- Determination of Alkyl Anilines and Alkyl Pyridines in Solvent Refined Coal Distillates and Aqueous Extracts by Gas Chromatography/Mass Spectrometry
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Derivatization with acetic anhydride in aqueous media coupled with capillary gas chromatography/mass spectrometry was used to distinguish alkyl anilines from alkyl pyridines.By use of this approach aniline, C-1 anilines, and C-2 anilines, as well as lesse
- Felice, Lawrence J.
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- Copper-promoted difunctionalization of unactivated alkenes with silanes
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An efficient copper-catalyzed cascade difunctionalization of N-allyl anilines toward the synthesis of silylated indolines using commercially available silanes has been reported. This strategy provides a new avenue for the synthesis of a diverse array of i
- Chen, Xiaoyu,Guo, Zhuangzhuang,Li, Jingya,Wu, Yangjie,Wu, Yusheng,Xue, Yingying,Zou, Dapeng
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supporting information
p. 989 - 994
(2022/02/11)
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- Method for promoting acylation of amine or alcohol by carbon dioxide
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The invention relates to a method for promoting acylation of amine or alcohol by carbon dioxide, which comprises the following steps of: mixing an amine compound, carboxylate or thiocarboxylate compound and a reaction solvent under the action of carbon dioxide, and reacting to obtain an amide compound, or under the action of carbon dioxide, mixing the alcohol compound, the thiocarboxylate compound and the reaction solvent [gamma]-valerolactone, and reacting to obtain the ester compound. According to the invention, under the promotion action of carbon dioxide, carboxylate or thiocarboxylate is used as an acylation reagent, and amine and alcohol are converted into amide and ester compounds in the absence of a transition metal catalyst, so that acylation reagents such as acyl chloride or anhydride with irritation and corrosivity are avoided; and the method has the advantages of simple operation, mild reaction conditions, high tolerance of substrate functional groups, strong applicability and high yield, and provides an efficient, reliable and economical preparation method for synthesis of amide and ester compounds.
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Paragraph 0033-0034
(2021/05/29)
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- Hydrazine Hydrate Accelerates Neocuproine–Copper Complex Generation and Utilization in Alkyne Reduction, a Significant Supplement Method for Catalytic Hydrogenation
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Diimine (HN═NH) is a strong reducing agent, but the efficiency of diimine oxidized from hydrazine hydrate or its derivatives is still not good enough. Herein, we report an in situ neocuproine–copper complex formation method. The redox potential of this complex enable it can serve as an ideal redox catalyst in the synthesis of diimine by oxidation of hydrazine hydrate, and we successfully applied this technique in the reduction of alkynes. This reduction method displays a broad functional group tolerance and substrate adaptability as well as the advantages of safety and high efficiency. Especially, nitro, benzyl, boc, and sulfur containing alkynes can be reduced to the corresponding alkanes directly, which provides a useful complementary method to traditional catalytic hydrogenation. Besides, we applied this method in the preparation of the Alzheimer’s disease drug CT-1812 and studied the mechanism.
- Chen, Guoliang,He, Xiaoyan,Huang, Gang,Lu, Xiuhong,Wang, Jincheng,Yang, Zhenjiao,Zhang, Yongsheng,Zhang, Zeng
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p. 17696 - 17709
(2021/12/09)
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- Catalyst-free generation of acyl radicals induced by visible light in water to construct C-N bonds
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We describe herein a catalyst-free and redox-neutral photochemical strategy for the direct generation of acyl radicals from α-diketones, and its selective conversion of nitrosoarenes to hydroxyamides or amides with AcOH or NaCl as an additive. The reaction was carried out under mild conditions in water with purple LEDs as the light source. A broad scope of substrates was demonstrated. Mechanistic experiments indicate that α-diketones cleave to give acyl radicals, with hydroxyamides being further reduced to amides.
- Ran, Maogang,He, Jiaxin,Yan, Boyu,Liu, Wenbo,Li, Yi,Fu, Yunfen,Li, Chao-Jun,Yao, Qiuli
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supporting information
p. 1970 - 1975
(2021/03/16)
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- Ethyl 2-Cyano-2-(2-nitrobenzenesulfonyloxyimino) Acetate (ortho-NosylOXY)-Mediated Double Beckmann Rearrangement of Ketoximes under Microwave Irradiation: A Mechanistic Perception
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A method for Beckmann rearrangement using ethyl 2-cyano-2-(2-nitrobenzenesulfonyloxyimino) acetate (o-NosylOXY) under microwave irradiation is reported. Ketoximes (19 examples) are converted to the corresponding amides/lactams with 69–97% yields in ~10 minutes without any Lewis acid or co-catalyst. This is an example of halogen-free organocatalytic Beckmann rearrangement. Nuclear magnetic resonance (NMR)- and high-resolution mass spectrometry (HRMS)-based detailed mechanistic investigation suggest that o-NosylOXY acts as an initiator. Such initiators are reported before based on density functional theory (DFT) calculations. However, we report here the HRMS signatures of two transient intermediates, the nitrilium ion and the nitrilium ion's dimeric species. Rigorous NMR-based investigation of the reaction mechanism is performed. Our results indicate that the reported Beckmann rearrangement proceeds via two consecutive rearrangements. (Figure presented.).
- Dev, Dharm,Kalita, Tapasi,Mondal, Tanmay,Mandal, Bhubaneswar
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p. 1427 - 1435
(2021/01/04)
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- Metal-Organic Framework-Confined Single-Site Base-Metal Catalyst for Chemoselective Hydrodeoxygenation of Carbonyls and Alcohols
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Chemoselective deoxygenation of carbonyls and alcohols using hydrogen by heterogeneous base-metal catalysts is crucial for the sustainable production of fine chemicals and biofuels. We report an aluminum metal-organic framework (DUT-5) node support cobalt(II) hydride, which is a highly chemoselective and recyclable heterogeneous catalyst for deoxygenation of a range of aromatic and aliphatic ketones, aldehydes, and primary and secondary alcohols, including biomass-derived substrates under 1 bar H2. The single-site cobalt catalyst (DUT-5-CoH) was easily prepared by postsynthetic metalation of the secondary building units (SBUs) of DUT-5 with CoCl2 followed by the reaction of NaEt3BH. X-ray photoelectron spectroscopy and X-ray absorption near-edge spectroscopy (XANES) indicated the presence of CoII and AlIII centers in DUT-5-CoH and DUT-5-Co after catalysis. The coordination environment of the cobalt center of DUT-5-Co before and after catalysis was established by extended X-ray fine structure spectroscopy (EXAFS) and density functional theory. The kinetic and computational data suggest reversible carbonyl coordination to cobalt preceding the turnover-limiting step, which involves 1,2-insertion of the coordinated carbonyl into the cobalt-hydride bond. The unique coordination environment of the cobalt ion ligated by oxo-nodes within the porous framework and the rate independency on the pressure of H2 allow the deoxygenation reactions chemoselectively under ambient hydrogen pressure.
- Antil, Neha,Kumar, Ajay,Akhtar, Naved,Newar, Rajashree,Begum, Wahida,Manna, Kuntal
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supporting information
p. 9029 - 9039
(2021/06/28)
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- Discovery of Novel Indole Derivatives as Fructose-1,6-bisphosphatase Inhibitors and X-ray Cocrystal Structures Analysis
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Liver fructose-1,6-bisphosphatase (FBPase) is a key enzyme in the gluconeogenesis, and its inhibitors are expected to be novel antidiabetic agents. Herein, a series of new indole and benzofuran analogues were designed and synthesized to evaluate the inhib
- Ji, Wenming,Liu, Quan,Liu, Shuainan,Shen, Zhufang,Wang, Xiaoyu,Xu, Bailing,Zhao, Linxiang,Zhao, Rui,Zhou, Jie
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supporting information
(2022/01/03)
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- Selective hydrodeoxygenation of hydroxyacetophenones to ethyl-substituted phenol derivatives using a FeRu?SILP catalyst
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The selective hydrodeoxygenation of hydroxyacetophenone derivatives is achieved opening a versatile pathway for the production of valuable substituted ethylphenols from readily available substrates. Bimetallic iron ruthenium nanoparticles immobilized on an imidazolium-based supported ionic liquid phase (Fe25Ru75?SILP) show high activity and stability for a broad range of substrates without acidic co-catalysts. This journal is
- Bordet, Alexis,Goclik, Lisa,Leitner, Walter,Offner-Marko, Lisa
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supporting information
p. 9509 - 9512
(2020/09/02)
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- Visible-light-induced Beckmann rearrangement by organic photoredox catalysis
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A facile and general strategy for efficient direct conversion of oximes to amides using an inexpensive organic photocatalyst and visible light is described. This radical Beckmann rearrangement can be performed under mild conditions. Various alkyl aryl ketoximes and diaryl ketoximes can be effectively converted into the corresponding amides in excellent yields.
- Tang, Li,Wang, Zhi-Lv,Wan, Hai-Lan,He, Yan-Hong,Guan, Zhi
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supporting information
p. 6182 - 6186
(2020/09/01)
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- An Electrochemical Beckmann Rearrangement: Traditional Reaction via Modern Radical Mechanism
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Abstract: Electrosynthesis as a potential means of introducing heteroatoms into the carbon framework is rarely studied. Herein, the electrochemical Beckmann rearrangement, i. e. the direct electrolysis of ketoximes to amides, is presented for the first time. Using a constant current as the driving force, the reaction can be easily carried out under neutral conditions at room temperature. Based on a series of mechanistic studies, a novel radical Beckmann rearrangement mechanism is proposed. This electrochemical Beckmann rearrangement does not follow the trans-migration rule of the classical Beckmann rearrangement.
- Tang, Li,Wang, Zhi-Lv,He, Yan-Hong,Guan, Zhi
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p. 4929 - 4936
(2020/08/21)
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- Ferric chloride–catalyzed deoxygenative chlorination of carbonyl compounds: A comparison of chlorodimethylsilane and dichloromethylsilane system
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Deoxygenative chlorination of carbonyl compounds using the HMe2SiCl/FeCl3/EtOAc and HMeSiCl2/FeCl3/EtOAc systems has been systemically investigated. The HMe2SiCl-FeCl3 system showed the advantages of good substrate applicability, mild reaction conditions, simple operation, low cost, and easy availability of raw materials. Also, it provided a simple and efficient synthesis route for carbonyl deoxychlorination via a one-pot method. Using the HMeSiCl2/FeCl3/EtOAc system, the β-methylchalcone derivative could be obtained in good yields in addition to obtaining the chlorinated compound. Finally, two plausible reaction routes were proposed to describe the formation of the chlorinated compound and the β-methylchalcone derivative.
- Xing, Bing-Han,Zhao, Xuan-Xuan,Qin, Yu-Jun,Zhang, Pu,Guo, Zhi-Xin
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p. 667 - 675
(2020/05/22)
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- From alkylarenes to anilines via site-directed carbon–carbon amination
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Anilines are fundamental motifs in various chemical contexts, and are widely used in the industrial production of fine chemicals, polymers, agrochemicals and pharmaceuticals. A recent development for the synthesis of anilines uses the primary amination of C–H bonds in electron-rich arenes. However, there are limitations to this strategy: the amination of electron-deficient arenes remains a challenging task and the amination of electron-rich arenes has a limited control over regioselectivity—the formation of meta-aminated products is especially difficult. Here we report a site-directed C–C bond primary amination of simple and readily available alkylarenes or benzyl alcohols for the direct and efficient preparation of anilines. This chemistry involves a novel C–C bond transformation and offers a versatile protocol for the synthesis of substituted anilines. The use of O2 as an environmentally benign oxidant is demonstrated, and studies on model compounds suggest that this method may also be used for the depolymerization of lignin.
- Liu, Jianzhong,Qiu, Xu,Huang, Xiaoqiang,Luo, Xiao,Zhang, Cheng,Wei, Jialiang,Pan, Jun,Liang, Yujie,Zhu, Yuchao,Qin, Qixue,Song, Song,Jiao, Ning
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- Photocarboxylation of Benzylic C-H Bonds
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The carboxylation of sp3-hybridized C-H bonds with CO2 is a challenging transformation. Herein, we report a visible-light-mediated carboxylation of benzylic C-H bonds with CO2 into 2-arylpropionic acids under metal-free conditions. Photo-oxidized triisopropylsilanethiol was used as the hydrogen atom transfer catalyst to afford a benzylic radical that accepts an electron from the reduced form of 2,3,4,6-tetra(9H-carbazol-9-yl)-5-(1-phenylethyl)benzonitrile generated in situ. The resulting benzylic carbanion reacts with CO2 to generate the corresponding carboxylic acid after protonation. The reaction proceeded without the addition of any sacrificial electron donor, electron acceptor or stoichiometric additives. Moderate to good yields of the desired products were obtained in a broad substrate scope. Several drugs were successfully synthesized using the novel strategy.
- Meng, Qing-Yuan,Schirmer, Tobias E.,Berger, Anna Lucia,Donabauer, Karsten,K?nig, Burkhard
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supporting information
p. 11393 - 11397
(2019/08/20)
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- Biocatalytic N-Acylation of Amines in Water Using an Acyltransferase from Mycobacterium smegmatis
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A straightforward one-step biocatalyzed synthesis of different N-acyl amides in water was accomplished using the versatile and chemoselective acyltransferase from Mycobacterium smegmatis (MsAcT). Acetylation of primary arylalkyl amines was achieved with a range of acetyl donors in biphasic systems within 1 hour and at room temperature. Vinyl acetate was the best donor which could be employed in the N-acetylation of a large range of primary amines in excellent yields (85–99%) after just 20 minutes. Other acyl donors (including formyl-, propionyl-, and butyryl-donors) were also efficiently employed in the biocatalytic N-acylation. Finally, the biocatalyst was tested in transamidation reactions using acetamide as acetyl donor in aqueous medium, reaching yields of 60–70%. This work expands the toolbox of preparative methods for the formation of N-acyl amides, describing a biocatalytic approach easy to accomplish under mild conditions in water. (Figure presented.).
- Contente, Martina Letizia,Pinto, Andrea,Molinari, Francesco,Paradisi, Francesca
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p. 4814 - 4819
(2018/11/10)
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- Promiscuous activity of C-acyltransferase from: Pseudomonas protegens: Synthesis of acetanilides in aqueous buffer
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Amide bond formation has considerable significance in synthetic chemistry. Although the C-acyltransferase from Pseudomonas protegens has been found to catalyze C-C bond formation in nature as well as in in vitro experiments with non-natural substrates, it is now shown that the enzyme is also able to catalyze amide formation using aniline derivatives as substrates with promiscuous activity. Importantly, the amide formation was enabled in aqueous buffer. Identifying phenyl acetate as the most suitable acetyl donor, the products were obtained with up to >99% conversion and up to 99% isolated yield.
- Zad?o-Dobrowolska, Anna,Schmidt, Nina G.,Kroutil, Wolfgang
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supporting information
p. 3387 - 3390
(2018/04/05)
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- Efficient Heterogeneous Gold(I)-Catalyzed Direct C(sp2)–C(sp) Bond Functionalization of Arylalkynes through a Nitrogenation Process to Amides
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The first heterogeneous gold(I)-catalyzed direct C(sp2)–C(sp) bond functionalization of arylalkynes through a nitrogenation process to amides has been achieved by using an ordered mesoporous silica (MCM-41)-immobilized phosphine gold(I) complex [MCM-41-PPh3-AuCl] as catalyst and silver carbonate (Ag2CO3) as cocatalyst with trimethylsilyl azide (TMSN3) as a nitrogen source, yielding a variety of amides in moderate to excellent yields under mild conditions. This heterogeneous phosphine gold(I) complex shows the same turnover numbers as the homogeneous chloro(triphenylphosphine)gold(I) (Ph3PAuCl) and can easily be recovered by simple filtration of the reaction solution and recycled at least eight times without significant loss of activity, providing a novel, efficient, practical and economic method for the synthesis of amides from alkynes. (Figure presented.).
- Nie, Quan,Yi, Feiyan,Huang, Bin,Cai, Mingzhong
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p. 3968 - 3976
(2017/11/20)
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- Monoprotected l-Amino Acid (l-MPAA), Accelerated Bromination, Chlorination, and Iodination of C(sp2)?H Bonds by Iridium(III) Catalysis
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Halogenated arenes are important structural motifs commonly found in biologically active molecules and used for a variety of transformations in organic synthesis. Herein, we report the mono-protected l-amino acid (l-MPAA) accelerated iridium(III)-catalyzed halogenation of (hetero)anilides at room temperature. This reaction constitutes the first example of an iridium(III)/l-MPAA-catalyzed general halogenation of (hetero)arenes through C(sp2)?H activation. Furthermore, we demonstrate the potential utility of our method through its use in the synthesis of a quinolone derivative.
- Kathiravan, Subban,Nicholls, Ian A.
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supporting information
p. 7031 - 7036
(2017/05/29)
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- AIBN-promoted amidation of anilines with 1, 3-diketones via oxidative cleavage of C–C bond under aerobic conditions
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N-Acylation of anilines with 1, 3-diketones promoted by AIBN (2-2′-azoisobutyronitrile) under metal-free and peroxide-free conditions in the presence of molecular oxygen as oxidant has been described. This protocol proceeds by the oxidative cleavage of C–C bond with simultaneous intermolecular C–N bond formation under mild conditions.
- Rao, Sadu Nageswara,Mohan, Darapaneni Chandra,Adimurthy, Subbarayappa
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p. 4889 - 4894
(2016/07/18)
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- Mild Deoxygenation of Aromatic Ketones and Aldehydes over Pd/C Using Polymethylhydrosiloxane as the Reducing Agent
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Herein, a practical and mild method for the deoxygenation of a wide range of benzylic aldehydes and ketones is described, which utilizes heterogeneous Pd/C as the catalyst together with the green hydride source, polymethylhydrosiloxane. The developed catalytic protocol is scalable and robust, as exemplified by the deoxygenation of ethyl vanillin, which was performed on a 30 mmol scale in an open-to-air setup using only 0.085 mol% Pd/C catalyst to furnish the corresponding deoxygenated product in 93% yield within 3 hours at room temperature. Furthermore, the Pd/C catalyst was shown to be recyclable up to 6 times without any observable decrease in efficiency and it exhibited low metal leaching under the reaction conditions.
- Volkov, Alexey,Gustafson, Karl P. J.,Tai, Cheuk-Wai,Verho, Oscar,B?ckvall, Jan-E.,Adolfsson, Hans
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supporting information
p. 5122 - 5126
(2015/04/27)
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- Activity investigation of imidazolium-based ionic liquid as catalyst for friedel-crafts alkylation of aromatic compounds
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N-Methylimidazolium ionic liquids were synthesised from N-methylimidazole and 1-bromobutane by two-step method. The alkylation of benzene and other aromatic compounds through improved Friedel-Crafts reaction was investigated in these ionic liquids. The imidazolium-based ionic liquids showed both high activity and high selectivity for this reaction. In particular, remarkable enhancement of the catalytic effect of the imidazolium-based ionic liquids was observed for the ionic liquids containing the PF6- anion. The effects of various types of anions, ionic liquid dosage, reaction temperature and molar ratio of aromatic compound to 1-bromobutane/tertbutyl alcohol were explored using [Bmim]PF6 or its mixture with AlCl3 as catalyst. The synthesis yielded improved results over those obtained using either neat AlCl3 or other imidazolium-based ionic liquids as catalyst. The ionic liquids can also be recycled and reused in contrast to traditional solvent-catalyst systems.
- Cai, Mingjian,Wang, Xiuge
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p. 649 - 653
(2015/01/30)
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- Palladium-catalyzed C-H bond acylation of acetanilides with benzylic alcohols under aqueous conditions
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Palladium-catalyzed dehydrogenative coupling reactions between acetanilides and benzylic alcohols under aqueous conditions are reported. A wide range of benzophenone derivatives could be obtained in good to excellent yields up to 98 %. Mechanism studies showed that a bimetallic palladium cyclopalladated complex might be involved in the catalysis.
- Luo, Feihua,Yang, Jun,Li, Zhengkai,Xiang, Haifeng,Zhou, Xiangge
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p. 2463 - 2469
(2015/04/22)
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- ZnAl2O4@SiO2 nanocomposite catalyst for the acetylation of alcohols, phenols and amines with acetic anhydride under solvent-free conditions
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A ZnAl2O4@SiO2 nanocomposite was prepared from metal nitrates and tetraethyl orthosilicate by the sol-gel process, and characterized by X-ray diffraction, Fourier transform infrared, transmission electron microscopy, and N2 adsorption-desorption measurements. The nanocomposite was tested as a heterogeneous catalyst for the acetylation of alcohols, phenols, and amines under solvent-free conditions. Under optimized conditions, efficient acetylation of these substrates with acetic anhydride over the ZnAl2O4@SiO2 nanocomposite was obtained. Acetylation of anilines and primary aliphatic amines proceeded rapidly at room temperature, while the reaction time was longer for the acetylation of alcohols and phenols, showing that an amine NH2 group can be selectively acetylated in the presence of alcoholic or phenolic OH groups. The catalyst can be reused without obvious loss of catalytic activity. The catalytic activity of the ZnAl2O4@SiO2 nanocomposite was higher than that of pure ZnAl2O4. The method gives high yields, and is clean, cost effective, compatible with substrates having other functional groups and it is suitable for practical organic synthesis.
- Farhadi, Saeed,Jahanara, Kosar
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p. 368 - 375
(2014/04/03)
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- Sol-gel derived LaFeO3/SiO2 nanocomposite: Synthesis, characterization and its application as a new, green and recoverable heterogeneous catalyst for the efficient acetylation of amines, alcohols and phenols
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LaFeO3/SiO2 nanocomposite was synthesized by the sol-gel process from metal nitrates and tetraethyl orthosilicate (TEOS) as the SiO2 source. The nanocomposite product was characterized by XRD, FT-IR, SEM, and surface area measurements and was used as a heterogeneous catalyst for the efficient acetylation of amines, alcohols and phenols to the corresponding acetates using acetic anhydride under solvent-free conditions. Among the various substrates, acetylation of amines was preceded rapidly, so that an amine group could be selectively acetylated in the presence of alcoholic or phenolic hydroxyl groups by the appropriate choice of reaction time. The catalyst can also be reused several times without the loss of activity. In addition, the catalytic activity of the LaFeO3/SiO2 nanocomposite was higher than that of the pure LaFeO3 nanoparticles. The method is high yielding, clean, cost effective, compatible with the substrates having other functional groups and very suitable for the practical organic synthesis.
- Farhadi, Saeed,Jahanara, Kosar,Sepahdar, Asma
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p. 1103 - 1112
(2014/08/05)
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- H2O2-mediated oxidative formation of amides from aromatic amines and 1,3-diketones as acylation agents via C-C bond cleavage at room temperature in water under metal-free conditions
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1,3-Diketones, as novel acylation agents, reacted with aromatic amines promoted by commercially available H2O2 (30% aq.) as the sole oxidant at room temperature under metal-free conditions in water, leading to a novel and rapid amide bond formation strategy. The reported method is high-yielding, simple and mild, and is the first example of the use of 1,3-diketones as acylation agents via C-C bond cleavage.
- Sun, Xi,Wang, Min,Li, Pinhua,Zhang, Xiuli,Wang, Lei
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supporting information
p. 3289 - 3294
(2013/12/04)
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- Synthesis of amides by palladium-catalyzed decarbonylative coupling of carboxylic acids with isocyanides
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Amides were synthesized from carboxylic acids and isocyanides under Pd II/AgI/base catalytic conditions. The reaction conditions were optimized, and the scope was studied. Various carboxylic acids and aryl isocyanides are compatible with this reaction, but alkyl isocyanides are not. A plausible mechanism, which features distinctive PdII-mediated decarbonylative coupling and unprecedented nucleophilic attack of carboxylates to PdII-ligated isocyanides, was proposed to account for this reaction. N-Arylamides are assembled in high yields from carboxylic acids and isocyanides under PdII/AgI/base catalytic conditions. The decarbonylative coupling features unprecedented nucleophilic attack of the carboxylate on the isocyanide, which acts as an electrophile as a result of its coordination to PdII, and this inverted reactivity is proposed to account for this transformation.
- Huang, Lin,Guo, Haili,Pan, Lingxia,Xie, Chunsong
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p. 6027 - 6031
(2013/09/24)
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- Novel acid-type cyclooxygenase-2 inhibitors: Design, synthesis, and structure-activity relationship for anti-inflammatory drug
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Cyclooxygenase (COX) is a key rate-limiting enzyme for prostaglandin (PG) production cascades in the human body. The mechanisms of both the anti-inflammation effects and the side-effects of traditional COX inhibitors are associated with the existence of two COX isoforms. Thus while COX-1 is predominantly expressed ubiquitously and constitutively, and it serves a housekeeping role in processes such as gastrointestinal (GI) mucosa protection, COX-2 is absent or exhibits a low level of expression in most tissues, and is highly upregulated in response to endotoxin, virus, inflammatory or tissue-injury stimuli/signals, and tumour promoter in the various types of organs, tissues, and cells. Furthermore, COX-2 contribution to PGE2 and PGI2 production evokes and sustains systemic or peripheral inflammatory disease, but it is not involved in the COX-1-mediated GI tract events. Also, hypersensitivity of aspirin owing to its inhibitory action against COX-1 is a significant concern clinically. Consequently, highly selective COX-2 inhibitors have been needed for the treatment of inflammatory- and inflammation related-diseases that include pyrexia, inflammation, pain, rheumatoid arthritis, osteoarthritis, and cancers. In this study, a series of novel [2-{[(4-substituted or 4,5-disubstituted)-pyridin-2-yl]carbonyl}-(5- or 6-substituted or 5,6-disubstituted)-1H-indol-3-yl]acetic acid analogues was designed, synthesized, and evaluated to identify potent and selective COX-2 inhibitors as potential agents against inflammatory diseases. As significant findings, the present study clarified unique structure-activity relationship of the analogues toward potent and selective COX-2 inhibition in vitro, and identified 2-{6-fluoro-2-[4-methyl-2-pridinyl)carbonyl]-1H-indol-3-yl}acetic acid as a potent and selective COX-2 inhibitor in vitro that demonstrated orally potent anti-inflammation efficacy against carrageenan-induced oedema formation in the foot of SPF/VAF male SD rats as a peripheral inflammation model in vivo.
- Hayashi, Shigeo,Ueno, Naomi,Murase, Akio,Nakagawa, Yoko,Takada, Junji
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experimental part
p. 179 - 195
(2012/07/27)
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- PYRAZOLO[1,5a]PYRIMIDINE DERIVATIVES AS IRAK4 MODULATORS
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Compounds of the formula I or II: wherein X, m, Ar, R1 and R2 are as defined herein. The subject compounds are useful for treatment of IRAK-mediated conditions.
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Page/Page column 74-75
(2012/02/01)
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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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- Hydrosilanes are not always reducing agents for carbonyl compounds, II: Ruthenium-catalyzed deprotection of tert-butyl groups in carbamates, carbonates, esters, and ethers
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Hydrosilanes act as a reagent to cleave the C-O bond of OtBu groups in carbamates, carbonates, esters, and ethers by catalysis of a triruthenium cluster. The reaction offers a novel deprotection method, for OiBu groups under neutral conditions, showing unique selectivities that have never been accomplished with conventional Bronsted or Lewis acidic promoters. Possible mechanisms for C-O cleavage are discussed on the basis of NMR spectroscopic analysis.
- Hanada, Shiori,Yuasa, Akihiro,Kuroiwa, Hirotaka,Motoyama, Yukihiro,Nagashima, Hideo
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supporting information; experimental part
p. 1021 - 1025
(2010/04/27)
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- Microwave-assisted synthesis of nano-sized cadmium oxide as a new and highly efficient catalyst for solvent free acylation of amines and alcohols
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In present studies, a new and efficient method for synthesis of cadmium oxide nanoparticles by using microwave (MW) activation is reported. To ensure the specific efficiency of microwave irradiation versus conventional heating, the synthesis of Cd(OH)2 as precursor of CdO was carried out under similar temperature (80 °C), time and reaction conditions without microwave irradiation. The formation of CdO was characterized by XRD, TEM, FT-IR analysis. Catalytic activity of CdO nanopowder for acylation of alcohols, phenols and amines has been investigated. The results show that the reaction times and yields of desired products were improved by using CdO.
- Mazaheritehrani,Asghari,Orimi, R. Lotfi,Pahlavan
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experimental part
p. 2554 - 2564
(2010/10/21)
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- Spinel-type zinc aluminate (ZnAl2O4) nanoparticles prepared by the co-precipitation method: A novel, green and recyclable heterogeneous catalyst for the acetylation of amines, alcohols and phenols under solvent-free conditions
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Zinc aluminate (ZnAl2O4) nanoparticles with an average particle size of about 8 nm were easily prepared by the co-precipitation method using aqueous ammonia solution as the precipitating agent. This nanosized spinel-type oxide was characterized by TGA, XRD, FT-IR, TEM, and surface area measurement and used as the heterogeneous catalyst for the acetylation reaction. Efficient acetylation of various amines, alcohols and phenols was carried out over ZnAl2O4 nanoparticles using acetic anhydride and/or acetyl chloride as the acetylating agents at room temperature without the use of a solvent. The method is highly selective, allowing the alcoholic hydroxyl group to be protected while the phenolic hydroxyl group remains intact, and the amine group can be acetylated in the presence of the hydroxyl group. This method is fast and has a high yield. It is also clean, safe, cost effective, compatible with substrates that have other functional groups and very suitable for practical organic synthesis. In addition, the catalyst can be reused without significant loss of activity. Indeed, the catalytic activity of the ZnAl2O4 nanoparticles is higher than that of bulk ZnAl2O4.
- Farhadi, Saeid,Panahandehjoo, Somayeh
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scheme or table
p. 293 - 302
(2010/09/04)
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- Concise total synthesis of
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An efficient nine-step total synthesis of the annulated indole natural products.
- Buszek, Keith R.,Brown, Neil,Luo, Diheng
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supporting information; experimental part
p. 201 - 204
(2009/06/20)
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- Microwave reaction of diazonium salts with nitrites
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A series of aryldiazonium tetrafluorborates dissolved in nitrites have been converted into the corresponding anilides in almost quantitative yield in 1 min by microwave irradiation. When bromoacetonitrile was used, 2,4-bis(bromophenyl) -quinazoline was formed. The reaction of malononitrile with the diazonium salt, in DMF as a solvent, afforded 2-(dimethylaminomethylene) malononitrile and phenylhydrazone propanedinitrile.
- Saez, Rebeca,Dolores Otero,Batanero, Belen,Barba, Fructuoso
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experimental part
p. 492 - 494
(2009/04/06)
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- SDS/Ac2O/H2O: Surfactant-mediated cleavage of imines with acetic anhydride to carbonyls and acetanilides in water
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Surfactant (SDS)-mediated cleavage of imines was achieved with acetic anhydride to the corresponding carbonyls (aldehydes and ketones) and acetanilides in water at 25-30°C with very good to excellent yields, thus contributing significantly to the green chemistry concept. Copyright Taylor & Francis Group, LLC.
- Sharma, Saikat Das,Gogoi, Pranjal,Boruah, Monalisa,Konwar, Dilip
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p. 2473 - 2481
(2008/02/10)
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- Eco-friendly reductive acetamidation of arylnitro compounds by thioacetate anion through in situ catalytic regeneration: application in the synthesis of Acetaminophen
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A novel one-step reductive acetamidation of arylnitro compounds mediated by thioacetate anion in thioacetic acid via in situ catalytic regeneration was developed and applied to an efficient synthesis of Acetaminophen.
- Bhattacharya, Apurba,Suarez, Victor,Tamez Jr., Victoriano,Wu, Jiejun
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p. 3221 - 3223
(2007/10/03)
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- One-step reductive amidation of nitro arenes: Application in the synthesis of Acetaminophen
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A novel thioacetate mediated one-step reductive acetamidation of aryl nitro compounds was developed and applied to an efficient synthesis of acetaminophen. The reaction also proceeds well without a solvent in the presence of a catalytic amount of surfactant.
- Bhattacharya, Apurba,Purohit, Vikram C.,Suarez, Victor,Tichkule, Ritesh,Parmer, Gaurang,Rinaldi, Frank
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p. 1861 - 1864
(2007/10/03)
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- ONE-POT REDUCTIVE ACETAMIDATION OF ARYL NITRO COMPOUNDS
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The present invention provides a method for the reductive acetamidation of an aryl nitro compound by reacting a substituted acid with an aryl nitro compound and adding a catalytic amount of a base with the substituted acid and the aryl nitro compound to form an acetamidation aryl nitro compound. The acetamidation aryl nitro compound is then purified.
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Page/Page column 12; 13
(2008/06/13)
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- Bis(3,4-methylenedioxyphenylamino) derivatives and electrophotographic photoreceptor containing the derivatives
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Disclosed are novel compounds useful in electrophotographic photoreceptors as charge-transporting materials having good miscibility with binder polymers and capable of forming a thin stable organic film having a high concentration; and an electrophotographic photoreceptor containing the same. The compounds are bis(3,4-methylenedioxyphenylamino) derivatives represented by general formula (1): wherein Ar1and Ar2each is an optionally substituted aryl group and Ar3is a phenylene group or an optionally substituted biphenylene group.
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- Convenient strategies for the preparation of modified 2(3H)-benzothiazolethiones
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4-Alkyl-2-bromoanilines and 4-alkoxy-2-chloroanilines were synthesized conveniently and submitted to cyclization reaction with potassium O-ethyl dithiocarbonate to afford 6-substituted 2(3H)-benzothiazolethiones in good yields.
- Chaudhuri, Narayan C.
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p. 3783 - 3790
(2007/10/03)
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- Side chain hydroxylation of aromatic compounds by fungi. 1. Products and stereochemistry
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The fungus Mortierella isabellina can convert ethylbenzene and a number of para-substituted derivatives to the corresponding optically active 1-phenylethanols with enantiomeric excess between 5 and 40percent and chemical yields up to 45percent. 2-Ethylnaphthalene, 2-ethylthiophene, and n-propylbenzene were similarly converted, as were the bicyclic compounds indane and tetraline.In most cases, the R absolute configuration of product predominated.The fungi Cunninghamella echinulata var. elegans and Helminthosporium species are also capable of performing some of these transformations.M. isabellina and C. elegans also produce 2-phenylethanols as products in some cases.The highest enantiomeric excesses during benzylic hydroxylation were obtained with Helminthosporium and are attributable, at least in part, to further stereoselective oxidation of the alcohol.Cross induction experiments with M. isabellina indicate that the same enzyme may be responsible for the benzylic hydroxylation of ethylbenzene, 2-ethylthiophene, and 2-ethylnaphthalene.
- Holland, Herbert L.,Bergen, Eleanor J.,Chenchaiah, P. Chinna,Khan, Shaheer H.,Munoz, Benito,et al.
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p. 502 - 507
(2007/10/02)
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