- Electron spin-lattice relaxation in radicals containing two methyl groups, generated by γ-irradiation of polycrystalline solids
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The effects of methyl rotation on electron spin-lattice relaxation times were examined by pulsed electron paramagnetic resonance for the major radicals in γ-irradiated polycrystalline α-amino isobutyric acid, dimethyl-malonic acid, and L-valine. The domin
- Harbridge, James R.,Eaton, Sandra S.,Eaton, Gareth R.
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Read Online
- Synthesis of Chiral Amines via a Bi-Enzymatic Cascade Using an Ene-Reductase and Amine Dehydrogenase
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Access to chiral amines with more than one stereocentre remains challenging, although an increasing number of methods are emerging. Here we developed a proof-of-concept bi-enzymatic cascade, consisting of an ene reductase and amine dehydrogenase (AmDH), to afford chiral diastereomerically enriched amines in one pot. The asymmetric reduction of unsaturated ketones and aldehydes by ene reductases from the Old Yellow Enzyme family (OYE) was adapted to reaction conditions for the reductive amination by amine dehydrogenases. By studying the substrate profiles of both reported biocatalysts, thirteen unsaturated carbonyl substrates were assayed against the best duo OYE/AmDH. Low (5 %) to high (97 %) conversion rates were obtained with enantiomeric and diastereomeric excess of up to 99 %. We expect our established bi-enzymatic cascade to allow access to chiral amines with both high enantiomeric and diastereomeric excess from varying alkene substrates depending on the combination of enzymes.
- Fossey-Jouenne, Aurélie,Jongkind, Ewald P. J.,Mayol, Ombeline,Paul, Caroline E.,Vergne-Vaxelaire, Carine,Zaparucha, Anne
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- Half-sandwiched ruthenium complex containing carborane schiff base ligand and preparation and application thereof
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The invention relates to a half-sandwiched ruthenium complex containing a carborane schiff base ligand and a preparation and an application thereof. The preparation method specifically comprises the following steps; i) dissolving o-carborane formaldehyde and aromatic amine in an organic solvent, carrying out reaction at 60-100 DEG C for 8-12h, cooling to room temperature after the reaction; ii) adding n-butyllithium, carrying out reaction at room temperature for 1.5-2.5h; ii) adding phellandrene ruthenium chloride dimer, carrying out reaction at room temperature for 3-6h, and obtaining the half-sandwiched ruthenium complex through separation. The half-sandwiched ruthenium complex is applied to catalyze transfer hydrogenation reaction of nitrile compounds. Compared with the prior art, the complex of the present invention is not sensitive to air and water, has stable properties, and shows high-efficiency catalytic activity in catalyzing the transfer hydrogenation reaction of nitrile compounds. The preparation method of the complex is simple and green, high in yield, mild in reaction conditions and good in universality.
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Paragraph 0067-0071
(2020/12/09)
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- One-pot reductive amination of carboxylic acids: a sustainable method for primary amine synthesis
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The reductive amination of carboxylic acids is a very green, efficient and sustainable method for the production of (bio-based) amines. However, with current technology, this reaction requires two to three reaction steps. Here, we report the first (heterogeneous) catalytic system for the one-pot reductive amination of carboxylic acids to amines, with solely H2 and NH3 as the reactants. This reaction can be performed with relatively cheap ruthenium-tungsten bimetallic catalysts in the green and benign solvent cyclopentyl methyl ether (CPME). Selectivities of up to 99% for the primary amine could be achieved at high conversions. Additionally, the catalyst is recyclable and tolerant for common impurities such as water and cations (e.g. sodium carboxylate).
- Coeck, Robin,De Vos, Dirk E.
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supporting information
p. 5105 - 5114
(2020/08/25)
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- Preparation of nitrogen-doped carbon supported cobalt catalysts and its application in the reductive amination
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The use of non-noble metal catalysts with high activity is of great importance for organic transformations. Herein, nitrogen-doped carbon supported cobalt catalysts with high surface area up to 981.2 m2/g were prepared via the simple pyrolysis of cobalt coordinated organic polymers with silica as the hard template. The pyrolysis temperature showed a great effect on the structure and properties of the as-prepared catalysts. The Co@NC-800 catalyst with the pyrolysis temperature of 800 °C demonstrated a high activity for the selective reductive amination of carbonyl compounds to primary amines with ammonia and hydrogen. Structurally-diverse primary amines with yields in the range from 81.8% to 100% were attained under the optimal conditions. The Co@NC-800 catalyst could be reused without the loss of its activity. The Co@NC-800 catalyst demonstrated comparable activity as the reported heterogeneous noble metal catalysts.
- Yuan, Ziliang,Liu, Bing,Zhou, Peng,Zhang, Zehui,Chi, Quan
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p. 347 - 356
(2019/01/24)
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- Organocatalytic Decarboxylation of Amino Acids as a Route to Bio-based Amines and Amides
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Amino acids obtained by fermentation or recovered from protein waste hydrolysates represent an excellent renewable resource for the production of bio-based chemicals. In an attempt to recycle both carbon and nitrogen, we report here on a chemocatalytic, metal-free approach for decarboxylation of amino acids, thereby providing a direct access to primary amines. In the presence of a carbonyl compound the amino acid is temporarily trapped into a Schiff base, from which the elimination of CO2 may proceed more easily. After evaluating different types of aldehydes and ketones on their activity at low catalyst loadings (≤5 mol%), isophorone was identified as powerful organocatalyst under mild conditions. After optimisation many amino acids with a neutral side chain were converted in 28–99 % yield in 2-propanol at 150 °C. When the reaction is performed in DMF, the amine is susceptible to N-formylation. This consecutive reaction is catalysed by the acidity of the amino acid reactant itself. In this way, many amino acids were efficiently transformed to the corresponding formamides in a one-pot catalytic system.
- Claes, Laurens,Janssen, Michiel,De Vos, Dirk E.
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p. 4297 - 4306
(2019/08/26)
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- Chemo-selective reduction of nitro and nitrile compounds using Ni nanoparticles immobilized on hyperbranched polymer-functionalized magnetic nanoparticles
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The nitro and nitrile groups in aromatic and aliphatic compounds containing various reducible substituents such as carboxylic acid, ketone, aldehyde and halogen are selectively reduced to the corresponding amines in water as a green solvent with excellent yields by employing NaBH4 in the presence of Fe3O4@PAMAM/Ni(0)-b-PEG nanocatalyst. The morphology and structural features of the catalyst were characterized using various microscopic and spectroscopic techniques. The designed catalyst system because of it being covered with hydrophilic polymers is soluble in a wide range of solvents (e.g. water and ethanol) and suitable for immobilizing and stabilizing Ni nanoparticles in aqueous mediums. In addition, the catalyst can be easily recovered from a reaction mixture by applying an external magnetic field and can be reused up to six runs without significant loss of activity.
- Tabatabaei Rezaei, Seyed Jamal,Mashhadi Malekzadeh, Asemeh,Poulaei, Sima,Ramazani, Ali,Khorramabadi, Hossein
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- Generation of novel family of reductases from PCR based library for the synthesis of chiral alcohols and amines
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Biocatalysis has shown tremendous potential in the synthesis of drugs and drug intermediates in the last decade. Screening of novel biocatalysts from the natural genome space is the growing trend to replenish the harsh chemical synthetic routes, commonly used in the pharmaceutical and chemical industry. Here, we report a novel ketoreductase (KERD) and a nitrile reductase isolated from the PCR based library generated from the genome of Rhodococcus ruber and Bacillus subtilis, respectively. Both the proteins are hypothetical in nature as there is no putative homology found in the database, although both the enzymes have significant activity towards the synthesis of chiral alcohols and amines. Enzyme activity over a wide range of substrates (aromatic and aliphatic) for both the novel catalysts was observed. From the unique gene sequence to activity over a broad range of substrate and >99% conversion at higher concentrations (100 mM and above) entitles both the hypothetical enzymes as novel. The novel KERD has shown >99% selectivity for the synthesis of (S)-phenylethanol which makes it a potential candidate for industrial catalysis. The novel nitrile reductase has also shown promising activity for the synthesis of (R)-2-phenylethanolamine, which is a difficult moiety to synthesize chemically. In this report, starting from a homology based library, two highly potent whole cell biocatalysts are obtained.
- Sehajpal, Pallvi,Kirar, Seema,Ghosh, Saptarshi,Banerjee, Uttam Chand
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- Metal-free hypervalent iodine/TEMPO mediated oxidation of amines and mechanistic insight into the reaction pathways
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A highly efficient metal free approach for the oxidation of primary and secondary amines to their corresponding aldehydes and ketones using PhI(OAc)2 in combination with a catalytic amount of TEMPO as an oxidizing agent is described. This protocol is rapid and provides diverse products under milder reaction conditions in excellent yields. In addition, the mechanistic study is well demonstrated by spectroscopic methods.
- Bansode, Ajay H.,Suryavanshi, Gurunath
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p. 32055 - 32062
(2018/09/29)
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- Catalytic Reductions and Tandem Reactions of Nitro Compounds Using in Situ Prepared Nickel Boride Catalyst in Nanocellulose Solution
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A mild and efficient method for the in situ reduction of a wide range of nitroarenes and aliphatic nitrocompounds to amines in excellent yields using nickel chloride/sodium borohydride in a solution of TEMPO-oxidized nanocellulose in water (0.01 wt %) is described. The nanocellulose has a stabilizing effect on the catalyst, which increases the turnover number and enables low loading of nickel catalyst (0.1-0.25 mol % NiCl2). In addition, two tandem protocols were developed in which the in situ formed amines were either Boc-protected to carbamates or further reacted with an epoxide to yield β-amino alcohols in excellent yields.
- Prathap, Kaniraj Jeya,Wu, Qiong,Olsson, Richard T.,Dinér, Peter
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supporting information
p. 4746 - 4749
(2017/09/23)
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- Versatile Dynamic Covalent Assemblies for Probing π-Stacking and Chirality Induction from Homotopic Faces
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Herein we report for the first time the use of dynamic covalent reactions (DCRs) for building a π-stacking model system and further quantifying its substituent effects (SEs), which remain a topic of debate despite the rich history of stacking. A general DCR between 10-methylacridinium ion and primary amines was discovered, in which π-stacking played a stabilizing role. Facile quantification of SEs with in situ competing π-stacking systems was next achieved in the form of amine exchange exhibiting structural diversity by simply varying components. The linear correlation with σm in Hammett plots indicates the dominance of purely electrostatic SEs, and the additivity of SEs is in line with the direct interaction model. With α-chiral amines π-stacking within the adduct enabled chirality transfer from homotopic faces. The strategy of dynamic covalent assembly should be appealing to future research of probing weak interactions and manipulating chirality.
- Ye, Hebo,Hai, Yu,Ren, Yulong,You, Lei
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supporting information
p. 3804 - 3809
(2017/03/27)
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- Selective hydrogenation of nitriles to primary amines catalyzed by a novel iron complex
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Hydrogenation of nitriles to primary amines constitutes an atom-efficient and environmentally benign synthetic reaction. Herein we present a novel complex based on earth-abundant iron, and its application in the catalytic homogeneous hydrogenation of (hetero)aromatic, benzylic, and aliphatic nitriles to selectively form primary amines.
- Chakraborty, Subrata,Leitus, Gregory,Milstein, David
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supporting information
p. 1812 - 1815
(2016/02/05)
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- Colloid and nanosized catalysts in organic synthesis: XII. Hydrogenation of carbonitriles catalyzed by nickel nanoparticles
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Hydrogenation of carbonitriles catalyzed by nickel nanoparticles in isopropanol proceeds under atmospheric pressure of hydrogen within 6-15 h to yield mainly secondary amines. Hydrogenation of α-aminonitriles results in reductive decyanation. β-Aminonitriles undergo hydrogenolysis at the nitrogen-carbon bond.
- Mokhov,Popov,Shcherbakova
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p. 273 - 280
(2016/04/20)
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- HIV INTEGRASE INHIBITORS
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The present invention features compounds that are HIV integrase inhibitors and therefore are useful in the inhibition of HIV replication, the prevention and/or treatment of infection by HIV, and in the treatment of AIDS and/or ARC.
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- Synthesis of a yolk/shell Fe3O4@poly(ionic liquid)s-derived nitrogen doped graphitic porous carbon materials and its application as support for nickel catalysts
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The synthesis of yolk/shell spheres including a movable magnetic core, a poly(ionic liquid)s-derived porous carbon shell, and nickel nanoparticles confined within the porous shell is reported. The as-prepared carbon shell is graphitic and porous, as proven by X-ray diffraction, Brunauer-Emmett-Teller equation, and transmission electron microscopy characterizations. The ensuing catalyst has been employed for the tandem dehydrogenation of sodium borohydride and hydrogenation of several nitro/nitrile compounds in aqueous media, which resulted in high yields with a very low amount of the catalyst.
- Nabid, Mohammad Reza,Bide, Yasamin,Habibi, Zahra
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p. 2258 - 2265
(2015/02/02)
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- Method for manufacturing ammonia-N
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PROBLEM TO BE SOLVED: To provide a method for producing an N-alkyl hydroxylamine, which produces a pure N-alkyl hydroxylamine in a high yield under a mild condition by a simple method, does not require a strict time management and is advantageous for industrial-scale production. SOLUTION: The method for producing an N-alkyl hydroxylamine includes bringing an N-alkyl nitro compound into contact with a hydrogen source in the presence of a solid catalyst supporting palladium on silica and in the absence of a significant quantity of a fourth reaction component. The method for producing an N-alkyl hydroxylamine includes bringing (A) an N-alkyl nitro compound into contact only with (B) a hydrogen source and (C) a solid catalyst supporting palladium on silica, or bringing (A) an N-alkyl nitro compound into contact only with (B) a hydrogen source, (C) a solid catalyst supporting palladium on silica and (D) a solvent that does not deactivate catalytic activity and has a pKa of ≥12. COPYRIGHT: (C)2012,JPOandINPIT
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Paragraph 0085-0086; 0088
(2018/12/01)
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- Tandem dehydrogenation of ammonia borane and hydrogenation of nitro/nitrile compounds catalyzed by graphene-supported NiPd alloy nanoparticles
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We report a facile synthesis of monodisperse NiPd alloy nanoparticles (NPs) and their assembly on graphene (G) to catalyze the tandem dehydrogenation of ammonia borane (AB) and hydrogenation of R-NO2 and/or R-CN to R-NH2 in aqueous methanol solutions at room temperature. The 3.4 nm NiPd alloy NPs were prepared by coreduction of nickel(II) acetate and palladium(II) acetlyacetonate by borane-tert-butylamine in oleylamine and deposition on G via a solution phase self-assembly process. G-NiPd showed composition-dependent catalysis on the tandem reaction with G-Ni 30Pd70 being the most active. A variety of R-NO 2 and/or R-CN derivatives were reduced selectively into R-NH 2 via G-Ni30Pd70 catalyzed tandem reaction in 5-30 min reaction time with the conversion yields reaching up to 100%. Our study demonstrates a new approach to G-NiPd-catalyzed dehydrogenation of AB and hydrogenation of R-NO2 and R-CN. The G-NiPd NP catalyst is efficient and reusable, and the reaction can be performed in an environment-friendly process with short reaction times and high yields.
- Goeksu, Haydar,Ho, Sally Fae,Metin, Oender,Korkmaz, Katip,Mendoza Garcia, Adriana,Gueltekin, Mehmet Serdar,Sun, Shouheng
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p. 1777 - 1782
(2014/06/24)
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- Preparation of functional styrenes from biosourced carboxylic acids by copper catalyzed decarboxylation in PEG
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A general protocol for the copper-catalyzed decarboxylation of α,β-unsaturated carboxylic acids in PEG, particularly of biosourced cinnamic acid analogues, is reported. Moderate to high isolated yields (31-96%) towards the styrene derivatives were obtained. For the first time, decarboxylation of α-amino acids to the corresponding amines was successfully performed with good to high yields and extended to the decarboxylation of a few condensed heterocyclic compounds. Both the use of PEG as a green solvent and direct separation of the pure product of the reaction by distillation permitted the reuse of the solvent and the Cu-based catalytic system over several cycles without deactivation. This was extended to the synthesis of 4-vinylguaiacol on the laboratory scale in an average 92% yield. This journal is the Partner Organisations 2014.
- Cadot, Stephane,Rameau, Nelly,Mangematin, Stephane,Pinel, Catherine,Djakovitch, Laurent
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supporting information
p. 3089 - 3097
(2014/06/10)
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- Direct amination of bio-alcohols using ammonia
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A slightly adapted catalyst system has been successfully applied in the direct amination of primary and secondary alcohols. Moreover, the applicability to diols has been shown, giving high selectivity towards the primary diamines. It was found that the Ru/P ratio as well as the amount of ammonia used are highly important in this system, especially for higher substrate loadings. The catalyst was employed on a larger batch scale for the conversion of isomannide to the corresponding diamine. Additionally, it was shown that the catalyst is stable for at least six consecutive runs. No significant loss of activity and selectivity was observed.
- Pingen, Dennis,Diebolt, Olivier,Vogt, Dieter
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p. 2905 - 2912
(2013/10/21)
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- Fast transimination in organic solvents in the absence of proton and metal catalysts. A key to imine metathesis catalyzed by primary amines under mild conditions
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Amine-imine exchange reactions of sterically unhindered reactants were found to be surprisingly fast at room temperature in a variety of nonaqueous solvents in the absence of proton and metal catalysts. The reaction mechanism suggested by ab initio calculations in the gas phase involves nucleophilic addition to the CN bond in concert with proton transfer from the amine NH bond to the imine nitrogen via a highly imbalanced transition state. These very fast transimination reactions were utilized in the catalysis of imine metathesis. Imine metathesis, usually carried out in organic solvents at high temperature in the presence of metal catalysts, occurs smoothly at room temperature in the presence of primary amines under nonacidic conditions as a result of coupled transimination processes. Kinetic data fully consistent with the proposed reaction mechanism were obtained.
- Ciaccia, Maria,Cacciapaglia, Roberta,Mencarelli, Paolo,Mandolini, Luigi,Di Stefano, Stefano
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p. 2253 - 2261
(2013/06/26)
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- Process for producing isobutene from isobutylamine
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The present invention concerns a new process for the sustainable chemical synthesis of isobutene, using isobutylamine obtained by fermentation of a recombinant microorganism as starting material, based on a chemical conversion of an amine to an olefin (alkene).
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Paragraph 0084-0087
(2013/04/23)
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- Synthesis of primary amines from secondary and tertiary amines: Ruthenium-catalyzed amination using ammonia
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Splitting of secondary and tertiary amines! The first selective catalytic synthesis of primary amines from secondary and tertiary amines with ammonia is reported. The products are obtained in yields up to 84 %. Copyright
- Baehn, Sebastian,Imm, Sebastian,Neubert, Lorenz,Zhang, Min,Neumann, Helfried,Beller, Matthias
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experimental part
p. 4705 - 4708
(2011/05/12)
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- Spiroborate catalyzed reductions with N,N-diethylaniline borane
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Reduction of esters, amides, and ketones by N,N-diethylaniline borane is accelerated by catalysts derived from spiroborate complexes. Esters are reduced at ambient temperature in less than 4 h with this amine borane and 5 mol % spiroborate 6. Functional group selectivity shows ketone and tertiary amide reduction is faster than ester or nitrile reduction.
- Coleridge, Brian M.,Angert, Thomas P.,Marks, Lucas R.,Hamilton, Patrick N.,Sutton, Christopher P.,Matos, Karl,Burkhardt, Elizabeth R.
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supporting information; experimental part
p. 5973 - 5976
(2010/11/21)
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- 2,3,4,5-TETRAHYDRO-1H-1,5-BENZODIAZEPINE DERIVATIVE AND MEDICINAL COMPOSITION
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The present invention has its object to provide a 2,3,4,5-tetrahydro-1H-1,5-benzodiazepine derivative represented with the Formula (1) , or the pharmaceutically acceptable salt, which is effective as a therapeutic and prophylactic agent for diabetes, diabetic nephropathy, or glomerulosclerosis.
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- Structure-stability correlations for imine formation in aqueous solution
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Imine formation between 25 aldehydes and 13 amines in aqueous solution in the pH range 7-11 was studied by 1H NMR spectroscopy. A three-parameter linear equation correlating logarithms of imine formation constants with pKa and HOMO energies of amines and LUMO energies of aldehydes is proposed. In view of the widespread occurrence of imine-forming processes in both chemistry and biology, the data presented are of significance for physical organic chemistry and of particular interest for dynamic combinatorial chemistry. Copyright
- Godoy-Alcantar,Yatsimirsky, Anatoly K.,Lehn
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p. 979 - 985
(2007/10/03)
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- Base induced carbon-nitrogen (C=N) double bond migration in Schiff bases
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Various Schiff bases have been prepared to study base induced carbon-nitrogen double bond migrations. Schiff bases derived from aliphatic aldehydes display highest selectivity. Hydrolysis of the resulting rearranged Schiff base provides an entry to make amines from aldehydes. The reaction has possible practical application.
- Gangadasu,Narender,China Raju,Jayathirtha Rao
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p. 2598 - 2600
(2007/10/03)
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- Non-metallocene compounds, method for the production thereof and use of the same for the polymerisation of olefins
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The invention relates to a method for producing special transition metal compounds, to novel transition metal compounds and to the use of the same for the polymerisation of olefins.
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- METHOD FOR TREATING CHRONIC PAIN USING MEK INHIBITORS
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The invention features a method for treating chronic pain using a compound selected from formulae (I), (II)A, (I)B and (I)C.
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- Spectroscopy of Hydrothermal Reactions, Part 26: Kinetics of Decarboxylation of Aliphatic Amino Acids and Comparison with the Rates of Racemization
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The kinetics of decarboxylation of six α-amino acids (glycine, alanine, aminobutyric acid, valine, leucine, and isoleucine) and β-aminobutyric acid were studied in aqueous solution at 310-330 deg C and 275 bar over the pH25 range 1.5-8.5 by using an in situ FT-IR spectroscopy flow reactor. Based on the rate of formation of CO2, the first-order or pseudo-first-order rate constants were obtained along with the Arrhenius parameters. The decarboxylation rates of amino acids follow the order Gly > Leu ca. Ile ca. Val > Ala > α-Aib > β-Aib. Differences in the concentration between 0.05 and 0.5 m had only a minor effect on the decarboxylation rate. The effect of the position of the amino group on the decarboxylation rate was investigated for α-, β-, and γ-aminobutyric acid and the order was found to be α > β >> γ. Although the pH dependence is complex, the decarboxylation rates of α-amino acids qualitatively have the inverse trend of the racemization rates.
- Li, Jun,Brill, Thomas B.
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p. 602 - 610
(2007/10/03)
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- One-pot sequence for the decarboxylation of α-amino acids
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Treatment of an α-amino acid with N-bromosuccinimide in water at pH 5 or in an alcoholic-aqueous ammonium chloride mixture, followed by addition of nickel(II) chloride and sodium borohydride, effected an overall decarboxylation via an intermediate nitrile to afford the corresponding amine in good yield.
- Laval, Gilles,Golding, Bernard T.
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p. 542 - 546
(2007/10/03)
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- Benzenesulfonamide derivatives and their use as MEK inhibitors
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Benzenesulfonamides of formula (I), in which W is OR1, NR2OR1, NRARB, NR2NRARB, or NR2(CH2)2-4NRARBand the other variables as defined in the claims, are inhibitors of MEK and are effective in the treatment of proliferative diseases, cancer, stroke, heart failure, xenograft rejection, arthritis, cystic fibrosis, hepatomegaly, cardiomegaly, Alzheimer's disease, complications of diabetes, septic shock, and viral infection.
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- 2-aminopyridine derivatives and combinatorial libraries thereof
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The present invention relates to novel 2-aminopyridine derivative compounds of the following formula: wherein R1to R5have the meanings provided herein. The invention further relates to combinatorial libraries containing two or more such compounds, as well as methods of preparing 2-aminopyridine derivative compounds.
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- Tripeptide α-ketoamides
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A novel class of tripeptide α-ketoamides useful for selectively inhibiting serine proteases, selectively inhibiting cysteine proteases, generally inhibiting all serine proteases, and generally inhibiting all cysteine proteases, having the formula M1—AA—AA—AA—CO—NR3R4.
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- Catalysis of ester aminolysis by cyclodextrins. The reaction of alkylamines with p-nitrophenyl alkanoates
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The effects of four cyclodextrins (α-CD, β-CD, hydroxypropyl-β-CD, and γ-CD) on the aminolysis of p-nitrophenyl alkanoates (acetate to heptanoate) by primary amines (n-propyl to n-octyl, isobutyl, isopentyl, cyclopentyl, cyclohexyl, benzyl) in aqueous solution have been investigated. Rate constants for amine attack on the free and CD-bound esters (k(N) and k(cN)) have ratios (k(cN)/k(N)) varying from 0.08 (retardation) to 180 (catalysis). For the kinetically equivalent process of free ester reacting with CD-bound amine (k(Nc)), the ratios k(Nc)/k(N) vary from 0.2 to 28. Either way, there is evidence of catalysis in some cases and retardation in others. Changes in reactivity parameters with structure indicate more than one mode of transition state binding to the CDs. Short esters react with short alkylamines by attack of free amine on the ester bound by its aryl group, but for longer amines, free ester reacts with CD-bound amine. Reaction of long esters with long amines, which is catalyzed by β-CD and γ-CD, involves inclusion of the alkylamino group and possibly the ester acyl group. The larger cavity of γ-CD may allow the inclusion of the ester aryl group, as well as the alkylamino group, in the transition state. Reaction between an ester bound to the CD by its acyl group and free amine appears not to be important.
- Gadosy,Boyd,Tee
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p. 6879 - 6889
(2007/10/03)
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- The first efficient hydroaminomethylation with ammonia: With dual metal catalysts and two-phase catalysis to primary amines
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Primary and unbranched secondary amines are obtained by the highly selective hydroaminomethylation of olefins with ammonia [Eq. (a)]. The selectivity is readily controlled with a new dual Rh/Ir catalyst in a two- phase system.
- Zimmermann, Burkhard,Herwig, Juergen,Beller, Matthias
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p. 2372 - 2375
(2007/10/03)
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- Kinetics and thermodynamics of the reaction of aliphatic N-bromamines with bromide ion in acid media, and the pKa of N-bromamines
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The kinetics of the oxidation of bromide ions by aliphatic N-bromamines in aqueous acid media were studied using a pH jump technique. The reaction is first order in both bromide ion and total bromamine concentrations, and takes place only through the protonated N-bromamine. For two of the N-bromamines studied (N-Br-dimethylamine and N-Br-diethylamine), hydrolysis competed with the reaction with bromide ions, whereas in all the other cases hydrolysis was too slow to be detected. The pKa values obtained from the kobs vs. [H+] data at 25°C are 2.88 for N-Br-dimethylamine, 3.24 for N-Br-diethylamine, 3.33 for N-Br-piperidine (all at I = 0.1 M), 2.26 for N-Br-isobutylamine and 2.92 for N-Br-sec-butylamine (both at I = 0.5 M).
- Antelo, Juan M.,Arce, Florencio,Crugeiras, Juan,Gray, Edward T.,Yebra, Patricia
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p. 651 - 655
(2007/10/03)
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- Preparation of amines
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A process for preparing an amine by catalytic reaction of an olefin with ammonia or a primary or secondary amine by contacting a mixture of the reactants in a reactor at 200° to 400° C. and an elevated pressure up to 700 bar in the presence of a catalyst consisting essentially of an X-ray amorphous (non-crystalline) mesoporous catalyst, some of which may have a microporous non-crystalline content. The catalyst has the composition where Q is at least one of the trivalent elements aluminum, boron, chromium, iron or gallium, and M is at least one of the tetravalent elements silicon, titanium or germanium. The molar ratio of a:b is from 0.5:1 to 1000:1 and the molar ratio of c:b is from 0 to 2:1. As prepared and used in the process, this non-crystalline catalyst has a specific BET surface area of from 200 to 1000 m2 /g.
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- Preparation process of aminoacetamide derivative
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Disclosed herein are novel processes for preparing aminoacetamide derivatives, wherein: (1) a secondary amine is reacted with a 2-haloacetamide in the presence or absence of at least one solvent selected from water, lower alcohols, aromatic solvents and acetic acid esters; (2) an N-benzylideneamine derivative is reacted with dimethyl sulfate or diethyl sulfate to form a secondary amine, and this secondary amine is then reacted with a 2-haloacetamide; and (3) a primary amine is reacted with benzaldehyde to form an N-benzylideneamine derivative, this product is then reacted with dimethyl sulfate or diethyl sulfate to form a secondary amine, and this secondary amine is further reacted with a 2-haloacetamide. The 2-aminoacetamide derivatives are useful as intermediates for the preparation of novel antibiotics.
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- Kinetics of the Formation, Decomposition, and Disproportionation Reactions of N-Chlorobutylamines
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The formation of N-chlorobutylamines is a reaction of order one with respect to hypochlorite and amine, and order -1 with respect to OH-.Kinetic studies show that N-chlorobutylamines undergo decomposition in basic aqueous media, and disproportionation (with formation of N,N-dichloramines) in acidic media, mechanisms are put forward for both these processes.
- Antelo, Juan M.,Arce, Florencio,Castro, Maria C.,Crugeiras, Juan,Perez-Moure, Juan C.,Rodriguez, Pilar
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p. 703 - 718
(2007/10/02)
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- Carbocyclic compounds useful as leukotriene antagonists
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This invention comprises novel carbocyclic compounds of formula I (wherein A, Z, R11 and R12 are defined in the specification) derived from acylsulfonamide derivatives of α-carbocyclyltoluic acids wherein said compounds of formula I antagonize the actions of one or more of the arachidonic acid metabolites known as leukotrienes. The invention also provides pharmaceutically acceptable salts of the formula I compounds; pharmaceutical compositions containing the formula I compound, or their salts, for use in the treatment of, for example, allergic or inflammatory diseases, or endotoxic or traumatic shock conditions; and processes for the manufacture of the formula I compounds, as well as intermediates for use in such manufacture.
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- Substituted pyridylethanolamine livestock production promoters
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For promoting livestock production, the novel substituted pyridylethanolamines of the formula STR1 in which R1 represents CN, --COOR8 or --CONR9 R10, R2 represents optionally substituted alkyl, R3 represents hydrogen, alkyl or alkenyl, R4 represents hydrogen or optionally substituted alkyl or alkenyl, or R3 and R4 represent, together with the nitrogen atom to which they are bonded, an optionally substituted heterocyclic radical, R5 represents OH, acyloxy or alkoxy, R6 represents hydrogen or alkyl, R7 represents hydrogen, alkyl, cycloalkyl, substituted alkyl, optionally substituted aralkyl, aryl or heterocyclyl, R6 and R7 can, together with the nitrogen atom to which they are bonded, represent an optionally substituted heterocyclic radical, R8 represents alkyl, and R9 and R10, independently of one another, represent hydrogen, alkyl or alkenyl or, together with the nitrogen atom to which they are bonded, represent an optionally substituted heterocyclic radical, or a physiologically tolerated salt or N-oxide thereof. Some intermediates are also new.
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- Temperature and pressure effects on the outer-sphere electron-transfer reaction between hexacyanoferrate(II) and pentaamminecobalt(III) complexes in aqueous solution. Comparison of experimental and theoretical volumes of activation
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The kinetics of a series of outer-sphere electron-transfer reactions of the type Co(NH3)4(NH2R)X(3-n)+ + Fe(CN)64- → Co2+ + 4NH3 + NH2R + Xn- + Fe(CN)63- (X = N3-, R = H; X = Cl-, R = H, CH3, i-C4H9) were studied as a function of temperature and pressure. It was possible to separate the ion-pair formation constant and the electron-transfer rate constant in a kinetic way, and the corresponding thermodynamic and activation parameters were determined. For the electron-transfer process, the rate and activation parameters lie in the ranges 0.06 ≤ k × 102 ≤ 20 s-1, 84 ≤ ΔH? ≤ 118 kJ mol-1, +11 ≤ ΔS? ≤ 113 J K-1 mol-1, and +19 ≤ ΔV? ≤ +34 cm3 mol-1. The experimentally observed activation volumes are in good agreement with those predicted theoretically on the basis of an average λ? value of 0.48 ± 0.07. The results are discussed in reference to related studies reported in the literature.
- Krack,Van Eldik
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p. 1700 - 1704
(2008/10/08)
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- Postcolumn Photolysis of Pesticides for Fluorometric Determination by High-Performance Liquid Chromatography
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A high-performance liquid chromatography postcolumn reaction detector that employs UV photolysis with an optional reaction by using o-phthalaldehyde-2-mercaptoethanol (OPA-MERC) followed by fluorescence detection was found to be useful for several classes of pesticides.In the presence of the OPA-MERC reagent, most carbamates, carbamoyl oximes, carbamothioic acids, and substituted ureas gave a sensitive response while the response of dithiocarbamates, phenylamides, and phenylcarbamates varied.The response of most of the pesticides tested was significantly affected bythe solvent used.Method detection limits for aldicarb sulfoxide, aldicarb, propoxur, thiram, and neburon in groundwater were 2.5, 2.3, 3.3, 3.8, and 2.0 νg/L, respectively.In the absence of OPA-MERC reagent, several of the substituted aromatic compounds also gave strong fluorescence after photolysis.This detector is applicable to a broad range of nitrogenous pesticides.
- Miles, Carl J.,Moye, H. Anson
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p. 220 - 226
(2007/10/02)
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- CATALYTIC HYDROGENATION OF OLEFINS IN BIPHASIC WATER-LIQUID SYSTEM
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Cyclic and linear olefins and polyenes with or without functional groups are hydrogenated under very mild reaction conditions.Emphasis is put on the advantages of this method which requires no solvent and a water-soluble non air-sensitive catalyst.
- Larpent, Chantal,Dabard, Renee,Patin, Henri
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p. 2507 - 2510
(2007/10/02)
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- Preparation of amines from olefins using certain transition metal catalysts
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Aliphatic and aromatic amines are produced by reacting an olefin with either ammonia or a primary or secondary amine in the presence of a catalytic amount of ruthenium or iron compound catalyst. The reaction is carried out in the liquid phase using an inert liquid, a product amine, or one of the reactants as a solvent. The temperatures used are 100° to 250° C. and the pressures are at least autogenous and up to 12,000 psig.
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- Prodrugs as drug delivery systems IV: N-Mannich bases as potential novel prodrugs for amides, ureides, amines, and other NH-acidic compounds
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The hydrolysis kinetics of a series of N-Mannich bases of carboxamides, thioamides, and other NH-acidic compounds were studied to assess their suitability as prodrugs for various drugs. The pH-rate profiles for the compounds were determined at 37° and were accounted for by assuming the spontaneous decomposition of both free and protonated Mannich bases. The reaction rate for the free base increased sharply with increasing steric effects of the amine component of the N-Mannich bases and also with increasing acidity of the amide component. N-Mannich bases may be potentially useful prodrugs for NH-acidic compounds such as various amides, imides, and ureides and for amines.
- Bundgaard,Johansen
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