- Oxidation of o-xylene to phthalic anhydride over V2O5/TiO2 catalysts: III. Study of organic residue formed on the catalyst surface
-
An organic residue is formed on V2O5/TiO2 (anatase) catalysts during the oxidation of o-xylene and o-tolualdehyde. V2O5 catalysts supported on TiO2 (0.6, 1, and 5% V2O5/TiO2), prepared by wet impregnation, were exposed to o-xylene/air and o-tolualdehyde/air mixtures under different operating conditions, and, after different times of exposure to reaction conditions, the catalysts were characterized by FTIR spectroscopy and temperature programmed oxidation. The compounds formed were also extracted and analyzed by mass spectrometry. Organic molecules containing no more than two aromatic rings, formed by dimerization of adsorbed molecules, were detected and their characteristics were found to vary with features of the catalytic surface and with operating conditions. Larger contents of residue were obtained at lower temperatures and lower contact times and, for some experimental conditions, a constant amount of such compounds was observed after l h of exposure under reaction conditions. The analysis of samples used with different reactant mixtures showed that adsorbed o-xylene can lead to the formation of a "residue" on the surface.
- Dias, Cristina R.,Portela, M. Farinha,Bond, Geoffrey C.
-
-
Read Online
- An evaporation study for phthalic acids - A rapid method for pharmaceutical characterization
-
The objective of this study was to develop and analyze an analytical method in order to evaluate preformulation candidates by their thermodynamic parameters and evaporation characteristics. Ortho, meta and tere-phthalic acids were chosen as model compounds. The relative advantages and disadvantages of a rapid thermogravimetric method have been studied in detail, which would aid in the preformulation characterization for pharmaceuticals. Methyl paraben was taken as the model compound for calibration, as its evaporation characteristics are well known. Using the Antoine and the Langmuir equation for evaporation conjointly, the parameter k, known as the coefficient of evaporation was determined. The value for this constant was validated by three methods simultaneously. Previously the use of such methods for compounds having uninhibited zero order evaporation has been documented. In the present study, phthalic acid was chosen as the model compound since its evaporation is a two-step overlapping phenomenon. In this study we have shown the use of Pressure Differential Scanning Calorimetry in separating such simultaneous endothermic processes. The Clausius-Clapeyron equation seemingly has anomalous behavior for vapor pressure over high temperature ranges. In this study a modification of the equation has been suggested to take into account the changes in the heat capacities that result due to high temperature effects. This study aims at documenting a concise method for rapid pharmaceutical characterization and suggests modifications for some basic thermodynamic parameters over higher temperature ranges.
- Chatterjee, Koustuv,Hazra, Anasuya,Dollimore, David,Alexander, Kenneth S.
-
-
Read Online
- Orthoamides and iminium salts, LXXXIX. Reactions of N,N,N',N',N'',N'',N''',N'''-octamethylacetylene-bis(carboxamidinium) tetrafluoroborate with nucleophilic reagents - New methods for the preparation of amidinium salts and ketene aminals
-
The acetylene-bis(carboxamidinium) salt 4 dehydrates carboxylic acids to the corresponding anhydrides, as the byproduct 2-oxo-but-2-en-amidinium salt 6b was isolated. Aromatic hydroxy compounds and 2-furyl-methylmercaptan add to the triple bond of the salt 4 to give 2-aryloxy- and 2-alkylmercapto-but-2-enebis( amidinium) salts 7-9. According to this reaction principle, 2-organoamino-buten-2-ene-bis(amidinium) salts 10 and 11 were prepared from 4 and primary and secondary amines, whereas 4-chlorobenzhydrazide reacted with 4 to give the imidazole-3-carboxamidinium salt 13. The reaction of CH2-acidic compounds as malononitrile or ethyl cyanoacetate with the bis(amidinium) salt 4 affords 2-cyanomethylene-but-3-enamidinium salts 15. With the CH-acidic diethyl 2-bromomalonate, compound 4 undergoes a Michael-initiated ring closure cyclopropenation reaction with further ring opening by the released Br- to the corresponding 2-diethoxycarbonylmethylene- 3-bromo-but-3-enamidinium salt 18. Unlike cyclopentadiene and furane, the reaction of N-methylpyrrole and bis(amidinium) salt 4 does not lead to Diels-Alder [4 + 2] cycloadduct but to the Michaeltype 1:1 adduct 20. Pyrrole- and thiophene-2-carboxamidinium salts 23-25 can be prepared from compound 4 and esters of glycine, N-methylglycine (sarcosine), and mercaptoacetic acid, respectively. The derivatives of quinoxaline-2-carboxamidinium salts 29 are accessible from aromatic 1,2-diamines and compound 4. The reaction of the CH2/NH-acidic cyanoacetamide with the bis(amidinium) salt 4 produced the 3-pyrroline-2-on derivatives 33.
- Drandarov, Konstantin,Tiritiris, Ioannis,Kantlehner, Willi
-
-
Read Online
- The Cyclometallation of Benzoic Acid and the X-Ray Crystal Structure of
-
The complexes (1a, M=Rh; 1b, M=Ir), and , containing cyclometallated benzoic acid, have been prepared and characterised; carbonylation of (1a) yields phthalic anhydride
- Kisenyi, Jonathan M.,Cabeza, Javier A.,Smith, Arnold J.,Adams, Harry,Sunley, Glenn J.,et al.
-
-
Read Online
- The Decisive Cooperation of Metal and Oxygen Ions of Nickel Oxide During the Oxidation of o-Xylene
-
As can be concluded from the experimental results at 450 deg C in the reaction mixtures consisting of N2-O2-o-Xylene, both nickel oxide pure and doped with Li2O or In2O3 is unsuited as catalyst for the oxidation of o-xylene to phthalic anhydride.In contrast to NiO which ionosorbs both oxygen and o-xylene, NiO-Li2O, a strong ionosorbent for o-xylene, prevents the ionosorption of oxygen because of the large concentration of holes.Since gaseous oxygen does not react with ionosorbed o-xylene but a reduction of nickel oxide to metallic nickel has been observed in spite of t he fact of enough oxygen in the gas phase it can be assumed that o-xylene is forced to remove oxygen ions from the NiO lattice under generation of oxygen-ion vacanxies and nickel atoms.The predominant portions of the reaction products are H2O and CO2.With undoped nickel oxide and NiO-In2O3 which were not reduced under the same experimental conditions, the reaction products had roughly the same composition. The reduction of NiO-LiO2 however will be prevented in a gas mixture with a high oxygen pressure which oxidizes the formed nickel atoms on the surface of NiO-Li2O to nickel oxide making possible the entrance of oxygen from the gas phase and, therefore, the oxidation of o-xylene. A turbulent motion of a 2-component catalyst powder from NiO-1molepercent Li2O covered with ionosorbed 0-xylene and ZnO-1molpercent In2O3 covered with ionosorbed oxygen in the same gas mixture resulted in the same reaction products as in the presence of sole NiO-Li2O under simultaneous reduction of nickel oxide.From that we can conclude that the oxidation of o-xylene by oxygen ions of NiO occurs more easily than the reaction with ionosorbed oxygen on ZnO-In2O3 which obviously seems to be bounded too strongly.This result is also confirmed by the prevention of the oxidation of gaseous o-xylene in the presence of only ZnO-In2O3. Finally, the operation of the carrier catalyst V2O5/TiO2 which is employed for the oxidation of o-xylene to phthalic anhydride will be prevented to a large extent in simultaneous presence of nickel oxide either pure or doped with Li2O and In2O3 in roughly the same amount.This result can be mentioned as a proof for the interaction of a 2-component catalyst the mechanism of which is at present not satisfactorily understood.
- Hauffe, K.,Buss, D. H.,Glemser, O.
-
-
Read Online
- Efficient synthesis of symmetrical anhydrides by cross dehydrogenative coupling of aryl aldehydes over CuFe2O4 nanoparticles
-
Nano copper ferrite catalyst is prepared and characterized by scanning electron microscopy, energy dispersive X-ray, X-ray diffraction, vibrational sample magnetometry, and Fourier transform infrared. The catalytic activity is probed for cross-dehydrogenative coupling of aromatic aldehydes in the presence of tert-butyl hydroperoxide as the oxidant. This catalytic protocol appears as a simple, rather cheap, clean, and efficient practical strategy for the synthesis of symmetrical anhydrides, with proper efficiency (66%). The catalyst can be easily separated from the reaction mixture by an external magnet and reused several times in subsequent reactions, without any measurable loss of its efficiency. Graphic abstract: [Figure not available: see fulltext.]
- Eidi, Esmaiel,Kassaee, Mohamad Z.,Nasresfahani, Zahra
-
p. 461 - 468
(2021/04/09)
-
- Chemical Modifications Induced by Phthalic Anhydride, a Respiratory Sensitizer, in Reconstructed Human Epidermis: A Combined HRMAS NMR and LC-MS/MS Proteomic Approach
-
Chemical skin and respiratory allergies are becoming a major health problem. To date our knowledge on the process of protein haptenation is still limited and mainly derived from studies performed in solution using model nucleophiles. In order to better understand chemical interactions between chemical allergens and the skin, we have investigated the reactivity of phthalic anhydride 1 (PA), a chemical respiratory sensitizer, toward reconstructed human epidermis (RHE). This study was performed using a new approach combining HRMAS NMR to investigate the in situ chemical reactivity and LC-MS/MS to identify modified epidermal proteins. In RHE, the reaction of PA appeared to be quite fast and the major product formed was phthalic acid. Two amide type adducts on lysine residues were observed and after 8h of incubation, we also observed the formation of an imide type cyclized adducts with lysine. In parallel, RHE samples topically exposed to phthalic anhydride (13C)-1 were analyzed using the shotgun proteomics method. Thus, 948 different proteins were extracted and identified, 135 of which being modified by PA, i.e., 14.2% of the extracted proteome. A total of 211 amino acids were modified by PA and validated by fragmentation spectra. We thus identified 154 modified lysines, 22 modified histidines, 30 modified tyrosines, and 5 modified arginines. The rate of modified residues, as a proportion of the total number of modifiable nucleophilic residues in RHE, was rather low (1%). At the protein level, modified proteins were mainly type I and type II keratins and other proteins which are abundant in the epidermis such as protein S100A, Caspase 14, annexin A2, serpin B3, fatty-acid binding protein 5, histone H2, H3, H4, etc. However, the most modified protein, mainly on histidine residues, was filaggrin, a protein that is of low abundance (0.0266 mol %) and rich in histidine.
- Khong, Minh-Thuong,Berl, Valérie,Kuhn, Lauriane,Hammann, Philippe,Lepoittevin, Jean-Pierre
-
p. 2087 - 2099
(2021/08/30)
-
- Thermal Decomposition of [Cu(H2O)2(C8H4O4)], [CuNi(H2O)4(C8H4O4)2], and [Ni(H2O)2(C8H4O4)2](H2O)2 with the Formation of Metal and Bimetal Nanoparticles
-
Abstract: A comparison is made of the thermoanalytical characteristics and the composition and structure of solid products of the thermal decomposition of ortho-phthalates [Cu(H2O)2(C8H4O4)], [CuNi(H2O)4(C8H4O4)2], and [Ni(H2O)2(C8H4O4)](H2O)2. It is found that the thermal decomposition of these compounds upon heating to 500°C in a He atmosphere can be conditionally divided into two stages: dehydration and decarboxylation. Polymer conglomerates containing uncoated Cu nanoparticles as large as 75 nm are embedded into the polymer matrix of the composite obtained via the thermal decomposition of [Cu(H2O)2(C8H4O4)]. Three types of nanoparticles with sizes of 40–85, 15–25, and 10–15 nm are embedded in the polymer matrices of composites. The particles are Cux/Ni1?x solid solutions of different compositions, obtained via the thermolysis of [CuNi(H2O)4(C8H4O4)2]. It is found that the onset temperature of [CuNi(H2O)4(C8H4O4)2] decarboxylation at the third part of the second stage with the formation of a three-phase region correlates with the temperature of decomposition of Cux/Ni1?–?x solid solutions in the binary metal system, due apparently to the quantum size effect.
- Ishchenko, A. V.,Rudina, N. A.,Yudanova, L. I.
-
p. 1663 - 1670
(2021/08/24)
-
- Photo-induced deep aerobic oxidation of alkyl aromatics
-
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
-
p. 1487 - 1492
(2021/07/10)
-
- Photoinduced FeCl3-Catalyzed Alkyl Aromatics Oxidation toward Degradation of Polystyrene at Room Temperature?
-
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)
-
- Pd-Catalyzed Asymmetric Dearomatization of Indoles via Decarbonylative Heck-Type Reaction of Thioesters
-
We report herein a palladium-catalyzed ligand-promoted asymmetric dearomatization of indoles via the decarbonylation of thioesters and the subsequent reductive Heck reaction. This protocol provides a facile and efficient way to construct an aza-quaternary stereocenter at the C2 position of indolines. A variety of functional groups and substitutions could be well tolerated, affording the substituted indolines with high enantioselectivities.
- Han, Ming-Liang,Huang, Wei,Liu, Yu-Wen,Liu, Min,Xu, Hui,Xiong, Hai,Dai, Hui-Xiong
-
supporting information
p. 172 - 177
(2021/01/09)
-
- Merging N-Hydroxyphthalimide into Metal-Organic Frameworks for Highly Efficient and Environmentally Benign Aerobic Oxidation
-
Two highly efficient metal-organic framework catalysts TJU-68-NHPI and TJU-68-NDHPI have been successfully synthesized through solvothermal reactions of which the frameworks are merged with N-hydroxyphthalimide (NHPI) units, resulting in the decoration of pore surfaces with highly active nitroxyl catalytic sites. When t-butyl nitrite (TBN) is used as co-catalyst, the as-synthesized MOFs are demonstrated to be highly efficient and recyclable catalysts for a novel three-phase heterogeneous oxidation of activated C?H bond of primary and secondary alcohols, and benzyl compounds under mild conditions. Based on the high efficiency and selectivity, an environmentally benign system with good sustainability, mild conditions, simple work-up procedure has been established for practical oxidation of a wide range of substrates.
- Wang, Man,Liang, Gan,Wang, Yunhao,Fan, Tao,Yuan, Baoling,Liu, Mingxian,Yin, Ying,Li, Liangchun
-
supporting information
p. 9674 - 9685
(2021/06/09)
-
- Insights into the catalytic mechanism of 5-hydroxymethfurfural to phthalic anhydride with MoO3/Cu(NO3)2in one-pot
-
Recently, we reported a synthetic approach to obtain renewable phthalic anhydride (PA) from 5-hydroxymethfurfural (HMF) with a yield of 63.2% using MoO3/Cu(NO3)2 as a catalyst in one pot, for the first time. The reaction pathway has been elucidated in our previous study. Herein, the synergistic catalytic mechanism of MoO3/Cu(NO3)2 for the oxidation of HMF to PA was investigated. The commercially available MoO3 (c-MoO3) with superior characteristics, including more lattice oxygen and better oxygen-donating capacity, provides higher activity for the oxidation of HMF to PA. More importantly, the synergy between c-MoO3 and Cu(NO3)2 ensured the high yield of PA through the Mo6+/Mo4+ redox couple facilitated by the redox cycling of Cu2+/Cu+ with the assistance of oxygen.
- Feng, Yunchao,Jia, Wenlong,Li, Weile,Lin, Lu,Sun, Yong,Tang, Xing,Zeng, Xianhai,Zhao, Xiaoyu,Zuo, Miao
-
p. 5656 - 5662
(2021/08/24)
-
- “On water” nano-Cu2O-catalyzed CO-free one-pot multicomponent cascade cyanation-annulation-aminolysis reaction toward phthalimides
-
An efficient nano-Cu2O-catalyzed cascade multicomponent reaction of 2-halobenzoic acids and trimethylsilyl cyanide with diverse amines was developed using water as a solvent, affording versatileN-substituted phthalimide derivatives in moderate to excellent yields. This novel strategy features carbon monoxide gas-free, environmentally benign, one-pot multistep transformation, commercially available reagents, a cheap catalyst without any additives, wide functional group tolerance, and operational convenience.
- Wen, Xiaowei,Liu, Xiaojuan,Yang, Zhiqi,Xie, Menglan,Liu, Yuxi,Long, Lipeng,Chen, Zhengwang
-
supporting information
p. 1738 - 1743
(2021/03/14)
-
- Oxidative α-C-C Bond Cleavage of 2° and 3° Alcohols to Aromatic Acids with O2at Room Temperature via Iron Photocatalysis
-
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
-
supporting information
p. 2915 - 2920
(2021/05/05)
-
- HCl-Catalyzed Aerobic Oxidation of Alkylarenes to Carbonyls
-
The construction of C?O bonds through C?H bond functionalization remains fundamentally challenging. Here, a practical chlorine radical-mediated aerobic oxidation of alkylarenes to carbonyls was developed. This protocol employed commercially available HCl as a hydrogen atom transfer (HAT) reagent and air as a sustainable oxidant. In addition, this process exhibited excellent functional group tolerance and a broad substrate scope without the requirement for external metal and oxidants. The mechanistic hypothesis was supported by radical trapping, 18O labeling, and control experiments.
- Ding, Ling,Liu, Yuxiu,Niu, Kaikai,Shi, Xiaodi,Song, Hongjian,Wang, Qingmin
-
-
- One-Pot Synthesis of Renewable Phthalic Anhydride from 5-Hydroxymethfurfural by using MoO3/Cu(NO3)2 as Catalyst
-
Herein, a synthetic pathway to renewable phthalic anhydride (PA) from 5-hydroxymethfurfural (HMF) in one pot is reported. The commonly available catalysts MoO3 and Cu(NO3)2 play a crucial role in integrating the multiple steps of the reaction, namely decarbonylation of HMF to active furyl intermediate (AFI), oxidation of HMF to maleic anhydride (MA), Diels–Alder cycloaddition of AFI and MA, and subsequent dehydration, in one pot. Under mild reaction conditions, a 63.2 % yield of PA is obtained from HMF. Compared with the currently reported route to renewable PA based on the Diels–Alder cycloaddition of biomass-derived MA and furan, this convenient one-pot synthesis represents a great improvement in efficiency.
- Jia, Wenlong,Sun, Yong,Zuo, Miao,Feng, Yunchao,Tang, Xing,Zeng, Xianhai,Lin, Lu
-
p. 640 - 646
(2020/01/22)
-
- Method for synthesizing phthalic anhydride by catalyzing furan and maleic anhydride
-
The invention belongs to the technical field of bio-based chemicals, and particularly relates to a method for synthesizing phthalic anhydride by catalyzing furan and maleic anhydride. According to thepreparation method for catalyzing furan and maleic anhydride to generate phthalic anhydride, furan and maleic anhydride are used as raw materials, a Diels-Alder reaction and a dehydration step are adopted for producing phthalic anhydride, wherein the furan and maleic anhydride are obtained from furfural converted from biomass. The method provided by the invention is green, economical and renewable, reduces the use of non-renewable traditional resources, provides advanced technical support for industrial production of bio-based phthalic anhydride, and has broad application prospects.
- -
-
Paragraph 0026; 0034-0037; 0053; 0057-0060; 0061; 0065-0068
(2020/11/23)
-
- Controlled Photocatalytic Hydrocarbon Oxidation by Uranyl Complexes
-
Controlled, photocatalytic C?H bond activations are key reactions in the toolkits of the modern synthetic chemist. While it is known that the uranyl(VI) ion, [UVIO2]2+, the environmentally dominant form of uranium, is photoactive, most literature examines its luminescent properties, neglecting its potential synthetic utility for photocatalytic C?H bond cleavage. Here, we synthesise and fully characterise an air-stable and hydrocarbon-soluble uranyl phenanthroline complex, [UVIO2(NO3)2(Ph2phen)], UPh2phen, and demonstrate that it can catalytically abstract hydrogen atoms from a variety of organic substrates under visible light irradiation. We show that the commercially available parent complex, uranyl nitrate ([UVIO2(NO3)2(OH2)2]?4H2O; UNO3), is also competent, but from electronic spectroscopy we attribute the higher rates and selectivity of UPh2phen to ligand-mediated electronic effects. Ketones are selectively formed over other oxygenated products (alcohols, etc.), and the catalytic oxidation of substrates containing a benzylic C?H position is particularly improved for UPh2phen. We also show uranyl-mediated photocatalytic C?C bond cleavage in a model lignin compound for the first time.
- Arnold, Polly L.,Purkis, Jamie M.,Rutkauskaite, Ryte,Kovacs, Daniel,Love, Jason B.,Austin, Jonathan
-
p. 3786 - 3790
(2019/03/07)
-
- Catalytic hydrogenation products of aromatic and aliphatic dicarboxylic acids
-
Hydrogenation of aromatic dicarboxylic acids gave 100 % selectivity to respective cyclohexane dicarboxylic acid with 5 % Pd/C catalyst. 5 % Ru/C catalyst was observed to give over hydrogenation products at 493 K and at lower temperature (453 K) the selectivity for cyclohexane dicarboxylic acids was increased. Hydrogenation of phthalic acid with Ru-Sn/Al2O3 catalyst was observed to give phthalide instead of 1,2-benzene dimethanol or 2-hydroxy methyl benzoic acid. Ru-Sn/Al2O3 catalyst selectively hydrogenated the carboxylic group of cyclohexane dicarboxylic acids to give cyclohexane dimethanol. Use of proper catalysts and reaction conditions resulted in desired products.
- Shinde, Sunil B.,Deshpande, Raj M.
-
p. 1137 - 1142
(2019/04/05)
-
- Automated on-line monitoring of the TiO2-based photocatalytic degradation of dimethyl phthalate and diethyl phthalate
-
A fully automated on-line system for monitoring the TiO2-based photocatalytic degradation of dimethyl phthalate (DMP) and diethyl phthalate (DEP) using sequential injection analysis (SIA) coupled to liquid chromatography (LC) with UV detection was proposed. The effects of the type of catalyst (sol-gel, Degussa P25 and Hombikat), the amount of catalyst (0.5, 1.0 and 1.5 g L-1), and the solution pH (4, 7 and 10) were evaluated through a three-level fractional factorial design (FFD) to verify the influence of the factors on the response variable (degradation efficiency, %). As a result of FFD evaluation, the main factor that influences the process is the type of catalyst. Degradation percentages close to 100% under UV-vis radiation were reached using the two commercial TiO2 materials, which present mixed phases (anatase/rutile), Degussa P25 (82%/18%) and Hombikat (76%/24%). 60% degradation was obtained using the laboratory-made pure anatase crystalline TiO2 phase. The pH and amount of catalyst showed minimum significant effect on the degradation efficiencies of DMP and DEP. Greater degradation efficiency was achieved using Degussa P25 at pH 10 with 1.5 g L-1 catalyst dosage. Under these conditions, complete degradation and 92% mineralization were achieved after 300 min of reaction. Additionally, a drastic decrease in the concentration of BOD5 and COD was observed, which results in significant enhancement of their biodegradability obtaining a BOD5/COD index of 0.66 after the photocatalytic treatment. The main intermediate products found were dimethyl 4-hydroxyphthalate, 4-hydroxy-diethyl phthalate, phthalic acid and phthalic anhydride indicating that the photocatalytic degradation pathway involved the hydrolysis reaction of the aliphatic chain and hydroxylation of the aromatic ring, obtaining products with lower toxicity than the initial molecules.
- Salazar-Beltrán, Daniel,Hinojosa-Reyes, Laura,Maya-Alejandro, Fernando,Turnes-Palomino, Gemma,Palomino-Cabello, Carlos,Hernández-Ramírez, Aracely,Guzmán-Mar, Jorge Luis
-
p. 863 - 870
(2019/04/17)
-
- Formamide Catalysis Facilitates the Transformation of Aldehydes into Geminal Dichlorides
-
Herein, a novel method for the transformation of aldehydes into geminal dichlorides based on phthaloyl chloride as reagent and N -formylpyrrolidine as Lewis base catalyst is disclosed. Given the mild reaction conditions, the current protocol is distinguished by high levels of functional group compatibility and scalability and is operationally simple. The in situ formation of a Vilsmeier Haack reagent type intermediate is likely to be essential for this organocatalytic nucleophilic substitution reaction.
- Huy, Peter Helmut
-
supporting information
p. 2474 - 2483
(2019/06/08)
-
- Selective vapor-phase oxidation of o-xylene to phthalic anhydride over Co-Mn/H3PW12O40@TiO2 using molecular oxygen as a green oxidant
-
The oxidation of o-xylene to phthalic anhydride over Co-Mn/H3PW12O40@TiO2 was investigated. The experimental results demonstrated that the prepared catalyst effectively catalyzed the oxidation of o-xylene to phthalic anhydride. Also, the synergistic effect between three metals plays vital roles in this reaction. From a green chemistry point of view, this method is environmentally friendly due to carrying out the oxidation in a fixed-bed reactor under solvent-free condition and using molecular oxygen as a green and cheap oxidizing agent. The resulting solid catalysts were characterized by FT-IR, XRD, XPS, ICP-OES, FESEM, TEM, EDX, DR-UV spectroscopy, BET and thermogravimetric analysis. The oxidation of o-xylene yields four products: o-tolualdehyde, phthaldialdehyde, phthalide and finally phthalic anhydride as the main product. The reaction conditions for oxidation of o-xylene were optimized by varying the temperature, weight hourly space velocity and oxygen flow rate (contact time). The optimum weight percentage of phosphotungstic acid (HPW) and Co/Mn for phthalic anhydride production were 15?wt % and 2?wt%, respectively. The best Co/Mn ratio was found to be 10/1. Oxygen flow rate was very important on the phthalic anhydride formation. The optimum conditions for oxidation of o-xylene were T?=?370?°C, WHSV?=?0.5?h?1 and oxygen flow rate?=?10?mL?min?1. Under optimized conditions, a maximum of 88.2% conversion and 75.5% selectivity to phthalic anhydride was achieved with the fresh catalyst. Moreover, reusability of the catalyst was studied and catalytic activity remained unchanged after at least five cycles.
- Masoomi, Kianoosh,Ghiaci, Mehran,Botelho do Rego
-
-
- A mild system for synthesis of aldoximes and ketoximes in the presence of N-hydroxyphthalimide in aqueous system
-
An efficient method for synthesis of oximes from aldehydes or ketones with N-hydroxyphthalimide or N-hydroxysuccinimide in water has been described. It is the first time to utilize NHPI as an oximation reagent to synthesize aldoximes and ketoximes from the corresponding organic carbonyl compounds without other reagents. The reaction tolerates various functional groups and affords the corresponding oximes in 76%–98% yields. The by-product phthalic acid can be recycled from the system. In addition, this method has been successfully applied to the synthesis of the precursor of some pharmacologically active amide molecules.
- Jiang, Xiaoying,Xu, Xiaohe,Lin, Yuyan,Yan, Yiyan,Li, Pingping,Bai, Renren,Xie, Yuanyuan
-
supporting information
p. 5879 - 5885
(2018/09/06)
-
- Method for preparing phthalic anhydride from 5-hydroxymethylfurfural
-
The invention discloses a method for preparing phthalic anhydride from 5-hydroxymethylfurfural, and relates to phthalic anhydride. The method comprises the following steps: mixing the biomass platformcompound 5-hydroxymethylfurfural as a reaction substrate with a mixed solvent, an oxidizing agent and a catalyst, performing heating reaction in a sealed manner, and then cooling to room temperatureto obtain reaction liquid of phthalic anhydride, extracting with an extractant immiscible with water, and recovering the extractant to obtain a white needle-like product phthalic anhydride. The methodof synthesizing the important chemical intermediate phthalic anhydride with the renewable biomass platform compound, 5-hydroxymethylfurfural as the reaction substrate, and is a phthalate anhydride synthesis method with high yield, easiness in separation, low cost and low pollution; the catalyst is used in a small amount, a system is simple and efficient, and easy to obtain, reaction conditions are mild, by-products are few, the conversion rate exceeds 99%, and the selectivity is greater than 30%; after purification and recrystallization, the purity of the product is high and exceeds 99.9%.
- -
-
Paragraph 0018-0059
(2018/12/14)
-
- Aerobic Oxygenation of Alkylarenes over Ultrafine Transition-Metal-Containing Manganese-Based Oxides
-
The oxygenation of alkylarenes to the corresponding aryl ketones is an important reaction, and the development of efficient heterogeneous catalysts that can utilize O2 as the sole oxidant is highly desired. In this study, we developed an efficient alkylarene oxygenation process catalyzed by ultrafine transition-metal-containing Mn-based oxides with spinel or spinel-like structures (M-MnOx, M=Fe, Co, Ni, Cu). These M-MnOx catalysts were prepared by a low-temperature reduction method in 2-propanol-based solutions using tetra-n-butyl ammonium permanganate (TBAMnO4) as the Mn source, and they exhibited high Brunauer–Emmett–Teller surface areas (typically >400 m2 g?1). Using fluorene as the model substrate, the catalytic activities of M-MnOx and Mn3O4 were compared. The catalytic activities of M-MnOx were significantly higher than that of Mn3O4, which demonstrates that the incorporation of transition metals in manganese oxide was critical. Among the series of M-MnOx catalysts examined, Ni-MnOx exhibited the highest catalytic activity for the oxygenation. In addition, the catalytic activity of Ni-MnOx was higher than that of a physical mixture of Mn3O4 and NiO. Furthermore, Ni-MnOx exhibited a broad substrate scope with respect to various types of structurally diverse (hetero)alkylarenes (16 examples). The observed catalysis was truly heterogeneous, and the Ni-MnOx catalyst was reusable for the oxygenation of fluorene at least three times and its high catalytic performance was preserved, for example, the reaction rate, final product yield, and product selectivity. The present Ni-MnOx-catalyzed oxygenation process is possibly initiated by a single-electron oxidation process, and herein a plausible oxygen-transfer mechanism is proposed based on several pieces of experimental evidence.
- Nakai, Satoru,Uematsu, Tsubasa,Ogasawara, Yoshiyuki,Suzuki, Kosuke,Yamaguchi, Kazuya,Mizuno, Noritaka
-
p. 1096 - 1106
(2018/01/15)
-
- TBHP/ n -Bu 4 PBr-Promoted Oxidative Cross-Dehydrogenative Coupling of Aryl Methanols: A Facile Synthesis of Symmetrical Carboxylic Anhydride Derivatives
-
A transition-metal-free oxidative cross-dehydrogenative coupling reaction has been developed for the preparation of symmetrical carboxylic anhydrides through self-coupling dual C-O bond formations of aryl methanols. In the presence of a catalytic amount of tetrabutylphosphonium bromide (TBPB) as transfer agent and aqueous tert -butyl hydroperoxide (TBHP) as oxidant and reactant, methylene groups of aryl methanols were efficiently oxidized to C=O and coupled with the peroxide oxygen from TBHP to form a diverse array of symmetrical carboxylic anhydride derivatives.
- Adib, Mehdi,Pashazadeh, Rahim
-
supporting information
p. 136 - 140
(2017/12/27)
-
- Oxidation of Polynuclear Aromatic Hydrocarbons using Ruthenium-Ion-Catalyzed Oxidation: The Role of Aromatic Ring Number in Reaction Kinetics and Product Distribution
-
Oxidation of aromatic hydrocarbons with differing numbers of fused aromatic rings (2–5), have been studied in two solvent environments (monophasic and biphasic) using ruthenium-ion-catalyzed oxidation (RICO). RICO reduces the aromaticity of the polyaromatic core of the molecule in a controlled manner by selective oxidative ring opening. Moreover, the nature of the solvent system determines the product type and distribution, for molecules with more than two aromatic rings. Competitive oxidation between substrates with different numbers of aromatic rings has been studied in detail. It was found that the rate of polyaromatic hydrocarbon oxidation increases with the number of fused aromatic rings. A similar trend was also identified for alkylated aromatic hydrocarbons. The proof-of-concept investigation provides new insight into selective oxidation chemistry for upgrading of polyaromatic molecules.
- Nowicka, Ewa,Clarke, Tomos J.,Sankar, Meenakshisundaram,Jenkins, Robert L.,Knight, David W.,Golunski, Stanislaw,Hutchings, Graham J.,Willock, David J.,Francisco, Manuel,Taylor, Stuart H.
-
p. 655 - 662
(2018/01/26)
-
- Mechanistic Insights into Selective Oxidation of Polyaromatic Compounds using RICO Chemistry
-
Ruthenium-ion-catalyzed oxidation (RICO) of polyaromatic hydrocarbons (PAHs) has been studied in detail using experimental and computational approaches to explore the reaction mechanism. DFT calculations show that regioselectivity in these reactions can be understood in terms of the preservation of aromaticity in the initial formation of a [3+2] metallocycle intermediate at the most-isolated double bond. We identify two competing pathways: C?C bond cleavage leading to a dialdehyde and C-H activation followed by H migration to the RuOx complex to give diketones. Experimentally, the oxidation of pyrene and phenanthrene has been carried out in monophasic and biphasic solvent systems. Our results show that diketones are the major product for both phenanthrene and pyrene substrates. These diketone products are shown to be stable under our reaction conditions so that higher oxidation products (acids and their derivatives) are assigned to the competing pathway through the dialdehyde. Experiments using 18O-labelled water do show incorporation of oxygen from the solvents into products, but this may take place during the formation of the reactive RuO4 species rather than directly during PAH oxidation. When the oxidation of pyrene is carried out using D2O, a kinetic isotope effect (KIE) is observed implying that water is involved in the rate-determining step leading to the diketone products.
- Nowicka, Ewa,Hickey, Niamh W.,Sankar, Meenakshisundaram,Jenkins, Robert L.,Knight, David W.,Willock, David J.,Hutchings, Graham J.,Francisco, Manuel,Taylor, Stuart H.
-
supporting information
p. 12359 - 12369
(2018/08/29)
-
- Heterogeneous catalysts for the cyclization of dicarboxylic acids to cyclic anhydrides as monomers for bioplastic production
-
Cyclic anhydrides, key intermediates of carbon-neutral and biodegradable polyesters, are currently produced from biomass-derived dicarboxylic acids by a high-cost multistep process. We present a new high-yielding process for the direct intramolecular dehydration of dicarboxylic acids using a reusable heterogeneous Lewis acid catalyst, Nb2O5·nH2O. Various dicarboxylic acids, which can be produced by a biorefinery process, are transformed into the corresponding cyclic anhydrides as monomers for polyester production. This method is suitable for the production of renewable polyesters in a biorefinery process.
- Rashed, Md. N.,Siddiki,Ali, Md. A.,Moromi, Sondomoyee K.,Touchy, Abeda S.,Kon, Kenichi,Toyao, Takashi,Shimizu, Ken-Ichi
-
p. 3238 - 3242
(2017/07/28)
-
- Efficient cyclodehydration of dicarboxylic acids with oxalyl chloride
-
Literature examples illustrating the use of oxalyl chloride to prepare dicarboxylic acid anhydrides are surprisingly limited. At the same time, we have discovered a method involving the use of this readily available reagent which allowed the preparation of novel cyclic anhydrides where other, more conventional, methods had failed. Herein, we demonstrate that the method is applicable to a wide diversity of substrates, delivers good to excellent yields of cyclic anhydrides without chromatographic purification and can be considered a synthetic tool of choice whenever dicarboxylic acid cyclodehydration is required.
- Kantin, Grigory,Chupakhin, Evgeny,Dar'in, Dmitry,Krasavin, Mikhail
-
supporting information
p. 3160 - 3163
(2017/07/18)
-
- Catalytic Converter Arrangement with Optimized Surface for Producing Phthalic Anhydride
-
A catalytic converter arrangement for producing phthalic anhydride by means of a gas phase oxidation of aromatic hydrocarbons, comprising a reactor with a gas inlet side for a reactant gas, a gas outlet side for a product gas, a first catalytic converter layer made of catalytic converter elements, and at least one second catalytic converter layer made of catalytic converter elements. The first catalytic converter layer is arranged on the gas inlet side, and the second catalytic converter layer is arranged downstream of the first catalytic converter layer in the gas flow direction. The catalytic converter elements have an outer layer of an active compound. The invention is characterized in that the active compound content in the first catalytic converter layer and/or in the second catalytic converter layer is below 7 wt. %, based on the total weight of the catalytic converter elements, and the ratio of the total surface of the active compound to the volume of the catalytic converter layer is preferably 10000 cm?1 to 20000 cm?1, in each catalytic converter layer.
- -
-
Paragraph 0075; 0084
(2017/04/11)
-
- Catalyst Arrangement With Optimized Void Fraction For The Production Of Phthalic Acid Anhydride
-
The invention relates to a catalyst arrangement for preparing phthalic anhydride by gas-phase oxidation of aromatic hydrocarbons, which comprises a reactor having a gas inlet end for a feed gas and a gas outlet end for a product gas and also a first catalyst zone made up of catalyst bodies and at least one second catalyst zone made up of catalyst bodies, where the first catalyst zone is arranged at the gas inlet end and the second catalyst zone is arranged downstream of the first catalyst zone in the gas flow direction and the length of the first catalyst zone in the gas flow direction is less than the length of the second catalyst zone in the gas flow direction, characterized in that the first catalyst zone has a higher gap content compared to the second catalyst zone.
- -
-
Paragraph 0081-0089
(2017/11/29)
-
- Liquid-phase oxidation of naphthalene with H 2O 2 in the presence of ordered mesoporous V- m-Al 2O 3 catalysts
-
Abstract: The ordered mesoporous V- m-Al 2O 3 catalysts were successfully synthesized via a facile one-pot evaporation-induced self-assembly (EISA) strategy and applied in the liquid-phase oxidation of naphthalene with hydrogen peroxide in the presence of ascorbic acid as a reductant. The physicochemical properties of the catalysts were investigated using various techniques, like XRD, N 2 sorption, UV-Vis spectra, Raman spectroscopy, XPS, XRF and TEM. Small-angle XRD, N 2 sorption and TEM results show that mesoporous V- m-Al 2O 3 catalysts possess a highly ordered mesostructure with large surface areas and narrow pore-size distributions. High-angle XRD, UV-Vis spectra and Raman spectroscopy results indicate that VO x species were homogeneously incorporated in the matrix of mesoporous Al 2O 3.The catalytic performance in the liquid oxidation of naphthalene with H 2O 2 over 8 V- m-Al 2O 3 catalyst (naphthalene conversion 45.4% and phthalic anhydride selectivity 61.0%) was higher than other catalysts. The vanadium species incorporated in the 8 V- m-Al 2O 3 sample were stable, and its catalytic stability was kept well even after repeated use for 5 times, which indicates a green and economical pathway for naphthalene degradation. Graphical Abstract: SYNOPSIS?In the presence of hydrogen peroxide as oxidant and ascorbic acid as reductant, ordered mesoporous V- m-Al 2O 3 catalysts were synthesized via a facile one-pot evaporation-induced self-assembly method and successfully applied to the liquid-phase oxidation of naphthalene.[Figure not available: see fulltext.].
- Zhou, Zhiwei,Yu, Yang,Qin, Juan,Zhang, Jiaqi,Cheng, Fulin,Wu, Wenliang
-
p. 1373 - 1380
(2017/09/25)
-
- acyl triazole derivative and its manufacturing method
-
PROBLEM TO BE SOLVED: To provide a novel acyl triazole derivative that can be synthesized at low cost by a convenient method, has a comparable reactivity to an acid chloride with an amine compound and an alcohol compound, and can be safely handled, and a method of manufacturing the same; the acyl triazole derivative that is useful as a reactant applied to polymerization reaction to be continued; and a monomer comprising the same.SOLUTION: An acyl triazole derivative is shown by formula (1). In the formula, A denotes a substituted arylene group, a 1,3-phenylene group, a bisarylene group, a polycyclic arylene group, an alkylene group or an aralkylene group.
- -
-
Paragraph 0053
(2017/04/03)
-
- New protocol of copper-catalyzed oxidative C(CO)[sbnd]C bond cleavage of aryl and aliphatic ketones to organic acids using O2 as the terminal oxidant
-
Catalytic oxidation of C[sbnd]C bond is a key technology to transform petroleum-based as well as sustainable biomass feedstock into more valuable oxygenates. We herein describe a convenient and useful oxidation strategy of converting ketones into carboxylic acids using homogeneous copper catalyst without additives and with O2as the terminal oxidant. A wide range of aryl and aliphatic ketones as well as β–O–4 lignin models were selectively oxidized to acids via C[sbnd]C bond cleavage. Mechanism studies by EPR and in situ NMR elucidate the principles of Cu/O2reactivity that involves C[sbnd]H bond and O2activation via a peroxide species. This provides an important foundation for expanding the scope of useful aerobic oxidation reactions using copper catalysts.
- Liu, Huifang,Wang, Min,Li, Hongji,Luo, Nengchao,Xu, Shutao,Wang, Feng
-
p. 170 - 179
(2017/01/22)
-
- Oxidative C(OH)[sbnd]C bond cleavage of secondary alcohols to acids over a copper catalyst with molecular oxygen as the oxidant
-
Selective oxidative cleavage of C[sbnd]C bond is pivotal for producing functionalized molecules, useful for organic synthesis and biomass utilization. We herein report the oxidative C(OH)[sbnd]C bond cleavage of secondary alcohols to acids over a copper/1, 10-phenanthroline complex with molecular oxygen as the oxidant. A wide range of secondary alcohols are converted into acids with up to 98% yields. More interestingly, it is effective for breaking up lignin model systems into acids, which is rarely achieved in previous studies. Density functional theory (DFT) calculations indicate a copper-oxo-bridged oxygen dimer is the active species for the C[sbnd]H bond cleavage which is the rate-determining step for C[sbnd]C bond.
- Wang, Min,Lu, Jianmin,Li, Lihua,Li, Hongji,Liu, Huifang,Wang, Feng
-
p. 160 - 167
(2017/03/21)
-
- Selectivity Control in the Tandem Aromatization of Bio-Based Furanics Catalyzed by Solid Acids and Palladium
-
Bio-based furanics can be aromatized efficiently by sequential Diels–Alder (DA) addition and hydrogenation steps followed by tandem catalytic aromatization. With a combination of zeolite H-Y and Pd/C, the hydrogenated DA adduct of 2-methylfuran and maleic anhydride can thus be aromatized in the liquid phase and, to a certain extent, decarboxylated to give high yields of the aromatic products 3-methylphthalic anhydride and o- and m-toluic acid. Here, it is shown that a variation in the acidity and textural properties of the solid acid as well as bifunctionality offers a handle on selectivity toward aromatic products. The zeolite component was found to dominate selectivity. Indeed, a linear correlation is found between 3-methylphthalic anhydride yield and the product of (strong acid/total acidity) and mesopore volume of H-Y, highlighting the need for balanced catalyst acidity and porosity. The efficient coupling of the dehydration and dehydrogenation steps by varying the zeolite-to-Pd/C ratio allowed the competitive decarboxylation reaction to be effectively suppressed, which led to an improved 3-methylphthalic anhydride/total aromatics selectivity ratio of 80 % (89 % total aromatics yield). The incorporation of Pd nanoparticles in close proximity to the acid sites in bifunctional Pd/H-Y catalysts also afforded a flexible means to control aromatic products selectivity, as further demonstrated in the aromatization of hydrogenated DA adducts from other diene/dienophile combinations.
- Genuino, Homer C.,Thiyagarajan, Shanmugam,van der Waal, Jan C.,de Jong, Ed,van Haveren, Jacco,van Es, Daan S.,Weckhuysen, Bert M.,Bruijnincx, Pieter C. A.
-
p. 277 - 286
(2017/01/17)
-
- Oxidative self-coupling of aldehydes in the presence of CuCl2/TBHP system: Direct access to symmetrical anhydrides
-
A simple synthesis of symmetrical anhydrides has been developed. Using tert-butylhydroperoxide (TBHP) as the oxidant and copper(II) chloride as the catalyst in acetonitrile, various aromatic and heteroaromatic aldehydes were reacted to provide symmetrical anhydrides in modest to good yields.
- Saberi, Dariush,Shojaeyan, Fatemeh,Niknam, Khodabakhsh
-
supporting information
p. 566 - 569
(2016/01/20)
-
- The use of BrCCl3-PPh3 in Appel type transformations to esters, O-acyloximes, amides, and acid anhydrides
-
Esters, acyloximes, amides and acid anhydrides have been prepared from the respective carboxylic acids, oximes, amines and alcohols by the use of the reagent combination BrCCl3-PPh3. The reactions obviate the handling acyl halides or more aggressive reagents PCl3, POCl3, or SOCl2. Furthermore, the environmentally hazardous CCl4 used in Appel-type reactions is replaced with BrCCl3, a reagent of less environmental concern.
- Al-Azani, Mariam,al-Sulaibi, Mazen,al Soom, Nuha,Al Jasem, Yosef,Bugenhagen, Bernhard,Al Hindawi, Bassam,Thiemann, Thies
-
p. 921 - 932
(2016/08/08)
-
- Synthetic strategy and antiviral evaluation of diamide containing heterocycles targeting dengue and yellow fever virus
-
High-Throughput screening of a subset of the CD3 chemical library (Centre for Drug Design and Discovery; KU Leuven) provided us with a lead compound 1, displaying low micromolar potency against dengue virus and yellow fever virus. Within a project aimed at discovering new inhibitors of flaviviruses, substitution of its central imidazole ring led to synthesis of variably substituted pyrazine dicarboxylamides and phthalic diamides, which were evaluated in cell-based assays for cytotoxicity and antiviral activity against the dengue virus (DENV) and yellow fever virus (YFV). Fourteen compounds inhibited DENV replication (EC50 ranging between 0.5 and 3.4 1/4M), with compounds 6b and 6d being the most potent inhibitors (EC50 0.5 1/4M) with selectivity indices (SI) > 235. Compound 7a likewise exhibited anti-DENV activity with an EC50 of 0.5 1/4M and an SI of >235. In addition, good antiviral activity of seven compounds in the series was also noted against the YFV with EC50 values ranging between 0.4 and 3.3 1/4M, with compound 6n being the most potent for this series with an EC50 0.4 1/4M and a selectivity index of >34. Finally, reversal of one of the central amide bonds as in series 13 proved deleterious to the inhibitory activity.
- Saudi, Milind,Zmurko, Joanna,Kaptein, Suzanne,Rozenski, Jef,Gadakh, Bharat,Chaltin, Patrick,Marchand, Arnaud,Neyts, Johan,Van Aerschot, Arthur
-
p. 158 - 168
(2016/06/09)
-
- Biphasic copper-catalyzed C–H bond activation of arylalkanes to ketones with tert-butyl hydroperoxide in water at room temperature
-
A facile C–H bond activation of arylalkanes to their corresponding ketones catalyzed by copper salts using tert-butyl hydroperoxide as an oxidant in water at room temperature is described. Easy product separation, simple reaction procedures (without using base or phase transfer catalysis), and catalyst recycling make the catalytic system attractive. It is also active beyond activated benzylic methylene positions and could tolerate factionalized arylalkanes with diverse groups.
- Hossain, Md. Munkir,Shyu, Shin-Guang
-
supporting information
p. 4252 - 4257
(2016/07/06)
-
- A Facile Solid-Phase Route to Renewable Aromatic Chemicals from Biobased Furanics
-
Renewable aromatics can be conveniently synthesized from furanics by introducing an intermediate hydrogenation step in the Diels-Alder (DA) aromatization route, to effectively block retro-DA activity. Aromatization of the hydrogenated DA adducts requires tandem catalysis, using a metal-based dehydrogenation catalyst and solid acid dehydration catalyst in toluene. Herein it is demonstrated that the hydrogenated DA adducts can instead be conveniently converted into renewable aromatics with up to 80 % selectivity in a solid-phase reaction with shorter reaction times using only an acidic zeolite, that is, without solvent or dehydrogenation catalyst. Hydrogenated adducts from diene/dienophile combinations of (methylated) furans with maleic anhydride are efficiently converted into renewable aromatics with this new route. The zeolite H-Y was found to perform the best and can be easily reused after calcination. Just heat and tumble: Furanics-derived hydrogenated Diels-Alder adducts can be conveniently converted, over acidic zeolites, into renewable aromatics using a solid-phase conversion strategy. The zeolite H-Y was found to perform the best and can be easily reused after calcination.
- Thiyagarajan, Shanmugam,Genuino, Homer C.,Van Der Waal, Jan C.,De Jong, Ed,Weckhuysen, Bert M.,Van Haveren, Jacco,Bruijnincx, Pieter C. A.,Van Es, Daan S.
-
supporting information
p. 1368 - 1371
(2016/02/12)
-
- Access to 1,2,3,4-Tetraoxygenated Benzenes via a Double Baeyer-Villiger Reaction of Quinizarin Dimethyl Ether: Application to the Synthesis of Bioactive Natural Products from Antrodia camphorata
-
The first systematic investigation into the Baeyer-Villiger reaction of an anthraquinone is presented. The double Baeyer-Villiger reaction of quinizarin dimethyl ether is viable, directly providing the dibenzo[b,f][1,4]-dioxocin-6,11-dione ring-system, which is otherwise difficult to prepare. This methodology provides rapid access to 1,2,3,4-tetraoxygenated benzenes, and has been exploited by application to the total synthesis of a natural occurring benzodioxole and its biphenyl dimer, which both display noteworthy biological activity. Interestingly, the axially chiral biphenyl was found to be configurationally stable, but the resolved enantiomers exhibit no optical activity at the αD-line.
- Newson, Harriet L.,Wild, Duncan A.,Yeung, Sing Yee,Skelton, Brian W.,Flematti, Gavin R.,Allan, Jane E.,Piggott, Matthew J.
-
p. 3127 - 3135
(2016/05/19)
-
- Efficient Synthesis of Unsaturated δ- and ε-Lactones/Lactams by Catalytic Cycloisomerization: When Pt Outperforms Pd
-
Platinum pincer complexes featuring an SCS indenediide backbone have been prepared and evaluated in the catalytic cycloisomerization of alkynoic acids and N-tosyl alkynylamides. One of the platinum complexes significantly outperforms its palladium analogue for the formation of 6- and 7-membered rings. The catalytic system takes advantage of the alkynophilicity of Pt and of the non-innocent character of the indenediide framework. Like for Pd, the catalytic performance is significantly improved by using an H-bond donor additive such as pyrogallol. For the first time, a large variety of ω-unsaturated δ- and ε-lactones/lactams could be prepared with high selectivities and in very good yields. (Figure presented.) .
- Ke, Diandian,Espinosa, Noel ángel,Mallet-Ladeira, Sonia,Monot, Julien,Martin-Vaca, Blanca,Bourissou, Didier
-
supporting information
p. 2324 - 2331
(2016/07/29)
-
- IMPROVED PROCESS FOR THE PREPARATION OF A BENZENE COMPOUND
-
A benzene compound is prepared in a process, which comprises (i) reacting a furan compound of formula (I): wherein R1 and R2 are the same or different and independently selected from the group consisting of hydrogen, alkyl, aralkyl, -CHO, -CH2OR3, -CH(OR4 )(OR5), -COOR6, wherein R3, R4 and R5 are the same or different and are independently selected from the group consisting of hydrogen, alkyl, aryl, alkaryl, aralkyl, alkylcarbonyl and arylcarbonyl, or wherein R4 and R5 together form an alkylene group, and wherein R6 is selected from the group consisting of hydrogen, alkyl and aryl, with an olefin of the formula (II): R7-CH=CH-R8; wherein R7 and R8 are the same or different and are independently selected from the group consisting of hydrogen, sulfonate, -CN, -CHO, and -COOR9, wherein R9 is selected from the group consisting of hydrogen, and an alkyl group, or R7 and R8 together form a –C(O)-O-(O)C- group or a –C(O)-NR10-C(O)- group, wherein R10 represents hydrogen, an aliphatic or an aromatic group, to produce an unsaturated bicyclic ether having an unsaturated carbon-carbon bond; (ii) hydrogenating the unsaturated carbon-carbon bond in the unsaturated bicyclic ether to produce a saturated bicyclic ether; and (iii) dehydrating and aromatizing the saturated bicyclic ether to produce the benzene compound.
- -
-
Page/Page column 17; 18
(2016/07/05)
-
- A PROCESS FOR THE SYNTHESIS OF CARBOXYLIC ACID DERIVATIVES
-
The present invention discloses one-pot synthesis of various carboxylic acid derivatives using copper catalyst and sodium cyanide as the cyanide source for bringing in carbonylative coupling in a single step.
- -
-
Page/Page column 8-9; 16
(2015/05/19)
-
- Synthesis, structural and antioxidant studies of some novel N-ethyl phthalimide esters
-
A series of N-ethyl phthalimide esters 4(a-n) were synthesized and characterized by spectroscopic studies. Further, the molecular structure of majority of compounds were analysed by single crystal X-ray diffraction studies. The X-ray analysis revealed the importance of substituents on the crystal stability and molecular packing. All the synthesized compounds were tested for in vitro antioxidant activity by DPPH radical scavenging, FRAP and CUPRAC methods. Few of them have shown good antioxidant activity.
- Kumar, C.S. Chidan,Loh, Wan-Sin,Chandraju, Siddegowda,Win, Yip-Foo,Tan, Weng Kang,Quah, Ching Kheng,Fun, Hoong-Kun
-
-
- Palladium-Catalyzed Aerobic Oxidative Dehydrogenation of Cyclohexenes to Substituted Arene Derivatives
-
A palladium(II) catalyst system has been identified for aerobic dehydrogenation of substituted cyclohexenes to the corresponding arene derivatives. Use of sodium anthraquinone-2-sulfonate (AMS) as a cocatalyst enhances the product yields. A wide range of functional groups are tolerated in the reactions, and the scope and limitations of the method are described. The catalytic dehydrogenation of cyclohexenes is showcased in an efficient route to a phthalimide-based TRPA1 activity modulator.
- Iosub, Andrei V.,Stahl, Shannon S.
-
supporting information
p. 3454 - 3457
(2015/03/30)
-
- Cuprous Oxide Catalyzed Oxidative C-C Bond Cleavage for C-N Bond Formation: Synthesis of Cyclic Imides from Ketones and Amines
-
Selective oxidative cleavage of a C-C bond offers a straightforward method to functionalize organic skeletons. Reported herein is the oxidative C-C bond cleavage of ketone for C-N bond formation over a cuprous oxide catalyst with molecular oxygen as the oxidant. A wide range of ketones and amines are converted into cyclic imides with moderate to excellent yields. In-depth studies show that both α-C-H and β-C-H bonds adjacent to the carbonyl groups are indispensable for the C-C bond cleavage. DFT calculations indicate the reaction is initiated with the oxidation of the α-C-H bond. Amines lower the activation energy of the C-C bond cleavage, and thus promote the reaction. New insight into the C-C bond cleavage mechanism is presented.
- Wang, Min,Lu, Jianmin,Ma, Jiping,Zhang, Zhe,Wang, Feng
-
supporting information
p. 14061 - 14065
(2016/01/25)
-
- Concise synthesis of cyclic carbonyl compounds from haloarenes using phenyl formate as the carbonyl source
-
Various cyclic carbonyl compounds were concisely synthesized by carbonylative cyclization of haloarenes bearing nucleophilic moieties under Pd catalysis. A broad substrate scope and a feasible large-scale synthesis clearly demonstrate the high applicability of the reaction as a general, user-friendly method for access to cyclic carbonyl compounds.
- Konishi, Hideyuki,Nagase, Hiroki,Manabe, Kei
-
supporting information
p. 1854 - 1857
(2015/01/30)
-
- Facile and direct synthesis of symmetrical acid anhydrides using a newly prepared powerful and efficient mixed reagent
-
An efficient mixed reagent for direct synthesis of symmetrical carboxylic anhydrides from carboxylic acids has been prepared. Carboxylic acids are converted to anhydrides using triphenylphosphine/ trichloroisocyanuric acid under mild reaction conditions at room temperature. Short reaction time, excellent yields of products, low cost, availability of reagents, simple experimental procedure, and easy work-up of the products are the main advantages of the presented method.
- Rouhi-Saadabad, Hamed,Akhlaghinia, Batool
-
p. 479 - 485
(2015/01/30)
-
- Gold nanoparticles supported on three-dimensional nitrogen-doped graphene: An efficient catalyst for selective aerobic oxidation of hydrocarbons under mild conditions
-
The development of efficient and selective aerobic oxidation of alkylarenes to form more functional compounds by heterogeneously catalysed routes still presents a great challenge in the fine chemical industry and is a major research topic. In this work, gold nanoparticles supported on three-dimensional nitrogen-doped graphene-based frameworks (Au NPs@3D-(N)GFs) were successfully synthesized and found to have an impressive performance as bifunctional catalysts (nitrogen dopant as base and gold nanoparticles as active site) in the controlled oxidation of alkylarenes. The catalyst was found to be a simple bench top, stable, recyclable and selective catalytic system for the aerobic oxidation of various types of alkylarenes into their corresponding ketones at room temperature under environmentally friendly conditions with good yields and high selectivity.
- Mahyari, Mojtaba,Laeini, Mohammad Sadegh,Shaabani, Ahmad,Kazerooni, Hanif
-
p. 456 - 461
(2015/06/30)
-
- Selective oxidation of alkyl-substituted polyaromatics using ruthenium-ion-catalyzed oxidation
-
Ruthenium-ion-catalyzed oxidation of a range of alkylated polyaromatics has been studied. 2-Ethylnaphthalene was used as a model substrate, and oxidation can be performed in either a conventional biphasic or in a monophasic solvent system. In either case the reaction rates and product selectivity are identical. The reaction products indicate that the aromatic ring system is oxidized in preference to the alkyl chain. This analysis is possible due to the development of a quantitative NMR protocol to determine the relative amounts of aliphatic and aromatic protons. From a systematic set of substrates we show that as the length of the alkyl chain substituent on a polyaromatic increases, the proportion of products in which the chain remains attached to the aromatic system increases. Larger polyaromatic systems, based on pyrene and phenanthrene, show greater reactivity than those with fewer aromatic rings, and the alkyl chains are more stable to oxidation.
- Nowicka, Ewa,Sankar, Meenakshisundaram,Jenkins, Robert L.,Knight, David W.,Willock, David J.,Hutchings, Graham J.,Francisco, Manuel,Taylor, Stuart H.
-
p. 4285 - 4293
(2015/03/14)
-