Transition metal and enzyme catalyzed reactions involving reactions with ammonia and amines

Roundhill, D. Max

doi:10.1021/cr00009a001

Cited by 363 publications

(156 citation statements)

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“…Due to the commercial importance of amines, amides, ammonium and alkylammonium salts, ureas, carbamates, isocyanates and amino acids, this reaction have gained considerable importance in synthetic organic and industrial chemistry [1]. The classical method for imine synthesis is amination of aldehydes or ketones, but direct hydroamination of alkynes with amines is 100% atom efficient and thermodynamically feasible hence can be used in domino reactions, where water is an undesired side product.…”

Section: Introductionmentioning

confidence: 99%

Hydroamination of Terminal Alkynes by Amines Catalyzed by Copper Heteropoly Salts: A Simple Approach Towards Imine Synthesis

Shanbhag¹,

Palraj²,

Halligudi³

2008

TOOCJ

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Abstract:The hydroamination reaction offers a very attractive route for the synthesis of alkylated amines and their derivatives with no byproduct formation. Heterogeneous intermolecular hydroamination reactions of alkynes with aromatic amines using different inexpensive copper salts of hetropolyacid catalysts were investigated. Among heteropoly salts, copper salts of silicotungstic acid showed highest activity. Reactivity of aromatic amines increased with increase in its basicity. Acidity in heterogeneous catalyst can act as promoter in hydroamination of alkynes.

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Section: Introductionmentioning

confidence: 99%

Hydroamination of Terminal Alkynes by Amines Catalyzed by Copper Heteropoly Salts: A Simple Approach Towards Imine Synthesis

Shanbhag¹,

Palraj²,

Halligudi³

2008

TOOCJ

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“…Stimulated by this difference in behavior, we set out to determine the preferred mode of reactivity in the well-characterized parent hydroxo and amide complexes: trans-(DMPE) 2 2 (H)Ru(OH) (2) (DMPE = 1,2-bis(dimethylphosphino) ethane). 8,12 This study has uncovered only 2-electron behavior for both the OH and NH 2 metal-bound fragments, and has revealed that complex 1 bears a surprisingly basic amido ligand, a property that is expressed without dissociation of the NH 2 group from the ruthenium center.…”

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confidence: 99%

Reactivity of a Parent Amidoruthenium Complex: A Transition Metal Amide of Exceptionally High Basicity

Fulton

2000

J. Am. Chem. Soc.

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Complexes with late metal-oxygen and -nitrogen single bonds (metal alkoxides and amides) play important roles in biological systems and have been implicated as intermediates in a variety of industrially important catalytic reactions. 1-3 When the metal-heteroatom bond reacts with carbon-hydrogen bonds of organic molecules, an important question concerns whether the transformation takes place via odd-or even-electron intermediates. For example, many late metal alkoxides undergo rapid overall even-electron RO − transfer reactions with electrophiles. 4-8 In other cases, metal-oxygen bonds have been proposed to react by initial hydrogen atom abstraction, an odd-electron process. 9-11 Stimulated by this difference in behavior, we set out to determine the preferred mode of reactivity in the well-characterized parent hydroxo and amide complexes: trans-(DMPE) 2 (H)-Ru(NH 2 ) (1) and trans-(DMPE) 2 (H)Ru(OH) (2) (DMPE = 1,2-bis(dimethylphosphino) ethane). 8,12 This study has uncovered only 2-electron behavior for both the OH and NH 2 metal-bound fragments, and has revealed that complex 1 bears a surprisingly basic amido ligand, a property that is expressed without dissociation of the NH 2 group from the ruthenium center.In analogy to reactions reported by Stack and Mayer and their co-workers, 9,11 our ruthenium amido and hydroxido complexes 1 and 2 cause the dehydrogenation of cyclohexadiene (1,4-CHD) and 9,10-dihydroanthracene (DHA) (eq 1). However, compounds 1 and 2 also catalyze the interconversion of 1,4-and 1,3-CHD more rapidly (t 1/2 = <5 min) than dehydrogenation occurs.The dehydrogenation and isomerization reactions could proceed by initial abstraction of a hydrogen atom (although the required oxidation state change is less favorable here than in the earlier-reported systems) or a proton, in addition to pathways that might involve interaction of the diene with the metal center. To explore this question, we extended the above reactions to a larger series of organic compounds having C-H bonds characterized by a wide range of bond dissociation energies and acidities.Two interrelated modes of reactivity were observed with organic compounds containing relatively acidic C-H bonds (Scheme 1). The first includes the generation of a stable ion pair formed by overall proton transfer from carbon to ruthenium-bound nitrogen (e.g., 1 + fluorene → 4a in THF or benzene). 13 The second is overall displacement of the nitrogen fragment from

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“…Higher reaction temperature results in the formation of thermodynamically more stable secondary, tertiary or cyclic amines with six-membered ring (pyrazines and/or piperazines). Actually, the formation of these substances is exothermic, whereas the reaction leading to primary amines is nearly thermoneutral 5,22 . The formed DMPIPs contain secondary nitrogen atoms in their molecules and, therefore, they can subsequently undergo the reductive amination to N-mono-or N,N-di-substituted dimethyl piperazines (N-SubDMPIPs).…”

Section: Effect Of Catalystmentioning

confidence: 99%

Reductive Amination of 1-Hydroxy-2-propanone Over Nickel and Copper Catalysts

Trégner¹

2018

Chem.Biochem.Eng.Q.

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The one-step reductive amination of 1-hydroxy-2-propanone (acetol) with ammonia to 2-aminopropanol (2-APOL) over commercial nickel and copper catalysts has been studied in the continuous fixed-bed reactor at the temperature from 130 to 220 °C and different molar ratios of reactants. It was found that the optimal molar ratios of H 2 /acetol and H 2 /NH 3 regarding the selectivity of 2-APOL were 25 and 1, respectively. The highest selectivity of approx. 45 % to desired 2-APOL at total conversion of acetol was achieved in the presence of the nickel catalyst. Major by-products of amination were cis and trans isomers of 2,5-and 2,6-dimethylpiperazines. Mechanism of the formation of these and other detected and/or potential by-products is discussed. So far, unpublished mass spectra of identified by-products, such as N-substituted dimethylpiperazines or various aminoalcohols, are reported in this paper.

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Transition metal and enzyme catalyzed reactions involving reactions with ammonia and amines

Cited by 363 publications

References 50 publications

Hydroamination of Terminal Alkynes by Amines Catalyzed by Copper Heteropoly Salts: A Simple Approach Towards Imine Synthesis

Hydroamination of Terminal Alkynes by Amines Catalyzed by Copper Heteropoly Salts: A Simple Approach Towards Imine Synthesis

Reactivity of a Parent Amidoruthenium Complex: A Transition Metal Amide of Exceptionally High Basicity

Reductive Amination of 1-Hydroxy-2-propanone Over Nickel and Copper Catalysts

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