anchored SBA-16 for liquid phase oxidation of p-xylene
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In this study, the results of synthesis and modified mesoporous surface of SBA-16 by using Schiff-base complexes [Co(II)-Mn(II)-Sal-APTES] were presented. Manganese(II) and cobalt(II)-Schiff bases complexes were synthesized by reaction between salicylalde
- Nui, Pham Xuan,Dung, Nguyen Nho,Van Thi, Tran Thi
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- Selectively Upgrading Lignin Derivatives to Carboxylates through Electrochemical Oxidative C(OH)?C Bond Cleavage by a Mn-Doped Cobalt Oxyhydroxide Catalyst
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Oxidative cleavage of C(OH)?C bonds to afford carboxylates is of significant importance for the petrochemical industry and biomass valorization. Here we report an efficient electrochemical strategy for the selective upgrading of lignin derivatives to carboxylates by a manganese-doped cobalt oxyhydroxide (MnCoOOH) catalyst. A wide range of lignin-derived substrates with C(OH)-C or C(O)-C units undergo efficient cleavage to corresponding carboxylates in excellent yields (80–99 %) and operational stability (200 h). Detailed investigations reveal a tandem oxidation mechanism that base from the electrolyte converts secondary alcohols and their derived ketones to reactive nucleophiles, which are oxidized by electrophilic oxygen species on MnCoOOH from water. As proof of concept, this approach was applied to upgrade lignin derivatives with C(OH)-C or C(O)-C motifs, achieving convergent transformation of lignin-derived mixtures to benzoate and KA oil to adipate with 91.5 % and 64.2 % yields, respectively.
- Zhou, Hua,Li, Zhenhua,Xu, Si-Min,Lu, Lilin,Xu, Ming,Ji, Kaiyue,Ge, Ruixiang,Yan, Yifan,Ma, Lina,Kong, Xianggui,Zheng, Lirong,Duan, Haohong
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- Synthesis of Dicarboxylic Acids from Aqueous Solutions of Diols with Hydrogen Evolution Catalyzed by an Iridium Complex
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A catalytic system for the synthesis of dicarboxylic acids from aqueous solutions of diols accompanied by the evolution of hydrogen was developed. An iridium complex bearing a functional bipyridonate ligand with N,N-dimethylamino substituents exhibited a high catalytic performance for this type of dehydrogenative reaction. For example, adipic acid was synthesized from an aqueous solution of 1,6-hexanediol in 97 % yield accompanied by the evolution of four equivalents of hydrogen by the present catalytic system. It should be noted that the simultaneous production of industrially important dicarboxylic acids and hydrogen, which is useful as an energy carrier, was achieved. In addition, the selective dehydrogenative oxidation of vicinal diols to give α-hydroxycarboxylic acids was also accomplished.
- Fujita, Ken-ichi,Toyooka, Genki
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- Electrochemical oxidation of benzyl chlorides: A new synthesis of 5-methyl-2-pyrazinecarboxylic acid
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A new high yield and selective electrochemical oxidation of benzyl chlorides to the corresponding aromatic acids at the nickel hydroxide electrode is reported. The utility of this method is exemplified by the new synthesis of 5-methyl-2-pyrazinecarboxylic acid, an important pharmaceutical intermediate.
- Borsotti,Foa,Gatti
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- Dehydro-aromatization of cyclohexene-carboxylic acids by sulfuric acid: Critical route for bio-based terephthalic acid synthesis
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A novel dehydro-aromatization reaction under mild reaction conditions was successfully developed using sulfuric acid as a cost-effective and efficient oxidant. This reaction simplified the synthesis of terephthalic acid (TA, an important aromatic monomer precursor) from biomass-derived isoprene and acrylic acid.
- Wang, Fei,Tong, Zhaohui
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- 9,10-Dihydroanthracene auto-photooxidation efficiently triggered photo-catalytic oxidation of organic compounds by molecular oxygen under visible light
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The development of mild and efficient process for the selective oxidation of organic compounds by molecular oxygen (O2) can be one of the key technologies for synthesizing oxygenates. This paper discloses an efficient and mild synthesis protocol for the O2-involved ethylbenzene (EB) photooxidation triggered by 910-dihydroanthracene (DHA) auto- photooxidation in acetone under visible light illumination, which can achieve 87.7 percent EB conversion and 99.5 percent acetylacetone (ACP) selectivity under ambient conditions. Also, 62.9 percent EB conversion and 96.3 percent ACP selectivity is obtained in air atmosphere. Furthermore, this protocol has a good adaptability for the photooxidation of other organic substrates such as tetrahydronaphthalene, diphenylmethane, toluene, cyclohexane, cyclohexene, alcohol, methylfuran and thioether to their corresponding oxygenates. A series of control and quenching tests, combined with EPR spectra, suggest that the photo-excited DHA can transfer its photo-electron to O2 to yield a superoxide radical anion (O2??), then DHA is preferentially oxidized to anthraquinone (AQ) by the active O2?? owing to its high reactivity. Finally, the in situ generated AQ as an active photo-catalyst can achieve the photooxidation of EB and other organic compounds by O2. The present photo-autoxidation protocol gives a good example for the O2-based selective oxidation of inert hydrocarbons under mild conditions.
- Chen, Mengke,Deng, Youer,Fu, Zaihui,Hu, Wenwei,Jiang, Dabo,Liu, Yachun,Mao, Feng,Su, Anqun,Yang, Bo,Zhang, Chao
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- Selective aerobic oxidation of para-xylene in sub- and supercritical water. Part 3: Effects of geometry and mixing in laboratory scale continuous reactors
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In this paper we report a strong dependence of the observed performance of the catalyst on the geometry and the configuration of laboratory scale reactors in the continuous aerobic oxidation of p-xylene in supercritical water. Small differences, such as t
- Pérez, Eduardo,Thomas, Morgan L.,Housley, Duncan,Hamley, Paul A.,Fraga-Dubreuil, Joan,Li, Jun,Lester, Edward,Poliakoff, Martyn
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- Silica sulfuric acid catalysis the oxidation of organic compounds with sodium bromate
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The oxidation of organic compounds by sodium bromate/silica sulfuric acid under solvent-free conditions and in CH2Cl2 have been studied at room temperature.
- Shaabani, Ahmad,Soleimani, Kamal,Bazgir, Ayoob
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- New crystalline modification of terephthalic acid
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The new crystalline modification of terephthalic acid can be obtained either from the commercially available triclinic modification by heating at 250 deg C or directly by a thermal hydrolysis of p-dicyanobenzene. It crystallises in a monoclinic system, space group C2/m with a = 8.940(2), b = 10.442(2), c = 3.790(1) Angstroem, V = 353.7(2) Angstroem3, β = 91.21(3) deg and Z = 2. Both carboxyl groups of terephthalic acid are coplanar with the phenyl ring. The molecules in the crystal are linked through the hydrogen bonds in the carboxyl groups into infinite chains. The orientational disorder is observed in the carboxyl groups. The structure of the monoclinic form is compared with the structure of both the triclinic modification.
- Sledz, M.,Janczak, J.,Kubiak, R.
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- Production of Terephthalic Acid from Corn Stover Lignin
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Funneling and functionalization of a mixture of lignin-derived monomers into a single high-value chemical is fascinating. Reported herein is a three-step strategy for the production of terephthalic acid (TPA) from lignin-derived monomer mixtures, in which redundant, non-uniform substitutes such as methoxy groups are removed and the desired carboxy groups are introduced. This strategy begins with the hydro-treatment of corn-stover-derived lignin oil over a supported molybdenum catalyst to selectively remove methoxy groups. The generated 4-alkylphenols are converted into 4-alkylbenzoic acids by carbonylation with carbon monoxide. The Co-Mn-Br catalyst then oxidizes various alkyl chains into carboxy groups, transforming the 4-alkylbenzoic acid mixture into a single product: TPA. For this route, the overall yields of TPA based on lignin content of corn stover could reach 15.5 wt %, and importantly, TPA with greater than 99 % purity was obtained simply by first decanting the reaction mixture and then washing the solid product with water.
- Song, Song,Zhang, Jiaguang,G?zayd?n, G?kalp,Yan, Ning
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- Oxygenation and chlorination of aromatic hydrocarbons with hydrochloric acid photosensitized by 9-mesityl-10-methylacridinium under visible light irradiation
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Efficient photocatalytic oxygenation of toluene occurs under visible light irradiation of 9-mesityl-10-methylacridinium (Acr+-Mes) in oxygen-saturated acetonitrile containing toluene and aqueous hydrochloric acid with a xenon lamp for 15 h. The oxygenated products, benzoic acid (70 %) and benzaldehyde (30 %), were formed after the photoirradiation. The photocatalytic reaction is initiated by intramolecular photoinduced electron transfer from the mesitylene moiety to the singlet excited state of the Acr+ moiety of Acr+-Mes, which affords the electron-transfer state, Acr ?-Mes?+. The Mes?+ moiety can oxidize chloride ion (Cl-) by electron transfer to produce chlorine radical (Cl?), whereas the Acr? moiety can reduce O2 to O 2 ?-. The Cl ? radical produced abstracts a hydrogen from toluene to afford benzyl radical in competition with the bimolecular radical coupling of Cl ?. The benzyl radical reacts with O2 rapidly to afford the peroxyl radical, leading to the oxygenated product, benzaldehyde. Benzaldehyde is readily further photooxygenated to yield benzoic acid with Acr?-Mes?+. In the case of an aromatic compound with electron-donating substituents, 1,3,5-trimethoxybenzene, photocatalytic chlorination occurred efficiently under the same photoirradiation conditions to yield a monochloro-substituted compound, 2,4,6-trimethoxychlorobenzene.
- Ohkubo, Kei,Mizushima, Kentaro,Fukuzumi, Shunichi
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- Introducing nanocrystalline CeO2 as heterogeneous environmental friendly catalyst for the aerobic oxidation of para-xylene to terephthalic acid in water
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CeO2 nanoparticles exposed in (100) and (111) surfaces have been synthesized and explored as a heterogeneous catalyst for the first time in the oxidation of para-xylene to terephthalic acid. The synthesis and catalysis reaction was environmenta
- Deori, Kalyanjyoti,Gupta, Dinesh,Saha, Basudeb,Awasthi, Satish K.,Deka, Sasanka
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- Highly Efficient Solid-State Hydrolysis of Waste Polyethylene Terephthalate by Mechanochemical Milling and Vapor-Assisted Aging
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Despite significant methodological and technological advancements in chemical recycling of synthetic polymers, an efficient and quantitative conversion of post-consumer polyethylene terephthalate (PET) into terephthalic acid (TPA) under ambient conditions
- ?trukil, Vjekoslav
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- Cobalt catalyst heterogenized on SBA-15 for p-xylene oxidation
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Cobalt(III) complex has been heterogenized onto a mesoporous material SBA-15 and successfully applied to the liquid phase oxidation of p-xylene in spite of not using either a solvent of bromide ion.
- Burri, Raju,Jun, Ki-Won,Kim, Young-Ho,Kim, Ji Man,Park, Sang-Eon,Yoo, Jin S.
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- Carboxylation of Benzoic Acid Using Cyclodextrin as Catalyst
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Benzoic acid is found to undergo carboxylation by warming with carbon tetrachloride in aqueous alkali in the presence of copper powder with β-cyclodextrin as catalyst.The reaction under mild conditions gives terephthalic acid in good yield with high selec
- Hirai, Hidefumi,Mihori, Hisashi
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- Solvent free oxidation of primary alcohols and diols using thymine iron(iii) catalyst
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In this study, we developed an efficient and selective iron-based catalyst system for the synthesis of ketones from secondary alcohols and carboxylic acids from primary alcohol. In situ generated iron catalyst of thymine-1-acetate (THA) and FeCl3 under solvent-free condition exhibits high activity. As an example, 1-octanol and 2-octanol were oxidized to 1-octanoic acid and 2-octanone with 89% and 98% yields respectively.
- Al-Hunaiti, Afnan,Niemi, Teemu,Sibaouih, Ahlam,Pihko, Petri,Leskelae, Markku,Repo, Timo
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- Efficient catalytic oxidation of methyl aromatic hydrocarbon with: N -alkyl pyridinium salts
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A series of N-alkyl pyridinium salts were synthesized and employed as metal-free catalyst for the selective oxidation of methyl aromatic hydrocarbon with molecular oxygen. The electronic effect of the substitutes was found to be an important factor for the catalytic performance. With the introduction of electron-donating substitute -N(CH3)2, the conversion of p-xylene and selectivity of p-toluic acid could be simultaneously increased. 1-Benzyl-4-N,N-dimethylaminopyridinium salt showed the highest catalytic activity, and 95% conversion with 84% of selectivity to p-toluic acid could be obtained for the selective oxidation of p-xylene. Several methyl aromatic hydrocarbons could all be efficiently oxidized with the reported catalyst at the absence of any metal species.
- Zhang, Qiaohong,He, Honghao,Wang, Huibin,Zhang, Zhan,Chen, Chen
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- Catalytic oxidation of alkyl aromatics using a novel silica supported Schiff base complex
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A new heterogeneous catalyst based on a chemically modified mesoporous silica gel and possessing immobilised chromium ions has been prepared and successfully applied to the aerial oxidation of alkyl aromatics at atmospheric pressure and in the absence of solvent.
- Chisem, Ian C.,Rafelt, John,Shieh, M. Tantoh,Chisem, Janet,Clark, James H.,Jachuck, Roshan,Macquarrie, Duncan,Ramshaw, Colin,Scott, Keith
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- Chemical recycling of waste poly(ethylene terephthalate) fibers into azo disperse dyestuffs
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In this study, waste poly(ethylene terephthalate) (PET) fibers were chemically recycled into azo disperse dyestuffs. First, waste PET fibers were glycolytically degraded by excess ethylene glycol utilizing zinc acetate dehydrate as a catalyst. The glycolysis product, bis(2-hydroxyethyl) terephthalate (BHET), was purified through recrystallization and hydrolyzed into terephthalic acid (TPA). Thereafter, BHET and TPA were nitrated, reduced and azotized to obtain diazonium salts. Finally, the obtained diazonium salts were coupled with N,N-dimethylaniline to obtain azo disperse dyestuffs (dye A and dye B, respectively). The depolymerized products (BHET and TPA) and azo disperse dyestuffs (dyes A and B) were characterized by FTIR and 1H NMR spectroscopy. Nylon and polyester filaments were dyed with the synthesized azo dyestuffs with the dye bath pH ranging from 3.6 to 5.8. The performances of the dyestuffs were described by maximum absorption wavelength, K/S, L, a and b values. This journal is
- Li, Mengjuan,Huang, Yanhong,Yu, Tianshi,Chen, Shiming,Ju, Anqi,Ge, Mingqiao
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- One-step synthesis of terephthalic acid from benzene in water using cyclodextrin as catalyst
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The one-pot synthesis of terephthalic acid from benzene has been achieved by treatment with tetrachloromethane, copper powder, and an aqueous sodium hydroxide solution using cyclodextrin as a catalyst at 30 °C under nitrogen in 46 mol% yield with 100% selectivity.
- Shiraishi, Yukihide,Tashiro, Shigetoshi,Toshima, Naoki
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- Solvent-Free Benzylic Oxidations Using Urea-Hydrogen Peroxide Complex (UHP) under Microwave Irradiation
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Urea-hydrogen peroxide complex (UHP) has been found to be an efficient oxidizing agent for the oxidation of various alkyl benzenes/naphthalene/ tetralin under microwave irradiation in solvent-free conditions.
- Paul, Satya,Nanda, Puja,Gupta, Rajive
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- Linker Installation: Engineering Pore Environment with Precisely Placed Functionalities in Zirconium MOFs
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Precise placement of multiple functional groups in a highly ordered metal-organic framework (MOF) platform allows the tailoring of the pore environment, which is required for advanced applications. To realize this, we present a comprehensive study on the linker installation method, in which a stable MOF with coordinatively unsaturated Zr6 clusters was employed and linkers bearing different functional groups were postsynthetically installed. A Zr-MOF with inherent missing linker sites, namely, PCN-700, was initially constructed under kinetic control. Twelve linkers with different substituents were then designed to study their effect on MOF formation kinetics and therefore resulting MOF structures. Guided by the geometrical analysis, linkers with different lengths were installed into a parent PCN-700, giving rise to 11 new MOFs and each bearing up to three different functional groups in predefined positions. Systematic variation of the pore volume and decoration of pore environment were realized by linker installation, which resulted in synergistic effects including an enhancement of H2 adsorption capacities of up to 57%. In addition, a size-selective catalytic system for aerobic alcohol oxidation reaction is built in PCN-700 through linker installation, which shows high activity and tunable size selectivity. Altogether, these results exemplify the capability of the linker installation method in the pore environment engineering of stable MOFs with multiple functional groups, giving an unparalleled level of control.
- Yuan, Shuai,Chen, Ying-Pin,Qin, Jun-Sheng,Lu, Weigang,Zou, Lanfang,Zhang, Qiang,Wang, Xuan,Sun, Xing,Zhou, Hong-Cai
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- Furan Carboxylic Acids Production with High Productivity by Cofactor-engineered Whole-cell Biocatalysts
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Furan carboxylic acids are useful chemicals in various industries. In this work, biocatalytic production of furan carboxylic acids was reported with high productivities by cofactor-engineered Escherichia coli cells. NADH oxidase (NOX) was introduced into E. coli harboring aldehyde dehydrogenases (ALDHs) to promote intracellular NAD+ regeneration, thus significantly enhancing ALDH-catalyzed oxidation. These engineered biocatalysts were capable of efficient aerobic oxidation of a variety of aromatic aldehydes. More importantly, they exhibited high substrate tolerance toward toxic furans. E. coli co-expressing vanillin dehydrogenase and NOX (E. coli_CtVDH1_NOX) enabled efficient oxidation of 250 mM of 5-hydroxymethylfurfural (HMF) to 5-hydroxymethyl-2-furancarboxylic acid (HMFCA), providing a productivity of 3.7 g/L h. With E. coli_CtVDH2_NOX as catalyst, up to 240 mM of furfural and 5-methoxymethylfurfural (MMF) could be smoothly oxidized. 2-Furoic acid (FCA, 227 mM) and 5-methoxymethyl-2-furancarboxylic acid (MMFCA, 287 mM) were produced in fed-batch synthesis, providing the productivities of 2.0 and 5.6 g/L h, respectively.
- Zhang, Xue-Ying,Wang, Xin,Li, Nan-Wei,Guo, Ze-Wang,Zong, Min-Hua,Li, Ning
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- Cobalt Salts-Catalyzed Carbonylation of Aromatic Halides under Photostimulation
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A novel method for the carbonylation of aromatic halides by the cobalt salt catalysts such as Co(OAc)2*4H2O, CoCl2*6H2O, CoSO4*7H2O, Co(OH)2, Co(OH)3, CoO, and Co2O3 was investigated in an aqueous alkaline solution under photostimulation.These salts were found to have a catalytic activity as high as that of Co2(CO)8 under mild conditions.
- Kudo, Kiyoshi,Shibata, Tadashi,Kashimura, Tsugunori,Mori, Sadayuki,Sugita, Nobuyuki
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- A recyclable nanoparticle-supported palladium catalyst for the hydroxycarbonylation of aryl halides in water
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Boomerang catalysis: A catalyst catchrelease system Is established by the noncovalent attachment of a Pd N-heterocyclic carbene complex to graphene-coated magnetic Co nanoparticles. The immobilization by pyrene tags (see scheme; blue) is reversible at elevated temperatures, releasing the homogeneous catalyst. The hydroxycarbonylation of aryl halides is performed in 16 iterative reactions with this highly active catalyst. (Figure Presented)
- Wittmann, Sebastian,Schaetz, Alexander,Grass, Robert N.,Stark, Wendelin J.,Reiser, Oliver
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- Selective oxidation of para-xylene to terephthalic acid by μ3-oxo-bridged Co/Mn cluster complexes encapsulated in zeolite-Y
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Novel, solid catalysts of μ3-oxo-bridged Co/Mn cluster complexes were prepared and their catalytic properties (in the "neat" state and when encapsulated in zeolite Y) in the selective oxidation of paraxylene to terephthalic acid with oxygen wer
- Ratnasamy,Chavan,Srinivas
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- Stepwise benzylic oxygenation via uranyl-photocatalysis
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Stepwise oxygenation at the benzylic position (1°, 2°, 3°) of aromatic molecules was comprehensively established under ambient conditions via uranyl photocatalysis to produce carboxylic acids, ketones, and alcohols, respectively. The accuracy of the stepwise oxygenation was ensured by the tunability of catalytic activity in uranyl photocatalysis, which was adjusted by solvents and additives demonstrated through Stern–Volmer analysis. Hydrogen atom transfer between the benzylic position and the uranyl catalyst facilitated oxygenation, further confirmed by kinetic studies. Considerably improved efficiency of flow operation demonstrated the potential for industrial synthetic application.
- Hu, Deqing,Jiang, Xuefeng
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supporting information
p. 124 - 129
(2022/01/19)
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- Gram-scale synthesis of carboxylic acids via catalytic acceptorless dehydrogenative coupling of alcohols and hydroxides at an ultralow Ru loading
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Acceptorless dehydrogenative coupling (ADC) of alcohols and water/hydroxides is an emergent and graceful approach to produce carboxylic acids. Therefore, it is of high demand to develop active and practical catalysts/catalytic systems for this attractive transformation. Herein, we designed and fabricated a series of cyclometallated N-heterocyclic carbene-Ru (NHC-Ru) complexes via ligand tuning of [Ru-1], the superior complex in our previous work. Gratifyingly, gram-scale synthesis of carboxylic acids was efficiently enabled at an ultralow Ru loading (62.5 ppm) in open air. Moreover, effects of distinct ancillary NHC ligands and other parameters on this catalytic process were thoroughly studied, while further systematic studies were carried out to provide rationales for the activity trend of [Ru-1]-[Ru-7]. Finally, determination of quantitative green metrics illustrated that the present work exhibited superiority over representative literature reports. Hopefully, this study could provide valuable input for researchers who are engaging in metal-catalyzed ADC reactions.
- Chen, Cheng,Cheng, Hua,Verpoort, Francis,Wang, Zhi-Qin,Wu, Zhe,Yuan, Ye,Zheng, Zhong-Hui
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- Continuous production method of benzoic acid derivative
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The invention relates to the technical field of preparation of benzoic acid derivatives. The invention particularly relates to a continuous production method of a benzoic acid derivative. The continuous reaction device is characterized by comprising a small-diameter sleeve, wherein the small-diameter sleeve is sleeved with a large-diameter sleeve, and a small pipeline is arranged between the small-diameter sleeve and the large-diameter sleeve, and a plurality of small holes are arranged on the small pipeline. The small-diameter casing is rotated, the large-diameter casing is fixed, and the reaction liquid composed of the nitric acid and the toluene derivative is between a small-diameter casing pipe and a large-diameter casing pipe.
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Paragraph 0032-0033; 0035
(2021/11/14)
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- Photo-tunable oxidation of toluene and its derivatives catalyzed by TBATB
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In this report, tetrabutylammonium tribromide (TBATB) was introduced as an efficient visible light active catalyst to carry out the aerobic oxidation of toluene, its derivatives, and some of methyl arenes to benzaldehydes, benzoic acids and ketones in good to high yields. All the oxidation reactions were performed under mild conditions using oxygen as a green oxidant, a catalytic amount of TBATB under blue (460 nm), royal blue (430 nm), and violet LED (400 nm) irradiation. It was found that the reactions selectivity was significantly affected by changing the solvent (from CH3CN to EtOAc) and LED wavelength (from blue to violet). In the following, our mechanistic studies revealed that the visible light oxidation of toluenes and methyl arenes over TBATB could be following a benzyl peroxy radical intermediate.
- Mardani, Atefeh,Kazemi, Foad,Kaboudin, Babak
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- Practical scale up synthesis of carboxylic acids and their bioisosteres 5-substituted-1H-tetrazoles catalyzed by a graphene oxide-based solid acid carbocatalyst
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Herein, catalytic application of a metal-free sulfonic acid functionalized reduced graphene oxide (SA-rGO) material is reported for the synthesis of both carboxylic acids and their bioisosteres, 5-substituted-1H-tetrazoles. SA-rGO as a catalytic material incorporates the intriguing properties of graphene oxide material with additional benefits of highly acidic sites due to sulfonic acid groups. The oxidation of aldehydes to carboxylic acids could be efficiently achieved using H2O2as a green oxidant with high TOF values (9.06-9.89 h?1). The 5-substituted-1H-tetrazoles could also be effectively synthesized with high TOF values (12.08-16.96 h?1). The synthesis of 5-substituted-1H-tetrazoles was corroborated by single crystal X-ray analysis and computational calculations of the proposed reaction mechanism which correlated well with experimental findings. Both of the reactions could be performed efficiently at gram scale (10 g) using the SA-rGO catalyst. SA-rGO displays eminent reusability up to eight runs without significant decrease in its productivity. Thus, these features make SA-rGO riveting from an industrial perspective.
- Mittal, Rupali,Kumar, Amit,Awasthi, Satish Kumar
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p. 11166 - 11176
(2021/03/31)
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- Preparation method of aromatic dicarboxylic acid derivative
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The invention provides a preparation method of an aromatic dicarboxylic acid derivative, wherein the preparation method comprises the following steps: step 1, carrying out a coupling reaction on dihalogenated aromatic hydrocarbon and metal cyanide at a temperature of 40-200 DEG C under metal catalysis in a solvent, and carrying out extraction layering concentration to obtain a dicyano compound after the reaction is finished; and step 2, carrying out a hydrolysis reaction on the obtained dicyanogen compound at the temperature of 60-200 DEG C under an acidic condition, and carrying out post-treatment to obtain the final product. According to the preparation method of the aromatic dicarboxylic acid derivative, dihalogenated aromatic hydrocarbon reacts with metal cyanide and then is hydrolyzedunder the acidic condition to obtain aromatic acid or the derivative thereof, and the preparation method has the remarkable advantages that the raw materials are cheap and easy to obtain, operation is easy and convenient, the yield is high, three wastes are easy to dispose, the product quality is high, and the substrate tolerance is good.
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- Oxidative α-C-C Bond Cleavage of 2° and 3° Alcohols to Aromatic Acids with O2at Room Temperature via Iron Photocatalysis
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The selective α-C-C bond cleavage of unfunctionalized secondary (2°) and tertiary alcohols (3°) is essential for valorization of macromolecules and biopolymers. We developed a blue-light-driven iron catalysis for aerobic oxidation of 2° and 3° alcohols to acids via α-C-C bond cleavages at room temperature. The first example of oxygenation of the simple tertiary alcohols was reported. The iron catalyst and blue light play critical roles to enable the formation of highly reactive O radicals from alcohols and the consequent two α-C-C bond cleavages.
- Zhang, Zongnan,Zhang, Guoxiang,Xiong, Ni,Xue, Ting,Zhang, Junjie,Bai, Lu,Guo, Qinyue,Zeng, Rong
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p. 2915 - 2920
(2021/05/05)
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- Photo-induced deep aerobic oxidation of alkyl aromatics
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Oxidation is a major chemical process to produce oxygenated chemicals in both nature and the chemical industry. Presently, the industrial manufacture of benzoic acids and benzene polycarboxylic acids (BPCAs) is mainly based on the deep oxidation of polyalkyl benzene, which is somewhat suffering from environmental and economical disadvantage due to the formation of ozone-depleting MeBr and corrosion hazards of production equipment. In this report, photo-induced deep aerobic oxidation of (poly)alkyl benzene to benzene (poly)carboxylic acids was developed. CeCl3 was proved to be an efficient HAT (hydrogen atom transfer) catalyst in the presence of alcohol as both hydrogen and electron shuttle. Dioxygen (O2) was found as a sole terminal oxidant. In most cases, pure products were easily isolated by simple filtration, implying large-scale implementation advantages. The reaction provides an ideal protocol to produce valuable fine chemicals from naturally abundant petroleum feedstocks. [Figure not available: see fulltext.].
- Wang, Chang-Cheng,Zhang, Guo-Xiang,Zuo, Zhi-Wei,Zeng, Rong,Zhai, Dan-Dan,Liu, Feng,Shi, Zhang-Jie
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p. 1487 - 1492
(2021/07/10)
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- Photoinduced FeCl3-Catalyzed Alkyl Aromatics Oxidation toward Degradation of Polystyrene at Room Temperature?
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While polystyrene is widely used in daily life as a synthetic plastic, the subsequently selective degradation is still very challenging and highly required. Herein, we disclose a highly practical and selective reaction for the catalytically efficient oxidation of alkyl aromatics (including 1°, 2°, and 3° alkyl aromatics) to carboxylic acids. While dioxygen was used as the sole terminal oxidant, this protocol was catalyzed by the inexpensive and readily available ferric compound (FeCl3) with irradiation of visible light (blue LEDs) under only 1 atmosphere of O2 at room temperature. This system could further facilitate the selective degradation of polystyrene to benzoic acid, providing an important and practical tool to generate high-value chemical from abundant polystyrene wastes.
- Zhang, Guoxiang,Zhang, Zongnan,Zeng, Rong
-
supporting information
p. 3225 - 3230
(2021/09/28)
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- FLOW CHEMISTRY SYNTHESIS OF ISOCYANATES
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The disclosure provides, inter alia, safe and environmentally-friendly methods, such as flow chemistry, to synthesize isocyanates, such as methylene diphenyl diisocyanate, toluene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, and tetramethylxylene diisocyanate.
- -
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Paragraph 0175; 0228-0229
(2021/06/22)
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- 1,2-Dibutoxyethane-Promoted Oxidative Cleavage of Olefins into Carboxylic Acids Using O2 under Clean Conditions
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Herein, we report the first example of an effective and green approach for the oxidative cleavage of olefins to carboxylic acids using a 1,2-dibutoxyethane/O2 system under clean conditions. This novel oxidation system also has excellent functional-group tolerance and is applicable for large-scale synthesis. The target products were prepared in good to excellent yields by a one-pot sequential transformation without an external initiator, catalyst, and additive.
- Ou, Jinhua,Tan, Hong,He, Saiyu,Wang, Wei,Hu, Bonian,Yu, Gang,Liu, Kaijian
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p. 14974 - 14982
(2021/10/25)
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- Hydrolysis of amides to carboxylic acids catalyzed by Nb2O5
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Hydrolysis of amides to carboxylic acids is an industrially important reaction but is challenging due to the difficulty of cleaving the resonance stabilized amidic C-N bond. Twenty-three heterogeneous and homogenous catalysts were examined in the hydrolysis of acetamide. Results showed that Nb2O5was the most effective heterogeneous catalyst with the greatest yield of acetic acid. A series of Nb2O5catalysts calcined at various temperatures were characterized and tested in the hydrolysis of acetamide to determine the effects of crystal phase and surface properties of Nb2O5on catalytic performance. The high catalytic performance observed was attributed mainly to the facile activation of the carbonyl bond by Lewis acid sites that function even in the presence of basic inhibitors (NH3and H2O). The catalytic studies showed the synthetic advantages of the present method, such as simple operation, catalyst recyclability, additive free, solvent free, and wide substrate scope (>40 examples; up to 95% isolated yield).
- Siddiki,Rashed, Md. Nurnobi,Touchy, Abeda Sultana,Jamil, Md. A. R.,Jing, Yuan,Toyao, Takashi,Maeno, Zen,Shimizu, Ken-Ichi
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p. 1949 - 1960
(2021/03/26)
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- A PROCESS FOR THE PREPARATION OF 4-CYANOBENZOYL CHLORIDES
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The present invention relates to a process for the preparation of 4-cyanobenzoyl chlorides of formula I through reaction of compounds of formula II with a chlorinating agent.
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Page/Page column 11-12
(2021/10/22)
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- Silica-Mediated Monohydrolysis of Dicarboxylic Esters
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A new method for the monohydrolysis of dicarboxylic esters is presented, involving as key step a silanolysis at elevated temperatures at the silica gel surface. In the second step, the surface bound silyl esters are cleaved off under mild conditions, giving a straightforward and fast access to half esters. Based on recovered starting material generally yields well above 70 % are achieved, both, with stiff aromatic as well as flexible aliphatic substrates, as long as the ester groups involved are remote enough from each other. Otherwise competing reactions are becoming determinative, anhydride formation in the case of phthalates and decarbonylative fragmentation in the case of malonates. The new method was also successfully tested on a multigram scale with a minimalistic apparatus setup.
- Dyker, Gerald
-
supporting information
p. 6773 - 6776
(2021/12/31)
-
- Oxidation of aromatic and aliphatic aldehydes to carboxylic acids by Geotrichum candidum aldehyde dehydrogenase
-
Oxidation reaction is one of the most important and indispensable organic reactions, so that green and sustainable catalysts for oxidation are necessary to be developed. Herein, biocatalytic oxidation of aldehydes was investigated, resulted in the synthesis of both aromatic and aliphatic carboxylic acids using a Geotrichum candidum aldehyde dehydrogenase (GcALDH). Moreover, selective oxidation of dialdehydes to aldehydic acids by GcALDH was also successful.
- Hoshino, Tomoyasu,Yamabe, Emi,Hawari, Muhammad Arisyi,Tamura, Mayumi,Kanamaru, Shuji,Yoshida, Keisuke,Koesoema, Afifa Ayu,Matsuda, Tomoko
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-
- Sequential Connection of Mutually Exclusive Catalytic Reactions by a Method Controlling the Presence of an MOF Catalyst: One-Pot Oxidation of Alcohols to Carboxylic Acids
-
A functionalized metal-organic framework (MOF) catalyst applied to the sequential one-pot oxidation of alcohols to carboxylic acids controls the presence of a heterogeneous catalyst. The conversion of alcohols to aldehydes was acquired through aerobic oxidation using a well-known amino-oxy radical-functionalized MOF. In the same flask, a simple filtration of the radical MOF with mild heating of the solution completely altered the reaction media, providing radical scavenger-free conditions suitable for the autoxidation of the aldehydes formed in the first step to carboxylic acids. The mutually exclusive radical-catalyzed aerobic oxidation (the first step with MOF) and radical-inhibited autoxidation (the second step without MOF) are sequentially achieved in a one-pot manner. Overall, we demonstrate a powerful and efficient method for the sequential oxidation of alcohols to carboxylic acids by employing a readily functionalizable heterogeneous MOF. In addition, our MOF in-and-out method can be utilized in an environmentally friendly way for the oxidation of alcohols to carboxylic acids of industrial and economic value with broad functional group tolerance, including 2,5-furandicarboxylic acid and 1,4-benzenedicarboxylic acid, with good yield and reusability. Furthermore, MOF-TEMPO, as an antioxidative stabilizer, prevents the undesired oxidation of aldehydes, and the perfect "recoverability"of such a reactive MOF requires a re-evaluation of the advantages of MOFs from heterogeneity in catalytic and related applications.
- Kim, Seongwoo,Lee, Ha-Eun,Suh, Jong-Min,Lim, Mi Hee,Kim, Min
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supporting information
p. 17573 - 17582
(2020/12/22)
-
- Catalytic oxidation of alcohols and alkyl benzenes to carbonyls using Fe3O4?SiO2?(TEMPO)-: Co -(Chlorophyll-CoIII) as a bi-functional, self-co-oxidant nanocatalyst
-
Chlorophyll b was extracted from heliotropium europaeum plant, demetalated, allylated and grafted to acrylated TEMPO through a copolymerization protocol. Then, the chlorophyll monomers were coordinated to Co ions, immobilized on magnetic nanoparticles and the resulting hybrid was used as a powerful catalyst for a variety of oxidation reactions. By using the present method, oxidation of benzylic alcohols and alkyl benzenes to carbonyls was accomplished in water under aerobic conditions. Moreover, direct oxidation of alcohols to carboxylic acids was performed by adding NaOCl to the mixture. All entries were oxidized to the corresponding desired product with high to excellent yields and up to 97% selectivity. The catalyst was thoroughly characterized by CV, TGA, VSM, XRD, XPS, DLS, FE-SEM, TEM, UV-Vis, EDX, and BET analyses. The activity of the catalyst was investigated by applying various components of the catalyst to the oxidation model separately. The reasonable mechanisms are suggested based on the cooperation between the TEMPO groups and cobalt(iii) (or Co(iv)) sites on the catalyst. The catalyst could be recovered and reused for at least 7 consecutive recycles without any considerable reactivity loss. This journal is
- Hamah-Ameen, Baram Ahmed,Kazemnejadi, Milad,Mahmoudi, Boshra,Rostami, Amin
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p. 6600 - 6613
(2020/11/16)
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- Cobalt-Catalyzed Acceptorless Dehydrogenation of Alcohols to Carboxylate Salts and Hydrogen
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The facile oxidation of alcohols to carboxylate salts and H2 is achieved using a simple and readily accessible cobalt pincer catalyst (NNNHtBuCoBr2). The reaction follows an acceptorless dehydrogenation pathway and displays good functional group tolerance. The amine-amide metal-ligand cooperation in cobalt catalyst is suggested to facilitate this transformation. The mechanistic studies indicate that in-situ-formed aldehydes react with a base through a Cannizzaro-type pathway, resulting in potassium hemiacetolate, which further undergoes catalytic dehydrogenation to provide the carboxylate salts and H2
- Gunanathan, Chidambaram,Kishore, Jugal,Pattanaik, Sandip,Pradhan, Deepak Ranjan
-
supporting information
(2020/03/03)
-
- Investigation of the requirements for efficient and selective cytochrome P450 monooxygenase catalysis across different reactions
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The cytochrome P450 metalloenzyme (CYP) CYP199A4 from Rhodopseudomonas palustris HaA2 catalyzes the highly efficient oxidation of para-substituted benzoic acids. Here we determined crystal structures of CYP199A4, and the binding and turnover parameters, with different meta-substituted benzoic acids in order to establish which criteria are important for efficient catalysis. When compared to the para isomers, the meta-substituted benzoic acids were less efficiently oxidized. For example, 3-formylbenzoic acid was oxidized with lower activity than the equivalent para isomer and 3-methoxybenzoic acid did not undergo O-demethylation by CYP199A4. The structural data highlighted that the meta-substituted benzoic acids bound in the enzyme active site in a modified position with incomplete loss of the distal water ligand of the heme moiety. However, for both sets of isomers the meta- or para-substituent pointed towards, and was in close proximity, to the heme iron. The absence of oxidation activity with 3-methoxybenzoic acid was assigned to the observation that the C[sbnd]H bonds of this molecule point away from the heme iron. In contrast, in the para isomer they are in an ideal location for abstraction. These findings were confirmed by using the bulkier 3-ethoxybenzoic acid as a substrate which removed the water ligand and reoriented the meta-substituent so that the methylene hydrogens pointed towards the heme, enabling more efficient oxidation. Overall we show relatively small changes in substrate structure and position in the active site can have a dramatic effect on the activity.
- Podgorski, Matthew N.,Coleman, Tom,Chao, Rebecca R.,De Voss, James J.,Bruning, John B.,Bell, Stephen G.
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- The Role of Acidity in Terephthalic Acid Synthesis from Renewable Carbon Source
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In this study, manganese-cobalt (MnCo) mixed oxide catalysts were prepared by two different routes: co-precipitation and citrate method. The structures and properties of the mixed oxide catalysts were investigated by several techniques: nitrogen adsorptio
- Boc?rnea, Amelia,Cavani, Fabrizio,Counsell, Jonathan,Florea, Mihaela,Nea?u, Florentina,Nea?u, Stefan,Trandafir, Mihaela-Mirela
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p. 6248 - 6258
(2020/12/01)
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- CATALYST SYSTEM FOR OXIDATION OF PARA-XYLENE AND/OR META-XYLENE TO CORRESPONDING CARBOXYLIC ACIDS
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A method for preparing an aromatic acid, the method comprising: contacting an alkyl aromatic compound, an oxidant, and a catalyst composition in a solvent under conditions effective to oxidize the alkyl aromatic compound and provide a reaction product com
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-
Paragraph 0046-0047
(2020/06/10)
-
- GREEN, COPPER-CATALYZED DISPROPORTIONATION OF AROMATIC AND HETEROAROMATIC CARBOXYLATES TO DICARBOXYLATES
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The present application relates to a process for preparation of a compound of Formula (I) and Formula (IV): wherein is as described herein; and wherein and R are as described herein.
- -
-
Paragraph 0108; 0111
(2020/06/08)
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- METHOD FOR MANUFACTURING TEREPHTHALIC ACID AND SYSTEM THEREOF
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A method for manufacturing terephthalic acid includes the following operations: providing a raw material, in which the raw material includes a first raw material including polyethylene terephthalate; performing a depolymerization reaction on the first raw
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- Method for preparing aromatic carboxylic acid compound
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The invention discloses a method for preparing an aromatic carboxylic acid compound. The method comprises the following steps: 1) heating carbon dioxide and hydrosilane in the presence of a copper catalyst in a reaction medium A; and 2) adding a reaction medium B, aryl halide, a palladium catalyst and a base to the reaction mixture in the step 1), sealing the reaction system, and performing a heating reaction. The method has the advantages that raw materials are simple and easy to obtain, the raw materials are cheap and stable, the catalyst is common, easy to obtain and stable, the reaction conditionsaremild, the aftertreatment is simple, the yield is high, and the like.
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Page/Page column 10-11; 12-13; 14
(2020/02/14)
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- Method for catalytic oxidation of toluene and derivatives thereof by metalloporphyrin
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The invention relates to a method for catalytic oxidation of toluene and derivatives thereof by metalloporphyrin. The method comprises the following steps: dispersing metalloporphyrin and N-hydroxyphthalimide (NHPI) into methylbenzene and derivatives thereof, sealing the reaction system, heating to 70-130 DEG C while stirring, introducing oxygen to 0.2-2.0 MPa, keeping the set temperature and oxygen pressure, carrying out reactions for 8 hours under stirring, and carrying out after-treatment on the reaction solution to obtain the product aromatic acid. The method has the advantages of no solvent, no additive, mild conditions, higher selectivity to aromatic acids and good tolerance to substrates. The method not only can effectively oxidize hydrocarbon containing primary benzyl C-H bonds, but also can provide important reference for constructing a more effective C-H bond oxidation system, and is a novel efficient and feasible selective catalytic oxidation method for methylbenzene and derivatives thereof.
- -
-
Paragraph 0075-0076
(2020/09/30)
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- Aerobic Co-/ N-Hydroxysuccinimide-Catalyzed Oxidation of p-Tolylsiloxanes to p-Carboxyphenylsiloxanes: Synthesis of Functionalized Siloxanes as Promising Building Blocks for Siloxane-Based Materials
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Synthesis of organosilicon products with a "polar" functional group within organic substituents is one of the most fundamentally and practically important challenges in today's chemistry of silicones. In our study, we suggest a solution to this problem, viz., a high-efficiency preparative method based on aerobic Co-/N-hydroxysuccinimide (NHSI) catalyzed oxidation of p-tolylsiloxanes to p-carboxyphenylsiloxanes. This approach is based on "green", commercially available, simple, and inexpensive reagents and employs mild reaction conditions: Co(OAc)2/NHSI catalytic system, O2 as the oxidant, process temperature from 40 to 60 °C, atmospheric pressure. This reaction is general and allows for synthesizing both mono- and di-, tri-, and poly(p-carboxyphenyl)siloxanes with p-carboxyphenyl groups at 1,1-, 1,3-, 1,5-, and 1,1,1-positions. All the products were obtained and isolated in gram amounts (up to 5 g) and in high yields (80-96%) and characterized by NMR, ESI-HRMS, GPC, IR, and X-ray data: p-carboxyphenylsiloxanes in crystalline state form HOF-like structures. Furthermore, it was shown that the suggested method is applicable for the oxidation of organic alkylarene derivatives (Ar-CH3, Ar-CH2-R) to the corresponding acids and ketones (Ar-C(O)OH and Ar-C(O)-R), as well as hydride silanes ([Si]-H) to silanols ([Si]-OH). The possibility of synthesizing monomeric (methyl) and polymeric (siloxane-containing PET analogue, Sila-PET) esters based on 1,3-bis(p-carboxyphenyl)disiloxane was studied. These processes occur with retention of the organosiloxane frame and allow to obtain the corresponding products in 90 and 99% yields.
- Goncharova, Irina K.,Silaeva, Kseniia P.,Arzumanyan, Ashot V.,Anisimov, Anton A.,Milenin, Sergey A.,Novikov, Roman A.,Solyev, Pavel N.,Tkachev, Yaroslav V.,Volodin, Alexander D.,Korlyukov, Alexander A.,Muzafarov, Aziz M.
-
supporting information
p. 2143 - 2151
(2019/02/05)
-
- N-Doped carbon nanofibers derived from bacterial cellulose as an excellent metal-free catalyst for selective oxidation of arylalkanes
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N-Doped carbon nanofibers derived from one-step pyrolysis of low-cost bacterial cellulose with the assistance of urea were reported. Owing to their interconnected nanofibrous structure and high specific surface area as well as high N doping, they exhibited excellent catalytic performance for selective oxidation of arylalkanes even with O2 as an oxidant in aqueous solution.
- Huang, Runkun,Cao, Changyan,Liu, Jian,Sun, Dongping,Song, Weiguo
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supporting information
p. 1935 - 1938
(2019/05/02)
-
- The sustainable room temperature conversion of: P -xylene to terephthalic acid using ozone and UV irradiation
-
Current industrial processes utilize Co/Mn bromides as catalysts to catalyze the oxidative conversion of para-xylene to terephthalic acid (TA) in acetic acid at high temperatures (>200 °C, air, 15-30 atm.). The decomposition of metallo-catalysts and solvents at high temperatures as well as a subsequent hydropurification process releases thousands of millions of tons of wastewater, global warming gas (CO2) and ozone depleting gas (CH3Br) into the global environment per year, causing global warming, ozone depletion, dramatic climate change, huge economic losses, and many other environmental problems. Herein, we report an alternative sustainable process with low energy demand for the room temperature oxidative conversion of p-xylene to terephthalic acid, with 96% TA yield and 98% selectivity, via ozone treatment and concurrent UV irradiation and without the generation and release of greenhouse gas (CO2), ozone depleting gas (CH3Br), and wastewater, or the need for a high energy-demand hydropurification process. The reaction mechanism involves the singlet O(1D)- and hydroxyl radical-mediated selective C-H functionalization of p-xylene.
- Hwang, Kuo Chu,Sagadevan, Arunachalam,Kundu, Pradip
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p. 6082 - 6088
(2019/11/20)
-
- Selective oxidation method for toluene compounds
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The invention discloses a selective oxidation method for toluene compounds. The method comprises the following steps: 1, putting a toluene compound represented by a formula (I) shown in the specification, a metalloporphyrin catalyst, an oxidant and a dispersing agent into a ball milling tank, sealing the ball milling tank, carrying out ball milling for 3-24 hours at room temperature and the rotating speed of 100-800 rpm, stopping ball milling once every 1-3 hours in the ball milling process, discharging gas in the ball milling tank, and after the reaction is finished, carrying out post-treatment on the reaction mixture to obtain a product benzoic acid compound represented by a formula (II) shown in the specification. Oxidation conversion of methylbenzene and derivatives thereof is achievedthrough solid-phase ball milling, the reaction mode is novel, the operation is convenient, and the energy consumption is low; an organic solvent and other auxiliaries are not needed, so that use of toxic and harmful organic reagents is effectively avoided, and the method is green and environmentally friendly; the peroxide content is low, and the safety coefficient is high; and benzoic acid and derivatives thereof have high selectivity and meet the social requirements of a green chemical process, an environmental compatibility chemical process and a biological compatibility chemical process inthe prior art.
- -
-
Paragraph 0116; 0117
(2019/12/25)
-
- Fe3O4@SiO2@Im[Cl]Mn(III)-complex as a highly efficient magnetically recoverable nanocatalyst for selective oxidation of alcohol to imine and oxime
-
An efficient and environmentally friendly oxidation process for the one-pot preparation of oxime, imine and carbonyl compounds through alcohol oxidation in the presence of H2O2 and/or O2 have been developed by a melamine-Mn(III) Schiff base complex supported on Fe3O4@SiO2–Cl nanoparticles, named as Fe3O4@SiO2@Im[Cl]Mn(III)-complex nanocomposite, at room temperature. Direct oxidation of alcohol to carboxylic acid was performed using the catalyst in the presence of molecular O2 at room temperature in a different approach. The oxidation products were obtained with excellent yields and high TOFs. The properties of the catalyst were characterized by Fourier transform infrared spectroscopy (FTIR), elemental analysis (C, H, N), X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), dynamic light scattering (DLS), energy dispersive X-ray analysis (EDX), X-ray photoelectron spectroscopy (XPS), inductive coupled plasma (ICP), cyclic voltammetry (CV), nuclear magnetic resonance (1H & 13C NMR), vibration sample magnetometer (VSM), Brunauer– Emmett–Teller (BET) and differential pulse voltammetry (DPV) analyses. The mechanism of the oxidation processes was investigated for the both H2O2 and O2 oxidants. The role of the imidazolium moiety in the catalyst as a secondary functionality was investigated. Chemoselectivity behavior of the catalyst was studied by some combinations. The catalyst could be recycled from the reaction mixture by a simple external magnet and reused for several times without any considerable reactivity loss.
- Kazemnejadi, Milad,Alavi, Seyyedeh Ameneh,Rezazadeh, Zinat,Nasseri, Mohammad Ali,Allahresani, Ali,Esmaeilpour, Mohsen
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p. 230 - 249
(2019/03/28)
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- Synthesis of polyoxometalates supported on HZSM-5 for the photocatalytic purification of crude terephthalic acid under mild conditions
-
Phosphomolybdic (PMo) and vanadium-containing phosphomolybdic (PV2Mo) acids were synthesized and supported on HZSM-5 zeolite via a wet impregnation technique and used as photocatalysts for the purification of terephthalic acid (TA) via an econo
- Hussein,Mady,Mahmoud,Shim,Yehia
-
p. 173 - 181
(2019/04/08)
-
- Palladium complex containing diphosphine m-carborane ligand as well as preparation and application of palladium complex
-
The invention relates to a palladium complex containing a diphosphine m-carborane ligand as well as a preparation and an application of the palladium complex. The preparation method of the palladium complex comprises the following steps of 1) adding an n-BuLi solution into a m-carborane solution, and then reacting for 30-60 minutes at a room temperature; 2) adding diphenyl phosphorus chloride, andreacting for 3-6 h at the room temperature; and 3) adding PdCl2, reacting at the room temperature for 3-5 hours, and carrying out post-treatment to obtain the palladium complex. The palladium complexis used for catalyzing the reaction of halohydrocarbon with carbon dioxide to synthesize carboxylic acid. Compared with the prior art, the synthesis process is simple and green, and has the excellentselectivity and high yield; the palladium complex has the stable physicochemical properties and is used as the catalyst, the halogenated hydrocarbon is used as a substrate, the palladium complex andthe halogenated hydrocarbon are jointly dissolved in toluene, and the carbon dioxide is introduced at the normal pressure for reaction, so that the corresponding carboxylic acid can be synthesized athigh yield.
- -
-
Paragraph 0055-0058
(2019/12/02)
-
- Method for synthesizing aromatic hydrocarbon compound
-
The invention relates to a method for preparing an aromatic compound through dehydrogenating a cycloalkane or cycloalkene compound in the presence of a palladium or palladium polymetal co-loaded catalyst. According to the method, the aromatic compound is synthesized at a low temperature under anaerobic conditions, a high-activity high-selectivity catalyst is developed, and an industrial moderate preparation method for the aromatic compound is established.
- -
-
Paragraph 0028-0033; 0041; 0042
(2019/03/26)
-
- Picolinamide Assisted Oxidation of CH2 Groups Bound to Organic and Organometallic Compounds Using Ferrocene as a Catalyst
-
Picolinamide group assisted sp3 C-H bond oxidation of methylene groups to the corresponding carbonyl compounds has been achieved by using simple bottle ferrocene as catalyst and Cu(OAc)2 or tert-butyl peroxybenzoate (TBPB) as oxidant under mild conditions. This method is applicable for picolinamide bound organic as well as organometallic compounds with yields in the range of 46-82%. Control experiments and mechanistic studies indicate that a radical mechanism is responsible for these oxidative transformations in which ferrocene acts as a catalyst.
- Dolui, Pritam,Hazra, Susanta,Deb, Mayukh,Elias, Anil J.
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p. 2015 - 2021
(2019/05/16)
-
- Method for Visible Light-Induced Photocatalytic Degradation of Methylparaben in Water Using Nanostructured Ag/AgBr@m-WO3
-
An efficient method of photocatalytic degradation of methylparaben in water using Ag nanoparticles (NPs) loaded AgBr-mesoporous-WO3 composite photocatalyst (Ag/AgBr@m-WO3), under visible light is presented. In this process, quantific
- Suliman, Mohammed A.,Gondal, Mohammed A.,Dastageer, Mohamed A.,Chuah, Gaik-Khuan,Basheer, Chanbasha
-
p. 1485 - 1494
(2019/07/18)
-
- CO2 activation by electrogenerated divalent samarium for aryl halide carboxylation
-
The reductive carboxylation of aryl halides has been investigated using a samarium electrode as a sacrificial anode to yield the corresponding benzoic acids, providing a smooth strategy for CO2 activation. Carboxylation occurred after an efficient reduction of carbon dioxide mediated by an electrogenerated Sm(ii)-complex acting as a strong monoelectronic reductive reagent.
- Bazzi, Sakna,Le Duc, Ga?tan,Schulz, Emmanuelle,Gosmini, Corinne,Mellah, Mohamed
-
supporting information
p. 8546 - 8550
(2019/10/02)
-
- Method for copper-catalyzed carboxylation reaction of arylboronic acid and carbon dioxide
-
The invention discloses a method for a copper-catalyzed carboxylation reaction of arylboronic acid and carbon dioxide. According to the method, carbon dioxide is used as a C1 source, copper catalysisis adopted, alkoxide serves as alkali, and a reaction is carried out in an organic solvent; the method is simple in process and easy to implement, and shows wide functional group compatibility; the method allows various arylboronic acids such as monosubstituted or polysubstituted phenylboronic acid, polycyclic aromatic hydrocarbon boronic acid and benzoheterocyclic boronic acid to be converted into corresponding arylcarboxylic acids with considerable yield under mild conditions; and the produced carboxylic acids have important application value, and can be used for deriving a great number of other common chemical substances, such as acyl halide, acid anhydride, ester and amide.
- -
-
Paragraph 0051; 0052
(2019/12/29)
-
- Method of co-producing methyl benzoic acid, methylbenzoyl chloride and phthaloyl dichloride
-
The invention discloses a method of co-producing methyl benzoic acid, methylbenzoyl chloride and phthaloyl dichloride. The method comprises the following steps: (1) continuously introducing xylene, acatalyst and oxygen-containing gas into an oxidizing reactor to react to obtain an oxidized reaction solution; (2) rectifying and separating the oxidized reaction solution to obtain a low-boiling-point component and an initial evaporative tower bottom; (3) rectifying the initial evaporative tower bottom to obtain a methyl benzoic acid product and a tower bottom; (4) carrying out an acylating chlorination reaction on the tower bottom and an acylating chlorination reagent to obtain an acyl chloride reaction solution; and (5) rectifying and separating the acyl chloride reaction solution to separately obtain methylbenzoyl chloride and phthaloyl dichloride products. The method provided by the invention has the advantages of being simple in process, small in equipment investment, green and environment-friendly and good in comprehensive economical benefit.
- -
-
Paragraph 15-17; 27; 28
(2018/06/16)
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- Oxidation of: P -toluic acid to terephthalic acid via a bromine-free process using nano manganese and manganese-copper mixed oxides
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The industrial process of terephthalic acid (TPA) production suffers from many environmental and economical drawbacks. Liquid-phase catalytic oxidation of alkylbenzene by oxygen is usually initiated by bromine in a corrosive acetic acid solvent. A recent
- Betiha, Mohamed A.,Kandile, Nadia G.,Badawi, Abdelfattah M.,Solyman, Sanaa M.,Afify, Ahmed S.
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p. 6343 - 6353
(2018/04/23)
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- Method for synthesizing benzoic acid compound from benzyl alcohol compound by ultrasonic-assisted oxidation
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The invention belongs to the field of synthesis of organic intermediates, and specifically discloses an ultrasonic-assisted synthesis method for a benzoic acid compound. The method comprises the following step: promoting air oxidation of benzyl alcohol by using diethylene glycol dimethyl ether under an ultrasonic-assisted action so as to obtain the benzoic acid compound, wherein a benzyl alcohol raw material is benzyl alcohol, or a benzoic acid derivative containing one to five substituents at different positions on the benzene ring of benzyl alcohol; and a reaction accelerator is the diethylene glycol dimethyl ether. The method provided by the invention has the advantages of easily-available raw materials, simple and convenient reaction conditions, short reaction time, greenness, energy conservation, high reaction selectivity and yield, excellent compatibility of substrate functional groups, and high application value.
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Paragraph 0154; 0155
(2018/09/29)
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- Bis(methoxypropyl) ether-promoted oxidation of aromatic alcohols into aromatic carboxylic acids and aromatic ketones with O2 under metal- and base-free conditions
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We describe an eco-friendly, practical and operationally simple procedure for the bis(methoxypropyl) ether-promoted oxidation of aromatic alcohols into aromatic carboxylic acids and aromatic ketones with atmospheric dioxygen as the sole oxidant. This chemical process is clean with high conversion and good selectivity, and an external initiator, catalyst, additive and base are not required. The virtue of this reaction is highlighted by its easily available and economical raw materials and excellent functional group tolerance (acid-, base- and oxidant-labile groups).
- Liu, Kai-Jian,Jiang, Si,Lu, Ling-Hui,Tang, Ling-Li,Tang, Shan-Shan,Tang, Hai-Shan,Tang, Zilong,He, Wei-Min,Xu, Xinhua
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supporting information
p. 3038 - 3043
(2018/07/13)
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