- Fabrication of three dimensional (3D) hierarchical Ag/WO3 flower-like catalyst materials for the selective oxidation of m-xylene to isophthalic acid
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A three dimensional (3D) hierarchical silver supported tungsten oxide flower-like microsphere catalyst has been fabricated using a cationic surfactant CTAB. It was found that the crystal-splitting mechanism plays a key role in the formation of this flower-like structure. This catalyst was proved to be highly effective in the liquid phase selective oxidation of m-xylene to isophthalic acid.
- Acharyya, Shankha S.,Ghosh, Shilpi,Bal, Rajaram
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Read Online
- Is carbon dioxide able to activate halogen/lithium exchange?
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The unexpected effect of carbon dioxide on halogen-lithium exchange (HLE) reactions of selected haloarenes with tBuLi was investigated. In an aliphatic hydrocarbon solvent (pentane), the HLE does not occur at ca. -70 C but, surprisingly, pouring the mixture of reactants onto dry ice and subsequent aqueous acidic hydrolysis gave carboxylic acids resulting from the quench of the first-formed aryllithiums with carbon dioxide. This suggests that CO 2 acts as a promoter of the HLE and, subsequently, serves as an electrophile to trap the aryllithium intermediates that are generated in situ. Theoretical DFT calculations were used to develop a plausible mechanism for the reaction, which indicates that CO2 is a much weaker donor than tetrahydrofuran (THF) so the cleavage of inert tBuLi cubic tetramers into more reactive solvated dimeric species (tBuLi)2(CO2) 4 is disfavored by 42.8 kJ per mol of (tBuLi)4. It is possible that this deaggregation process occurs to some extent when a large excess of CO2 is used. Copyright
- Durka, Krzysztof,Lulinski, Sergiusz,Dabrowski, Marek,Serwatowski, Janusz
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Read Online
- Modulating Reactivity and Selectivity of 2-Pyrone-Derived Bicyclic Lactones through Choice of Catalyst and Solvent
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2-Pyrones, such as coumalic acid, are promising biobased molecules that through Diels-Alder reactions can provide access to a wide range of biobased chemicals, including molecules with functionality that are not easily accessible via conventional petrochemical routes. A complete reaction network and kinetic parameters for three individual diversification routes that start from a single bicyclic lactone produced via the Diels-Alder cycloaddition of coumalic acid and ethylene were examined experimentally and probed through complementary first-principle density functional theory (DFT) calculations, in situ nuclear magnetic resonance (NMR) spectroscopy, and thin film solid-state NMR spectroscopy. These experiments provide insights into the routes for several molecular structures from bicyclic lactones by leveraging Lewis or Br?nsted acid catalysts to selectively alter the reaction pathway. The bicyclic lactone bridge can be decarboxylated to access dihydrobenzenes at a substantially reduced activation barrier using γ-Al2O3 as the catalyst or selectively ring-opened via Br?nsted acids to yield 1,3-diacid six membered rings. DFT computations and microkinetic modeling in combination with experimental results provide molecular insights into the catalytically active sites on γ-Al2O3 and provide a general mechanism for the catalyzed bicyclic lactone decarboxylation in polar aprotic solvents, which involves CO2 extrusion as the kinetically relevant step. Solid-state NMR spectroscopy provides direct evidence of strong binding of the bicyclic lactone to the γ-Al2O3 surface, fully consistent with DFT simulation results and experimental reaction kinetics. In addition, the role of the solvent was examined and found to be an additional means to improve reaction rates and selectively produce alternative structures from the bicyclic intermediate. The rate of the decarboxylation reaction was increased dramatically by using water as the solvent whereas methanol acted as a nucleophile and selectively induced ring-opening, showing that both pathways are operative in the absence of catalyst. Taken together, the results demonstrate an approach for selective diversification of the coumalate platform to a range of molecules.
- Pfennig, Toni,Chemburkar, Ashwin,Johnson, Robert L.,Ryan, Matthew J.,Rossini, Aaron J.,Neurock, Matthew,Shanks, Brent H.
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- Palladium-catalyzed carbonylation of aryl iodides in aqueous media
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Carbonylation of ArI in aqueous media under 1 atm CO in the presence of phosphineless palladium complexes and some base leads to aromatic acids.
- Bumagin, N. A.,Nikitin, K. V.,Beletskaya, I. P.
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Read Online
- Photoinduced transformations of Acid Violet 7 and Acid Green 25 in the presence of TiO2 suspension
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An azo dye (Acid Violet 7) and an anthraquinone dye (Acid Green 25) were degraded in aqueous solution using titanium dioxide as photocatalyst. Their fate was studied through dyes decomposition, identification of the main and secondary transformation produ
- Fabbri,Calza,Prevot, A. Bianco
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Read Online
- 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
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supporting information
p. 3225 - 3230
(2021/09/28)
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- MOF-Zn-NHC as an efficient N-heterocyclic carbene catalyst for aerobic oxidation of aldehydes to their corresponding carboxylic acids: Via a cooperative geminal anomeric based oxidation
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As an efficient heterogenous N-heterocyclic carbene (NHC) catalyst, MOF-Zn-NHC was used in the aerobic oxidation of aryl aldehydes to their corresponding carbocyclic acids via an anomeric based oxidation. Features such as mild reaction conditions and no need for a co-catalyst or oxidative reagent can be considered as the major advantages of the presented method in this study. This journal is
- Babaee, Saeed,Zarei, Mahmoud,Zolfigol, Mohammad Ali
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p. 36230 - 36236
(2021/12/02)
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- Fuel-Driven Dynamic Combinatorial Libraries
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In dynamic combinatorial libraries, molecules react with each other reversibly to form intricate networks under thermodynamic control. In biological systems, chemical reaction networks operate under kinetic control by the transduction of chemical energy. We thus introduced the notion of energy transduction, via chemical reaction cycles, to a dynamic combinatorial library. In the library, monomers can be oligomerized, oligomers can be deoligomerized, and oligomers can recombine. Interestingly, we found that the dynamics of the library's components were dominated by transacylation, which is an equilibrium reaction. In contrast, the library's dynamics were dictated by fuel-driven activation, which is a nonequilibrium reaction. Finally, we found that self-assembly can play a large role in affecting the reaction's kinetics via feedback mechanisms. The interplay of the simultaneously operating reactions and feedback mechanisms can result in hysteresis effects in which the outcome of the competition for fuel depends on events that occurred in the past. In future work, we envision diversifying the library by modifying building blocks with catalytically active motifs and information-containing monomers.
- Bergmann, Alexander M.,Boekhoven, Job,Kriebisch, Christine M. E.
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p. 7719 - 7725
(2021/05/26)
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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
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supporting information
p. 6773 - 6776
(2021/12/31)
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- Manufacturing Process of Aromatic Dicarboxylic Acids by Using a Cobalt/Manganese/Bromide Catalyst System Having Improved Oxidation Reaction Efficiency
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The present invention relates to a process for manufacturing aromatic dicarboxylic acids, such as isophthalic acid, by oxidizing xylene in the presence of a cobalt/manganese/bromide (CMB) catalyst system, and to a method of improving oxidation reaction efficiency of a catalyst by adding zirconium bromide as a bromine precursor in an activation process of a catalyst component recovered from a mother liquor of the oxidation reaction of xylene containing the CMB catalyst system.(AA) Mother liquid(BB,DD) Acetic acid(CC) Br precursor(EE) ProductCOPYRIGHT KIPO 2020
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Paragraph 0047--0060
(2020/10/07)
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- Oxidation of aromatic and aliphatic aldehydes to carboxylic acids by Geotrichum candidum aldehyde dehydrogenase
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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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- 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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- Catalytic Oxidative Deamination by Water with H2Liberation
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Selective oxidative deamination has long been considered to be an important but challenging transformation, although it is a common critical process in the metabolism of bioactive amino compounds. Most of the synthetic methods developed so far rely on the use of stoichiometric amounts of strong and toxic oxidants. Here we present a green and efficient method for oxidative deamination, using water as the oxidant, catalyzed by a ruthenium pincer complex. This unprecedented reaction protocol liberates hydrogen gas and avoids the use of sacrificial oxidants. A wide variety of primary amines are selectively transformed to carboxylates or ketones in good to high yields. It is noteworthy that mechanistic experiments and DFT calculations indicate that in addition to serving as the oxidant, water also plays an important role in assisting the hydrogen liberation steps involved in amine dehydrogenation.
- Tang, Shan,Rauch, Michael,Montag, Michael,Diskin-Posner, Yael,Ben-David, Yehoshoa,Milstein, David
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supporting information
p. 20875 - 20882
(2020/12/23)
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- 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.
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Paragraph 0108; 0112
(2020/06/08)
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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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Paragraph 0140-0143; 0176
(2020/02/14)
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- 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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- Preparation method of isophthalic acids
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The invention provides a preparation method of isophthalic acids. The preparation method comprises the following steps: performing oxidation reaction on m-xylene; an oxidant for the oxidation reactionis ozone, and the oxidation reaction is performed in a solvent under UV light irradiation. The preparation method provided by the invention has the characteristics of being low in energy consumption,less in greenhouse gas emission, low in equipment investment and high in yield; the yield can reach 96 percent.
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Paragraph 0036; 0037; 0039-
(2019/03/08)
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- Surveying Iron-Organic Framework TAL-1-Derived Materials in Ligandless Heterogeneous Oxidative Catalytic Transformations of Alkylarenes
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The use of carbonized materials derived from metal-organic frameworks (MOFs) in catalytic organic transformations is less well explored than is the use of MOFs. Here, we survey the oxidative performance of heterogeneous catalyst materials derived from the polycrystalline iron-organic framework TAL-1.
- Alam, Mahboob,J?rving, Ivar,K??rik, Maike,Kongi, Nade?da,Leis, Jaan,Ping, Kefeng,Starkov, Pavel
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supporting information
p. 1536 - 1540
(2019/08/07)
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- Synthesis method of isophthalic acid
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The invention discloses a synthesis method of isophthalic acid. The synthesis method comprises the following steps that (1) 20 mL of m-dimethylbenzene is taken and placed in a reaction kettle, a solvent is added, the temperature of the reaction kettle is controlled to be 160-170 DEG C, the reaction pressure is controlled to be 0.85-0.9 MPa, the volume fraction of oxygen in the reaction kettle is controlled to be 30-35%, then 1,4-dichloro-2,3-dichloroanthraquinone and N-carboxylphthalimide metal catalysts are added, and a reaction is conducted for 6-8 h and then stopped; and (2) reaction liquidis cooled to the room temperature, then N,N-dimethylformamide is added for dilution and dissolution, the adding amount of the N,N-dimethylformamide is 8-10 times the volume of m-dimethylbenzene, andobtained white crystals or powder is a target product. According to the synthesis method, the m-dimethylbenzene is oxidized through the metal catalysts under the high temperature and low pressure to synthesize the isophthalic acid, a reaction route is simple, the comprehensive raw material cost is low, and the yield is high.
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Paragraph 0009-0013
(2019/12/25)
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- Green synthesis method of aromatic acid
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The invention relates to a synthesis method of organic acid, in particular to a green synthesis method of aromatic acid, and belongs to the field of organic synthesis. According to the green synthesismethod of the aromatic acid, an aromatic cyano compound is used as a substrate, a corresponding aromatic acid ammonium salt is obtained after catalytic hydrolysis under catalysis of an alkali catalyst, the obtained aromatic acid ammonium salt is hydrolyzed to obtain the aromatic acid, at the same time, byproduct ammonia water is produced, and the alkali catalyst can be repeatedly applied for manytimes; and the structural formula of the aromatic cyano compound is as follows (please see the specification for the formula). The green synthesis method has the characteristics of simple operation,high product yield, easy separation and basically no generation of salt containing wastewater, small generation amount of wastewater, environmental friendliness and the like, in addition, the catalystcan further be reused for many times, and after repeated application of the catalyst, the total yield of a product can be close to 100%.
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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.
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supporting information
p. 2143 - 2151
(2019/02/05)
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- 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)
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- The sustainable room temperature conversion of: P -xylene to terephthalic acid using ozone and UV irradiation
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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)
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- The Cu(I)- and HNO3-catalyzed oxidation of substituted toluenes to the benzoic acid based on NOx recycling
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Based on the recycling of NOx, the Cu(I)- and HNO3-catalyzed oxidation of 2-chloro-4-(methylsulfonyl)toluene to 2-chloro-4-(methylsulfonyl)benzoic acid has been developed with an excellent yield of 84.2% and a purity of 99.7%. The optimized reaction conditions (160?°C, oxygen pressure 1.5?MPa, HNO3 concentration 25?wt%, HNO3: substrate 0.5:1) use 1.0?mol% CuI as catalyst. The dosage of HNO3 in the new process is only 25% of the stoichiometric amount and 12.5% of the amount of the traditional process. The NOx emission is 5% amount of the traditional process. The oxidation of several additional toluene derivatives with comparable yields demonstrates the generality to these reaction conditions.
- Wei, Mengyi,Qian, Chao,Chen, Xinzhi
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- Method of co-producing methyl benzoic acid, methylbenzoyl chloride and phthaloyl dichloride
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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.
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Page/Page column 18-24; 27; 28
(2018/06/16)
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- Tandem one-pot CO2 reduction by PMHS and silyloxycarbonylation of aryl/vinyl halides to access carboxylic acids
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The present study discloses the synthesis of aryl/vinyl carboxylic acids from Csp2-bound halides (Cl, Br, I) in a carbonylative path by using silyl formate (from CO2 and hydrosilane) as an instant CO-surrogate. Hydrosilane provides hydride for reduction and its oxidation product silanol serves as a coupling partner. Mono-, di-, and tri-carboxylic acids were obtained from the corresponding aryl/vinyl halides.
- Paridala, Kumaraswamy,Lu, Sheng-Mei,Wang, Meng-Meng,Li, Can
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supporting information
p. 11574 - 11577
(2018/10/31)
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- Dry Chemistry of Ferrate(VI): A Solvent-Free Mechanochemical Way for Versatile Green Oxidation
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The +6 oxidation state of iron generally exists in the form of ferrate(VI) with high redox potential and environmentally friendly nature. Although ferrate(VI) has been known for over a century, its chemistry is still limited to the solvent-based reactions that suffers from the insolubility/instability of this oxidant and the environmental issues caused by hazardous solvents. Herein, we explore the solvent-free reactivity of ferrate(VI) under mechanical milling, revealing that its strong oxidizing power is accessible in the “dry” solid state towards a broad variety of substrates, for example, aromatic alcohols/aldehydes and carbon nanotubes. More significantly, solvent-free mechanochemistry also reshapes the oxidizing ability of ferrate(VI) due to the underlying solvent-free effect and the promotive mechanical actions. This study opens up a new chemistry of ferrate(VI) with promising application in green oxidative transformation of both organic and inorganic substrates.
- Zhang, Zhao-Yang,Ji, Deyang,Mao, Wenting,Cui, Yu,Wang, Qing,Han, Lu,Zhong, Hongliang,Wei, Zhongming,Zhao, Yixin,N?rgaard, Kasper,Li, Tao
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supporting information
p. 10949 - 10953
(2018/08/01)
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- Ru(II) complexes bearing 2,6-bis(benzimidazole-2-yl)pyridine ligands: A new class of catalysts for efficient dehydrogenation of primary alcohols to carboxylic acids and H2in the alcohol/CsOH system
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Mono-cationic Ru(II)-complexes [Ru(L)X(CH3CN)2]?X 1～4 (1, L = 2,6-bis(benzimidazol-2-yl) pyridine (L1), X = Cl; 2, L = L1, X = OTf; 3, L = 2-(N-benzyl-benzimidazole-2-yl)-6-(benzimidazole-2-yl)pyridine (L2), X = Cl; 4, L = 2,6-bis(N-benzyl-benzimidazole-2-yl)pyridine (L3), X = Cl) were prepared and fully characterized. The two acetonitrile ligands of each complex are coordinated to the metal center cis to each other. Complex 2 was also structurally characterized by X-ray crystallography. It was found that complexes 1～4 can catalyze the acceptorless dehydrogenation of primary alcohols to corresponding carboxylic acids and H2in the basic aqueous solution, and the reactivity follows the order 1 = 2 > 4 > 3. Furthermore, complexes 1 or 2 can efficiently catalyze the conversion of various primary alcohols to carboxylic acid in good yields (72%–98%) and high selectivity in an alcohol/CsOH system (1/1, mol/mol). Using an excess amount of alcohol to CsOH results in the formation of the carboxylic acid in higher yield (up to 100%, based on CsOH) and higher turnover numbers (TON ～ 10000) accompanied by the H2evolution. Complexes 1 and 2 can act as a new class of phosphine- and N-heterocycle carbene free Ru(II) complexes for efficient conversion of primary alcohols to carboxylic acids and H2in a homogeneous system.
- Dai, Zengjin,Luo, Qi,Meng, Xianggao,Li, Renjie,Zhang, Jing,Peng, Tianyou
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- PRODUCTION OF XYLENE DERIVATIVES
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The present invention relates to the production of xylene derivatives from furfural and its derivatives. The invention describes new routes for converting furfural and its derivatives into xylene derivatives including novel intermediates.
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Page/Page column 25
(2017/07/06)
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- Metal-Free Dehomologative Oxidation of Arylacetic Acids for the Synthesis of Aryl Carboxylic Acids
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A novel I2-promoted direct conversion of arylacetic acids into aryl carboxylic acids under metal-free conditions has been described. This remarkable transformation involves decarboxylation followed by an oxidation reaction enabled just by using DMSO as the solvent as well as an oxidant. Notably, aryl carboxylic acids are isolated by simple filtration technique and obtained in good to excellent yields. This protocol is free from chromatographic purification, which makes it applicable for large-scale synthesis.
- Kalmode, Hanuman P.,Vadagaonkar, Kamlesh S.,Shinde, Suresh L.,Chaskar, Atul C.
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p. 3781 - 3786
(2017/04/11)
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- Liquid-Crystalline Star-Shaped Supergelator Exhibiting Aggregation-Induced Blue Light Emission
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A family of closely related star-shaped stilbene-based molecules containing an amide linkage are synthesized, and their self-assembly in liquid-crystalline and gel states was investigated. The number and position of the peripheral alkyl tails were systematically varied to understand the structure-property relation. Interestingly, one of the molecules with seven peripheral chains was bimesomorphic, exhibiting columnar hexagonal and columnar rectangular phases, whereas the rest of them stabilized the room-temperature columnar hexagonal phase. The self-assembly of these molecules in liquid-crystalline and organogel states is extremely sensitive to the position and number of alkoxy tails in the periphery. Two of the compounds with six and seven peripheral tails exhibited supergelation behavior in long-chain hydrocarbon solvents. One of these compounds with seven alkyl chains was investigated further, and it has shown higher stability and moldability in the gel state. The xerogel of the same compound was characterized with the help of extensive microscopic and X-ray diffraction studies. The nanofibers in the xerogel are found to consist of molecules arranged in a lamellar fashion. Furthermore, this compound shows very weak emission in solution but an aggregation-induced emission property in the gel state. Considering the dearth of solid-state blue-light-emitting organic materials, this molecular design is promising where the self-assembly and emission in the aggregated state can be preserved. The nonsymmetric design lowers the phase-transition temperatures.The presence of an amide bond helps to stabilize columnar packing over a long range because of its polarity and intermolecular hydrogen bonding in addition to promoting organogelation.
- Pathak, Suraj Kumar,Pradhan, Balaram,Gupta, Monika,Pal, Santanu Kumar,Sudhakar, Achalkumar Ammathnadu
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p. 9301 - 9312
(2016/10/06)
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- Co-production method for methyl benzoic acid and phthalic acid
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The invention discloses a co-production method for methyl benzoic acid and phthalic acid. The co-production method comprises the following steps: (1) continuously introducing fresh dimethylbenzene, a catalyst and oxygen-containing gas into a primary oxidation reactor for a reaction to obtain a primary oxidation reaction solution containing methyl benzoic acid and an eight-carbon oxygen-contained compound; (2) carrying out continuous cooling, crystallization and filtration on the primary oxidation reaction solution to obtain filter liquor and filter cake, circulating 1-98% of the filter liquor back the primary oxidation reactor continuously, and continuous rectifying the filter cake continuously, to obtain a low-boiling point front cut fraction, distillation raffinate and a methyl benzoic acid product separately; (3) adding the remaining filter liquor in the step (2) and the obtained front cut fraction and distillation raffinate in the step (2) into a secondary oxidation reactor continuously, and meanwhile continuously introducing a Co/Mn/Br catalyst, acetic acid and oxygen-containing gas into the secondary oxidation reactor for an oxidation reaction to obtain a secondary oxidation reaction mixture; and (4) continuously cooling, crystallizing and filtrating the secondary oxidation reaction mixture to obtain a filter liquor and a phthalic acid product. The co-production method has advantages of a simple process, a low cost, a high yield, good selectivity, good economic benefits, and environmental protection.
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Paragraph 0088; 0089; 0114; 0117; 0119
(2016/10/07)
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- PREPARATION METHOD OF CARBOXYLIC ACIDS OR KETONES USING OZONE, SINGLET STATE-OXYGEN ATOM OR HYDROXYL FREE RADICAL
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A preparation method of carboxylic acids or ketones using ozone, singlet state oxygen atom O(1D) or hydroxyl free radical is provided. The method includes: filling ozone, singlet state oxygen atom O(1D) and/or hydroxyl free radical to cycloalkanes or benzenes at a pre-determined temperature and a pre-determined pressure in the presence or absence of light irradiation to produce carboxylic acids or ketones. The reaction occurs at room temperature and atmospheric pressure without producing harmful side products. The preparation method is a simple, low energy consuming, and eco-friendly method.
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Paragraph 0040-0043; 0046
(2016/05/10)
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- IONIC LIQUID COMPOSITION
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The present disclosure provides a composition for preparing aryl carboxylic acid; said composition comprising: at least one ionic liquid, at least one catalyst, at least one non-oxidizable polar solvent, and at least one oxidizable multi-alkylated arylene compound with no two successive ring positions bearing alkyl group. The present disclosure also provides a process for preparing aryl carboxylic acid.
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Paragraph 0105-0106
(2016/05/19)
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- Production of aromatic carboxylic acid
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PROBLEM TO BE SOLVED: To provide a production method of an aromatic carboxylic acid (except for terephthalic acid) by liquid phase oxidation of an alkyl group-containing aromatic hydrocarbon using a molecular oxygen-containing gas in the presence of a catalyst comprising a heavy metal compound and a bromine compound in a solvent containing a lower aliphatic carboxylic acid, the method providing an aromatic carboxylic acid with stable qualities by reducing fluctuations in the catalyst component in the liquid phase oxidation reaction system. SOLUTION: The method includes: cooling an oxidation reaction slurry obtained by liquid phase oxidation to separate into an aromatic carboxylic acid crystal and an oxidation reaction mother liquid, using 25 to 95% of the oxidation reaction mother liquid as a recycling mother liquid in a circulated manner in the liquid phase oxidation system, while purging the rest of the oxidation reaction mother liquid as a purge mother liquid to the outside of the system to recover the catalyst component. In the recovering process, a plurality of pyridine ring-containing chelate resin columns is used; and the recovered catalyst liquid from an elution step is retained in a recovered catalyst liquid tank for 1.5 to 6 hours and then introduced into the liquid phase oxidation reaction system. COPYRIGHT: (C)2012,JPOandINPIT
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Paragraph 0037
(2017/01/02)
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- A high-throughput screening method for determining the substrate scope of nitrilases
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Nitrile compounds are intermediates in the synthesis of pharmaceuticals such as atorvastatin. We have developed a chromogenic reagent to screen for nitrilase activity as an alternative to Nessler's reagent. It produces a semi-quantifiable blue colour and hydrolysis of 38 nitrile substrates by 23 nitrilases as cell-free extracts has been shown. This journal is
- Black, Gary W.,Brown, Nicola L.,Perry, Justin J. B.,Randall, P. David,Turnbull, Graeme,Zhang, Meng
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supporting information
p. 2660 - 2662
(2015/03/05)
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- Manganese dioxide and N,N′,N″-trihydroxyisocyanuric acid: A novel and recyclable catalytic system for aerobic oxidation of toluene derivatives in PEG-1000-based dicationic acidic ionic liquid
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N,N′,N″-trihydroxyisocyanuric acid (THICA) with MnO2 promotes the aerobic oxidation of toluene derivatives to corresponding acids in PEG-1000-based dicationic acidic ionic liquid (PEG1000-DAIL). It is demonstrated that THICA/MnO2 is very active and selective and several toluene derivatives are efficiently oxidized to corresponding acids under mild conditions. Both the catalyst and PEG1000-DAIL can be reused after simple separation. A plausible mechanism is also proposed based on the experimental observations.
- Lu, Tingting,Zhang, Lijie,Ge, Zhongxue,Ji, Yueping,Lu, Ming
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p. 276 - 279
(2015/04/27)
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- Electrophilicity and nucleophilicity of commonly used aldehydes
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The present approach for determining the electrophilicity (E) and nucleophilicity (N) of aldehydes includes a kinetic study of KMNO4 oxidation and NaBH4 reduction of aldehydes. A transition state analysis of the KMNO4 promoted aldehyde oxidation reaction has been performed, which shows a very good correlation with experimental results. The validity of the experimental method has been tested using the experimental activation parameters of the two reactions. The utility of the present approach is further demonstrated by the theoretical versus experimental relationship, which provides easy access to E and N values for various aldehydes and offers an at-a-glance assessment of the chemical reactivity of aldehydes in various reactions. the Partner Organisations 2014.
- Pratihar, Sanjay
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p. 5781 - 5788
(2014/07/22)
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- Inclusion complex containing epoxy resin composition for semiconductor encapsulation
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The invention is an epoxy resin composition for sealing a semiconductor, including (A) an epoxy resin and (B) a clathrate complex. The clathrate complex is one of (b1) an aromatic carboxylic acid compound, and (b2) at least one imidazole compound represented by formula (II): wherein R2 represents a hydrogen atom, C1-C10 alkyl group, phenyl group, benzyl group or cyanoethyl group, and R3 to R5 represent a hydrogen atom, nitro group, halogen atom, C1-C20 alkyl group, phenyl group, benzyl group, hydroxymethyl group or C1-C20 acyl group. The composition has improved storage stability, retains flowability when sealing, and achieves an effective curing rate applicable for sealing delicate semiconductors.
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- Superacid BF3-H2O promoted benzylation of arenes with benzyl alcohols and acetates initiated by trace water
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A convenient procedure employing simple starting materials benzyl alcohols and acetates as the benzyl donors to assemble a series of diarylalkanes through benzylation of arenes using in situ prepared superacid BF3-H 2O as an efficient promoter has been developed. The beneficial role of water in the reaction has been clarified with combination of control experiments and 11B NMR analysis. This reaction is a self-promoted model, which is triggered by the trace of water and continuously promoted by self released by-product water (or carboxylic acid). A wide range of substrates are investigated and the moderate to excellent yields and the good regioselectivities for secondary benzyl alcohols as well as arenes bearing electron-withdrawing groups have been achieved. As a result, moisture in the reaction system has been utilized as an efficient initiator in all benzylation cases.
- Zhang, Shuting,Zhang, Xiaohui,Ling, Xuege,He, Chao,Huang, Ruofeng,Pan, Jing,Li, Jiaqiang,Xiong, Yan
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p. 30768 - 30774
(2014/08/05)
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- Catalytic transformation of alcohols to carboxylic acid salts and H 2 using water as the oxygen atom source
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The oxidation of alcohols to carboxylic acids is an important industrial reaction used in the synthesis of bulk and fine chemicals. Most current processes are performed by making use of either stoichiometric amounts of toxic oxidizing agents or the use of pressurized dioxygen. Here, we describe an alternative dehydrogenative pathway effected by water and base with the concomitant generation of hydrogen gas. A homogeneous ruthenium complex catalyses the transformation of primary alcohols to carboxylic acid salts at low catalyst loadings (0.2 mol%) in basic aqueous solution. A consequence of this finding could be a safer and cleaner process for the synthesis of carboxylic acids and their derivatives at both laboratory and industrial scales.
- Balaraman, Ekambaram,Khaskin, Eugene,Leitus, Gregory,Milstein, David
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p. 122 - 125
(2013/08/24)
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- Palladium-catalyzed synthesis of aromatic carboxylic acids with silacarboxylic acids
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Aryl iodides and bromides were easily converted to their corresponding aromatic carboxylic acids via a Pd-catalyzed carbonylation reaction using silacarboxylic acids as an in situ source of carbon monoxide. The reaction conditions were compatible with a wide range of functional groups, and with the aryl iodides, the carbonylation was complete within minutes. The method was adapted to the double and selective isotope labeling of tamibarotene.
- Friis, Stig D.,Andersen, Thomas L.,Skrydstrup, Troels
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supporting information
p. 1378 - 1381
(2013/04/24)
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- Birch Reductive Alkylation of Methyl m-(Hydroxymethyl)benzoate Derivatives and the Behavior of o- and p-(Hydroxymethyl)benzoates under Reductive Alkylation Conditions
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Birch reductive alkylation of methyl m-(hydroxymethyl)benzoate derivatives, using lithium in ammonia-tetrahydrofuran in the presence of tertbutyl alcohol, can be achieved without significant loss of benzylic oxygen substituents. Similar treatment of o- and p-(hydroxymethyl)benzoate derivatives results largely in loss of benzylic oxygen substituents. The results are rationalized by computations describing electron density patterns in the putative radical anion intermediate involved in these reactions.
- Fretz, Samuel J.,Hadad, Christopher M.,Hart, David J.,Vyas, Shubham,Yang, Dexi
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supporting information
p. 83 - 92
(2013/03/29)
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- Oxidation of benzyl alcohols, benzyl halides, and alkylbenzenes with oxone
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Oxidation of benzyl alcohols, benzyl halides, and alkylbenzenes to their corresponding oxidation products has been shown to be accomplished directly with oxone. The methodology that involves mere stirring/heating of the reactants and oxone in acetonitrile/water (1:1, v/v) is simple and practical, but is limited to substrates that do not contain sensitive functionalities and heteroaromatic rings.
- Parida, Keshaba Nanda,Jhulki, Samik,Mandal, Susovan,Moorthy, Jarugu Narasimha
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p. 9763 - 9768,6
(2020/08/20)
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- Metal free: A novel and efficient aerobic oxidation of toluene derivatives catalyzed by N′, N″, Nprime;, -trihydroxyisocyanuric acid and dimethylglyoxime in PEG-1000-based dicationic acidic ionic liquid
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A non-metal catalytic system containing of N′, N″, Nprime;, -trihydroxyisocyanuric acid (THICA) and dimethylglyoxime (DMG) is described for the selective oxidation of toluene derivatives with dioxygen in PEG-1000-based dicationic acidic ionic liquid (PEG1000-DAIL). Several toluene derivatives were efficiently oxidized to corresponding acids under mild conditions. The oxidation followed a radical pathway and a possible mechanism was proposed. Both the catalyst and PEG1000-DAIL could be reused at least eight times without significantly decreasing the catalytic activity.
- Lu, Tingting,Mao, Yang,Yao, Kai,Xu, Jian,Lu, Ming
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p. 124 - 128
(2012/10/29)
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- Copper-catalyzed aerobic oxidative synthesis of aromatic carboxylic acids
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A simple, practical and efficient copper-catalyzed method for synthesis of aromatic carboxylic acids has been developed. The protocol uses inexpensive CuI/l-proline as the catalyst/ligand, and readily available aryl halides and malononitrile as the starting materials, and the corresponding aromatic carboxylic acids were obtained in moderate to good yields. The method is of tolerance towards functional groups in the substrates.
- Yang, Daoshan,Yang, Haijun,Fu, Hua
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supporting information; experimental part
p. 2348 - 2350
(2011/03/21)
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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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experimental part
p. 4061 - 4065
(2010/08/07)
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- Pd/C and NaBH4 in basic aqueous alcohol: An efficient system for an environmentally benign oxidation of alcohols
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We report the oxidation of a wide range of alcohols using an environmentally benign and economical process. The use of Pd/C heterogeneous catalysts along with NaBH4in aqueous ethanol or methanol and either K2CO3 or KOH as base at room temperature under molecular oxygen or air give the corresponding oxidation products. This protocol is versatile since it is capable of oxidizing alcohols to its desired carbonyl or carboxyl counterpart. Room temperature reaction in aqueous system and recyclability of the catalyst are among the advantages of this manipulation. These advantages make the process safe and cheaper rendering it favorable from both economic and environmental viewpoints. Georg Thieme Verlag Stuttgart New York.
- An, Gwangil,Ahn, Hyunseok,De Castro, Kathlia A.,Rhee, Hakjune
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experimental part
p. 477 - 485
(2010/06/13)
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- Metal free oxidation of alkyl substituted aromatics with aqueous tert-butyl hydroperoxide under microwave irradiation
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Oxidation of alkyl substituted aromatic compounds to ketones and carboxylic acids can be achieved by 70% aqueous TBHP (tert-butyl hydroperoxide) under microwave irradiation with no additional organic solvent, metal based reagent or catalyst. Methyl aromatics (toluenes and xylenes) can be oxidized directly to the industrially important benzoic and phthalic acids. An addition of a tiny amount of ionic liquid and simultaneous cooling improves the efficiency of these oxidations. For other alkyl substituted aromatics, ketones are obtained in good yields. The Royal Society of Chemistry 2009.
- He, Hao,Pei, Bao-Jian,Lee, Albert W. M.
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experimental part
p. 1857 - 1861
(2011/03/20)
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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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experimental part
p. 3420 - 3427
(2009/12/03)
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