- Smart solution chemistry: Prolonging the lifetime of ortho-phthalaldehyde disinfection solutions
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The oxidation of ortho-phthalaldehyde to phthalic acid in aqueous solutions can be remedied by the addition of various cyclic acetals, which, when reacted with phthalic acid, yields ortho-phthalaldehyde, thus prolonging the lifetime of the ortho-phthalaldehyde disinfection solution.
- Brewer, Bobby N.,Mead, Keith T.,Pittman Jr., Charles U.,Lu, Kaitao,Zhu, Peter C.
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Read Online
- Suspending ionic single-atom catalysts in porphyrinic frameworks for highly efficient aerobic oxidation at room temperature
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Room temperature and atmosphere pressure are highly desired catalytic conditions for aerobic oxidation of inert sp3 C–H bonds. To meet this challenge, we developed a simple strategy by suspending ionic single atoms (ISAs) inside the anionic pores of metal–organic frameworks (MOFs). CZJ-22-Cu, consisting of suspended ISA copper(II) inside the anionic pores, exhibits exceptionally high catalytic efficiency in aerobic oxidation of ethers to esters at room temperature and atmosphere pressure, in which turnover number (TON) 77,100 and turnover frequency (TOF) 7710 h?1 have been realized for aerobic oxidation of isobenzofuran. The unmatched catalytic properties of CZJ-22-Cu are attributed to the unique features of suspended ISAs inside the anionic pores, which result in high surface free energy of redox-active centers, and the substrate-selective accumulation nature of the inside pores, which would significantly improve the reactivity and reaction rate.
- He, Wei-Long,Yang, Xiu-Li,Zhao, Min,Wu, Chuan-De
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Read Online
- Oxidaition of cyclic benzylic ethers by an electronically tuned nitroxyl radical
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The reactivity of an electronically tuned nitroxyl radical catalyst for the oxidation of cyclic benzylic ethers has been investigated. The oxidation of phthalan resulted in oxidative cleavage of the saturated ring to give an aromatic dialdehyde. Additionally, oxidation of isochromans afforded isochromanones, which are often seen in natural products, in a rapid manner.
- Furuta, Takumi,Hamada, Shohei,Kawabata, Takeo,Kobayashi, Yusuke,Yano, Kyoko
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supporting information
(2021/10/04)
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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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supporting information
p. 1962 - 1970
(2021/01/25)
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- Synthesis of new Zn (II) complexes for photo decomposition of organic dye pollutants, industrial wastewater and photo-oxidation of methyl arenes under visible-light
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Synthesis of new Schiff's base Zn-complexes for photo-oxidation of methyl arenes and xylenes are reported under visible light irradiation conditions. All the synthesized new ligands and Zn-complexes are thoroughly characterized with various spectral analyses and confirmed as 1:1 ratio of Zn and ligand with distorted octahedral structure. The bandgap energies of the ligands are higher than its Zn-complexes. These synthesized new Zn(II) complexes are used for the photo-fragmentation of organic dye pollutants, photodegradation of food industrial wastewater and oxidation of methyl arenes which are converted into its respective aldehydes with moderate yields under visible light irradiation. The photooxidation reaction dependency on the intensity of the visible light was also studied. With the increase in the dosage of photocatalyst, the methyl groups are oxidized to get aldehydes and mono acid products, which are also identified from LC-MS data. Finally, [Zn(PPMHT)Cl] is with better efficiency than [Zn(PTHMT)Cl] and [Zn(MIMHPT)Cl] for oxidation of methyl arenes is reported under visible-light-driven conditions.
- Ahemed, Jakeer,Bhongiri, Yadagiri,Chetti, Prabhakar,Gade, Ramesh,Kore, Ranjith,Pasha, Jakeer,Pola, Someshwar,Rao D, Venkateshwar
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- Efficient synthesis of 4-substituted-ortho-phthalaldehyde analogues: Toward the emergence of new building blocks
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4-Methoxy-ortho-phthalaldehyde and 4-hydroxy-ortho-phthalaldehyde are potentially useful molecules for fluorimetric analysis of a variety of amines and for the elaboration of complex molecular architectures. Nevertheless, literature generally describes their synthesis in very low yield (below 5%), mainly due to the inefficiency of the last oxidation step. In this paper, we report a reliable synthesis of 4-substituted-ortho-phthalaldehyde analogues in 51% overall yield owing to the addition of a protecting step of the unstable key intermediate 4,5-dihydroisobenzofuran-5-ol. Oxidation and deprotection steps were also studied in order to provide an effective availability of these two dialdehyde compounds that may increase their future applications.
- Moitessier, Clémence,Rifai, Ahmad,Danjou, Pierre-Edouard,Mallard, Isabelle,Cazier-Dennin, Francine
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p. 721 - 726
(2019/04/17)
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- Synthesis of 1,2-phenylenedimethanols by base-promoted reduction of isobenzofuran-1(3H)-ones with silane
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An efficient method for preparation of substituted 1,2-phenylenedimethanols and aliphatic 1,4-diols that are valuable intermediates in organic synthesis, has been developed by the base-promoted reduction of isobenzofuran-1(3H)-ones and γ-lactones with silane under mild conditions. Compared with traditional procedures using stoichiometric amounts of metal hydrides and alkyl reductants, the present method avoids the use of sensitive reagents and is operationally simple and a broad variety of functional groups are tolerated.
- Liu, Bin,Zhou, Xigeng
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supporting information
p. 725 - 728
(2018/12/11)
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- New methods to synthesize phthalaldehyde and its diacetals
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A new synthesis of phthalaldehyde that avoided formation of HBr involved treatment of 1,2-bis(dibromomethyl)benzene with trimethyl orthoformate (1: 6, 90 °C, 10 mol.% ZnCl2) to obtain acyclic diacetal without admixture of cyclic one (1,3-dimethoxy-1,3-dihydrobenzo-[c]furan) followed by hydrolysis to give the target dialdehyde. Phthalaldehyde reacted with CH(OMe)3 in the presence of trifluoroacetic acid to yield exclusively cyclic diacetal. Acyclic diacetal was phosphorylated by treatment with secondary chlorophosphines and by the reaction with PCl3 followed by treatment with PIII acid ester.
- Gazizov,Khairullin,Ivanova, S. Yu.,Kirillina, Yu. S.,Romanenko,Gazizova
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p. 1878 - 1882
(2019/10/21)
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- Synthesis of Phthalic Aldehyde and Its Diacetals
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Acyclic phthalaldehyde diacetal without cyclic 1,3-dihydro-1,3-dimethoxybenzo[c]furan impurity has been obtained via the reaction of 1,2-bis(dibromomethyl)benzene with trimethyl orthoformate (1:6) at 90°C in the presence of 10 mol% of ZnCl2. Hydrolysis of phthalaldehyde diacetal has led to the formation of phthalaldehyde without HBr evolution. The reaction of phthalaldehyde with trimethyl orthoformate in the presence of trifluoroacetic acid has proceeded abnormally, with the formation of the cyclic diacetal. The acyclic diacetal has been phosphorylated by chlorophosphines and the action of PCl3 and a P(III) acid ester in sequence.
- Khairullin,Gazizov,Kirillina, Yu. S.,Ivanova, S. Yu.,Khairullina,Gazizova
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p. 2178 - 2184
(2020/01/08)
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- Selective vapor-phase oxidation of o-xylene to phthalic anhydride over Co-Mn/H3PW12O40@TiO2 using molecular oxygen as a green oxidant
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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
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- Oxidation Catalysis by an Aerobically Generated Dess–Martin Periodinane Analogue
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Hypervalent iodine(V) reagents, such as Dess–Martin periodinane (DMP) and 2-iodoxybenzoic acid (IBX), are broadly useful oxidants in chemical synthesis. Development of strategies to generate these reagents from dioxygen (O2) would immediately enable use of O2 as a terminal oxidant in a broad array of substrate oxidation reactions. Recently we disclosed the aerobic synthesis of I(III) reagents by intercepting reactive oxidants generated during aldehyde autoxidation. In this work, aerobic oxidation of iodobenzenes is coupled with disproportionation of the initially generated I(III) compounds to generate I(V) reagents. The aerobically generated I(V) reagents exhibit substrate oxidation chemistry analogous to that of DMP. The developed aerobic generation of I(V) has enabled the first application of I(V) intermediates in aerobic oxidation catalysis.
- Maity, Asim,Hyun, Sung-Min,Wortman, Alan K.,Powers, David C.
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supporting information
p. 7205 - 7209
(2018/05/29)
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- Earth-Abundant Mixed-Metal Catalysts for Hydrocarbon Oxygenation
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The oxygenation of aliphatic and aromatic hydrocarbons using earth-abundant Fe and Cu catalysts and "green" oxidants such as hydrogen peroxide is becoming increasingly important to atom-economical chemical processing. In light of this, we describe that dinuclear CuII complexes of pyrrolic Schiff-base macrocycles, in combination with ferric chloride (FeCl3), catalyze the oxygenation of π-activated benzylic substrates with hydroperoxide oxidants at room temperature and low loadings, representing a novel design in oxidation catalysis. Mass spectrometry and extended X-ray absorption fine structure analysis indicate that a cooperative action between CuII and FeIII occurs, most likely because of the interaction of FeCl3 or FeCl4- with the dinuclear CuII macrocycle. Voltammetric measurements highlight a modulation of both CuII and FeIII redox potentials in this adduct, but electron paramagnetic resonance spectroscopy indicates that any Cu-Fe intermetallic interaction is weak. High ketone/alcohol product ratios, a small reaction constant (Hammett analysis), and small kinetic isotope effect for H-atom abstraction point toward a free-radical reaction. However, the lack of reactivity with cyclohexane, oxidation of 9,10-dihydroanthracene, oxygenation by the hydroperoxide MPPH (radical mechanistic probe), and oxygenation in dinitrogen-purge experiments indicate a metal-based reaction. Through detailed reaction monitoring and associated kinetic modeling, a network of oxidation pathways is proposed that includes "well-disguised" radical chemistry via the formation of metal-associated radical intermediates.
- Pankhurst, James R.,Curcio, Massimiliano,Sproules, Stephen,Lloyd-Jones, Guy C.,Love, Jason B.
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supporting information
p. 5915 - 5928
(2018/05/28)
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- Oxidation of Polynuclear Aromatic Hydrocarbons using Ruthenium-Ion-Catalyzed Oxidation: The Role of Aromatic Ring Number in Reaction Kinetics and Product Distribution
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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.
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p. 655 - 662
(2018/01/26)
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- Practical Aerobic Oxidation of Alcohols: A Ligand-Enhanced 2,2,6,6-Tetramethylpiperidine-1-oxy/Manganese Nitrate Catalyst System
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A highly efficient, ligand-enhanced 2,2,6,6-tetramethylpiperidine-1-oxy (TEMPO)/Mn(NO3)2 catalyst system for the aerobic oxidation of alcohols is described. From the series of coordinating ligands studied herein, 2-picolinic acid (PyCOOH) improves the catalytic activity of TEMPO/Mn(NO3)2 remarkably. Under ambient air at room temperature in acetic acid, the ligand-enhanced catalyst converts aliphatic and benzylic primary alcohols that bear various functional groups into their respective aldehydes with near quantitative conversions. The applicability of the catalyst for convenient preparative synthesis was demonstrated by conducting oxidations on a gram scale. A change of TEMPO to the sterically less demanding 9-azabicyclo[3.3.1]nonane N-oxyl results in a Mn catalyst that is also able to oxidize secondary alcohols to ketones. Mechanistic studies showed that alcohols are oxidized by the oxoammonium cation derived from the nitroxyl radical. The active oxidant is regenerated by Mn(NO3)2, and this process is greatly promoted by the coordination of PyCOOH to Mn.
- Lagerblom, Kalle,Lagerspets, Emi,Keskiv?li, Juha,Cook, Chris,Ekholm, Filip,Parviainen, Arno,Repo, Timo
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p. 3880 - 3887
(2017/09/28)
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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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- Ruthenium nanoparticles supported on mesoporous MCM-41 as an efficient and reusable catalyst for selective oxidation of arenes under ultrasound irradiation
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Mesoporous MCM-41 was used as a support for the uniform dispersion of ruthenium nanoparticles having an average particle size of ~5 nm. The obtained nanocomposite, MCM-41-Ru, was characterized using inductively coupled plasma, transmission electron microscopy, energy dispersive X-ray analysis, X-ray diffraction, and BET surface area measurements. The material was employed as an efficient and recyclable catalyst in the ultrasound-assisted oxidation of arenes. It was observed that ultrasound irradiation in combination with KBrO3 as the oxidant, in the presence of MCM-41-Ru nanoparticles, accelerates the oxidation reaction to afford the desired products in good yields. The recovered catalyst retained activity for successive runs, with a continuous change in the nature of its active sites.
- Khorshidi, Alireza
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p. 153 - 158
(2016/01/12)
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- IBX oxidation of benzenedimethanols in the presence of cucurbit[8]uril
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The cucurbit[8]uril (Q[8]) mediated oxidation of benzenedimethanols with o-iodoxybenzoic acid (IBX) in aqueous solution has been investigated, and the results reveal the supramolecular catalysis depends on the electronic and geometric structure of substrate. In the cases of o-benzenedimethanol (1a) and m-benzenedimethanol (1b), the IBX oxidation could be obviously enhanced by the addition of Q[8] at different extent. There is no observation of the catalytic activity of Q[8] when p-benzenedimethanol (1c) is subjected to the IBX oxidation. The addition amount of Q[8] is discussed herein, and the addition of more than 10% mol catalyst cannot improve the oxidation much more. The investigation of host-guest interactions by isothermal titration calorimetry implies the supramolecular catalysis is related to the formation of complexes between benzenedimethanols and cucurbit[8]uril. The supramolecular catalysis of Q[8] (cucurbit[8]uril) on the IBX (o-iodoxybenzoic acid) oxidation of o,m,p-benzenedimethanols in aqueous solvent and the host-guest interactions have been investigated.
- Cong, Hang,Chen, Qiuju,Geng, Qingxia,Tao, Zhu,Yamato, Takehiko
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p. 545 - 549
(2015/05/27)
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- A new synthetic route to substituted tetracenes and pentacenes via stereoselective [4+2] cycloadditions of 1,4-dihydro-1,4-epoxynaphthalene and isobenzofuran
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Stereoselective [4+2] cycloadditions of 1,4-dihydro-1,4-epoxynaphthalene and isobenzofuran were described. Among several possibilities, syn-exo and/or anti-endo isomers were selectively produced depending on the substitution pattern of the reactants. Importantly, the syn-exo isomer underwent acid promoted aromatization, affording the corresponding tetracene. These findings enabled us to prepare a substituted pentacene with electron withdrawing groups.
- Eda, Shohei,Eguchi, Fumiaki,Haneda, Hiroshi,Hamura, Toshiyuki
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p. 5963 - 5966
(2015/03/30)
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- Ultrasonic-assisted ruthenium-catalyzed oxidation of some organic compounds in aqueous medium
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Ultrasonic generation of ruthenium complexes K2[RuO3(OH)2] and [RuO4] is reported from K2[RuCl5(H2O)] with excess K2S2O8 in 1 M KOH and/or with excess KIO4 in biphasic solvent system (H2O/CH2Cl2/CH3CN) at room temperature. Dehydrogenation of some primary amines to nitriles and primary alcohols to their respective acids by K2[RuCl5(H2O)] with excess K2S2O8 at room temperature was reported. A number of nitriles were hydrated to amides by the same catalyst system at 100 °C. The oxidation of two arenes and four alkenes to their aldehydes, ketones or acids by K2[RuCl5(H2O)] with excess KIO4 using ultrasonic irradiation technique was also reported. Cyclic voltammetric, electronic and Raman spectroscopic techniques have been used to elucidate the nature of the active species present in these catalytic oxidation reactions.
- Shoair, Abdel Ghany F.
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- Anchorage of a ruthenium complex into modified MOF: Synergistic effects for selective oxidation of aromatic and heteroaromatic compounds
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The structure of IRMOF-3 was modified with pyridine-2-aldehyde and then the Schiff base moieties were used to anchor ruthenium complex to this metal-organic framework. The prepared catalyst was characterized by X-ray powder diffraction (XRD), diffuse reflectance spectroscopy (DRS), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and FTIR methods. The results show that the prepared catalyst acquires a high potential for selective oxidation of aromatic and heteroaromatic compounds under mild conditions and easy workups.
- Tabatabaeian, Khalil,Zanjanchi, Mohammad Ali,Mahmoodi, Nosrat. O.,Eftekhari, Tooraj
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p. 101013 - 101022
(2015/12/08)
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- Selective oxidation of alkyl-substituted polyaromatics using ruthenium-ion-catalyzed oxidation
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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.
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p. 4285 - 4293
(2015/03/14)
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- IBX works efficiently under solvent free conditions in ball milling
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IBX (2-iodoxybenzoic acid), discovered in 1893, is an oxidant in synthetic chemistry whose extensive use is impeded by its explosiveness at high temperature and poor solubility in common organic solvents except DMSO. Since the discovery of Dess-Martin Periodinane in 1983, several modified IBX systems have been reported. However, under ball milling conditions, IBX works efficiently with various organic functionalities at ambient temperature under solvent free conditions. Also, the waste IBA (2-iodosobenzoic acid) produced from the reactions was in situ oxidized to IBX in the following step using oxone and thus reused for multiple cycles by conserving its efficiency (only ~6% loss after 15 cycles). This work describes an overview of a highly economical synthetic methodology which overcomes the problems of using IBX, efficiently in gram scale and in a non-explosive way. This journal is the Partner Organisations 2014.
- Achar, Tapas Kumar,Maiti, Saikat,Mal, Prasenjit
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p. 12834 - 12839
(2014/04/03)
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- Metal-free, visible-light photoredox catalysis: Transformation of arylmethyl bromides to alcohols and aldehydes
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A mild, simple, and controllable metal-free photocatalytic system for the transformation of arylmethyl bromides to corresponding alcohols and aldehydes in high yields with visible-light irradiation has been achieved. Eosin Y was found to be an efficient promoter for this oxidative dehalogenation reaction under photo irradiation conditions.
- Li, Jian,Wang, Hongni,Liu, Li,Sun, Jiangtao
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p. 49974 - 49978
(2014/12/10)
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- Facile organocatalytic domino oxidation of diols to lactones by in situ-generated TetMe-IBX
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The domino oxidation of diols to lactones is an important transformation, and catalytic protocols that allow this conversion smoothly are scarce. Capitalizing on the established reactivity of tetramethyl-IBX (TetMe-IBX) and its in situ generation in the presence of a co-oxidant, such as oxone, we have shown that a variety of diols can be converted to the corresponding lactones in respectable yields by employing the precursor of TetMe-IBX, namely, tetramethyl-o-iodobenzoic acid (TetMe-IA), as a catalyst in 5 mol % in the presence of 2 equiv of oxone.
- Jhulki, Samik,Seth, Saona,Mondal, Manas,Moorthy, Jarugu Narasimha
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p. 2286 - 2293
(2014/03/21)
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- Poly(4-vinylpyridinium) perchlorate as an efficient solid acid catalyst for the chemoselective preparation of 1,1-diacetates from aldehydes under solvent-free conditions
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Poly(4-vinylpyridinium) perchlorate has been used as a supported, recyclable, environmentally-benign catalyst for the formation of acylals from aliphatic and aromatic aldehydes in good to excellent yields under solvent-free conditions. Notably, the reaction conditions were tolerant of ketones. This methodology offers several distinct advantages, including its operational simplicity and high product yield, as well as being green in terms of avoiding the use of toxic catalysts and solvents. Furthermore, the catalyst can be recovered and reused several times without any loss in its activity.
- Khaligh, Nader Ghaffari
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p. 329 - 334
(2014/04/03)
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- Study of the atmospheric chemistry of 2-formylcinnamaldehyde
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2-Formylcinnamaldehyde is a significant product of the reaction of naphthalene with OH radicals, and its photolysis and gas-phase reactions with O3, NO3 radicals, and OH radicals have been investigated in this work. 2-Formylcinnamaldehyde was observed to undergo photolysis by black lamps, with a photolysis rate of 0.14 × J(NO2), where J(NO2) is the NO2 photolysis rate. The measured rate constants for the reactions of 2-formylcinnamaldehyde with O3, NO3 radicals, and OH radicals (in units of cm3 molecule-1 s-1) were 1.8 × 10-18, 4.3 × 10-14, and 2.1 × 10-11, respectively, with those for the O3 and NO3 reactions being for the E-isomer. 2-Formylcinnamaldehyde was observed to undergo significant adsorption and desorption from the reaction chamber Teflon film walls, and the photolysis rate and rate constants are subject to significant uncertainties. In the atmosphere, the dominant chemical loss processes for 2-formylcinnamaldehyde will be photolysis during daylight hours and reaction with NO3 radicals during nighttime. Phthaldialdehyde and glyoxal were observed as products of the OH radical and O3 reactions, and photolysis of E-2- formylcinnamaldehyde led to formation of Z-2-formylcinnamaldehyde plus two other molecular weight 160 isomers. The present results are compared with previous literature data, and reaction mechanisms are discussed.
- Aschmann, Sara M.,Arey, Janet,Atkinson, Roger
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p. 7876 - 7886
(2013/09/23)
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- Green oxidative synthesis of primary amides from primary alcohols or aldehydes catalyzed by a cryptomelane-type manganese oxide-based octahedral molecular sieve, OMS-2
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In this study, a new green synthetic route to primary amides, that is, aerobic oxidative amidation of primary alcohols or aldehydes with ammonia, has been developed. In the presence of a cryptomelane-type manganese oxide-based octahedral molecular sieve (OMS-2), various kinds of structurally diverse primary alcohols or aldehydes including aromatic, olefinic, heteroaromatic, and aliphatic ones can be converted into the corresponding primary amides in moderate to high yields (20 examples from primary alcohols and 11 examples from aldehydes). Furthermore, gram-scale amidation is also effective, and the analytically pure primary amides can easily be isolated. The present catalysis by OMS-2 is truly heterogeneous in nature, and the retrieved OMS-2 catalyst can be reused several times (at least 12 times for the amidation of 2-pyridinemethanol). Though the formation rates of the corresponding primary amide are gradually decreased by repeating reuse experiments, OMS-2 can be regenerated by calcination. The present OMS-2-catalyzed amidation of primary alcohols is composed of four relay steps: (i) oxidative dehydrogenation of primary alcohols, (ii) dehydrative condensation of aldehydes with ammonia, (iii) oxidative dehydrogenation of aldimines, and (iv) hydration of nitriles to form the corresponding primary amides. All steps (i)-(iv) can be promoted by the presence of OMS-2. The Royal Society of Chemistry 2013.
- Yamaguchi, Kazuya,Kobayashi, Hiroaki,Wang, Ye,Oishi, Takamichi,Ogasawara, Yoshiyuki,Mizuno, Noritaka
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p. 318 - 327
(2013/03/14)
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- The formation of aldehydes from the photochemically activated reaction of Cp*Ir(CO)(Cl)(CH2R) complexes with water
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The iridium complexes Cp*Ir(CO)(Cl)(CH2R), which do not contain any β-hydrogen atoms, react with water to form aldehydes. This reaction was found to be photochemically activated, and a possible pathway involving radical intermediates has been proposed and studied experimentally and computationally.
- Lee, Jia Ying,Fan, Wai Yip,Mak, Kar Hang Garvin,Leong, Weng Kee
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supporting information
p. 275 - 280
(2013/03/13)
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- Ultrasound assisted the chemoselective 1,1-diacetate protection and deprotection of aldehydes catalyzed by poly(4-vinylpyridinium)hydrogen sulfate salt as a eco-benign, efficient and reusable solid acid catalyst
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Poly(4-vinylpyridinium) hydrogen sulfate solid acid was found to be efficient catalyst for preparation of 1,1-diacetate using ultrasound irradiation at ambient temperature and neat condition. Deprotection of the resulting 1,1-diacetates were achieved using the same catalyst in methanol solvent under ultrasound irradiation at room temperature. This new method consistently has the advantage of excellent yields and short reaction times. Utilization of solvent free, simple reaction conditions, isolation, and purification makes this manipulation very interesting from an economic and environmental perspective. Further, the catalyst can be reused and recovered for several times.
- Khaligh, Nader Ghaffari,Shirini, Farhad
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supporting information
p. 19 - 25
(2013/01/15)
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- Development of manganese(VI) oxidising agents soluble in organic solvents
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Two manganate(VI) reagents have been prepared from permanganate salts that show excellent oxidising properties in common organic solvents. Georg Thieme Verlag Stuttgart · New York.
- Ellis, Rhys,Lee, Kee-Han,Ainsworth, Matthew,Kerr, Alexander,Viseux, Eddy M. E.
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experimental part
p. 1371 - 1373
(2012/06/30)
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- Zinc-catalyzed benzylic C-H bond oxidation
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A zinc-catalyzed oxidation of benzylic substrates has been developed. The corresponding carbonyl containing compounds have been produced in moderate to excellent yields. Both arenes and heteroarenes can be applied as substrates by using H2O2 as the oxidant.
- Wu, Xiao-Feng
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supporting information
p. 6123 - 6126
(2012/11/07)
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- Introduction of N-sulfonic acid poly(4-vinylpyridinum) chloride as an efficient and reusable catalyst for the chemoselective 1,1-diacetate protection and deprotection of aldehydes
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N-sulfonic acid poly(4-vinylpyridinium) chloride is easily prepared by the reaction of poly(4-vinylpyridine) with neat chlorosulfonic acid. This reagent can be used as an efficient catalyst for the preparation of 1,1-diacetates at room temperature and neat condition. Deprotection of the resulting 1,1-diacetates can also be achieved using the same catalyst in methanol. This new method consistently has the advantages of excellent yields and short reaction times. Further, the catalyst can be reused and recovered for several times.
- Shirini, Farhad,Jolodar, Omid Goli
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experimental part
p. 61 - 69
(2012/04/17)
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- Application of flow chemistry to the selective reduction of esters to aldehydes
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The reduction of esters to aldehydes is an important transformation in organic chemistry and several reducing agents have been described. However, the use of this reaction in medicinal and natural product chemistry is limited due to the instability of the intermediates and the high reactivity of the reaction products. In the current article, the general and selective reduction of esters with diisobutyl-tert-butoxyaluminum hydride in flow is reported. This reagent allows esters to be reduced in the presence of different functional groups, including those considered to be of similar or higher reactivity. Copyright
- De Munoz, Juan M.,Alcazar, Jesus,De La Hoz, Antonio,Diaz-Ortiz, Angel
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supporting information; experimental part
p. 260 - 263
(2012/02/16)
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- Catalytic oxidation of aromatic oxygenates by the heterogeneous catalyst Co-ZIF-9
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The catalytic activity of Co-ZIF-9, a zeolitic imidazolate framework of sodalite topology, in the oxidation of small aromatic molecules including phthalan, vanillyl alcohol, guaiacol, syringol, veratryl alcohol, and cinnamyl alcohol by molecular oxygen has been investigated. Co-ZIF-9 selectively oxidized the substrates and thus represents a promising heterogeneous catalyst for the oxidation of small aromatic substrates. Phthalan was converted to three different products, i.e. phthalide, phthalaldehyde, and small amounts of phthalic acid. In addition to phthalan, the alcohol functionality of vanillyl alcohol, veratryl alcohol, and cinnamyl alcohol was also similarly oxidized to yield the corresponding aldehydes in high yields and excellent selectivity. The effect of solvent, temperature and NaOH addition on the Co-ZIF-9 catalytic system has been studied. The presence of NaOH in the solution greatly enhanced the oxidation activity. The structure and stability of the heterogeneous catalyst was probed by UV-vis diffuse reflection spectroscopy, confirming the coordination geometry of cobalt in the catalyst framework, thermal gravimetric analysis, establishing the thermal stability of the structure, and XRD to monitor crystallinity of the catalyst. The heterogeneous nature of the catalyst was established by a hot filtration experiment, ICP analysis of the liquid phase, and by UV-vis absorption spectroscopy on the hot filtered reaction mixture.
- Zakzeski, Joseph,Dbczak, Agnieszka,Bruijnincx, Pieter C.A.,Weckhuysen, Bert M.
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experimental part
p. 79 - 85
(2011/12/16)
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- Two chemodivergent anionic domino processes from cyclic α-nitroketones and aromatic aldehydes
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Treatment of cyclic α-nitroketones and aromatic 1,2-dialdehydes with DBU in tetrahydrofuran containing small amounts of water proceeded through two chemodivergent one-pot domino pathways, whose outcome depended on the ring size of the starting nitroketone. Thus, α-nitrocyclohexanone underwent diastereoselective α′-arylmethylenation reactions through a nitroaldol/aldol/reverse nitroaldol mechanism. On the other hand, α-nitrocycloheptanone and α-nitrocyclooctanone afforded 2-nitroindane-1,2-diols containing three contiguous stereocenters in a highly diastereoselective fashion through a nitroaldol/retro-Dieckmann/intramolecular nitroaldol process.
- Giorgi, Giorgio,Arroyo, Francisco J.,López-Alvarado, Pilar,Menéndez, J. Carlos
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experimental part
p. 5582 - 5589
(2011/08/10)
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- Oxidation of benzylic azides catalysed by iron(III) chloride with hydrogen peroxide as oxidant
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A simple and general method for the oxidation of benzylic azides to aldehydes using the inexpensive and environmentally benign iron (III) chloride as catalyst with 30% aqueous H2O2 as oxidant is described. Broad substrate scope and high tolerance against several functional groups make the process synthetically useful.
- Zhang, Hong-Ping,Dai, You-Zhi,Tao, Li-Ming
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experimental part
p. 720 - 722
(2012/03/09)
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- A green chemistry method for the regeneration of carbonyl compounds from oximes by using cupric chloride dihydrate as a recoverable promoter for hydrolysis
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A mild, efficient, general, and green method for the regeneration of carbonyl compounds from their corresponding oximes is described. Cupric salts promoted hydrolysis of oximes was studied, and the best reaction conditions for the hydrolysis have been found. Carbonyl compounds were obtained in 85-98% yields after the treatment of oximes with 2 molar equivalent of CuCl 22H2O at reflux (around 75 C) in a mixed solvent of acetonitrile and water (4:1). In addition, cupric salt was readily recovered in an almost quantitative yield via the complete precipitation of Cu(OH) 22H2O. Georg Thieme Verlag Stuttgart · New York.
- Quan, Na,Shi, Xiao-Xin,Nie, Liang-Deng,Dong, Jing,Zhu, Rui-Heng
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experimental part
p. 1028 - 1032
(2011/06/17)
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- A green process for the oxidative lactonization of 1,2-benzenedimethanol by tungstic acid with aqueous H2O2
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A new economic and green route to synthesize phthalide from 1,2-benzenedimethanol using aqueous hydrogen peroxide as the oxidant and tungstic acid as the catalyst under organic solvent-free conditions is presented. This process proceeds with advantages from the viewpoint of green chemistry, in which the only by-product of H2O2 is water and the catalyst can also be easily recovered. The desired product with high purity and good yield can be conveniently obtained when cooled after reaction.
- Zhu, Quan-Jing,Dai, Wei-Lin,Fan, Kang-Nian
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scheme or table
p. 205 - 208
(2011/02/27)
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- Photocatalytic degradation of polycyclic aromatic hydrocarbons in GaN:ZnO solid solution-assisted process: Direct hole oxidation mechanism
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GaN:ZnO exhibits excellent activity for the photodegradation of PAHs, and the activity can be obviously improved by loading Pt. The degradation of PAHs in the system of GaN:ZnO is induced by the formation of holes. The holes generated then interact with PAHs to produce PAHs+, which is active enough to react with O2.
- Kou, Jiahui,Li, Zhaosheng,Guo, Yong,Gao, Jun,Yang, Ming,Zou, Zhigang
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experimental part
p. 48 - 54
(2010/10/01)
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- PROCESS FOR THE SAFE OZONOLYSIS OF ORGANIC COMPOUNDS IN FLAMMABLE SOLVENTS
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An improved process for the safe ozonolysis of unsaturated, organic carbon compounds having one or more olefinic or aromatic double bonds in the molecule in flammable solvents for the preparation of mono- or biscarbonyl or hydroxy compounds, in which ozonolysis is carried out with the use of an ozone-carrying inert gas/O2 stream, in which the oxygen concentration in the inert gas/O2 stream is above the known limiting oxygen concentration of the homogeneous fuel/gas mixtures and below the safety-critical limiting oxygen concentration of the heterogeneous mixture of the liquid fuel and oxygen-containing gas which is dependent on the reaction conditions and at which ignition and flame propagation no longer take place.
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Page/Page column 20-21
(2008/12/06)
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- Effect of substituents at 1,4-positions of polycyclic aromatic compounds and preparation of 2,3-difunctionalized pentacenes and naphthacenes
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Effects of substituents at 1,4-positions of polycyclic aromatic compounds were investigated in the case of reduction of 2,3-bis(alkoxycarbonyl)arenes with the LiAlH4/AlCI3 system. 2,3-Bis(alkoxycarbonyl)dihydronaphthacenes and dihydropentacenes 1 were treated with a mixture of LiAlH4 and AlCl3. The products were dependent on the substituents at 1,4-positions. Similar type of influence of the substituents at 1,4-positions was observed in the oxidation of diols 2 to dialdehydes 4. Without substituents at 1,4-positions, dialdehydes 4 were conveniently obtained. However, with substituents at 1,4-positions, dialdehydes 4 were not obtained. Instead,1,3-dihydroisobenzofuran-l,3-diol or 1,3-dihydroisobenzofuran-l-ol derivatives 5, 6 were obtained in good yields. Preparation of pentacene imides and pentacene carboxylic acid anhydride was also reported.
- Li, Shi,Zhou, Lishan,Song, Zhiyi,Bao, Fengyu,Kanno, Ken-ichiro,Takahashi, Tamotsu
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experimental part
p. 519 - 536
(2009/09/08)
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- Expeditious oxidation of alcohols to carbonyl compounds using iron(III) nitrate
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An efficient and solvent-free protocol for the oxidation of alcohols to corresponding carbonyl compounds using iron(III) nitrate nonahydrate has been developed.
- Namboodiri, Vasudevan V.,Polshettiwar, Vivek,Varma, Rajender S.
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p. 8839 - 8842
(2008/03/18)
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- Forming germicidal aromatic dialdehydes with acetals
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Methods of forming germicidal aromatic dialdehydes by hydrolyzing acetals are disclosed. Compositions and kits including both germicidal aromatic dialdehydes and acetals that are capable of being converted to germicides are disclosed. In one aspect, an acetal may be converted to germicide gradually in a deployed germicidal solution to accommodate for loss of the germicide or otherwise to modify the germicidal efficacy of the deployed germicidal solution.
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Page/Page column 9-11
(2008/06/13)
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- PROCESS FOR THE PRODUCTION OF COMPOUNDS VIA HAZARDOUS INTERMEDIATES IN A SERIES OF MICROREACTORS
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Multi-step process for the preparation of compounds via hazardous intermediates comprising the steps of a) preparing in a microreactor a hazardous intermediate and b) optionally performing one or more reaction steps on the hazardous intermediate in one or more additional microreactors and c) further converting the hazardous intermediate with a suitable reaction agent in a subsequent microreactor until a stable end product is formed.
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Page/Page column 15-16
(2008/06/13)
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- Forming germicidal aromatic dialdehydes with acetals
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Methods of forming germicidal aromatic dialdehydes by hydrolyzing acetals are disclosed. Compositions and kits including both germicidal aromatic dialdehydes and acetals that are capable of being converted to germicides are disclosed. In one aspect, an acetal may be converted to germicide gradually in a deployed germicidal solution to accommodate for loss of the germicide or otherwise to modify the germicidal efficacy of the deployed germicidal solution.
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Page/Page column 8-9
(2008/06/13)
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- Process for preparing high-purity, halogen-free o-phthaladehyde
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Improved process for preparing high-purity, halogen-free o-phthalaldehyde, in which a) tetrahalo-o-xylene is hydrolyzed at a temperature of 155-160° C. and a pressure of from 2 to 5 bar, where appropriate in the presence of a phase-transfer catalyst, to o-phthalaldehyde, which b) is converted in an acidic alcoholic solution at a temperature of from 0 to the reflux temperature into the corresponding dialkoxyphthalane and, subsequently, c) an acetal cleavage is effected by acid hydrolysis at a pH >1.5 to pH 7, resulting in high-purity, halogen-free o-phthalaldehyde.
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Page/Page column 2-3
(2008/06/13)
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- Process for the preparation of aqueous ortho-phthalic aldehyde solutions
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Preparation of aqueous ortho-phthalaldehyde (OPA) solution (I) comprises adding OPA acetal (II) in water, adjusting the pH to greater than 7 by adding acid and eliminating the acetal as corresponding alcohols at 10-90[deg]C.
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Page/Page column 3-4
(2008/06/13)
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- PROCESS FOR PRODUCING AROMATIC ALDEHYDE
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A process for producing an aromatic aldehyde compound represented by a general formula (3): (wherein R' and n are as defined below), which comprises reacting a benzyl compound represented by a general formula (1): (wherein R may represents hydrogen atom, n represents an integer of 1 to 6, and R' may be the same or different and represent a hydrogen atom or an alkyl gorup, an alkyl group or a phenyl group which may have a substituent) with an oxy-compound of bromine represented by the formula (2): ????????MBrOm?????(2) (wherein M represents a hydrogen atom or a metal atom, and m represents an integer of 1 to 3) in the presence of an acid catalyst. According to this method, an aromatic aldehyde compound can be produced in high selectivity by a simple operation without using an expensive catalyst or transition metal.
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Page/Page column 14
(2008/06/13)
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- Method for producing aqueous ortho-phthalaldehyde solutions
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A method for producing aqueous ortho-phthalaldehyde solutions which comprises introducing an acetal of the o-phthalaldehyde into water and subsequently setting a pH 7 by adding an acid, whereupon, then at a temperature between 10° C. and 90° C., the acetal is converted into the o-phthalaldehyde by eliminating the corresponding alcohol, and also use of OPA acetals for producing these solutions.
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Page/Page column 1-2
(2008/06/13)
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