- V2O5/TiO2 Catalysts for the Vapor-Phase Oxidation of β-Picoline: Influence of the TiO2-Carrier
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The heterogeneously catalyzed vapor-phase oxidation of β-picoline to nicotinic acid over a series of V2O5/TiO2 was investigated. Characterizations of the catalysts were carried out using X-ray diffraction, temperature-programmed desorption, and N2-adsorption. It was found that the use of an anatase type of TiO2-carrier with a higher BET surface area enhances the activity of the V/Ti-oxide catalyst enormously. TiO2-materials with different BET surface areas (between 10 and 270 m2/g) were used. Since these different materials originate from different processes, namely, the chloride and the sulfate process, the influence of the sulfate content was investigated. Additionally, the use of different TiO2 crystalline structures (anatase vs rutile) was evaluated, and a sulfate-free TiO2-material was modified with sulfate and cerium oxide during vanadia impregnation. The results of these experiments verified that the sulfate content itself did not have a strong influence on the catalyst activity. XRD-characterization of the catalysts demonstrated that only the TiO2 and the V2O5 phase could be detected. This corresponds with other investigations in the literature and strengthens the assumption that there is a synergetic effect of a V2O5 layer supported by TiO2 as a catalyst carrier. Therefore the increase of the interface between these two crystalline phases is the determining factor to improve the catalyst's activity.
- Heinz,Hoelderich,Krill,Boeck,Huthmacher
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- Selective photocatalytic oxidation of 3-pyridinemethanol on platinized acid/base modified TiO2
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TiO2catalysts, modified with acidic or alkaline solutions and then platinized, were used for the partial photocatalytic oxidation of 3-pyridinemethanol to 3-pyridinemethanal and vitamin B3under environmentally friendly conditions. The reaction took place in water under UVA light and air oxygen. Catalysts were characterized by TEM, photoluminescence, DRIFT-IR, Raman, DRS, XPS, and photocurrent measurements. The photocatalytic activity results show that Pt loading of untreated samples leads to a significant activity improvement (hence product yield) as much as acid and alkaline treatments do. Moreover, the alkaline treated TiO2samples exhibit a further increase in activity after loading with Pt. Pt acts as an electron scavenger promoting electron transfer from the TiO2conduction band, consequently boosting the photogenerated pair numbers available for the reactive process. Photocurrent measurements show that the TiO2photocatalysts' active sites increase significantly after platinization and alkaline/acid treatment. The treated and/or Pt loaded catalysts showed good thermal stability (at least up to 400 °C).
- ?etinkaya, S?d?ka,Augugliaro, Vincenzo,Garlisi, Corrado,Lewin, Erik,Palmisano, Giovanni,Sá, Jacinto,Yurdakal, Sedat
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- Degradation of quinoline by wet oxidation - Kinetic aspects and reaction mechanisms
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The high temperature, high pressure wet oxidation reaction of quinoline has been studied as a function of initial concentration, pH and temperature. At neutral to acidic pH, it is effective in the oxidation of quinoline at 240°C and above, whereas under alkaline conditions the reaction is markedly slowed down. The results indicate that the reaction is an auto-catalysed, free radical chain reaction transforming 99% of quinoline to other substances. Of the quinoline, 30-50% was oxidised to CO2 and H2O depending on the initial concentration. Wet oxidation of deuterium-labelled quinoline was used as a method for verifying and quantifying the reaction products. Fifteen reaction products were identified and quantitatively determined, accounting for 70% of the carbon present after treatment. Nicotinic acid was a main product, accounting for up to 35% of the parent substance. The formation of succinic acid is suggested to be a result of a coupling reaction of the acetic acid radical. A reaction mechanism is suggested for the degradation of quinoline; it involves hydroxyl radicals and the possible interaction with autoclave walls is discussed. The high temperature, high pressure wet oxidation reaction of quinoline has been studied as a function of initial concentration, pH and temperature. At neutral to acidic pH, it is effective in the oxidation of quinoline at 240°C and above, whereas under alkaline conditions the reaction is markedly slowed down. The results indicate that the reaction is an auto-catalysed, free radical chain reaction transforming 99% of quinoline to other substances. Of the quinoline, 30-50% was oxidised to CO2 and H2O depending on the initial concentration. Wet oxidation of deuterium-labelled quinoline was used as a method for verifying and quantifying the reaction products. Fifteen reaction products were identified and quantitatively determined, accounting for 70% of the carbon present after treatment. Nicotinic acid was a main product, accounting for up to 35% of the parent substance. The formation of succinic acid is suggested to be a result of a coupling reaction of the acetic acid radical. A reaction mechanism is suggested for the degradation of quinoline; it involves hydroxyl radicals and the possible interaction with autoclave walls is discussed.
- Thomsen, Anne Belinda
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- Mild reductive deoximation with TiCl4/NaI reagent system
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The application of the TiCl4/NaI reagent system in the reductive cleavage of oximes under mild conditions is reported.
- Balicki,Kaczmarek
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- 3-picoline oxidation over monoclinic orthovanadate Cr0.5Al0.5VO4 catalysts
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Monoclinic orthovanadate CrVO4-I was found to be active for the vapor phase oxidation of 3-picoline to nicotinic acid and was further activated by the solid solution formation with Al at the Cr site.
- Zhaoxia, Song,Kadowaki, Eriko,Shishido, Tetsuya,Wang, Ye,Takehira, Katsuomi
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- TiO2/graphene-like photocatalysts for selective oxidation of 3-pyridine-methanol to vitamin B3 under UV/solar simulated radiation in aqueous solution at room conditions: The effect of morphology on catalyst performances
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Graphene-like layers, synthesized through a two-step oxidation/reduction wet treatment of a high surface carbon black, have been used to prepare composites with TiO2 nanoparticles by liquid phase deposition, followed by calcination at 200 °C. The photocatalytic activity of the TiO2/graphene-like composites has been tested for the selective conversion of 3-pyridine methanol to 3-pyridine carboxyaldehyde and nicotinic acid (vitamin B3), under de-aerated and UV/solar simulated conditions, in the presence of cupricions. Two different composite morphologies have been explored and a dependence of the photocatalytic activity has been assessed. An enhanced photocatalytic activity, with respect to the neat TiO2, has been observed and attributed to the broader variety of stable free-radical species generated, at a given photo-catalyst morphology, within the delocalized π-electron systems.
- Alfè, Michela,Spasiano, Danilo,Gargiulo, Valentina,Vitiello, Giuseppe,Capua, Roberto Di,Marotta, Raffaele
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- Micellar effects on kinetics and mechanism of Vilsmeier–Haack formylation and acetylation with Pyridines
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An efficient preparation of Vilsmeier–Haack formylated and acetylated derivatives with pyridine and substituted pyridines has been developed by employing micelles as catalyst. Their kinetic study reveals a phenomenal rate enhancement in anionic SDS, cationic CTAB, and nonionic TX-100 micellar media. The Vilsmeier–Haack reaction follows second order kinetics. Piszkiewicz’s co-operativity model was used to interpret the results in micellar media. The observed activation parameters ΔH and ΔS values were calculated from Eyring’s plots. The main features of this study were easy process, mild reaction conditions and readily available reagents. Graphical abstract: [Figure not available: see fulltext.].
- Alyami, Bandar A.,Iqubal, S. M. Shakeel,Khan, Aejaz Abdullatif,Mohammed, Tasneem
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- A Magnetically Recyclable Palladium-Catalyzed Formylation of Aryl Iodides with Formic Acid as CO Source: A Practical Access to Aromatic Aldehydes
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A magnetically recyclable palladium-catalyzed formylation of aryl iodides under CO gas-free conditions has been developed by using a bidentate phosphine ligand-modified magnetic nanoparticles-anchored- palladium(II) complex [2P-Fe 3O 4@SiO 2-Pd(OAc) 2] as catalyst, yielding a wide variety of aromatic aldehydes in moderate to excellent yields. Here, formic acid was employed as both the CO source and the hydrogen donor with iodine and PPh 3as the activators. This immobilized palladium catalyst can be obtained via a simple preparative procedure and can be facilely recovered simply by using an external magnetic field, and reused at least 9 times without any apparent loss of catalytic activity.
- You, Shengyong,Zhang, Rongli,Cai, Mingzhong
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p. 1962 - 1970
(2021/01/25)
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- One-Pot Direct Oxidation of Primary Amines to Carboxylic Acids through Tandem ortho-Naphthoquinone-Catalyzed and TBHP-Promoted Oxidation Sequence
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Biomimetic oxidation of primary amines to carboxylic acids has been developed where the copper-containing amine oxidase (CuAO)-like o-NQ-catalyzed aerobic oxidation was combined with the aldehyde dehydrogenase (ALDH)-like TBHP-mediated imine oxidation protocol. Notably, the current tandem oxidation strategy provides a new mechanistic insight into the imine intermediate and the seemingly simple TBHP-mediated oxidation pathways of imines. The developed metal-free amine oxidation protocol allows the use of molecular oxygen and TBHP, safe forms of oxidant that may appeal to the industrial application.
- Kim, Hun Young,Oh, Kyungsoo,Si, Tengda
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supporting information
p. 18150 - 18155
(2021/12/09)
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- Novel pymetrozine intermediate nicotinaldehyde synthesis method and synthesis device
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The invention discloses a novel pymetrozine intermediate nicotinaldehyde synthesis method. The method comprises the following steps: preparing a mixed solution; adding a main catalyst and a cocatalyst; and carrying out a reaction, cooling a reaction product, performing pressure reduced distillation and filtration to obtain a nicotinaldehyde solution. The invention further discloses synthesis equipment adopting the novel pymetrozine intermediate nicotinaldehyde synthesis method, the synthesis equipment comprises a reaction kettle, a stirring shaft and a reduced pressure distiller, the stirringshaft is arranged in the reaction kettle and is rotatably connected with the reaction kettle, the reduced pressure distiller is connected with the reaction kettle, and the reduced pressure distiller is connected with the reaction kettle and is located at the lower side of the reaction kettle. According to the present invention, the main catalyst and the co-catalyst are matched with each other, andthe experiment conditions are controlled, such that the process steps are simple and can be suitable for large-scale production, and the synthesis apparatus of the nicotinaldehyde synthesis method step is improved; the reaction kettle and the reduced pressure distiller are matched so as to improve the yield of the nicotinaldehyde; therefore, the product can be automatically produced, and the nicotinaldehyde can be produced on a large scale.
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Paragraph 0041-0046
(2021/03/31)
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- Photoredox-Catalyzed Simultaneous Olefin Hydrogenation and Alcohol Oxidation over Crystalline Porous Polymeric Carbon Nitride
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Booming of photocatalytic water splitting technology (PWST) opens a new avenue for the sustainable synthesis of high-value-added hydrogenated and oxidized fine chemicals, in which the design of efficient semiconductors for the in-situ and synergistic utilization of photogenerated redox centers are key roles. Herein, a porous polymeric carbon nitride (PPCN) with a crystalline backbone was constructed for visible light-induced photocatalytic hydrogen generation by photoexcited electrons, followed by in-situ utilization for olefin hydrogenation. Simultaneously, various alcohols were selectively transformed to valuable aldehydes or ketones by photoexcited holes. The porosity of PPCN provided it with a large surface area and a short transfer path for photogenerated carriers from the bulk to the surface, and the crystalline structure facilitated photogenerated charge transfer and separation, thus enhancing the overall photocatalytic performance. High reactivity and selectivity, good functionality tolerance, and broad reaction scope were achieved by this concerted photocatalysis system. The results contribute to the development of highly efficient semiconductor photocatalysts and synergistic redox reaction systems based on PWST for high-value-added fine chemical production.
- Qiu, Chuntian,Sun, Yangyang,Xu, Yangsen,Zhang, Bing,Zhang, Xu,Yu, Lei,Su, Chenliang
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p. 3344 - 3350
(2021/07/26)
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- Preparation of tungstophosphoric acid/cerium-doped NH2-UiO-66 Z-scheme photocatalyst: a new candidate for green photo-oxidation of dibenzothiophene and quinoline using molecular oxygen as the oxidant
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The goal of this study was to introduce an effective visible-light induced photocatalytic system with a good ability for photocatalytic oxidative desulfurization (PODS) and denitrogenation (PODN) using molecular oxygen (O2) as an oxidant. In this regard, tungestophosphoric acid (PW12) was supported onto cerium-doped NH2-UiO-66 (PW12/Ce-NUiO-66) and employed for the photo-oxidation of dibenzothiophene (DBT) and quinoline (Qu). Herein, using cerium (Ce) as a “mediator” facilitated the separation of charge carriers, while NH2-UiO-66 remarkably enhanced the surface area with plentiful adsorption sites and shifted the adsorption edge of PW12to the visible region. The sum of these factors resulted in superior photocatalytic ability and maximum efficiency of 99 ± 1% was achieved by using 30PW12/Ce-NUiO-66 as the optimum photocatalyst in the PODN system and 89 ± 1% in the PODS system under visible light irradiation for 90 min. The traditional Z-scheme mechanism was proposed as the main pathway for this photocatalytic system.
- Fakhri, Hanieh,Esrafili, Ali,Farzadkia, Mahdi,Boukherroub, Rabah,Srivastava, Varsha,Sillanp??, Mika
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p. 10897 - 10906
(2021/06/27)
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- Palladium-Catalyzed Reductive Carbonylation of (Hetero) Aryl Halides and Triflates Using Cobalt Carbonyl as CO Source
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An efficient protocol for the reductive carbonylation of (hetero) aryl halides and triflates under CO gas-free conditions using Pd/Co2(CO)8 and triethylsilane has been developed. The mild reaction conditions, enhanced chemoselectivity and, easy access to heterocyclic and vinyl carboxaldehydes highlights its importance in organic synthesis.
- Dogga, Bhushanarao,Joseph, Jayan T.,Kumar, C. S. Ananda
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supporting information
p. 309 - 313
(2020/12/23)
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- Partial photocatalytic oxidations of 3-pyridinemethanol and 3-picoline by TiO2 prepared in HCl, HNO3 and H2SO4 at different temperatures
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Home prepared TiO2 photocatalysts were prepared from TiCl4 precursor in the absence and presence of HCl (1?6 M), HNO3 (1 M) or H2SO4 (1 M) at room temperature (RT), 60 or 100 °C. The TiO2 catalysts were characterised by XRD, BET, SEM and TGA techniques. TiO2 catalyst could not form at low temperature (up to 60 °C) in the presence of H2SO4. Just rutile phase was obtained for all TiO2 samples prepared at RT and 60 °C in HCl or HNO3. At 100 °C mainly both brookite and rutile phases were obtained in the presence of HCl or HNO3, whilst mainly anatase phase appeared in the presence of H2SO4. Nanorod structured TiO2 was formed in the presence of 1 M HCl or HNO3 at RT and 60 °C. The prepared TiO2 catalysts were used for partial oxidation of 3-pyridinemethanol to 3-pyridinemethanal and vitamin B3 in water under UVA irradiation. Moreover, photocatalytic oxidation of 3-picoline, precursor of 3-pyridinemethanol, was also performed, but much lower product selectivity values were obtained with respect to 3-pyridinemethanol oxidation. However, selective 3-picoline oxidation could be performed at pH 2 with low activity. Degussa P25 was used for comparison and almost all home prepared catalysts showed a higher selectivity, but they showed to be less active than Degussa P25. The high selectivity of the home prepared samples was not due to the type of TiO2 phase, but mainly to the hydrophilicity of the TiO2 surface which allowed desorption of valuable products instead of their over-oxidation.
- ?etinkaya, S?d?ka,Yurdakal, Sedat
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p. 237 - 247
(2020/12/13)
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- Method for preparing aldehyde compounds by oxidative cleavage of carbon-carbon bonds of terminal alkene compounds
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The invention discloses a method for preparing aldehyde compounds by oxidizing and breaking carbon-carbon bonds of terminal alkene compounds. The method comprises the following steps: adding an alkene-terminated compound, an additive and a nitrogen-doped mesoporous carbon-loaded monatomic catalyst into a fatty primary alcohol solvent, putting into a pressure container, sealing, introducing oxygen source gas with a certain pressure, controlling the pressure of the oxygen source gas to be 0.1-1MPa and the reaction temperature to be 80-150 DEG C, and obtaining a reaction product, namely the aldehyde compound. The nitrogen-doped mesoporous carbon-loaded monatomic catalyst adopted by the invention is high in activity, the highest separation yield of the aldehyde compound as a reaction product reaches 99%, the method is wide in application range, the reaction conditions are easy to control, the catalyst can be recycled, the post-treatment is simple, and the method is suitable for industrial production.
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Paragraph 0071-0072; 0089-0090
(2021/06/06)
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- Method for reducing carboxylic acid into aldehyde compounds
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The invention discloses a method for reducing carboxylic acid into aldehyde compounds, and belongs to the field of organic chemical synthesis. Specifically, in an argon atmosphere, a carboxylic acid compound, a transition metal nickel compound, an anhydride compound, a ligand and a reducing agent are dissolved in an organic solvent, the mixture is heated and subjected to stirring reaction, after the reaction is finished, the pressure is reduced to remove the organic solvent, column chromatography separation is performed, and various aldehyde compounds are obtained. The method has the advantages of simple synthesis steps, mild reaction conditions, simplicity and easiness in operation, realization of successful reduction of the carboxylic acid compound into the aldehyde organic compounds, small use amount of the reaction catalyst, high product yield, and provision of a new approach for reduction of the carboxylic acid compound into the aldehyde compounds. Compared with a conventional method, the method has the advantages that raw materials are cheap, easy to obtain and environmentally friendly, substrate universality and functional group compatibility are improved, and the method hascertain innovativeness and unique research significance in organic synthesis methodology.
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Paragraph 0055-0058
(2020/02/27)
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- The Synergy Effect in Tio2 Supported Bi-Mo Catalysts for Facile and Environmentally-Friendly Synthesis of Pyridylaldehydes from Oxidation of Picolines
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Abstract: The oxidation of picolines to pyridlaldehydes was studied over bismuth molybdate catalysts supported on TiO2. The research results showed that α-Bi2Mo3O12 was superior to β-Bi2Mo2O9 and γ-Bi2MoO6 in terms of reactivity. Further doping MoO3 to α-Bi2Mo3O12/TiO2 gave rise to increased catalytic performance, which was due to the synergy effect of α-Bi2Mo3O12 and MoO3. The effect was on one hand manifested in the intimate relationship between α-Bi2Mo3O12 and MoO3 in stabilizing the crystallographic structure of catalysts and thereafter maintaining the surface area of the catalyst, as indicated by the BET surface area and XRD analysis. Moreover, NH3-TPD analysis demonstrated the effect in modifying the surface acidity of the catalysts, and thus facilitating the substrate adsorption as the picolines are alkaline substances. Additionally, the effect between α-Bi2Mo3O12 and MoO3 rendered the modification of the electronic properties and thereafter the oxygen desorption properties and reducible properties of the catalysts, as evidenced in the H2-TPR and O2-TPD analysis.
- Dai, Liyan,Jie, Yu,Zhylko, Viachaslau
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p. 181 - 186
(2020/03/30)
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- 1,1,1,3,3,3-Hexafluoroisopropanol as an efficient medium for the room temperature oxidation of styrenes to benzaldehydes
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A room temperature N-hydroxyphthalimide-catalyzed oxidation of styrene derivatives to the corresponding aldehydes has been developed. The use of 1,1,1,3,3,3-hexafluoroisopropanol as the solvent was determined as being key for efficient oxidation. The incorporated oxygen atom originates from molecular dioxygen.
- Zhang, Zhuyong,Chen, Weidong,Luo, Junfei
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supporting information
(2020/10/23)
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- PROCESS FOR REGENERATING A LIQUID ABSORBENT
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The invention provides a process for regenerating a liquid absorbent, comprising: contacting the liquid absorbent with a hydrophobic medium, wherein the liquid absorbent comprises at least one amine of Formula (I) and degradation product thereof comprising at least one imine of Formula (II), wherein each Ar is independently an aromatic group and each R is independently selected from hydrogen, an organyl group and NH2; and selectively extracting the degradation product into or through the hydrophobic medium.
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Paragraph 105
(2020/11/12)
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- Rhodium-catalyzed reductive carbonylation of aryl iodides to arylaldehydes with syngas
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The reductive carbonylation of aryl iodides to aryl aldehydes possesses broad application prospects. We present an efficient and facile Rh-based catalytic system composed of the commercially available Rh salt RhCl3·3H2O, PPh3 as phosphine ligand, and Et3N as the base, for the synthesis of arylaldehydes via the reductive carbonylation of aryl iodides with CO and H2 under relatively mild conditions with a broad substrate range affording the products in good to excellent yields. Systematic investigations were carried out to study the experimental parameters. We explored the optimal ratio of Rh salt and PPh3 ligand, substrate scope, carbonyl source and hydrogen source, and the reaction mechanism. Particularly, a scaled-up experiment indicated that the catalytic method could find valuable applications in industrial productions. The low gas pressure, cheap ligand and low metal dosage could significantly improve the practicability in both chemical researches and industrial applications.
- Chen, Suqing,Liu, Zhenghui,Mu, Tiancheng,Wang, Peng,Yan, Zhenzhong,Yu, Dongkun,Zhao, Xinhui
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p. 645 - 656
(2020/05/14)
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- Organosuperbase dendron manganese complex grafted on magnetic nanoparticles; heterogeneous catalyst for green and selective oxidation of ethylbenzene, cyclohexene and oximes by molecular oxygen
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Magnetic Fe3O4 nanoparticles as a support were modified with an amino-terminated organosilicon and cyanoric choloride ligands. The novel manganese complex was grafted on modified magnetic support (Mn(II)-Met@MMNPs). The nanocatalyst structure, particle size, morphology and surface properties was well characterized by elemental analysis, ICP-AES, AAS, EDS, FT-IR, SEM, TEM, DLS, VSM, TGA, XRD and XPS. In order to develop an effective heterogeneous nanocatalyst for eco-friendly aerobic, highly active and selective catalytic reactions, synthesized nanocatalyst was applied in oxidation of various organic compounds. The catalytic performance of the manganese nanocatalyst in the aerobic oxidation of ethylbenzene (EB), cyclohexene (CYHE) and various aldoximes and ketoxime were studied. Selective aerobic oxidation of EB and CYHE and various oximes were catalyzed by the Mn-nanocatalyst using N-hydroxyphthalimide (NHPI) with molecular oxygen as the green oxidant without the need of any reducing agent, and respectively the acetophenone (AcPO) as a benzylic product, 2-cyclohexene-1-one (CYHE[dbnd]O) as an allylic product and corresponding carbonyl compounds were obtained. The oxidation process has been optimized for Mn-nanocatalyst by considering the effect of different parameters such as the ratio and amount of Mn-nanocatalyst/NHPI, reaction time and solvent for achieving maximum conversion and selectivity to products. Due to their significant low cost, informal preparation, easy magnetically separation from reaction mixture, excellent catalytic performance, simple recovery and reusability without any metal leaching, the Mn-nanocatalyst has huge application prospect in selective and green oxidation process.
- Faraji, Ali Reza,Ashouri, Fatemeh,Hekmatian, Zahra,Heydari, Somayyeh,Mosazadeh, Sima
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- Metal-free nitrogen -doped carbon nanosheets: A catalyst for the direct synthesis of imines under mild conditions
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Herein, a highly stable, porous, multifunctional and metal-free catalyst was developed, which exhibited significant catalytic performance in the oxidation of amines and transfer hydrogenation of nitriles under mild conditions; this could be attributed to the presence of numerous active sites and their outstanding BET surface area. The obtained results showed that most of the yields of imines exceeded 90%, and the cycling performance of the catalyst could be at least seven runs without any decay in the reaction activity, which could be comparable to those of metal catalysts. Subsequently, a kinetic study has demonstrated that the apparent activation energy for the direct synthesis of imines from amines is 67.39 kJ mol-1, which has been performed to testify that the catalytic performances are rational. Via catalyst characterizations and experimental data, graphitic-N has been proven to be the active site of the catalyst. Hence, this study is beneficial to comprehend the mechanism of action of a metal-free N-doped carbon catalyst in the formation of imines.
- Wang, Kaizhi,Jiang, Pengbo,Yang, Ming,Ma, Ping,Qin, Jiaheng,Huang, Xiaokang,Ma, Lei,Li, Rong
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p. 2448 - 2461
(2019/05/17)
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- PdO nanoparticles supported on triazole functionalized porous triazine polymer as an efficient heterogeneous catalyst for carbonylation of aryl halides
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A well-defined triazole functionalized porous triazine based polymers act as solid heterogeneous catalyst after incorporating palladium oxide nanoparticles (PdO@TTAS) have been synthesized and thoroughly characterized by various techniques such as, FT-IR, UV-DRS, solid state 13C CP-MAS, XPS, powder X-ray diffraction, TGA, SEM and TEM analysis has been detailed illustrated. It is important to note that synthesized catalytic performance for carbonylation of aryl halides (X?=?I, Br) with EDC.HCl (N-(3-dimethylaminopropyl)-N′-ethylcarbodiimide hydrochloride), and formic acid was found to be an effective CO source in the presence of triethylamine as a base and DMF as a solvent medium at 80?°C for about 3?hr. The PdO@TTAS catalyst exhibits superior catalytic performance and along with good yield (up to 90%). Moreover, studying the heterogeneity and reusability of the environmentally friendly solid catalyst can be easily separated by simple filtration and then recycled for several times. In this reaction method, we avoided ligand, additive, promoters and CO gas, due to additional problem arise by using gaseous CO, highly toxic greenhouse gases and high pressurized reaction setup.
- Sadhasivam, Velu,Balasaravanan, Rajendran,Siva, Ayyanar
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supporting information
(2019/07/03)
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- Functional group transformation from amines to aldehydes via IBX oxidation
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IBX oxidation of secondary aryl amines has been applied towards their functional group transformation to aldehydes using a facile post-process with satisfactory yields. The oxidation of N-benzylmethylamine was used as a model substrate and suggested that the ratio of IBX oxidant to amine should be 2:1. Subsequently, several aryl amines were subjected to these standard conditions, which revealed that the oxidative activity depends on the electronic and steric structures of the substituent groups in the substrates. The oxidative selectivity to secondary amines was also discovered.
- Chen, Li-Xia,Huang, Yin-Hui,Cong, Hang,Tao, Zhu
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p. 661 - 667
(2018/02/28)
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- Metal-free hypervalent iodine/TEMPO mediated oxidation of amines and mechanistic insight into the reaction pathways
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A highly efficient metal free approach for the oxidation of primary and secondary amines to their corresponding aldehydes and ketones using PhI(OAc)2 in combination with a catalytic amount of TEMPO as an oxidizing agent is described. This protocol is rapid and provides diverse products under milder reaction conditions in excellent yields. In addition, the mechanistic study is well demonstrated by spectroscopic methods.
- Bansode, Ajay H.,Suryavanshi, Gurunath
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p. 32055 - 32062
(2018/09/29)
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- Reduction of N,N-Dimethylcarboxamides to Aldehydes by Sodium Hydride–Iodide Composite
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A new and concise protocol for selective reduction of N,N-dimethylamides into aldehydes was established using sodium hydride (NaH) in the presence of sodium iodide (NaI) under mild reaction conditions. The present protocol with the NaH-NaI composite allows for reduction of not only aromatic and heteroaromatic but also aliphatic N,N-dimethylamides with wide substituent compatibility. Retention of α-chirality in the reduction of α-enantioriched amides was accomplished. Use of sodium deuteride (NaD) offers a new step-economical alternative to prepare deuterated aldehydes with high deuterium incorporation rate. The NaH-NaI composite exhibits unique chemoselectivity for reduction of N,N-dimethylamides over ketones.
- Chan, Guo Hao,Ong, Derek Yiren,Yen, Zhihao,Chiba, Shunsuke
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- Base-Free and Acceptorless Dehydrogenation of Alcohols Catalyzed by an Iridium Complex Stabilized by a N, N, N-Osmaligand
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The preparation of a N,N,N-osmaligand, its coordination to iridium to afford an efficient catalyst precursor, and the catalytic activity of the latter in dehydrogenation reactions of hydrogen carriers based on alcohols are reported. Complex OsH2Cl2(PiPr3)2 (1) reacts with 3-(2-pyridyl)pyrazol to give the osmium(II) complex 2H, which contains an acidic hydrogen atom. Deprotonation of the latter by the bridging methoxy groups of the dimer [Ir(μ-OMe)(n4-COD)]2 (COD = 1,5-cyclooctadiene) leads to Ir(2)( n 4-COD) (3), where osmaligand 2 has a free-nitrogen atom. Iridium complex 3 catalyzes the dehydrogenation of secondary and primary alcohols to ketones and aldehydes or esters, respectively, and the dehydrogenation of diols to lactones. Cyclooctatriene is detected during the catalysis by GC-MS, suggesting that the true catalyst of the reactions is a dihydride IrH2(2)-species with osmaligand 2 acting as N,N,N-pincer. The presence of a phenyl group in the substrates favors the catalytic processes. The dehydrogenative homocoupling of primary alcohols to esters appears to take place via the transitory formation of hemiacetals.
- Alabau, Roberto G.,Esteruelas, Miguel A.,Martínez, Antonio,Oliván, Montserrat,O?ate, Enrique
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p. 2732 - 2740
(2018/09/10)
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- Rhodium-Catalyzed Formylation of Aryl Halides with CO2 and H2
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The reductive formylation of aryl iodides/bromides to aryl aldehydes using CO2/H2 is presented for the first time. It was realized over a catalytic system composed of RhI3 or RhI3/Pd(dppp)Cl2 (dppp = 1,3-bis(diphenyphosphino)propane) and PPh3 in the presence of Ac2O/Et3N at 100 °C, affording aromatic aldehydes in good to excellent yields, together with good functional-group tolerance and broad substrate scope. The reaction proceeds through three cascade steps, involving HCOOH formation, CO release, and formylation of aryl halides.
- Liu, Zhenghui,Yang, Zhenzhen,Yu, Bo,Yu, Xiaoxiao,Zhang, Hongye,Zhao, Yanfei,Yang, Peng,Liu, Zhimin
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supporting information
p. 5130 - 5134
(2018/09/13)
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- METHOD FOR PRODUCING CARBONYL COMPOUND
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PROBLEM TO BE SOLVED: To provide a method for producing a carbonyl compound, allowing for improvement of ease of production and furthermore allowing for reduction of production cost, by positively utilizing inexpensive iodine. SOLUTION: A carbonyl compound is produced by mixing primary alcohol or secondary alcohol, and iodic acid (HIO3) in a non-solvent or an aprotic polar solvent based on the following general formula (1), where R1 is an optionally substituted linear- or branched 1-12C aliphatic group, or an optionally substituted aromatic group; R2 is a hydrogen atom, an optionally substituted linear- or branched 1-12C alkyl group, or an optionally substituted aromatic group; R1 and R2 each may be coupled with each other to form a ring of aromatic group or a non-aromatic group. SELECTED DRAWING: None COPYRIGHT: (C)2018,JPOandINPIT
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Paragraph 0032-0035; 0037-0040
(2018/03/23)
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- Palladium-Catalyzed Formylation of Aryl Iodides with HCOOH as CO Source
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A facile and practical method for the synthesis of aromatic aldehydes by palladium-catalyzed reductive carbonylation starting from aryl iodides and HCOOH is described. Compared to the known formylation procedure, HCOOH serves not only as the most convenient and environmental-friendly C1 source but also as the reviving agent in the reductive elimination process of a Pd-catalyst. Furthermore, this procedure is also applied successfully to the modification of natural products, such as vindoline, tabersonin, and vincamine, to obtain the corresponding products in good yields.
- Sun, Guanglong,Lv, Xue,Zhang, Yinan,Lei, Min,Hu, Lihong
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supporting information
p. 4235 - 4238
(2017/08/23)
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- Simple formylation of aromatic compounds using a sodium formate/triphenylphosphine ditriflate system
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A new procedure was developed for formylation of arenes to produce aromatic aldehydes using a sodium formate/triphenylphosphine ditriflate system in ethanol at room temperature in good yields. The simplicity of the procedure, short reaction times, and mild reaction conditions are the other advantages of this metal- and carbon monoxide-free protocol.
- Khodaei, Mohammad M.,Alizadeh, Abdolhamid,Hezarkhani, Hadis Afshar
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supporting information
p. 840 - 843
(2017/06/13)
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- Merging Photoredox with Br?nsted Acid Catalysis: The Cross-Dehydrogenative C?O Coupling for sp3 C?H Bond Peroxidation
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A photoredox and Br?nsted acid synergistically catalyzed cross-dehydrogenative C?O coupling reaction is developed in which isochroman peroxyacetals are formed through sp3 C?H bond peroxidation. The reported method is characterized by its extremely mild reaction conditions, excellent yields, and broad substrate scope. An oxocarbenium ion p-chlorobenzenesulfonate was speculated to be the reactive intermediate. The role of hemiacetals and oxygenated dimers on the effective stabilization of the oxocarbenium ion was investigated; the presence of acid appeared to establish equilibrium between hemiacetals and oxygenated dimers with the oxocarbenium ion pairs. The broad applicability of the method highlights the potential of the protocol for molecule synthesis.
- Xia, Qing,Wang, Qiang,Yan, Changcun,Dong, Jianyang,Song, Hongjian,Li, Ling,Liu, Yuxiu,Wang, Qingmin,Liu, Xiangming,Song, Haibin
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supporting information
p. 10871 - 10877
(2017/08/18)
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- Visible-Light-Promoted Nickel- and Organic-Dye-Cocatalyzed Formylation Reaction of Aryl Halides and Triflates and Vinyl Bromides with Diethoxyacetic Acid as a Formyl Equivalent
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A simple formylation reaction of aryl halides, aryl triflates, and vinyl bromides under synergistic nickel- and organic-dye-mediated photoredox catalysis is reported. Distinct from widely used palladium-catalyzed formylation processes, this reaction proceeds by a two-step mechanistic sequence involving initial in situ generation of the diethoxymethyl radical from diethoxyacetic acid by a 4CzIPN-mediated photoredox reaction. The formyl-radical equivalent then undergoes nickel-catalyzed substitution reactions with aryl halides and triflates and vinyl bromides to form the corresponding aldehyde products. Significantly, besides aryl bromides, less reactive aryl chlorides and triflates and vinyl halides serve as effective substrates for this process. Since the mild conditions involved in this reaction tolerate a plethora of functional groups, the process can be applied to the efficient preparation of diverse aromatic aldehydes.
- Huang, He,Li, Xiangmin,Yu, Chenguang,Zhang, Yueteng,Mariano, Patrick S.,Wang, Wei
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supporting information
p. 1500 - 1505
(2017/02/05)
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- Method for directly synthesizing aldehydes from amines
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The invention discloses a method for directly synthesizing aldehydes from amines. The method comprises the following steps: mixing an oxidizer and amines in a mole ratio of (1.8-2.2):1, and heating under reflux in 120-200 times by mole of chloroform solution (on the basis of the mole of amines) to react for 6-24 hours; and after the reaction is finished, naturally cooling to room temperature, filtering to remove IBX (o-iodoxybenzoic acid) and the reduction product thereof ortho-iodosobenzoic acid, sequentially washing the filtrate with a 10% NaOH solution, a 1M hydrochloric acid solution, water and a saturated sodium chloride solution, respectively washing three times (about 10ml each time), and carrying out rotary evaporation to remove the solvent chloroform, thereby obtaining the corresponding product aldehyde. The method has the advantages of high yield, high selectivity, low cost and low energy consumption.
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Paragraph 0012
(2017/06/24)
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- Fe3O4 magnetic nanoparticles (MNPs) as an efficient catalyst for selective oxidation of benzylic and allylic C-H bonds to carbonyl compounds with tert-butyl hydroperoxide
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Fe3O4 magnetic nanoparticles (MNPs) were prepared by a co-precipitation method with oleic acid as a surfactant and characterized by FT-IR, TEM, DLS, XRD, VSM techniques. XRD, DLS and TEM analysis of this catalyst clearly showed the formation of cubic structure Fe3O4 MNPs, with a mean size of 16 nm. Moreover, a magnetization measurement revealed that the Fe3O4 MNPs had superparamagnetic behaviour and the saturation magnetization of the catalyst was 54.6 emu g-1. The Fe3O4 MNPs in combination with tert-butyl hydroperoxide catalyzed the oxidation of various benzylic and allylic C-H bonds to the corresponding carbonyl compounds in excellent yields. These oxidation reactions were effectively and economically performed under mild conditions, and therefore the dual challenge of cost effectiveness and benign nature of the processes was met.
- Zarghani, Monireh,Akhlaghinia, Batool
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p. 38592 - 38601
(2016/05/24)
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- Reaction of 3-arylidenepropenoic acid derivatives with triethylamine and other amines; Unexpected reductions and vinylogations
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Exposure of ethyl 2-cyano-3-(2-methoxy-5-nitrophenyl)acrylate 1f to triethylamine in hot ethanol resulted in the formation of the dihydro derivative 2f and vinylogue 3f in high yields. Single crystal X-ray data are provided for 3f. Similar reactions were observed for various analogues. The reaction was studied changing aryl substituent, amines and solvents. Pyridyl, thienyl analogues were also examined. The study was extended to cyclic molecules incorporating such systems like thiazolidinedione 8, 3-cyanocoumarin 9 and 4-arylidene-isoquinoline-2,4-diones 11. The last group gave vinylogated products, 4-cinnamylidene-isoquinolinediones and 4-hydroxylated species. A few examples of arylidene derivatives from malononitrile, ethyl acetoacetate, acetyl acetone and ethyl methylsufonylacetate were investigated. Ethyl cinnamate and β-nitrostyrene were unaffected. The reaction is considered to be possibly radical mediated, since addition of free radical quencher suppressed the reaction. Contrary to the effects of thermal conditions, irradiation of 1f in ethanol at 254 and 365 nm gave complex mixtures. A few other interesting observations in this study are noted: vinylogation of 1f with acetaldehyde to 3f; formation of 3f from 1f by the treatment with triethylamine, palladium carbon and reduction of 1f to 2f by triethylammonium formate in DMF.
- Harisha, Attimogae Shivamurthy,Nayak, Suresh Parameshwar,Nagarajan, Kuppuswamy,Row, Tayur Narasingarow Guru,Hosamani, Amar A.
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p. 2880 - 2889
(2016/05/24)
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- An Efficient and General Method for Formylation of Aryl Bromides with CO2 and Poly(methylhydrosiloxane)
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The formylation of aryl halides with CO2 to generate aryl aldehydes is challenging. Herein, we report a novel synthesis of aryl aldehydes by formylation of aryl bromides with CO2 and a waste silane, poly(methylhydrosiloxane) (PMHS). It has been discovered that a simple combination of 1,3-bis(diphenyphosphino)propane (DPPP)-chelated Pd catalyst, Pd(DPPP)Cl2, with 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) is able to effectively catalyze the reaction, leading to aryl aldehydes in moderate to excellent yields, and without any by-products in most cases. Moreover, this route could be extended to the formylation of aryl iodides with high efficiency. This approach is simple, less costly, and environmentally friendly, and also widens the applications of CO2 to form value-added chemicals by the construction of new C-C bonds.
- Yu, Bo,Yang, Zhenzhen,Zhao, Yanfei,Hao, Leiduan,Zhang, Hongye,Gao, Xiang,Han, Buxing,Liu, Zhimin
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supporting information
p. 1097 - 1102
(2016/01/16)
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- Palladium-catalyzed formal hydroacylation of allenes employing carboxylic anhydrides and hydrosilanes
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The formal hydroacylation reaction of allenes has been developed employing carboxylic anhydrides as acyl sources and hydrosilanes as reducing reagents in the presence of a commercially available palladium complex as a catalyst. The reaction affords α,β-unsaturated ketones regio- and stereoselectively. The similar catalyst system is also effective for the reduction of carboxylic anhydrides to the corresponding aldehydes employing hydrosilanes.
- Fujihara, Tetsuaki,Hosomi, Takuro,Cong, Cong,Hosoki, Tomoya,Terao, Jun,Tsuji, Yasushi
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supporting information
p. 4570 - 4574
(2015/03/30)
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- Reactivity-based dynamic covalent chemistry: Reversible binding and chirality discrimination of monoalcohols
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In an effort to develop reactivity-based dynamic covalent bonding and to expand the scope and application of the dynamic covalent chemistry, in situ-generated simple generic iminium ions were utilized for the dynamic covalent binding of monoalcohols with high affinity. Hammett analysis was conducted to manipulate the equilibrium and correlate with the reactivity of reactants. The structural features of aldehydes and secondary amines were identified, and both polar and steric effects have significant impact on the binding. In particular, the substrates which can participate in π-π and polar-π interactions are able to afford apparent equilibrium constants in the magnitude of 104 M-2, demonstrating the power of weak supramolecular forces to stabilize the dynamic covalent assembly. The generality of the assembly was validated with a series of mono secondary alcohols. To showcase the practicality of our system, chirality discrimination and ee measurement of chiral secondary alcohols were achieved.
- Zhou, Yuntao,Ye, Hebo,You, Lei
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p. 2627 - 2633
(2015/03/18)
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- Palladium-catalyzed synthesis of aldehydes from aryl halides and tert-butyl isocyanide using formate salts as hydride donors
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An efficient one-pot palladium-catalyzed hydroformylation of aryl halides to produce aromatic aldehydes has been achieved, employing tert-butyl isocyanide as a C1 resource and formate salt as a hydride donor without any additional bases. Characterized by its mild reaction conditions, easy operation and lower toxicity, this reaction can tolerate a wide array of functional groups with moderate to excellent yields.
- Zhang, Ying,Jiang, Xiao,Wang, Jin-Mei,Chen, Jing-Lei,Zhu, Yong-Ming
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p. 17060 - 17063
(2015/03/30)
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- Palladium-catalyzed carbonylations of aryl bromides using paraformaldehyde: Synthesis of aldehydes and esters
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Carbonylation reactions represent useful tools for organic synthesis. However, the necessity to use gaseous carbon monoxide is a disadvantage for most organic chemists. To solve this problem, novel protocols have been developed for conducting palladium-catalyzed reductive carbonylations of aryl bromides and alkoxycarbonylations using paraformaldehyde as an external CO source (CO gas free). Hence, aromatic aldehydes and esters were synthesized in moderate to good yields.
- Natte, Kishore,Dumrath, Andreas,Neumann, Helfried,Beller, Matthias
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supporting information
p. 10090 - 10094
(2015/03/31)
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- Direct imine formation by oxidative coupling of alcohols and amines using supported manganese oxides under an air atmosphere
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Manganese oxides loaded on various supports have been prepared and studied for the direct imine formation by oxidative coupling of alcohols and amines. Among the catalysts, hydroxyapatite supported manganese oxides (MnO x/HAP) show the best activity and selectivity for this reaction in the absence of an additional base using air as the environmentally benign terminal oxidant. NH3-/CO2-TPD results show that the amphoteric properties of MnOx/HAP are crucial for this reaction to obtain a satisfactory yield. Various aromatic alcohols and amines are smoothly transformed into the corresponding imines in good to excellent yields. The catalyst is reusable and gives 98% yield of the product in all 9 reuse tests. Compared with the fresh catalyst, the XRD and SEM of the reactivated MnO x/HAP after nine reactions do not show any obvious change. This journal is the Partner Organisations 2014.
- Chen, Bo,Li, Jun,Dai, Wen,Wang, Lianyue,Gao, Shuang
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p. 3328 - 3334
(2014/06/10)
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- Flash vacuum thermolysis of N-(3-and 4-Pyridylmethylidene)-tert- butylamines: Mechanisms of formation of pyrrolopyridines and naphthyridines
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Pyrrolopyridines and naphthyridines are formed by flash vacuum thermolysis (FVT) of 3-and 4-pyridylmethylidene-tert-butylimines 8 and 15. Elimination of a methyl radical generates resonance stablized 2-azaallyl radicals a1 and b1. The formation of pyrrolopyridines 9, 16 and 17 is rationalized in terms of cyclization of 1-aziridinyl radicals a2 and b2. Formation of naphthyridine 10 from imine 8, and of 11 and 18 from imine 15, are in accord with cyclization of 1-azaallyl radicals a6 and b9. Formation of naphthyridine 11 from 8, and of 10 and 19 from 15, indicate the operation of the spiro-cyclization pathways forming intermediates a9 and b14. Formation of the 1,8-naphthyridine 20 (3%) indicates a rearrangement through aziridine b22 and biradical b23. DFT calculations at the CAM-B3LYP/6-311G(d,p) level support the proposed reaction mechanisms.
- Justyna, Katarzyna,Lesniak, Stanislaw,Nazarski, Ryszard B.,Rachwalski, Michal,Vu, Thien Y.,Huynh, Thi Kieu Xuan,Khayar, Said,Dargelos, Alain,Chrostowska, Anna,Wentrup, Curt
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supporting information
p. 3020 - 3027
(2014/05/20)
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- Aldehydes and ketones formation: Copper-catalyzed aerobic oxidative decarboxylation of phenylacetic acids and α-hydroxyphenylacetic acids
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Aromatic aldehydes or ketones from copper catalyzed aerobic oxidative decarboxylation of phenylacetic acids and α-hydroxyphenylacetic acids have been synthesized. This reaction combined decarboxylation, dioxygen activation, and C-H bond oxidation steps in a one-pot protocol with molecular oxygen as the sole terminal oxidant. This reaction represents a novel decarboxylation of an sp3-hybridized carbon and the use of a benzylic carboxylic acid as a source of carbonyl compounds.
- Feng, Qiang,Song, Qiuling
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p. 1867 - 1871
(2014/03/21)
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- Pd/C-catalyzed direct formylation of aromatic iodides to aryl aldehydes using carbon dioxide as a C1 resource
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Pd/C-catalyzed direct formylation of aromatic iodides to aryl aldehydes using CO2 as a C1 resource was realized for the first time in the presence of hydrosilanes and base DBU under mild conditions, giving a series of aldehydes in good yields. The Royal Society of Chemistry 2014.
- Yu, Bo,Zhao, Yanfei,Zhang, Hongye,Xu, Jilei,Hao, Leiduan,Gao, Xiang,Liu, Zhimin
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supporting information
p. 2330 - 2333
(2014/03/21)
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- Cooperative catalysis of palladium nanoparticles and cobalt oxide support for formylation of aryl iodides under syngas atmosphere
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Formylation of aryl iodides proceeded effectively in the presence of palladium nanoparticles on cobalt oxide under a syngas atmosphere to afford aldehydes up to 91% yield. A cooperative effect between palladium nanoparticles and cobalt species derived from the support was integral to efficient transformation. Both palladium and cobalt were revealed to exist as zero valent metals after H2 treatment from X-ray absorption near edge structure and X-ray diffraction spectra. The catalyst could be reused at least 7 times without significant loss of activity.
- Hamasaki, Akiyuki,Yasutake, Yutaro,Norio, Takafumi,Ishida, Tamao,Akita, Tomoki,Ohashi, Hironori,Yokoyama, Takushi,Honma, Tetsuo,Tokunaga, Makoto
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p. 146 - 152
(2013/11/19)
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- Diphosphino-functionalised MCM-41-supported palladium complex: An efficient and recyclable catalyst for the formylation of aryl halides
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The heterogeneous formylation of aryl halides with HCO2Na at atmospheric pressure by carbon monoxide was readily achieved in the presence of the diphosphino-functionalised MCM-41-supported palladium complex in DMF to afford the corresponding aromatic aldehydes in good to excellent yields. This heterogeneous palladium catalyst can be recovered by simple filtration and reused 10 times without any loss of activity.
- Jiang, Jianwen,Wang, Pingping,Cai, Mingzhong
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p. 218 - 222
(2014/05/06)
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- A phosphine-free heterogeneous formylation of aryl halides catalyzed by a thioether-functionalized MCM-41-immobilized palladium complex
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Thioether-functionalized MCM-41-immobilized palladium(II) complex [MCM-41-S-PdCl2] was found to be a highly efficient catalyst for the formylation of aryl iodides or bromides with CO (1 atm) using HCO2Na as a hydrogen source. This phosphine-free heterogeneous palladium complex can be easily recovered by simple filtration and reused for at least 10 consecutive trials without any decreases in activity.
- Hao, Wenyan,Ding, Guodong,Cai, Mingzhong
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- Palladium-catalyzed reduction of carboxylic acids to aldehydes with hydrosilanes in the presence of pivalic anhydride
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A palladium catalyst system that allows the reduction of carboxylic acids to the corresponding aldehydes with hydrosilanes as reducing agent and pivalic anhydride as an indispensable reagent has been developed. A simple mixture of commercially available bis(dibenzylideneacetone)palladium(0) [Pd(dba) 2], tri(para-tolyl)phosphane and methylphenylsilane realized the reduction of various aliphatic carboxylic acids as well as benzoic acids to aldehydes in good to high yields. Copyright
- Fujihara, Tetsuaki,Cong, Cong,Terao, Jun,Tsuji, Yasushi
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supporting information
p. 3420 - 3424
(2013/12/04)
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- FTIR study of β-picoline and pyridine-3-carbaldehyde transformation on V-Ti-O catalysts. the effect of sulfate content on β-picoline oxidation into nicotinic acid
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Surface complexes of β-picoline, 3-pyridine-carbaldehyde and nicotinic acid on 20 wt.% V2O5/TiO2 catalysts containing 0.07 and 6.3l wt.% SO42- were studied by FTIR spectroscopy and temperature program
- Chesalov, Yuriy A.,Andrushkevich, Tamara V.,Sobolev, Vladimir I.,Chernobay, Galina B.
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p. 118 - 130
(2013/11/19)
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- Palladium-catalyzed reductive carbonylation of aryl halides with N-formylsaccharin as a CO source
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Easy peasy: The title reaction employs N-formylsaccharin, which is an easily accessible crystalline compound, as an effective CO source. The reactions proceed with a small excess of the CO source at moderate temperatures and were successfully applied to a wide range of aryl bromides. DMF=N,N- dimethylformamide, dppb=1,4-bis-(diphenylphosphino)butane. Copyright
- Ueda, Tsuyoshi,Konishi, Hideyuki,Manabe, Kei
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supporting information
p. 8611 - 8615
(2013/09/12)
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- Reductive carbonylation of aryl halides employing a two-chamber reactor: A protocol for the synthesis of aryl aldehydes including 13C- and D-isotope labeling
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A protocol has been developed for conducting the palladium-catalyzed reductive carbonylation of aryl iodides and bromides using 9-methylfluorene-9- carbonyl chloride (COgen) as a source of externally delivered carbon monoxide in a sealed two-chamber system (COware), and potassium formate as the in situ hydride source. The method is tolerant to a wide number of functional groups positioned on the aromatic ring, and it can be exploited for the isotope labeling of the aldehyde group. Hence, reductive carbonylations run with 13COgen provide a facile access to 13C-labeled aromatic aldehydes, whereas with DCO2K, the aldehyde is specifically labeled with deuterium. Two examples of double isotopic labeling are also demonstrated. Finally, the method was applied to the specific carbon-13 labeling of the β-amyloid binding compound, florbetaben.
- Korsager, Signe,Taaning, Rolf H.,Lindhardt, Anders T.,Skrydstrup, Troels
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p. 6112 - 6120
(2013/07/26)
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- Copper(II) complexes of a new tetradentate bis-benzimidazolyl diamide ligand with disulfanediyl linker: Synthesis, characterization, and oxidation of some pyridyl, napthyl, and benzyl alcohols
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The bis-benzimidazolyl diamide ligand 3,3’-disulfanediyl-bis-(N-((1H-benzo[d]imidazol-2-yl)methyl) propanamide) (L) having N, S, and O donors has been synthesized and utilized to prepare copper(II) complexes of general composition [Cu(L)X]·X·nH2O, where X is Cl-or (Formula Found). Ligands and complexes were characterized by elemental analysis, UV-visible, IR spectroscopy, 1H NMR, mass spectrometry, conductance, electron paramagnetic resonance, cyclic voltammetry, fluorescence, single-crystal, and PXRD. [Cu(L)(NO3)]NO3·H2O crystallizes in the monoclinic C2/c space group with one molecule in the asymmetric unit. Copper adopts a distorted octahedral geometry with four coordination sites occupied by the ligand and two sites by a bidentate nitrate. [Cu(L)(NO3)] NO3·H2O has been utilized as a catalyst to oxidize alcohols with tert-butyl hydroperoxide as an alternative source of oxygen. The oxidized products have been characterized by GCMS.
- Tyagi, Nidhi,Kumar, Ravinder,Mahiya, Kuldeep,Mathur, Pavan
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p. 3335 - 3348
(2017/09/07)
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