- Spectral and mechanistic investigations of ruthenium(III) catalyzed oxidation of atenolol by diperiodatocuprate(III) in aqueous alkaline medium 1
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The kinetics of ruthenium(III) catalyzed oxidation of atenolol by diperiodatocuprate(III) in aqueous alkaline medium at a constant ionic strength of I = 0.10 M has been studied spectrophotometrically at 27°C. The reaction between diperiodatocuprate(III) and atenolol in alkaline medium in presence of ruthenium(III) exhibits 2: 1 stoichiometry (atenolol: diperiodatocuprate(III)). The main products were identified by spot test, IR, NMR, and LC-MS. The reaction is of first order in DPC concentrations and has less than unit order in both ATN and alkali concentrations. The order in ruthenium(III) was unity. Intervention of free radicals was observed in the reaction. Increase in periodate concentration decreases the rate. The oxidation reaction in alkaline medium has been shown to proceed via a ruthenium(III)-atenolol complex, which reacts with monoperiodatocuprate(III) in a rate determining step followed by other fast steps to give the products. Probable mechanism is proposed and discussed. The activation parameters with respect to the slow step of the mechanism and thermodynamic quantities were determined and discussed. Pleiades Publishing, Ltd., 2012.
- Patil,Nandibewoor,Chimatadar
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- Synthesis method of N-methylisopropylamine
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The invention relates to the field of preparation of pesticide and medical intermediates, in particular to a preparation method of N-methylisopropylamine. The method comprises the following steps: taking isopropylamine as a raw material, taking dimethyl carbonate as a reaction solvent, and carrying out heat preservation reaction under the catalysis of a basic catalyst; and after the reaction is finished, filtering to remove the catalyst, carrying out rectification separation on filtrate, and separating the solvent dimethyl carbonate from the product. The method effectively controls the generation of a byproduct disubstituted N, N-dimethyl isopropylamine, and effectively controls the conversion rate and selectivity of raw materials, and compared with the prior art, the novel synthesis method of N-methyl isopropylamine has the following effective effects: the raw materials are easy to obtain, the reaction is mild, the reaction steps are simple, the cost of the raw materials is lower, the selected solvent dimethyl carbonate is relatively low in toxicity and can be recycled, so that the product is a green chemical product with a development prospect, and the method is extremely low in three-waste amount and relatively great in industrial application prospect.
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Paragraph 0017; 0026-0035
(2021/05/29)
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- Reviving electrocatalytic reductive amination: A sustainable route from biogenic levulinic acid to 1,5-dimethyl-2-pyrrolidone
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The electrocatalytic reductive amination offers a green pathway to N-containing platform and fine chemicals by using water as a hydrogen source and benign reaction conditions. However, systematic studies about suitable reaction conditions and application to biogenic substrates are rare. Here, we present the electrochemical transformation of levulinic acid to 1,5-dimethyl-2-pyrrolidone. Data from Smirnov et al. for the amination of conventional ketones were validated and extended by systematically investigating the impact of electrode material, substrate concentration, current density, solvent, electrolyte, and pH value. High substrate concentrations in an aqueous electrolyte with a high pH value enable imine formation and copper is identified as the most selective cathode material at current densities lower than 40 mA cm-2. The application of optimized reaction conditions to levulinic acid, followed by a short heating procedure for dehydrative ring closure, led to 1,5-dimethyl-2-pyrrolidone in 78% yield. The systematic approach of this work presents the first example of an electrochemical levulinic acid amination and provides a methodology for the benign synthesis of other N-containing species. This journal is
- Holzh?user, F. Joschka,Kurig, Nils,Mürtz, Sonja D.,Palkovits, Regina
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p. 8428 - 8433
(2021/11/17)
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- Photometric Characterization of the Reductive Amination Scope of the Imine Reductases from Streptomyces tsukubaensis and Streptomyces ipomoeae
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Imine reductases (IREDs) have emerged as promising enzymes for the asymmetric synthesis of secondary and tertiary amines starting from carbonyl substrates. Screening the substrate specificity of the reductive amination reaction is usually performed by time-consuming GC analytics. We found two highly active IREDs in our enzyme collection, IR-20 from Streptomyces tsukubaensis and IR-Sip from Streptomyces ipomoeae, that allowed a comprehensive substrate screening with a photometric NADPH assay. We screened 39 carbonyl substrates combined with 17 amines as nucleophiles. Activity data from 663 combinations provided a clear picture about substrate specificity and capabilities in the reductive amination of these enzymes. Besides aliphatic aldehydes, the IREDs accepted various cyclic (C4–C8) and acyclic ketones, preferentially with methylamine. IR-Sip also accepted a range of primary and secondary amines as nucleophiles. In biocatalytic reactions, IR-Sip converted (R)-3-methylcyclohexanone with dimethylamine or pyrrolidine with high diastereoselectivity (>94–96 % de). The nucleophile acceptor spectrum depended on the carbonyl substrate employed. The conversion of well-accepted substrates could also be detected if crude lysates were employed as the enzyme source.
- Matzel, Philipp,Krautschick, Lukas,H?hne, Matthias
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p. 2022 - 2027
(2017/10/07)
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- Ligand-controlled α- And β-arylation of acyclic N-boc amines
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The palladium-catalyzed ligand-controlled arylation of α-zincated acyclic amines, obtained by directed α-lithiation and transmetalation, is described. Whereas PtBu3 gave rise to α-arylated Boc-protected amines, more flexible N-phenylazole-based phosphine ligands induced major β-arylation through migrative cross-coupling. All manner of control: The arylation of α-zincated acyclic Boc-protected amines was selectively performed at the α- or β-position in a ligand-controlled manner. α-Arylation occurs by direct reductive elimination of the α-palladated intermediate whereas β-arylation involves palladium migration along the alkyl chain. Boc=tert-butoxycarbonyl.
- Millet, Anthony,Dailler, David,Larini, Paolo,Baudoin, Olivier
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supporting information
p. 2678 - 2682
(2014/03/21)
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- METHOD FOR THE CONTINUOUS PRODUCTION OF AN AMINE
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The invention relates to a method for the continuous production of an amine by reacting a primary or secondary alcohol, aldehyde and/or ketone with hydrogen and a nitrogen compound, selected from the group including ammonia, primary and secondary amines, at a temperature in the range of from 80 to 350 °C in the presence of a zirconium dioxide-containing catalyst, the catalytically active weight of the catalyst prior to its reduction with hydrogen containing 90 to 99.8 % by weight of zirconium dioxide (ZrO2), 0.1 to 5.0 % by weight of oxygen-containing compounds of palladium and 0.1 to 5.0 % by weight of oxygen-containing compounds of platinum.
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Page/Page column 22
(2008/06/13)
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- Kinetic and mechanistic investigation of oxidative degradation and deamination of atenolol by diperiodatonickelate(IV) in aqueous alkaline medium
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The kinetics of oxidation of atenolol by diperiodatonickelate(IV) (DPN) in aqueous alkaline medium at a constant ionic strength of 1.0 mol dm-3 was studied spectrophotometrically. The reaction is first order in [DPN], less than unit order in [alkali] and zero order in [ATN]. Addition of periodate has no effect on the reaction. Effect of added products, ionic strength and dielectric constant of the reaction medium have been investigated. The main products were identified by I.R., N.M.R., fluorimetry and mass spectral studies. A mechanism involving the deprotonated diperiodatonickelate (IV) (DPN) as the reactive species of the oxidant has been proposed. The reaction constants involved in the different steps of mechanism are calculated. The thermodynamic activation parameters with respect to the slow step of the mechanism are computed and discussed.
- Mulla, R. M.,Kulkarni, R. M.,Nandibewoor, S. T.
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p. 601 - 620
(2007/10/03)
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- Electrochemical oxidation of N-p-toluenesulfinamides
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Matrix presented Contrasting and interesting electrochemical behavior is observed in anodic oxidation of N-substituted p-toluenesulfinamides under controlled current conditions. For sulfinamides derived from secondary alkylamines and primary arylamines, the N-sulfinyl group is removed and the corresponding amines are formed; for sulfinamides derived from primary alkylamines, sulfur oxidation yields the corresponding sulfonamides in good yields.
- D'Oca, Marcelo G. Montes,Russowsky, Dennis,Canto, Karen,Gressler, Tanara,Goncalves, Reinaldo S.
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p. 1763 - 1766
(2007/10/03)
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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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- Stereodynamics of N-Ethyl-N-methyl-2-aminopropane. 1H and 13C DNMR Studies. Molecular Mechanics Calculations
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N-Ethyl-N-methyl-2-aminopropane (EMAP) is one of the simplest tertiary aliphatic amines that has a chiral center at nitrogen.Racemization occurs by inversion-rotation at the pyramidal nitrogen.For each EMAP enantiomer, additional conformational interconversions occur via isolated rotation about carbon-nitrogen bonds.The 1H and 13C dynamic NMR (DNMR) spectra of EMAP and a selectively deuterated derivative decoalesce into four subspectra at 95 K.The spectrum at 95 K is best rationalized in terms of five equilibrium conformations present at concentrations high enough to be NMR-detectable including two conformations that interchange rapidly even at 95 K.A two-letter designation is used to name the various conformations.The first letter defines the orientation of the ethyl methyl group (G denotes gauche to the lone pair and to the N-methyl group; G' denotes gauche to the lone pair and to the isopropyl group; A denotes anti to the lone pair).The second letter defines the orientation of the isopropyl methine proton (G denotes gauche to the lone pair and to the N-methyl group; G' denotes gauche to the lone pair and to the ethyl group; A denotes anti to the lone pair).The major subspectrum at 95 K is assigned to a family of G'G' and GG' conformations (59percent) that interconvert rapidly at 95 K.The other three subspectra are assigned to the GG (34percent), AA (5percent), and GA (2percent) conformations.Simulations of the DNMR spectra reveal a barrier to inversion-rotation at nitrogen (ΔG(excit.) = 7.5 kcal/mol at 160 K) that is higher than the barriers for a number of observable isolated rotations about the N-CH2 and N-CH bonds (ΔG(excit.) = 4.7-6.4 kcal/mol).A 5000-point optimized energy surface computed as a function of two dihedral angles by using Allinger's MM2(87) computer program, MM2(87) energy calculations for all the optimized equilibrium conformations of EMAP, and MM2(87)-calculated isolated rotation barriers show excellent agrreement with the DNMR data.
- Brown, Jay H.,Bushweller, C. Hackett
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p. 11411 - 11419
(2007/10/02)
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- ELECTROCHEMICAL REDUCTIVE AMINATION. I. AMINATION OF ALIPHATIC KETONES BY PRIMARY AMINES
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The reductive amination of aliphatic ketones in aqueous solutions of primary amines was realized by an electrochemical method.The best yields of the secondary amines were obtained at lead and cadmium cathodes in an aqueous electrolytic solution at pH 11-12.Elongation and branching in the carbon chain of the radicals both of the ketone and of the primary amine lead to a reduction in the yield of the secondary amine.The yield of the secondary amine is mainly determined by the rate of the chemical reaction leading to the formation of the azomethine compound, preceding the electrochemical reduction stage.
- Smirnov, Yu. D.,Tomilov, A. P.
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- PHOSPHONIUM DIAZA-DIYLIDS AND AZA-YLDIID AS NEW AND EFFICIENT REAGENTS FOR PRIMARY AND SECONDARY AMINES SYNTHESIS
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Metallated aminophosphonium ylids, diaza-diylids and aza-yldiid, are investigated as reagents for primary and secondary amines synthesis.
- Cristau, Henri-Jean,Garcia, Chantal,Kadoura, Jumah,Torreilles, Eliane
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p. 151 - 154
(2007/10/02)
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- Reactions of Carbonyl Compounds in Basic Solutions. Part 15. The Alkaline Hydrolysis of N-Methyl, N-Phenyl and Bicyclo Lactams, Penicillins and N-Alkyl-N-methylacetamides
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The rate coefficients for the alkaline hydrolysis of a series of N-methyl, N-phenyl and bicyclo lactams, penicillins and N-alkyl-N-methylacetamides in water or in aqueous dimethyl sulphoxide have been measured at several temperatures.The reactions were first order in both substrates and base.The reactivities are related to the structures of the substrates, especially N-substitution, ring size and fused ring effects.The reactivities, as well as the activation parameters, kinetic solvent and solvent isotope effects, are used to suggest the detailed mechanisms.All the β-lactams appear to react with rate-determining addition of hydroxide anion; while the N-alkyl γ- and δ-lactams and N-alkyl-N-methylacetamides have rate-determining ring fission of the tetrahedral adduct, assisted by water-catalysis.The reactivity of penicillin in alkaline hydrolysis has been analysed by studies of model compounds.These show that the increased reactivity of the penicillin β-lactam ring arises from the direct action of the fused ring structure and the acetylamino side chain.
- Bowden, Keith,Bromley, Keith
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p. 2111 - 2116
(2007/10/02)
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- Katalytische C-C- und C-N-Kupplungsreaktionen von Carbodiimiden durch Uebergangsmetallcluster
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N,N'-Dialkyl carbodiimides react with hydrogen in the presence of ruthenium clusters to give new N,N',N''-trialkyl guanidines.The reaction with terminal acetylenes, catalyzed by a bimetallic cluster system, leads to new N,N'-dialkyl propiolamidines.
- Schmidt, Gerhard F.,Suess-Fink, Georg
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p. 207 - 212
(2007/10/02)
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- Ion-Dipole Complexes in the Unimolecular Reactions of Isolated Organic Ions. Effect of N-Methylation on Olefin and Amine Loss from Protonated Aliphatic Amines
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The slow unimolecular fragmentation reactions os 18 gaseous protonated aliphatic amines of general formula R1NH(1+)R2R3 (R1=Prn, Pri, Bun, Bui, Bus, or But; R2,R3=H,CH3) are reported and discussed.Two decomposition routes are observed for a metastable ions R1NH(1+)R2R3.The first involves elimination of a neutral amine, R2R3NH, and formation of a carbocation, R1(1+), via a mechanism involving an incipient cation bound to the developing amine by an ion-dipole attraction.Rearrangement of the cation, to give thermodynamically more stable isomers, is feasible in these ion-dipole complexes.Further reorganization of the complexes leads to a species in which an incipient olefin 1-H> and an amine 2R3NH> are co-ordinated to a common proton.Dissociation of these proton-bound complexes, with retention of the proton by the developing amine, results in olefin loss, which is the secondreaction undergone by metastable ions R1NH(1+)R2R3.The relative abundance of amine expulsion is greater for protonated amines containing a primary alkyl group, R1, than is the case for isomeric ions containing secondary or tertiary alkyl groups.Progressive methylation of the nitrogen atom decreases the relative abundance of amine loss from R1NH(1+)R2R3, regardless of the nature of the principal alkyl group.These two trends are explained in terms of the energetics of the intermediates and products involved in the decomposition of the protonated amines.
- Bowen, Richard D.,Harrison, Alex G.,Reiner, Eric J.
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p. 1009 - 1014
(2007/10/02)
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- BESTIMMUNG DER IONENPAAR-BASIZITAT VON LITHIUM- UND KALIUMAMIDEN
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Ion pair basicities of lithio and potassio salts of some secondary amines were determined by equilibration with benzyl compounds.With these bases it is possible to span a range of about 19 pK-units from pK = 27 up to 46.The structural dependence of thermodynamic as well as kinetic basicity is discussed.Some new effective amide bases for preparative purposes are recommended.For the first time the pK-value of toluene has been determined by direct equilibration.It amounts to 40.7 in tetrahydrofuran.
- Ahlbrecht, Hubertus,Schneider, Gunther
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p. 4729 - 4742
(2007/10/02)
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