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Reductive Amination (reductive + amination)
Kinds of Reductive Amination Selected AbstractsEfficient and Highly Chemoselective Direct Reductive Amination of Aldehydes using the System Silane/Oxorhenium ComplexesADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 13 2010Sara C. A. Sousa Abstract This work reports a novel method for direct reductive amination of aldehydes with silanes catalyzed by several high-valent oxorhenium(V) and oxorhenium(VII) complexes. The catalytic system PhSiH3/ReIO2(PPh3)2 (2.5,mol%) was very efficient for the synthesis of secondary amines and highly chemoselective, tolerating a wide range of functional groups such as NO2, CF3, SO2R, CO2R, F, Cl, Br, I, CN, OH, OCH3, SCH3, NCOR, and double bonds. This novel method was also employed in the synthesis of tertiary amines with moderate yields. [source] Single Nucleotide-Catalyzed Biomimetic Reductive AminationADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 13 2010Atul Kumar Abstract We have successfully developed a single nucleotide (adenosine 5,-diphosphate)-catalyzed enantioselective direct reductive amination of aldehydes and ketones using a Hantzsch ester as reducing agent. The process is a simple, efficient and a real mimic of the NADH reduction approach for the synthesis of structurally diverse amines. This reaction is the first report demonstrating the ability of a single nucleotide as catalyst and one of the most genuine biomimetic reactions of organic chemistry. [source] Chiral Amine Synthesis , Recent Developments and Trends for Enamide Reduction, Reductive Amination, and Imine ReductionADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 5 2010Thomas Abstract The review examines the chiral amine literature from 2000,2009 (May) concerning enantioselective and diastereoselective methods for N -acylenamide and enamine reduction, reductive amination, and imine reduction. The reaction steps for each strategy, from ketone to primary chiral amine, are clearly defined, with best methods and yields for starting material preparation and final deprotection noted. Categories of chiral amines have been defined in Section 1 to allow the reader to quickly understand whether their specific target amine falls within a difficult to synthesize, or not, structural class. Amino acids are not considered in this work. [source] Origin of Enantioselectivity in the Organocatalytic Reductive Amination of ,-Branched AldehydesADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 4 2009Tommaso Marcelli Abstract The reason for enantioselectivity in the reductive amination of ,-branched aldehydes was investigated. The relative energies of all the diastereomeric transition states for hydride transfer of a suitable computational model were calculated at the B3LYP/6-311+G(2d,2p) level of theory. Our calculations successfully reproduce and rationalize the experimentally observed stereochemical outcome of the reaction. [source] A Versatile Catalyst for Reductive Amination by Transfer Hydrogenation,ANGEWANDTE CHEMIE, Issue 41 2010Chao Wang Ein Iridiumkatalysator ermöglicht die reduktive Aminierung von Carbonylgruppen mit beispielloser Substratbreite, Selektivität und Aktivität in Gegenwart von Ameisensäure als Wasserstoffquelle (siehe Schema). Das Katalysatorsystem ist wesentlich besser als die verbreitet eingesetzten Borhydride. [source] Catalytic Asymmetric Reductive Amination of ,-Branched Ketones,ANGEWANDTE CHEMIE, Issue 27 2010Vijay Maßgebliche Substituenten: Die Titelreaktion nutzt die dynamische kinetische Racematspaltung und liefert so cis -2-substituierte Cyclohexylamine mit hohen Diastereo- und Enantioselektivitäten. [source] ChemInform Abstract: One-Pot Reductive Amination of Carbonyl Compounds Using Sodium Borohydride,Amberlyst 15.CHEMINFORM, Issue 40 2010Heshmatollah Alinezhad Abstract The title reaction can also be carried out in THF at 25 °C with comparable yields. [source] ChemInform Abstract: Highly Chemoselective Reductive Amination of Carbonyl Compounds Promoted by InCl3/Et3SiH/MeOH System.CHEMINFORM, Issue 15 2009On-Yi Lee Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source] ChemInform Abstract: Hydrogen-Transfer Reductive Amination of Aldehydes Catalyzed by Nickel Nanoparticles.CHEMINFORM, Issue 40 2008Francisco Alonso Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source] ChemInform Abstract: One-Pot Reductive Amination of Aldehydes Catalyzed by a Hydrio-Iridium(III) Complex in Aqueous Medium.CHEMINFORM, Issue 36 2008Rung-Yi Lai Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source] ChemInform Abstract: Effect of Hydrochloric Acid on the Reductive Amination of 1-(3-Nitropyridin-2-yl)pyridinium Salts.CHEMINFORM, Issue 4 2008R. S. Begunov Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source] Diastereoselective Reductive Amination of Aryl Trifluoromethyl Ketones and ,-Amino Esters.CHEMINFORM, Issue 27 2007Greg Hughes Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF. [source] Direct Reductive Amination and Selective 1,2-Reduction of ,,,-Unsaturated Aldehydes and Ketones by NaBH4 Using H3PW12O40 as Catalyst.CHEMINFORM, Issue 21 2007Akbar Heydari Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF. [source] Direct Reductive Amination of Carbonyl Compounds Using Bis(triphenylphosphine) Copper(I) Tetrahydroborate.CHEMINFORM, Issue 21 2007Mayur J. Bhanushali Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF. [source] Rapid Microwave-Assisted Reductive Amination of Ketones with Anilines.CHEMINFORM, Issue 4 2007Helen V. Bailey Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF. [source] Enantioselective Organocatalytic Reductive Amination.CHEMINFORM, Issue 21 2006R. Ian Storer Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF. [source] Microwave-Accelerated Methodology for the Direct Reductive Amination of AldehydesCHEMINFORM, Issue 18 2006Jussi J. Kangasmetsae Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF. [source] Efficient Synthesis of N-Alkyl Tetrahydroisoquinolines by Reductive Amination.CHEMINFORM, Issue 51 2005Hephzibah J. Kumpaty Abstract For Abstract see ChemInform Abstract in Full Text. [source] Effective Reductive Amination of Carbonyl Compounds with Hydrogen Catalyzed by Iridium Complex in Organic Solvent and in Ionic Liquid.CHEMINFORM, Issue 45 2005Daisuke Imao Abstract For Abstract see ChemInform Abstract in Full Text. [source] Synthesis of Hydroquinone-, Biphenol-, and Binaphthol-Containing Aza Macroheterocycles via Regioselective Hydroformylation and Reductive Amination.CHEMINFORM, Issue 5 2004Goran Angelovski Abstract For Abstract see ChemInform Abstract in Full Text. [source] ChemInform Abstract: Reductive Amination of 1-[3-(2-Alkylbenzofuranyl)]-2-phenylethanones.CHEMINFORM, Issue 37 2001Synthesis of 1-[3-(2-Alkylbenzofuranyl)]-2-phenylethylamines. Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source] Capillary electrophoresis analysis of glucooligosaccharide regioisomersELECTROPHORESIS, Issue 6 2004Gilles Joucla Abstract Complex gluco-oligosaccharide mixtures of two regioisomer series were successfully separated by CE. The gluco-oligosaccharide series were synthesized, employing a dextransucrase from Leuconostoc mesenteroides NRRL B-512F, by successive glucopyranosyl transfers from sucrose to the acceptor glucose or maltose. The glucosyl transfer to both acceptors, occurring through the formation of ,1,6 linkages, differed for the two series only in the glucosidic bond to the reducing end namely ,1,6 or ,1,4 bond for glucose or maltose acceptor, respectively. Thus, the combination of the two series results in mixed pairs of gluco-oligosaccharide regioisomers with different degrees of polymerization (DP). These regioisomer series were first derivatized by reductive amination with 9-aminopyrene-1,4,6-trisulfonate (APTS). Under acidic conditions using triethyl ammonium acetate as electrolyte, the APTS-gluco-oligosaccharides of each series were separated enabling unambiguous size determination by coupling CE to electrospray-mass spectrometry. However, neither these acidic conditions nor alkaline buffer systems could be adapted for the separation of the gluco-oligosaccharide regioisomers arising from the two combined series. By contrast, increased resolution was observed in an alkaline borate buffer, using differential complexation of the regioisomers with the borate anions. Such conditions were also successfully applied to the separation of glucodisaccharide regioisomers composed of ,1,2, ,1,3, ,1,4, and ,1,6 linkages commonly synthesized by glucansucrase enzymes. [source] Synthesis of Amino-Bridged Oligosaccharide MimeticsEUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 5 2010Janna Neumann Abstract Synthesis of amino-bridged oligosaccharides using reductive amination opens rapid access to novel glycomimetic target structures as potential ligands for the receptor protein NKR P1 of natural killer cells. Emphasis was laid on fast and facile synthetic routes. The carbonyl building blocks were easily obtained by oxidation with Dess,Martin periodinane or iodoxybenzoic acid (IBX). For the required amino-functionalized units, reduction of azide precursors was advantageous, and generation of the novel oligosaccharides was achieved by subsequent reductive amination. The target saccharide structures feature a bridging nitrogen atom inserted between two non-anomeric positions as well as including one anomeric position. [source] A Practical and Efficient Approach to PNA Monomers Compatible with Fmoc-Mediated Solid-Phase Synthesis Protocols,EUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 34 2008Andrea Porcheddu Abstract A straightforward synthesis of orthogonally protected PNA monomers is described. Protected aminoethylglycine (Aeg) monomers were efficiently prepared by reductive amination of N -Fmoc-glycinaldehyde with glycine methyl ester and the subsequent acylation of the free amine with N -bis-Boc-protected nucleobase acetic acids. The exocyclic amine group of the nucleobases, including the notoriously difficult-to-protect guanine nucleobase, was protected with a bis-Boc carbamate group; this increased the solubility of the nucleobases in the most common organic solvents. The current protocol allows all Aeg monomers to be prepared on both the micro- and macroscale, which avoids or minimizes the use of toxic reagents or solvents, and moreover, cheap starting materials are used. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008) [source] Synthesis of Novel Di- and Trisaccharide Mimetics with Non-Glycosidic Amino BridgesEUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 7 2007Janna Neumann Abstract Synthesis of novel di- and trisaccharides using enzymatic glycosylation, Dess,Martin oxidation and reductive amination allows rapid access to the target structures. Thus, a novel class of glycomimetics was obtained having nitrogen inserted as bridging atom between two non-anomeric positions. Novel di- and trisaccharide mimetics were designed using N -acetylglucosamine as a basis structure. A third monosaccharide unit was attached via an unnatural sugar,sugar bond without participation of the anomeric center. Their synthesis, proceeding via oxidation, glycosylation and reductive amination, required only a few steps, thus allowing rapid access to the target structures. Generation of the novel pseudo-disaccharide was achieved by Dess,Martin oxidation and a subsequent reductive amination. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007) [source] Conversion of a glutamate dehydrogenase into methionine/norleucine dehydrogenase by site-directed mutagenesisFEBS JOURNAL, Issue 22 2001Xing-Guo Wang In earlier attempts to shift the substrate specificity of glutamate dehydrogenase (GDH) in favour of monocarboxylic amino-acid substrates, the active-site residues K89 and S380 were replaced by leucine and valine, respectively, which occupy corresponding positions in leucine dehydrogenase. In the GDH framework, however, the mutation S380V caused a steric clash. To avoid this, S380 has been replaced with alanine instead. The single mutant S380A and the combined double mutant K89L/S380A were satisfactorily overexpressed in soluble form and folded correctly as hexameric enzymes. Both were purified successfully by Remazol Red dye chromatography as routinely used for wild-type GDH. The S380A mutant shows much lower activity than wild-type GDH with glutamate. Activities towards monocarboxylic substrates were only marginally altered, and the pH profile of substrate specificity was not markedly altered. In the double mutant K89L/S380A, activity towards glutamate was undetectable. Activity towards l -methionine, l -norleucine and l -norvaline, however, was measurable at pH 7.0, 8.0 and 9.0, as for wild-type GDH. Ala163 is one of the residues that lines the binding pocket for the side chain of the amino-acid substrate. To explore its importance, the three mutants A163G, K89L/A163G and K89L/S380A/A163G were constructed. All three were abundantly overexpressed and showed chromatographic behaviour identical with that of wild-type GDH. With A163G, glutamate activity was lower at pH 7.0 and 8.0, but by contrast higher at pH 9.0 than with wild-type GDH. Activities towards five aliphatic amino acids were remarkably higher than those for the wild-type enzyme at pH 8.0 and 9.0. In addition, the mutant A163G used l -aspartate and l -leucine as substrates, neither of which gave any detectable activity with wild-type GDH. Compared with wild-type GDH, the A163 mutant showed lower catalytic efficiencies and higher Km values for glutamate/2-oxoglutarate at pH 7.0, but a similar kcat/Km value and lower Km at pH 8.0, and a nearly 22-fold lower S0.5 (substrate concentration giving half-saturation under conditions where Michaelis,Menten kinetics does not apply) at pH 9.0. Coupling the A163G mutation with the K89L mutation markedly enhanced activity (100,1000-fold) over that of the single mutant K89L towards monocarboxylic amino acids, especially l -norleucine and l -methionine. The triple mutant K89L/S380A/A163G retained a level of activity towards monocarboxylic amino acids similar to that of the double mutant K89L/A163G, but could no longer use glutamate as substrate. In terms of natural amino-acid substrates, the triple mutant represents effective conversion of a glutamate dehydrogenase into a methionine dehydrogenase. Kinetic parameters for the reductive amination reaction are also reported. At pH 7 the triple mutant and K89L/A163G show 5 to 10-fold increased catalytic efficiency, compared with K89L, towards the novel substrates. In the oxidative deamination reaction, it is not possible to estimate kcat and Km separately, but for reductive amination the additional mutations have no significant effect on kcat at pH 7, and the increase in catalytic efficiency is entirely attributable to the measured decrease in Km. At pH 8 the enhancement of catalytic efficiency with the novel substrates was much more striking (e.g. for norleucine ,,2000-fold compared with wild-type or the K89L mutant), but it was not established whether this is also exclusively due to more favourable Michaelis constants. [source] A convenient synthesis of oxazolidinone derivatives linezolid and eperezolid from (S)-glyceraldehyde acetonideHETEROATOM CHEMISTRY, Issue 3 2008Guangyu Xu A new convenient method for the synthesis of oxazolidinone antibacterials Linezolid and Eperezolid from readily available (S)-glyceraldehyde acetonide was developed. The key steps include reductive amination of arylamine and (S)-glyceraldehyde acetonide in the presence of NaBH4 and 4 Å sieve, followed by hydrolysis and regioselective cyclization. © 2008 Wiley Periodicals, Inc. Heteroatom Chem 19:316,319, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.20435 [source] Efficient and Highly Chemoselective Direct Reductive Amination of Aldehydes using the System Silane/Oxorhenium ComplexesADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 13 2010Sara C. A. Sousa Abstract This work reports a novel method for direct reductive amination of aldehydes with silanes catalyzed by several high-valent oxorhenium(V) and oxorhenium(VII) complexes. The catalytic system PhSiH3/ReIO2(PPh3)2 (2.5,mol%) was very efficient for the synthesis of secondary amines and highly chemoselective, tolerating a wide range of functional groups such as NO2, CF3, SO2R, CO2R, F, Cl, Br, I, CN, OH, OCH3, SCH3, NCOR, and double bonds. This novel method was also employed in the synthesis of tertiary amines with moderate yields. [source] Single Nucleotide-Catalyzed Biomimetic Reductive AminationADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 13 2010Atul Kumar Abstract We have successfully developed a single nucleotide (adenosine 5,-diphosphate)-catalyzed enantioselective direct reductive amination of aldehydes and ketones using a Hantzsch ester as reducing agent. The process is a simple, efficient and a real mimic of the NADH reduction approach for the synthesis of structurally diverse amines. This reaction is the first report demonstrating the ability of a single nucleotide as catalyst and one of the most genuine biomimetic reactions of organic chemistry. [source] Deracemisation of Mandelic Acid to Optically Pure Non-Natural L -Phenylglycine via a Redox-Neutral Biocatalytic CascadeADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 6 2010Verena Resch Abstract A biocatalytic redox-neutral reaction cascade was designed for the deracemisation of racemic mandelic acid to yield optically pure L -phenylglycine employing three enzymes. The cascade consisted of three steps: a racemisation, an enantioselective oxidation and a stereoselective reductive amination. The enantioselective oxidation of D -mandelic acid to the corresponding oxo acid was coupled with the stereoselective reductive amination of the latter; thus the oxidation as well as the reduction reactions were performed simultaneously. The formal hydrogen abstracted in the first step , the oxidation , was consumed in the reductive amination allowing a redox-neutral cascade due to a cascade-internal cofactor recycling. The enantiomers of the starting material were interconverted by a racemase (mandelate racemase) ensuring that in theory 100% of the starting material can be transformed. Using this set-up racemic mandelic acid was transformed to optically pure L -phenylglycine (ee >97%) at 94% conversion without the requirement of any additional redox reagents in stoichiometric amounts. [source] | ||||||||||||||||||||||||||||