- Zirconium-hydride-catalyzed site-selective hydroboration of amides for the synthesis of amines: Mechanism, scope, and application
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Developing mild and efficient catalytic methods for the selective synthesis of amines is a longstanding research objective. In this respect, catalytic deoxygenative amide reduction has proven to be promising but challenging, as this approach necessitates selective C–O bond cleavage. Herein, we report the selective hydroboration of primary, secondary, and tertiary amides at room temperature catalyzed by an earth-abundant-metal catalyst, Zr-H, for accessing diverse amines. Various readily reducible functional groups, such as esters, alkynes, and alkenes, were well tolerated. Furthermore, the methodology was extended to the synthesis of bio- and drug-derived amines. Detailed mechanistic studies revealed a reaction pathway entailing aldehyde and amido complex formation via an unusual C–N bond cleavage-reformation process, followed by C–O bond cleavage.
- Han, Bo,Jiao, Haijun,Wu, Lipeng,Zhang, Jiong
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p. 2059 - 2067
(2021/09/02)
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- Mild catalytic deoxygenation of amides promoted by thorium metallocene
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The organoactinide-catalyzed (Cp*2ThMe2) hydroborated reduction of a wide range of tertiary, secondary, and primary amides to the corresponding amines/amine-borane adductsviadeoxygenation of the amides is reported herein. The catalytic reactions proceed under mild conditions with low catalyst loading and pinacolborane (HBpin) concentration in a selective fashion. Cp*2ThMe2is capable of efficiently catalysing the gram-scale reaction without a drop in efficiency. The amine-borane adducts are successfully converted into free amine products in high conversions, which increases the usefulness of this catalytic system. A plausible mechanism is proposed based on detailed kinetics, stoichiometric, and deuterium labeling studies.
- Eisen, Moris S.,Saha, Sayantani
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supporting information
p. 12835 - 12841
(2020/10/05)
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- A BEt3-Base catalyst for amide reduction with silane
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Reported herein is the development of a simple but practical catalytic system for the selective reduction of amides with hydrosilane or hydrosiloxane. Low-cost and readily available triethylborane (1.0 M in THF), in combination with a catalytic amount of an alkali metal base, was found to catalyze the reduction of all three amide classes (tertiary, secondary, and primary amides) to form amines under mild conditions. In addition, the selective transformation of secondary amides to aldimines and primary amides to nitriles can also be achieved by using a proper combination of BEt3 and base. The scope of these BEt3-base-catalyzed amide hydrosilylation reactions has been explored in depth. Preliminary results of mechanistic studies suggest a modified Piers' silane Si-H···B activation mode wherein the hydride abstraction by BEt3 is promoted by the coordination of an alkoxide or hydroxide anion to the Si center.
- Yao, Wubing,Fang, Huaquan,He, Qiaoxing,Peng, Dongjie,Liu, Guixia,Huang, Zheng
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- A BEt3-Base Catalyst for Amide Reduction with Silane
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Reported herein is the development of a simple but practical catalytic system for the selective reduction of amides with hydrosilane or hydrosiloxane. Low-cost and readily available triethylborane (1.0 M in THF), in combination with a catalytic amount of an alkali metal base, was found to catalyze the reduction of all three amide classes (tertiary, secondary, and primary amides) to form amines under mild conditions. In addition, the selective transformation of secondary amides to aldimines and primary amides to nitriles can also be achieved by using a proper combination of BEt3 and base. The scope of these BEt3-base-catalyzed amide hydrosilylation reactions has been explored in depth. Preliminary results of mechanistic studies suggest a modified Piers' silane Si-H···B activation mode wherein the hydride abstraction by BEt3 is promoted by the coordination of an alkoxide or hydroxide anion to the Si center.
- Yao, Wubing,Fang, Huaquan,He, Qiaoxing,Peng, Dongjie,Liu, Guixia,Huang, Zheng
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p. 6084 - 6093
(2019/05/24)
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- Determination of basic strength of aliphatic amines through ion pair formation in some ionic liquid solutions
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(Chemical Equation Presented) To have an evaluation of the basic strength of aliphatic amines in ionic liquid solution, the stability constants relevant to the formation of amine/p-nitrophenol ion pairs were determined in different ionic liquids at 298 K.
- D'Anna, Francesca,Vitale, Paola,Noto, Renato
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experimental part
p. 6224 - 6230
(2009/12/08)
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- Oligomeric aminodiol-containing compounds, libraries thereof, and process of preparing the same
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Oligomeric compounds comprising a plurality of aminodiol monomer subunits joined by linking groups are provided, as well as libraries of such compounds and processes for preparing the oligomeric compounds and libraries.
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- Piperadinyl-substituted pyridylalkane, alkene and alkine carboxamides
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The invention relates to new piperidinyl-substituted pyridyl carboxamides of the general formula (I), wherein the structure element E has meanings (E1) or (E2) and whereby the heterocyclic ring can optionally have a double bond. These substances have especially high cytostatic activities and pronounced immunosuppressive properties which make them suitable for therapeutic treatment in broad tumor spectrum.
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- Transition-metal complex-catalyzed reduction of amides with hydrosilanes: A facile transformation of amides to amines
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The reaction of amides with hydrosilanes is catalyzed by a variety of transition-metal complexes in the presence or absence of halides and amines as co-catalysts to afford the corresponding amines in good yields.
- Igarashi, Mamoru,Fuchikami, Takamasa
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p. 1945 - 1947
(2007/10/03)
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- Scavenger assisted combinatorial process for preparing libraries of amides, carbamates and sulfonamides
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This invention relates to a novel solution phase process for the preparation of amide, carbamate, and sulfonamide combinatorial libraries. These libraries have utility for drug discovery and are used to form wellplate components of novel assay kits.
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- Hydrogenation of amides by the use of bimetallic catalysts consisting of group 8 to 10, and group 6 or 7 metals
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Hydrogenation of amides can be catalyzed by bimetallic systems, which consist of Group 8 to 10 late transition-metals and Group 6 or 7 early transition-metals, under the mild conditions to afford the corresponding amines selectively in good to excellent yields.
- Hirosawa, Chitaru,Wakasa, Noriko,Fuchikami, Takamasa
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p. 6749 - 6752
(2007/10/03)
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- Selective Cleavage of Carbon-Nitrogen Bonds with Platinum
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The selective hydrogenolysis of carbon-nitrogen bonds relative to carbon-carbon bonds with a heterogeneous platinum catalyst is studied on a wide variety of nitrogen-containing organic molecules.Nitriles, secondary and primary amines, nitro compounds, heterocycles, and aromatic amides are cleanly converted to the parent hydrocarbon and ammonia in the gas phase with a platinum on silica catalyst and hydrogen.Aliphatic amides pass the catalyst unchanged.Unusual is the high platinum content of the catalyst (40percent) which proved to be essential for the catalytic activity reported.
- Guttieri, Mary J.,Maier, Wilhelm F.
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p. 2875 - 2880
(2007/10/02)
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