- A mild, simple and general procedure for the oxidation of benzyl alcohols to benzaldehydes
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The enzyme/cofactor system laccase/2,2'-azino-bis(3 ethyl-benzothiazoline-6-sulfonic acid) catalyzes the oxidation of benzyl alcohols to the corresponding benzaldehydes by molecular oxygen. The reaction proceeds under physiological conditions to yield the products quantitatively.
- Rosenau,Potthast,Chen,Gratzl
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Read Online
- Samarium-based Grignard-type addition of organohalides to carbonyl compounds under catalysis of CuI
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Grignard-type additions were readily achieved under the mediation of CuI (10 mol%) and samarium (2 equiv.) by employing various organohalides,e.g.benzyl, aryl, heterocyclic and aliphatic halides (Cl, Br or I), and diverse carbonyl compounds (e.g.carbonic esters, carboxylic esters, acid anhydrides, acyl chlorides, ketones, aldehydes, propylene epoxides and formamides) to afford alcohols, ketones and aldehydes, respectively, with high efficiency and chemoselectivity, in which the organosamarium intermediate might be involved.
- Liu, Chen,Liu, Yongjun,Qi, Yan,Song, Bin,Wang, Liang,Xiao, Shuhuan
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supporting information
p. 6169 - 6172
(2021/06/30)
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- Nickel catalyzed hydrosilane reduction of (het)arenecarboxylic acids into aldehydes
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Nickel-catalyzed reduction of (het)arenecarboxylic acids with hydrosilanes in the presence of dimethyl dicarbonate as the activator affords the corresponding aldehydes. The role of the activator is the conversion of the acids into their anhydrides undergoing C–O cleavage. The good yields were achieved in case of substrates bearing electron-donating and electron-neutral groups.
- Wang, Liang,Wang, Yaoyao,Tao, Yu,Zhang, Nana,Li, Shubai
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p. 271 - 273
(2021/05/04)
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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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- Differences in the Mechanisms of MnO2Oxidation between Lignin Model Compounds with the p-Hydroxyphenyl, Guaiacyl, and Syringyl Nuclei
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The purpose of this study was to examine how the rate and mechanism of MnO2 oxidation differ between the p-hydroxyphenyl (H), guaiacyl (G), and syringyl (S) types of simple nonphenolic lignin model compounds as well as the p-ethylphenyl (E) type compounds. The oxidation was conducted using an excess amount of MnO2 in a sulfate buffer solution at a pH value of 1.5 at room temperature. MnO2 oxidized at least the G and S nuclei, although it commonly oxidizes alcohols present at the benzyl position. The oxidation rates of the benzyl alcohol derivatives were in the order of G- > S- ? H- > E-type, which suggests that the rates are determined by the electronic effects of their methoxy and ethyl functional groups on not only their benzyl positions but also their aromatic π-electron systems. The kinetic isotope effect was observed in the MnO2 oxidations of the same derivatives deuterated at their benzyl hydroxymethyl groups. The observed magnitudes were in the order of E- ? H- > G- ? S-type, suggesting that the contribution of oxidation of their aromatic nuclei, which is another reaction mode of the oxidation of their benzyl positions, increases in the reverse order.
- Sun, Shirong,Akiyama, Takuya,Yokoyama, Tomoya,Matsumoto, Yuji
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p. 6819 - 6825
(2020/07/02)
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- Hydroxylamine promoted Fe(III)/Fe(II) cycle on ilmenite surface to enhance persulfate catalytic activation and aqueous pharmaceutical ibuprofen degradation
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This study demonstrates a new system for the degradation of emerging pharmaceutical contaminants (e.g., ibuprofen) in water by coupling the naturally occurring ilmenite with hydroxylamine (HA) and persulfate (PS). Ilmenite was able to activate persulfate to generate sulfate radicals (SO4?·) and hydroxyl radicals (HO·). The radical generation was greatly improved by adding small amount of hydroxylamine into the solution, due to the efficient Fe(III)/Fe(II) cycle on the ilmenite surface promoted by HA, which was confirmed by X-ray photoelectron spectroscopy and electron paramagnetic resonance (EPR) spectroscopy analysis. SO4?· and HO· contributed comparably to ibuprofen degradation, which was verified by the radical scavenging tests. The degradation was enhanced with increasing ilmenite, PS and HA dosages, but the HA exhibited strong scavenging effect at its high concentrations. The ilmenite/PS/HA process worked well in the real treated wastewater, because the surface-controlled radical generation was less affected by the water matrix. However, the formation of bromate in the bromide-containing water by this process should be concerned. Ibuprofen was partially mineralized, and the degradation products were identified by ESI-tqMS. A radical-induced degradation pathway was proposed based on the product identification. This work provides the mechanistic insights on persulfate activation based on the surface-controlled catalytic processes. It also offers a new strategy to degrade emerging contaminants in water and sheds light on the environmental functions of natural minerals.
- Yin, Ran,Hu, Lingling,Xia, Dehua,Yang, Jingling,He, Chun,Liao, Yuhong,Zhang, Qing,He, Jia
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p. 294 - 302
(2019/05/10)
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- Method for reducing carboxylic acid compound into aldehyde
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The invention discloses a method for reducing a carboxylic acid compound into aldehyde. In a nitrogen atmosphere, in an organic solvent, a ligand/Cu catalyst, the carboxylic acid compound, an anhydride compound and hydrosilane are added by a one-pot method, a reaction is performed under the condition of the temperature of 20-120 DEG C for 2-20 h, after the reaction is completed, quenching and column chromatography separation are performed to obtain the product. The carboxylic acid compound can be successfully converted into aldehyde through one-pot reaction, especially unsaturated carboxylic acid can be reduced, and the reaction yield is generally relatively high. Compared with the prior art, the method has the outstanding advantages that the cheap copper salt is used as a catalyst, so that the experiment cost is greatly reduced. Meanwhile, the used method enlarges the application range of the reaction substrate, improves the compatibility of functional groups, and provides a new synthesis way for reducing the carboxylic acid compound into aldehyde.
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Paragraph 0040-0043
(2020/02/27)
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- Method for directly introducing aldehyde group to aromatic ring
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The invention relates to a method for directly introducing an aldehyde group to an aromatic ring. A purpose of the invention is mainly to solve the problems of low aromatic hydrocarbon conversion rateand low aromatic aldehyde selectivity in the prior art. According to the technical scheme, the method comprises the step of performing a carbonylation reaction on aromatic hydrocarbon and CO under the catalysis of a catalyst to obtain aromatic aldehyde, wherein the catalyst comprises a carrier, an ionic liquid and a compound-state auxiliary agent metal, the carrier is a silicon-based material, the ionic liquid comprises aluminum halide and an imidazole salt represented by a chemical formula I, R1 and R2 are independently selected from C1-C8 alkyl, X is selected from chlorine and bromine, thealuminum halide is represented as AlY3, Y is selected from chlorine and bromine, and the compound-state auxiliary metal comprises at least one selected from Cu, Fe, Cr, V and Mn.
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Paragraph 0095-0097
(2020/05/08)
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- A method for the preparation of aldehydes
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The invention discloses a method for the preparation of ketone, relates to the field of organic synthesis. This invention adopts the organic solvent as a medium, cyclopropene [...] derivative as an active agent, activated DMSO oxidation [...] oxidation. The method of the invention is simple, easy to operate, rapid reaction rate, mild reaction, the reaction rate can be adjusted, more economic, to achieve industrial laid the foundation.
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Paragraph 0090; 0091
(2019/05/28)
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- Cyclopropenium-Activated DMSO for Swern-Type Oxidation
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Swern oxidation is widely used to convert alcohols into their corresponding carbonyl compounds. However, the conventional method with use of the volatile oxalyl chloride as an activator requires the reaction to be conducted below -60 °C. We discovered that 3,3-dichloro-1,2-diphenylcyclopropene (DDC) can be used as a new activator for Swern-type oxidations of alcohols, which can be conducted at -20 °C. This new protocol features mild and fast reactions with easy operation. Furthermore, the activator DDC is easy to handle, and diphenylcyclopropenone can be recovered quantitively. This new type of Swern oxidation shows a broad scope of substrates including benzylic, allylic, aliphatic, and biobased alcohols, and gives high yields of up to 93%.
- Guo, Tianfo,Gao, Yu,Li, Zhenjiang,Liu, Jingjing,Guo, Kai
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supporting information
p. 329 - 332
(2019/02/12)
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- Method for preparing aromatic aldehyde
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The invention relates to a method for preparing aromatic aldehyde. The invention mainly aims to solve the problems of low conversion rate of aromatic hydrocarbon and low yield of aromatic aldehyde inthe prior art. The method comprises a step of subjecting aromatic hydrocarbon and CO to a carbonylation reaction under the catalysis of a catalyst so as to obtain aromatic aldehyde, wherein the catalyst comprises ionic liquid, a compound active metal and a compound auxiliary metal, the ionic liquid is quaternary ammonium salt type ionic liquid, the compound active metal comprises Zr, and the compound auxiliary metal comprises Ru. With such a technical scheme, the above technical problems are well solved, and the method can be used for industrial production of aromatic aldehyde.
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Paragraph 0107-0109; 0121
(2019/12/25)
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- Synthesis of Substituted Benzaldehydes via a Two-Step, One-Pot Reduction/Cross-Coupling Procedure
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The synthesis of functionalized (benz)aldehydes, via a two-step, one-pot procedure, is presented. The method employs a stable aluminum hemiaminal as a tetrahedral intermediate, protecting a latent aldehyde, making it suitable for subsequent cross-coupling with (strong nucleophilic) organometallic reagents, leading to a variety of alkyl and aryl substituted benzaldehydes. This very fast methodology also facilitates the effective synthesis of a 11C radiolabeled aldehyde. Aluminum-ate complexes enable transmetalation of alkyl fragments onto palladium and subsequent cross-coupling.
- Heijnen, Dorus,Helbert, Hugo,Luurtsema, Gert,Elsinga, Philip H.,Feringa, Ben L.
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supporting information
p. 4087 - 4091
(2019/06/14)
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- Visible-Light-Driven Photocatalytic Hydrogenation of Olefins Using Water as the H Source
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In this work, a highly efficient PCN-KCl (KCl-modified polymeric carbon nitride) nanosheet photocatalyst was synthesized with the assistance of KCl. The as-prepared PCN-KCl catalyst shows a more than 30-fold enhancement in the photocatalytic activity for H2 evolution from water compared to the pristine PCN. More importantly, when PCN-KCl was composited with a second catalyst (Pd nanoparticles), the simultaneous production and utilization of active H species for alkenes hydrogenation was achieved by visible light irradiation under ambient conditions.
- Fan, Xin,Yao, Yanling,Xu, Yangsen,Yu, Lei,Qiu, Chuntian
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p. 2596 - 2599
(2019/05/10)
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- Biobased Poly(ethylene furanoate) Polyester/TiO2 Supported Nanocomposites as Effective Photocatalysts for Anti-inflammatory/Analgesic Drugs
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In the present study, polymer supported nanocomposites, consisting of bio-based poly(ethylene furanoate) polyester and TiO2 nanoparticles, were prepared and evaluated as effective photocatalysts for anti-inflammatory/analgesic drug removal. Nanocomposites were prepared by the solvent eVaporation method containing 5, 10, 15, and 20 wt% TiO2 and characterized using Fourier Transform Infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), wide-angle X-ray diffraction (WAXD), thermogravimetric analysis (TGA), and scanning electron microscopy (SEM). Thin films of them have been prepared by the melt press and optimization of the photocatalytic procedure was conducted for the most efficient synthesized photocatalyst. Finally, mineralization was evaluated by means of Total organic carbon (TOC) reduction and ion release, while the transformation products (TPs) generated during the photocatalytic procedure were identified by high-resolution mass spectrometry.
- Koltsakidou, Anastasia,Terzopoulou, Zoi,Kyzas, George Z.,Bikiaris, Dimitrios N.,Lambropoulou, Dimitra A.
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- Photoredox-Catalysis-Modulated, Nickel-Catalyzed Divergent Difunctionalization of Ethylene
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Divergent synthesis that enables a catalytic reaction to selectively produce different products from common substrates will allow the charting of wider chemical space and the unveiling of distinct mechanistic paradigms. A common strategy for it employs different ligands to modulate organometallic catalysts. Dramatic developments in photocatalysis have enabled previously inaccessible transformations. In particular, photoredox catalysis modulates the oxidation state of transition-metal complexes, offering enormous opportunities for methodology development. Herein, we developed a photo-mediated divergent ethylene difunctionalization via modulating oxidation states of the nickel catalyst by using different photoredox catalysts. This work will inspire new perspectives for value-added chemical synthesis using ethylene as a feedstock and shed light on photoredox-catalyst-based divergent synthesis, which fundamentally differs from ligand-controlled transition-metal catalysis.Divergent synthesis represents a powerful strategy for directly accessing different molecular scaffolds originating from the same starting materials. Access to different end products via transition-metal catalysis is conventionally achieved by ligand control. We herein demonstrate the use of ethylene feedstock and commercially available aryl halides to accomplish the divergent synthesis of 1,2-diarylethanes, 1,4-diarylbutanes, or 2,3-diarylbutanes in a highly selective fashion through the synergistic combination of nickel and photoredox catalysis. Mechanistic studies suggest that the observed selectivity was due to different active states of Ni(I) and Ni(0) modulated by Ru- and Ir-based photoredox catalysts, respectively. The ability to access different organometallic oxidation states via photoredox catalysis promises to inspire new perspectives for synergistic transition-metal-catalyzed divergent synthesis.Functionalization of ethylene without polymerization is challenging under photo-irradiation conditions. We have demonstrated that the photo-transformation of ethylene can be controllable by merging photoredox and transition-metal catalysis. In our study, the use of different photoredox catalysts was able to modulate the oxidation state of the nickel catalyst. Through different oxidation states, the nickel-catalyzed couplings proceeded via distinct pathways to generate divergent ethylene difunctionalization products selectively from the same feedstock.
- Li, Jiesheng,Luo, Yixin,Cheo, Han Wen,Lan, Yu,Wu, Jie
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supporting information
p. 192 - 203
(2019/01/21)
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- Synthetic alkyl aromatic aldehyde (by machine translation)
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The invention relates to synthetic alkyl aromatic aldehyde. To solve the problems in the prior art and the location of the alkyl aromatic hydrocarbon conversion of alkyl aromatic aldehyde the problem of low selectivity, the invention adopts the method of synthetic alkyl aromatic aldehyde, included in the catalyst under the catalysis of the alkyl aromatic hydrocarbon to CO carbonylation reaction to obtain the alkyl aromatic aldehyde, wherein said catalyst comprises a rare earth perfluoroalkyl sulfonate and the accelerator and the technical scheme, better solved this technical problem, can be used in the industrial production of alkyl aromatic aldehyde. (by machine translation)
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Paragraph 0090-0092; 0100; 0101
(2019/04/30)
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- Method for synthesizing alkyl aromatic aldehydes by carbonylating alkyl aromatic hydrocarbons
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The invention relates to a method for synthesizing alkyl aromatic aldehydes by carbonylating alkyl aromatic hydrocarbons. The problems of low conversion rate of alkyl aromatic hydrocarbons and low selectivity of para-alkyl aromatic aldehydes in the prior art are mainly solved. The method for synthesizing alkyl aromatic aldehydes by carbonylating alkyl aromatic hydrocarbons is characterized in thatthe alkyl aromatic hydrocarbons and CO undergo a carbonylation reaction under the catalysis of a catalyst in order to obtain the alkyl aromatic aldehydes, wherein the catalyst includes a halogenatedalkylimidazolium salt and rare earth perfluoroalkyl sulfonate. The method well solves the problems, and can be used in the industrial production of the alkyl aromatic aldehydes.
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Paragraph 0101-0103; 0111
(2019/04/30)
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- Method for synthesizing alkyl aromatic aldehydes
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The invention relates to a method for synthesizing alkyl aromatic aldehydes. The problems of low conversion rate of alkyl aromatic hydrocarbons and low selectivity of para-alkyl aromatic aldehydes inthe prior art are mainly solved. The method for synthesizing the alkyl aromatic aldehydes is characterized in that the alkyl aromatic hydrocarbons and CO undergo a carbonylation reaction under the catalysis of a catalyst in order to obtain the alkyl aromatic aldehydes, wherein the catalyst includes a halogenated alkylimidazolium salt, aluminum halide and an accelerator. The method well solves theproblems, and can be used in the industrial production of the alkyl aromatic aldehydes.
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Paragraph 0102-0104; 0112
(2019/04/30)
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- Cobalt Vanadium Oxide Supported on Reduced Graphene Oxide for the Oxidation of Styrene Derivatives to Aldehydes with Hydrogen Peroxide as Oxidant
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Cobalt vanadium oxide supported on reduced graphene oxide showed excellent performance in the oxidation of styrene derivatives to the corresponding aldehydes with hydrogen peroxide as oxidant. An electron-donating group at the para -position of the aromatic ring facilitates the formation of the corresponding aldehyde. Compared with conventional methods, the newly designed heterogeneous catalytic system offers a promising prospect because of its economic applicability and environmental friendliness.
- Zou, Hui,Hu, Chuanfeng,Chen, Kaihao,Xiao, Guansheng,Peng, Xinhua
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supporting information
p. 2181 - 2184
(2018/10/02)
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- Nickel boride mediated chemoselective deprotection of 1,1-diacetates to aldehydes and deprotection with concomitant reduction to alcohols at ambient temperature
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A variety of 1,1-diacetates have been chemoselectively and efficiently deprotected to the corresponding aldehydes as well as deprotected and concomitantly reduced to the corresponding alcohols in high yields at ambient temperature with nickel boride generated in situ using different molar ratios of sodium borohydride and nickel (II) chloride in methanol at room temperature. Deprotection and reduction of a variety of aromatic, aliphatic and heterocyclic acylals have been achieved efficiently. Mild reaction conditions, easy work-up, high yields and chemoselectivity demonstrate the efficiency of this new method.
- Bartwal, Gaurav,Saroha, Mohit,Khurana, Jitender.M.
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- Highly Efficient Oxidation of Amines to Aldehydes with Flow-based Biocatalysis
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A new mild and efficient process for the aqueous preparation of aldehydes, which are employed as flavour and fragrance components in food, beverage, cosmetics, as well as in pharmaceuticals, was developed using a continuous-flow approach based on an immobilised pure transaminase-packed bed reactor. HEWT, an ω-transaminase from the haloadapted bacterium Halomonas elongata, has been selected for its excellent stability and substrate scope. Sixteen different amines were rapidly (3–15 min) oxidised to the corresponding aldehydes (90 to 99 %) with only 1 to 5 equivalents of sodium pyruvate. The process was fully automated, allowing for the in-line recovery of the pure aldehydes (chemical purity >99 % and isolated yields above 80 %), without any further work-up procedure.
- Contente, Martina L.,Dall'Oglio, Federica,Tamborini, Lucia,Molinari, Francesco,Paradisi, Francesca
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p. 3843 - 3848
(2017/09/25)
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- Palladium Nanoparticle Loaded Bifunctional Silica Hybrid Material: Preparation and Applications as Catalyst in Hydrogenation Reactions
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Bifunctional mesoporous silica was prepared by co-condensation of tetraethyl orthosilicate (TEOS) with functionalized organosilanes containing azides or alkoxyamines. Orthogonal functional groups at the particles were selectively addressed in subsequent chemical modifications through “click”-chemistry (“click to ligand” strategy) and radical nitroxide exchange. Palladation with PdCl2 delivered Pd nanoparticle-loaded silica material bearing sulfoxides and additional aminoamides as stabilizing ligands by means of in situ reduction of the PdII-salt. These functional particles were successfully applied to the hydrogenation of alkynes and alkenes. Aldehyde hydrodeoxygenation and benzyl ether cleavage were achieved with these hybrid catalysts under mild conditions. Particles were analyzed by IR, TEM/STEM, EDX, and solid-state NMR spectroscopy.
- Surmiak, Sabrina K.,Doerenkamp, Carsten,Selter, Philipp,Peterlechner, Martin,Sch?fer, Andreas H.,Eckert, Hellmut,Studer, Armido
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p. 6019 - 6028
(2017/05/05)
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- Aerobic Oxidation of 4-Alkyl-N,N-dimethylbenzylamines Catalyzed by N-Hydroxyphthalimide: Protonation-Driven Control over Regioselectivity
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A change in regioselectivity has been observed in the hydrogen atom transfer (HAT) reactions from 4-alkyl-N,N-dimethylbenzylamines (alkyl = ethyl, isopropyl, and benzyl) to the phthalimide N-oxyl radical (PINO) by effect of protonation. This result can be rationalized on the basis of an acid-induced deactivation of the C-H bonds α to nitrogen toward HAT to PINO as evidenced by the 104-107-fold decrease in the HAT rate constants in acetonitrile following addition of 0.1 M HClO4. This acid-induced change in regioselectivity has been successfully applied for selective functionalization of the less activated benzylic C-H bonds para to the CH2N(CH3)2 group in the aerobic oxidation of 4-alkyl-N,N-dimethylbenzylamines catalyzed by N-hydroxyphthalimide in acetic acid.
- Bietti, Massimo,Lanzalunga, Osvaldo,Lapi, Andrea,Martin, Teo,Mazzonna, Marco,Polin, Mariangela,Salamone, Michela
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p. 5761 - 5768
(2017/06/07)
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- Palladium-Catalyzed Ligand-Controlled Selective Synthesis of Aldehydes and Acids from Aryl Halides and Formic Acid
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Selective synthesis is in the core of modern organic chemistry. In this communication, a novel ligand-dependent palladium-catalyzed carbonylation procedure for the divergent synthesis of aldehydes and carboxylic acids from easily available aryl halides was established. Under the same reaction conditions, the reaction pathway could be controlled by the ligands applied to give formylated and carboxylated products selectively. Sterically hindered monodentate ligands facilitated the reductive carbonylation and provided aldehydes, whereas bidentate ligands preferred the carboxylation reaction and produced carboxylic acids. A wide range of functional groups were tolerated, and the products were, in general, obtained in moderate to excellent yields.
- Wu, Fu-Peng,Peng, Jin-Bao,Meng, Ling-Shen,Qi, Xinxin,Wu, Xiao-Feng
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p. 3121 - 3124
(2017/08/29)
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- Metal-catalyzed formal amidation of alkenes under CO-free condition
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An effective procedure for synthesis of amides from alkenes and [Formula presented] via Pd and Fe catalysts under mild conditions is described. A series of benzamides containing various functional groups can be obtained in reasonable yield and the possible reaction pathway is proposed in this Letter.
- Zhang, Yuanyuan,Ye, Wenjing,Leng, Xue,He, Ying,Zhang, Hui,Xiao, Xiao
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p. 4203 - 4206
(2016/08/24)
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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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- A Convenient Palladium-Catalyzed Reductive Carbonylation of Aryl Iodides with Dual Role of Formic Acid
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Palladium-catalyzed reductive carbonylation of aryl halides represents a straightforward pathway for the synthesis of aromatic aldehydes. The known reductive carbonylation procedures either require CO gas or complexed compounds as CO sources. In this communication, we developed a palladium-catalyzed reductive carbonylation of aryl iodides with formic acid as the formyl source. As a convenient, practical, and environmental friendly methodology, no additional silane or H2 was required. A variety of aromatic aldehydes were isolated in moderate to excellent yields under mild reaction conditions. Notably, this is the first procedure on using formic acid as the formyl source. Say no to CO gas! A convenient, practical, and environmental friendly palladium-catalyzed reductive carbonylation of aryl iodides with formic acid as the formyl source has been developed (see scheme). No additional silane or H2 was required here. A variety of aromatic aldehydes were isolated in moderate to excellent yields under mild reaction conditions.
- Qi, Xinxin,Li, Chong-Liang,Wu, Xiao-Feng
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supporting information
p. 5835 - 5838
(2016/04/26)
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- Investigations in sono-enzymatic degradation of ibuprofen
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The drug ibuprofen (IBP) appears frequently in the wastewater discharge from pharmaceutical industries. This paper reports studies in degradation of IBP employing hybrid technique of sono-enzymatic treatment. This paper also establishes synergy between individual mechanisms of enzyme and sonolysis for IBP degradation by identification of degradation intermediates, and Arrhenius & thermodynamic analysis of the experimental data. Positive synergy between sonolysis and enzyme treatment is attributed to formation of hydrophilic intermediates during degradation. These intermediates form due to hydroxylation and oxidation reactions induced by radicals formed during transient cavitation. Activation energy and enthalpy change in sono-enzymatic treatment are lower as compared to enzyme treatment, while frequency factor and entropy change are higher as compared to sonolysis. Degradation of IBP in sono-enzymatic treatment is revealed to be comparable with other hybrid techniques like photo-Fenton, sono-photocatalysis, and sono-Fenton.
- Chakma, Sankar,Moholkar, Vijayanand S.
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p. 485 - 494
(2015/11/24)
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- Bimetallic synergistic Au/CuO-hydroxyapatite catalyst for aerobic oxidation of alcohols
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A catalyst consisting of Au supported on copper oxide-modified hydroxyapatite (Au/CuO-HAP) was prepared using a homogeneous deposition-precipitation method. The catalyst was characterized using atomic absorption spectrometry, N2 adsorption-desorption, powder X-ray diffraction, transmission electron microscopy, and X-ray photoelectron spectroscopy. The catalytic performance in liquid-phase aerobic oxidation of alcohols was investigated. The catalytic activity and benzaldehyde selectivity in benzyl alcohol oxidation with the bimetallic Au/CuO-HAP catalyst were significantly better than those with monometallic Au/HAP and CuO-HAP catalysts. The conversion of benzyl alcohol and selectivity for benzaldehyde at 120 °C for 1.5 h under aerobic oxidation conditions were 99.7% and 98.4%, respectively. Various aromatic alcohols were selectively converted to their corresponding aldehydes or ketones over Au/CuO-HAP. The Au/CuO-HAP catalyst could be reused at least four times without loss of activity.
- Tian, Tao,Liu, Ying,Zhang, Xungao
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p. 1358 - 1364
(2015/09/01)
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- Activation of DMSO for Swern-type oxidation by 1,1-dichlorocycloheptatriene
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A new dimethylsulfoxide activation method employing 1,1-dichlorocycloheptatriene has been developed for a mild Swern-type oxidation of a variety of alcohols. The carbonyl products can be obtained in good to excellent yields from this operationally simple and efficient method. This work is the first report of dimethylsulfoxide activation by a simple chlorinated hydrocarbon reagent, which has the unique ability of equilibrating to its reactive aromatic cationic form.
- Nguyen, Thanh Vinh,Hall, Michael
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supporting information
p. 6895 - 6898
(2015/01/09)
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- Photooxidative cleavage of aromatic alkenes into aldehydes using catalytic iodine and molecular oxygen under visible light irradiation
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We report a method for the photooxidative cleavage of aromatic alkenes to give aldehydes using molecular oxygen as the terminal oxidant, visible light, a catalytic amount of iodine and trifluoroacetic acid.
- Fujiya, Akitoshi,Kariya, Atsumasa,Nobuta, Tomoya,Tada, Norihiro,Miura, Tsuyoshi,Itoh, Akichika
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p. 884 - 888
(2014/04/03)
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- Selective side-chain oxidation of alkyl-substituted aromatics on TiO 2 partially coated with WO3 as a photocatalyst
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TiO2 particles partially coated with WO3 (WO 3/TiO2) were used as photocatalysts for selective oxidation of toluene to benzaldehyde with molecular oxygen (O2) under photoirradiation at λ > 300 nm. The catalysts loaded with 8-10 wt% WO3 exhibit very high oxidation activity and produce benzaldehyde with ca. 50% selectivity, which is the highest selectivity among the photocatalytic systems reported so far. This is achieved because subsequent photocatalytic decomposition of the formed benzaldehyde is suppressed on the catalysts. On the photoactivated WO3/TiO2, the exposed TiO2 surface behaves as the oxidation site, whereas the WO 3 surface is much less active for oxidation. The WO3 loading decreases the amount of benzaldehyde adsorbed onto the TiO2 surface. This thus suppresses photocatalytic decomposition of benzaldehyde on the TiO2 surface, resulting in high benzaldehyde selectivity. The WO3/TiO2 catalyst successfully promotes side-chain oxidation of several kinds of alkyl-substituted aromatics and selectively produces aldehydes and ketones. The Royal Society of Chemistry 2013.
- Tsukamoto, Daijiro,Shiraishi, Yasuhiro,Hirai, Takayuki
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p. 2270 - 2277
(2013/09/02)
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- Kinetics and mechanism of oxidation of alcohols
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This paper describes the kinetics and mechanism of oxidation of several monohydric alcohols to the corresponding aldehydes and ketones by bis(quinuclidine)bromine(I) bromide in the presence of pyridinium trifluoroacetate. All evidence from the thermodynamic parameters, deuterium kinetic isotope effect, and Hammett reaction constants supports a two-step mechanism and suggests that the transfer of hydride ion from the substrate to the oxidant is the rate-determining step.
- Laila, Abdulhameed
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p. 307 - 312
(2013/05/23)
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- ANTIBACTERIAL AGENTS: ARYL MYXOPYRONIN DERIVATIVES
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The invention provides compounds of formula la, lb and Ic: [Formula Ia, Ib, and Ic] and salts thereof, wherein variables are as described in the specification, as well as compositions comprising a compound of formula Ia-Ic, methods of making such compounds, and methods of using such compounds, e.g., as inhibitors of bacterial RNA polymerase and as antibacterial agents.
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Page/Page column 74
(2014/01/09)
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- Metal-ligand core-shell nanocomposite catalysts for the selective semihydrogenation of alkynes
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Catalysts with a sheltered upbringing: Novel core-shell nanocomposite catalysts consisting of active metal nanoparticles encapsulated by macroligands have been prepared. They have Pd nanoparticles (PdNPs) as an active core and shell ligands having sulfoxide moieties coordinated to the PdNPs. The shell protects the catalyst from coordination by alkenes and allows the lead-free selective semihydrogenation of a wide range of alkynes without any additives (see scheme). Copyright
- Mitsudome, Takato,Takahashi, Yusuke,Ichikawa, Satoshi,Mizugaki, Tomoo,Jitsukawa, Koichiro,Kaneda, Kiyotomi
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supporting information
p. 1481 - 1485
(2013/04/10)
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- An efficient sonochemical oxidation of benzyl alcohols into benzaldehydes by FeCl3/HNO3 in acetone
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Sonochemical oxidation of benzyl alcohols into corresponding aldehydes by FeCl3/HNO3 in acetone at room temperature has been reported. All substrates give good yield of the products within 10-25 min. The reaction of selected substrates were also studied under reflux and at the room temperature. Further, various Lewis acids were used to evaluate their catalytic efficacy.
- Naik, Ramesh,Nizam, Aatika,Siddekha, Aisha,Pasha
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experimental part
p. 1124 - 1127
(2012/03/11)
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- Facile regio- and stereoselective hydrometalation of alkynes with a combination of carboxylic acids and group 10 transition metal complexes: Selective hydrogenation of alkynes with formic acid
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A facile, highly stereo- and regioselective hydrometalation of alkynes generating alkenylmetal complex is disclosed for the first time from a reaction of alkyne, carboxylic acid, and a zerovalent group 10 transition metal complex M(PEt3)4 (M = Ni, Pd, Pt). A mechanistic study showed that the hydrometalation does not proceed via the reaction of alkyne with a hydridometal generated by the protonation of a carboxylic acid with Pt(PEt 3)4, but proceeds via a reaction of an alkyne coordinate metal complex with the acid. This finding clarifies the long proposed reaction mechanism that operates via the generation of an alkenylpalladium intermediate and subsequent transformation of this complex in a variety of reactions catalyzed by a combination of Bronsted acid and Pd(0) complex. This finding also leads to the disclosure of an unprecedented reduction of alkynes with formic acid that can selectively produce cis-, trans-alkenes and alkanes by slightly tuning the conditions.
- Shen, Ruwei,Chen, Tieqiao,Zhao, Yalei,Qiu, Renhua,Zhou, Yongbo,Yin, Shuangfeng,Wang, Xiangbo,Goto, Midori,Han, Li-Biao
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supporting information; experimental part
p. 17037 - 17044
(2011/12/04)
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- Biooxidation of Primary Alcohols to Aldehydes through Hydrogen Transfer Employing Janibacter terrae
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Chemoselective oxidations still represent a challenge for chemists. Lyophilized cells of Janibacter terrae were employed for the chemoselective oxidation of primary alcohols to the corresponding aldehydes by hydrogen transfer with the use of acetaldehyde as the hydrogen acceptor. Secondary alcohol moieties were transformed at a much slower rate. The substrate spectrum encompasses substituted benzyl alcohols, whereby substrates with a substituent in the meta position were well tolerated, whereas only very small substituants were tolerated in the ortho position. Furthermore, nalkanols and allylic alcohols were transformed with good conversions. The biocatalyst was compatible with DMSO as a water miscible organic solvent up to 30 % v/v.
- Orbegozo, Thomas,De Vries, Johannes G.,Kroutil, Wolfgang
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experimental part
p. 3445 - 3448
(2010/09/05)
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- A general and efficient suzuki-miyaura cross-coupling protocol using weak base and no water: The essential mole of acetate
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A weak base, CsOAc, promotes Suzuki-Miyaura cross-coupling and related Pd-catalyzed reactions under anhydrous conditions as effectively as stronger bases. Aryl triflates exhibit unusual reaction rates, which are comparable to that: of bromoarenes. A negle
- Wang, Bing,Sun, Hui-Xia,Sun, Zhi-Hua
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experimental part
p. 3688 - 3692
(2009/12/03)
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- Carbonylation of aryl halides: Extending the scope of the reaction
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Carbonylation reactions are being increasingly favoured in pharmaceutical chemistry for the atom-efficient introduction of carbonyl centres in aldehydes, acids, esters, and amides. Convenient procedures for simple aryl iodides and bromides are well established, and now the need is to develop improved conditions to allow the reactions to be extended to the more unreactive substrates, such as sterically hindered compounds and aryl chlorides. Sterically hindered compounds such as 2-iodo- or 2-bromo-m-xylenes can be converted using alkoxy and aminocarbonylation, while dehalogenation becomes a significant side reaction for reductive carbonylation. Less hindered compounds such as 2-iodo- or bromotoluene can be reacted successfully. Changing the aryl ligands of PdCl2{Ph2P(CH2)3PPh2} to alkyl groups improves the rate of oxidative addition but slows the carbonyl insertion step such that rates for the majority of aryl bromides are not improved by this change. Complexes such as PdCl2{Cy 2P(CH2)3PCy2} offer better performance for alkoxy and aminocarbonylation of aryl chlorides. However, for reductive carbonylation dehalogenation is a significant side reaction. Increasing CO pressure results in additional CO coordination to the catalytic intermediates and slows the reaction, while the dehalogenation is little affected, so reaction selectivity suffers. Thus, CO pressure is a critical parameter, particularly for reductive carbonylation, in achieving the optimum performance.
- Barnard, Christopher F.J.
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p. 566 - 574
(2013/01/03)
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- Addition reactions and redox esterifications of carbonyl compounds by N-heterocyclic carbenes of indazole
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Thermal decarboxylation converts 1,2-dimethylindazolium-3-carboxylate into indazol-3-ylidene, which reacts in situ with ketones to form stable 1:1 adducts. When the reaction is conducted with aromatic aldehydes in alcohols, redox esterifications to benzoates are observed. Model reactions such as redox esterifications of aromatic aldehydes with sodium alcoholates in the presence of 1,2-dimethylindazolium salt and oxidations of sodium benzylates by 1,2-dimethylindazolium salt to aldehydes lend support to a Cannizzaro-type mechanism of this reaction.
- Schmidt, Andreas,Habeck, Tobias,Snovydovych, Bohdan,Eisfeld, Wolfgang
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p. 3515 - 3518
(2008/02/11)
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- Production method of alkylbenzaldehydes
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In the production of an alkylbenzaldehyde by a method comprising a step of preparing a solution of complex of a starting alkylbenzene and a hydrogen fluoride-boron trifluoride catalyst and a step of formylation by bringing the solution of complex into contact with carbon monoxide, an alkylbenzene having at least one primary alkyl group having two or more carbon atoms on its benzene ring is used as the starting alkylbenzene. The preparation of the solution of complex is carried out in the presence of an aliphatic or alicyclic saturated hydrocarbon having 6 to 10 carbon atoms which contains at least one tertiary carbon atom but contains no quaternary carbon atom. By the combined use of the specific alkylbenzene and the aliphatic or alicyclic saturated hydrocarbon, the disproportionation of the alkylbenzene is prevented and the alkylbenzaldehyde is produced at high yields.
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Page/Page column 5
(2008/06/13)
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- Process for making an aldehyde
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A process for making an aromatic aldehyde in which a sulfoxide is reacted with a dihalogenated aromatic compound in the absence of an effective amount of an activating reagent. The aldehyde may then be used to make other compounds, such as a compound that acts as a cPLA inhibitor.
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- 9,10-Dicyanoanthracene photosensitized oxidation of aryl alkanols: Evidence for an electron transfer mechanism
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9,10-Dicyanoanthracene (DCA) photosensitizes the oxidation of a series of para substituted aryl alkanols in oxygen-saturated acetonitrile. Product analysis and Hammett correlations support an electron transfer mechanism for the title reaction.
- Lykakis, Ioannis N.,Lestakis, Stellios,Orfanopoulos, Michael
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p. 6247 - 6251
(2007/10/03)
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- Lanthanide assisted cross-coupling of aryl bromides with triethylaluminum
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Cerium trichloride, as well as some other lanthanide salts, promote the palladium-catalyzed cross-coupling of triethylaluminum with bromoarenes. The lanthanide compounds also increase the selectivity by diminishing the undesired hydrodebromination process
- Shenglof, Margarita,Gelman, Dmitri,Molander, Gary A.,Blum, Jochanan
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p. 8593 - 8595
(2007/10/03)
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- New Pd-catalyzed selective reduction of carboxylic acids to aldehydes.
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A catalyst generated in situ from palladium acetate and tricyclohexylphosphine efficiently catalyzes the reduction of carboxylic acids with sodium hypophosphite in the presence of pivalic anhydride to give aldehydes with high selectivity. The low cost and convenient handling of the reagents makes this process a valuable alternative to hydrogenations and metal hydride reductions.
- Goossen, Lukas J,Ghosh, Keya
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p. 836 - 837
(2007/10/03)
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- Benzylic oxidation of aromatics with cerium(IV) triflate; Synthetic scope and mechanistic insight
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The synthetic utility of cerium(IV) triflate Ce(OTf)4 as a reagent for benzylic oxidation has been tested for a variety of aromatic compounds. Insight is provided into various factors that govern these oxidations and their progress. It has been shown that the mode of preparation of Ce(OTf)4 and the % H2O present in the sample have a marked influence on oxidation ability. A variety of mono- and dialkylbenzenes, haloalkylbenzenes, bicyclic and tricyclic ring systems, and alkoxybenzenes have been surveyed. The method offers an easy to perform one-pot reaction for the room temperature synthesis of aromatic ketones and aldehydes from aromatics and has the potential to find wider application.
- Laali, Kenneth K.,Herbert, Mark,Cushnyr, Brad,Bhatt, Anand,Terrano, David
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p. 578 - 583
(2007/10/03)
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- Nighttime tropospheric chemistry: Kinetics and product studies in the reaction of 4-Alkyl- and 4-Alkoxytoluenes with NO3 in gas phase
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Alkylbenzenes are important constituents of gasoline and industrial solvents and contribute to the formation of tropospheric ozone. The removal of these compounds from the troposphere is due to reaction with OH during the day and with NO3 during the night. Five para-substituted toluenes are reacted with the nitrate radical in gas phase. Samples to be used for product analysis were preconcentrated and analyzed by GC-MSD analysis with the use of a reference curve. The yields of methanol, ethanol, and formaldehyde were determined by FTIR analysis of the reaction mixture in the chamber. Carbonyl compounds, benzyl alcohols, and nitroderivatives were formed. In the case of the alkoxytoluenes, products were also an alkanol, benzyl alcohols, and nitrophenols. Indirect rate constants measurements were performed by comparing by FTIR measurements the decay of the aromatic compound under investigation to that of a reference compound, with a known rate constant for the reaction with NO3 added to the gas mixture. Wall loss constants were evaluated by FTIR. A Hammett correlation with ρ = - 4.3 ± 0.6; r2-= 0.87 was obtained. This and the kinetic isotope effect of 1.5-1.8 suggest a reaction mechanism occurring via an addition-elimination pathway.
- Bolzacchini, Ezio,Meinardi, Simone,Orlandi, Marco,Rindone, Bruno,Hjorth, Jens,Restelli, Gianbattista
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p. 461 - 468
(2007/10/03)
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- Interactive free energy relationship for multiple substituent effects in the oxidative cleavage of aromatic anils by N-chlorobenzamide in aqueous methanol medium
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The kinetics of the oxidation of about forty, two aromatic anils prepared from (i) unsubstituted benzaldehyde and unsubstituted aniline (ii) substituted benzaldehydes and unsubstituted aniline (iii)unsubstituted benzaldehyde and substituted anilines and (iv) substituted benzaldehydes and substituted anilines by N-chlorobenzamide in aqueous methanol medium is enhanced by electron-releasing substituents both in benzaldehydes as well as in aniline moieties while electron withdrawing substituents retarded the rate. For the series with various substituents in the ring-X (benzaldehyde) and with hydrogen in the ring-Y (aniline), the p value is -0.40. For the series with various substituents in the ring-Y and with hydrogen in the ring- X, the ρ value is -2.65. Linear plots are obtained between p(x(y)) (obtained from Hammett's plot for various substituents in the benzaldehyde moiety) and ρ(y) (substituent constants for substituents in aniline moiety) with a slope of -1.46 and between p(y(x)) (obtained from Hammett's plot for various substituents in the aniline moiety) and o (substituent constants for substituents in benzaldehyde moiety) with a slope of -1.51. This relationship has been analysed quantitatively in terms of interactive free energy relationship for multiple substituent effects.
- Mohamed Kassim,Basheer Ahamed
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p. 533 - 540
(2007/10/03)
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