- Enhancing the efficiency of the ruthenium catalysts in the reductive amination without an external hydrogen source
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Catalytic reductive reactions are essential for laboratory and industrial-scale organic synthesis. However, the nowadays trend is the development of new, progressively more complicated reducing systems, which hinders the application of such highly efficie
- Afanasyev, Oleg I.,Chusov, Denis,Fatkulin, Artemy R.,Tsygankov, Alexey A.
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p. 404 - 409
(2022/01/13)
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- Nickel(II)-NΛNΛO Pincer Type Complex-Catalyzed N-alkylation of Amines with Alcohols via the Hydrogen Autotransfer Reaction
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A highly sustainable catalytic protocol for the coupling of alcohols and amines for selective monoalkylated amines using Ni(II)-NΛNΛO pincer type complexes through the borrowing hydrogen methodology is described. An array of Ni(II) catalysts (1-3) was synthesized and characterized by various spectral and analytical methods. Furthermore, the distorted square planar geometry of the complexes (1 and 2) was substantiated with single crystal X-ray diffraction study. The inexpensive nickel-based catalytic methodology displays a broad substrate scope for the N-alkylation of aromatic and heteroaromatic amines using a diverse range of primary alcohols with excellent yields up to 97%. The present approach is environmentally benign, which liberates water as the sole byproduct. A short synthesis of drug intermediates such as mepyramine and chloropyramine illustrates the utility of the present protocol.
- Balamurugan, Gunasekaran,Ramesh, Rengan,Malecki, Jan Grzegorz
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p. 7125 - 7135
(2020/06/08)
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- Nickel-Catalyzed Amination of Aryl Thioethers: A Combined Synthetic and Mechanistic Study
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Herein, we report a nickel-1,2-bis(dicyclohexylphosphino)ethane (dcype) complex for the catalytic Buchwald-Hartwig amination of aryl thioethers. The protocol shows broad applicability with a variety of different functional groups tolerated under the catalytic conditions. Extensive organometallic and kinetic studies support a nickel(0)-nickel(II) pathway for this transformation and revealed the oxidative addition complex as the resting state of the catalytic cycle. All the isolated intermediates have proven to be catalytically and kinetically competent catalysts for this transformation. The fleeting transmetalation intermediate has been successfully synthesized through an alternative synthetic organometallic pathway at lower temperature, allowing for in situ NMR study of the C-N bond reductive elimination step. This study addresses key factors governing the mechanism of the nickel-catalyzed Buchwald-Hartwig amination process, thus improving the understanding of this important class of reactions.
- Bismuto, Alessandro,Delcaillau, Tristan,Müller, Patrick,Morandi, Bill
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p. 4630 - 4639
(2020/05/19)
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- Catalyst- And solvent-free efficient access to: N -alkylated amines via reductive amination using HBpin
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A sustainable approach which works under catalyst- and solvent-free conditions for the synthesis of structurally diverse secondary amines has been uncovered. This one-pot protocol works efficiently at room temperature and is compatible with a wide range of sterically and electronically diverse aldehydes and primary amines. Notably, this simple process offers scalability, excellent functional group tolerance, chemoselectivity, and is also effective at the synthesis of biologically relevant molecules. This journal is
- Bauri, Somnath,Pandey, Vipin K.,Rit, Arnab
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p. 3853 - 3857
(2020/07/27)
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- Cobalt-Catalyzed Reductive Alkylation of Amines with Carboxylic Acids
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Direct reductive alkylation of amines with carboxylic acid is carried out by using an inexpensive, air-stable cobalt/triphos catalytic system with molecular hydrogen as the reductant. This efficient synthetic method proceeds through reduction and condensation, followed by reduction of the in situ-generated imine into the amine in a green catalytic process.
- Emayavaramban, Balakumar,Chakraborty, Priyanka,Sundararaju, Basker
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p. 3089 - 3093
(2018/12/11)
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- A process for preparing amine compound using carbon-supported cobalt-rhodium nanoparticel catalyzed hydrogen-free recuctive amination
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The present invention relates to hydrogen-free reductive amination of an aldehyde and/or ketone and an amine and/or nitroarene using cobalt-rhodium heterometal nanoparticles supported on carbon as a non-homogeneous catalyst. According to the present invention, it is possible to carry out amination under significantly lower pressure as compared to the reductive amination carried out in the presence of a conventional rhodium or ruthenium catalyst. In addition, there is no need for using an additional ligand, acid or base. Further, it is possible to use water generated in a reaction system by a water-gas shift reaction as a hydrogen source with no use of an external hydrogen source, and thus to use a solvent without purification. Thus, it is possible to simplify the reaction procedure. The catalyst system according to the present invention provides a simple method for preparing secondary and tertiary amines from various aldehydes and amines.
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Paragraph 0066;0075
(2017/04/25)
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- Remarkable Differences in Reactivity between Benzothiazoline and Hantzsch Ester as a Hydrogen Donor in Chiral Phosphoric Acid Catalyzed Asymmetric Reductive Amination of Ketones
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Described herein are differences in behavior between a Hantzsch ester and a benzothiazoline as hydrogen donors in the chiral phosphoric acid catalyzed asymmetric reductive amination of ketones with p-anisidine. The asymmetric reductive amination of ketone
- Kim, Kyung-Hee,Akiyama, Takahiko,Cheon, Cheol-Hong
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p. 274 - 279
(2016/03/01)
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- Hydrogen-Free Cobalt-Rhodium Heterobimetallic Nanoparticle-Catalyzed Reductive Amination of Aldehydes and Ketones with Amines and Nitroarenes in the Presence of Carbon Monoxide and Water
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Cobalt-rhodium heterobimetallic nanoparticle-catalyzed reductive amination of aldehydes and ketones with amines in the presence of 5 atm carbon monoxide without an external hydrogen source has been developed. Water added and generated in situ produces hydrogen via a water-gas-shift reaction. The reaction can be extended to the tandem reduction of aldehydes and ketones with nitroarenes. The catalytic system is stable under the reaction conditions and could be reused eight times without losing any catalytic activity. (Chemical Equation Presented).
- Park, Jang Won,Chung, Young Keun
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p. 4846 - 4850
(2015/08/18)
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- Interrupted imino-nazarov cyclization of 1-aminopentadienyl cation and related cascade process
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Facile 4π conrotatory imino-Nazarov cyclization of a 1-aminopentadienyl cation generated from condensation an aldehyde and secondary aniline in the presence of a catalytic amount of a Lewis acid has been developed. Silver(I)-catalyzed intramolecular arene trapping of the resulting cyclic oxyallyl cation leads to formation of tricyclic indoline-fused cyclopentanone. The use of lanthanide salts allows transformation after the initial trapping to afford tetrahydroquinoline-fused cyclopentenone in a concise manner. Taking control: The fate of an oxyallyl cation formed through a 4π conrotatory imino-Nazarov cyclization can be controlled to access cyclopentanoid frameworks. In the presence of silver(I), intramolecular arene trapping leads to indoline-fused cyclopentanones. Gadolinium(III) facilitates a cascade transformation to furnish tetrahydroquinoline-fused cyclopentenones. Tf=trifluoromethanesulfonyl.
- William, Ronny,Wang, Siming,Ding, Feiqing,Arviana, Elise Nerissa,Liu, Xue-Wei
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p. 10742 - 10746
(2015/05/13)
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- Scalable methodologies for the synthesis of novel unsymmetrically substituted secondary amines
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Fast, easy, and scalable methodologies for the synthesis of unsymmetrically substituted secondary amines containing naphthalene, indole, pyridine and imidazole moieties through reductive amination were explored. The investigated operating procedures were
- Roman, Gheorghe
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p. 131 - 140
(2012/06/18)
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