- Highly Selective Hydrogenative Conversion of Nitriles into Tertiary, Secondary, and Primary Amines under Flow Reaction Conditions
-
Flow reaction methods have been developed to selectively synthesize tertiary, secondary, and primary amines depending on heterogeneous platinum-group metal species under catalytic hydrogenation conditions using nitriles as starting materials. A 10 % Pd/C-packed catalyst cartridge affords symmetrically substituted tertiary amines in good to excellent yields. A 10 % Rh/C-packed catalyst cartridge enables the divergent synthesis of secondary and primary amines, with either cyclohexane or acetic acid as a solvent, respectively. Reaction parameters, such as the metal catalyst, solvent, and reaction temperature, and continuous-flow conditions, such as flow direction and second support of the catalyst in a catalyst cartridge, are quite important for controlling the reaction between the hydrogenation of nitriles and nucleophilic attack of in situ-generated amines to imine intermediates. A wide variety of aliphatic and aromatic nitriles could be highly selectively transformed into the corresponding tertiary, secondary, and primary amines by simply changing the metal species of the catalyst or flow parameters. Furthermore, the selective continuous-flow methodologies are applied over at least 72 h to afford three different types of amines in 80–99 % yield without decrease in catalytic activities.
- Yamada, Tsuyoshi,Park, Kwihwan,Furugen, Chikara,Jiang, Jing,Shimizu, Eisho,Ito, Naoya,Sajiki, Hironao
-
-
- Selective Synthesis of Primary Amines from Nitriles under Hydrogenation Conditions
-
The hydrogenation of aliphatic nitriles over Pd/C, Pd/Al2O3, and Pd?Au/Al2O3 catalysts were evaluated for the selective hydrogenation of aliphatic nitriles to the corresponding primary amines. The highest selectivity (>99%) toward primary amines was achieved when the reaction was carried out in acetic acid using 10 mol% of 25% Pd-5% Au/Al2O3 under relatively low hydrogen pressure (0.8 MPa). Characterization of the catalysts by XRD, CO adsorption experiments, and EXAFS revealed that the excellent selectivity of 25% Pd-5% Au/Al2O3 toward the synthesis of primary amines is determined by the electronic properties and/or the surface structure resulting from alloying Pd with Au. (Figure presented.).
- Yoshimura, Masatoshi,Komatsu, Akira,Niimura, Masaru,Takagi, Yukio,Takahashi, Tohru,Ueda, Shun,Ichikawa, Tomohiro,Kobayashi, Yutaka,Okami, Hiroki,Hattori, Tomohiro,Sawama, Yoshinari,Monguchi, Yasunari,Sajiki, Hironao
-
p. 1726 - 1732
(2018/03/21)
-
- Hydrogenolysis of Amide Acetals and Iminium Esters
-
Amide acetals and iminium esters were hydrogenated into amines under very mild reaction conditions over common hydrogenation catalysts. This finding provides a new strategy for the selective reduction of amides. The synthetic utility of this approach was demonstrated by the selective reduction of amides bearing ester and nitrile groups.
- Kadyrov, Renat
-
p. 170 - 172
(2017/12/26)
-
- Colloid and nanosized catalysts in organic synthesis: XVII. Reductive amination of carbonitriles in the presence of supported nickel nanoparticles
-
Reductive amination of carbonitriles catalyzed by nickel nanoparticles applied onto a solid support in a plug flow reactor in the gas phase or the gas–liquid–solid catalyst system occurs at atmospheric pressure of hydrogen affording the nonsymmetrical secondary or tertiary amines. The effect of the support type on the target product yield and conversion of the substrate has been studied.
- Popov, Yu. V.,Mokhov,Latyshova,Panov,Shirkhanyan
-
p. 2546 - 2551
(2017/12/26)
-
- Continuous Production of Dialkylamines by Selective Hydrogenation of Nitriles on a Nickel-Zeolite Catalyst
-
Hydrogenation of aliphatic nitriles in the presence of nickel supported by NaX zeolite was studied. The data obtained were used to develop a continuous method for obtaining dialkylamines with the yield of the target product of up to 98%.
- Popov, Yu. V.,Mokhov,Latyshova,Panov,Pletneva, M. Yu.
-
p. 1778 - 1782
(2018/03/21)
-
- Colloid and nanosized catalysts in organic synthesis: XVI.1 Continuous hydrogenation of carbonitriles catalyzed by nickel nanoparticles applied on a support
-
Conversion of the starting nitriles and selectivity of the products formation during continuous hydrogenation of various nitriles catalyzed by Ni0/Ceokar-2 have been studied as functions of temperature. Performing the process at temperature 120–260°С has led to the formation of a mixture of products containing di- and trialkylamines as well as the corresponding imines and enamines.
- Popov, Yu. V.,Mokhov,Latyshova,Nebykov,Panov,Pletneva, M. Yu.
-
p. 2276 - 2281
(2017/11/24)
-
- Catalyst-Dependent Selective Hydrogenation of Nitriles: Selective Synthesis of Tertiary and Secondary Amines
-
In the presence of palladium on carbon (Pd/C) as a catalyst, hydrogenation of aliphatic nitriles in cyclohexane efficiently proceeded at 25-60 °C under ordinary hydrogen gas pressure to afford the corresponding tertiary amines. However, the use of rhodium on carbon (Rh/C) led to the highly selective generation of secondary amines. Hydrogenation of aromatic nitriles and cyclohexanecarbonitrile selectively produced secondary amines in the presence of either Pd/C or Rh/C.
- Monguchi, Yasunari,Mizuno, Masahiro,Ichikawa, Tomohiro,Fujita, Yuki,Murakami, Eri,Hattori, Tomohiro,Maegawa, Tomohiro,Sawama, Yoshinari,Sajiki, Hironao
-
p. 10939 - 10944
(2017/10/27)
-
- Reaction of primary amines with Pt/C catalyst in water under microwave irradiation: A convenient synthesis of secondary amines from primary amines
-
Upon microwave irradiation in water, Pt/C converts primary amines into secondary amines in good yield via retro-reductive and reductive amination.
- Miyazawa, Akira,Saitou, Kaori,Tanaka, Kan,G?dda, Thomas M.,Tashiro, Masashi,Prakash, G. K. Surya,Olah, George A.
-
p. 1437 - 1439
(2007/10/03)
-
- Alkyl substituent effect on the polarity of phenols-tri-n-alkylamine complexes
-
The formation constants and the dipole moments of the H-bonded adducts of 1:1 and 2:1 stoichiometries formed between three different phenols (phenol, 2,4,6-trichlorophenol, and 2,4-dinitrophenol) and different tri-n-alkylamines are determined in solvents
- Pawelka, Zbigniew,Zeegers-Huyskens, Therese
-
p. 1012 - 1018
(2007/10/03)
-
- Push-pull mechanism of hydrodenitrogenation over silica-supported MoP, WP, and MoS2 hydroprocessing catalysts
-
The mechanism of liquid-phase catalytic hydrodenitrogenation at 3.1 MPa on silica-supported molybdenum phosphide, MoP/SiO2, and tungsten phosphide, WP/SiO2, was studied using a series of pentylamines of different structures. The reactivity pattern suggested that removal of nitrogen occurred primarily by an E2 elimination mechanism involving acidic and base sites on the catalyst surfaces in a push-pull process. Infrared spectroscopy and temperature-programmed reaction studies of ethylamine indicated that alkyl ammonium species formed on Bronsted acid sites were intermediates in the reaction. Similar results were obtained with a reference MoS2/SiO2 sample tested at the same conditions. This suggested that sulfur was probably present on the active surface and assisted in the removal of sulfur.
- Clark,Wang,Deck,Oyama
-
p. 116 - 126
(2007/10/03)
-
- Amine oxide process
-
A process for accelerating the oxidation of tert-amines by hydrogen peroxide by conducting the reaction in the presence of an ascorbic acid promoter.
- -
-
-
- Catalytic hydrogenation of valeronitrile over Raney nickel. Part 1: Influence of reaction parameters on activity and selectivity
-
The liquid phase hydrogenation of valeronitrile in the presence of Raney nickel was studied under different experimental conditions in order to examinate the effect of the reaction parameters on the rate and selectivity of hydrogenation.The factors included stirring speed, catalyst concentration, temperature, hydrogen pressure, reactant concentration, added ammonia, nature of the solvent.The results were found to be independent of the catalyst loading.Decreasing the hydrogen pressure, lower temperatures, high concentrations of valeronitrile and large amounts of ammonia were found to be beneficial in obtaining primary amine.The effects of alcohol as solvent were attributed to the presence of the carbonyl compounds obtained by dehydrogenation of alcohols.
- Besson, M.,Bonnier, J. M.,Joucla, M.
-
-
- The Chemistry of N-Substituted Benzotriazoles. Part 14. Novel Routes to Secondary and Tertiary Amines and to N,N-Disubstituted Hydroxylamines
-
Tertiary amines of types R4R3CHNR1R2 (2), (R2CH2)2NR1 (10) and 11, or (R2CH2)3N (12), secondary amines of type (R2CH2)2NH (8), and N,N-disubstituted hydroxylamines of type (R2CH2)2NOH (9), are prepared in high yield by the action of Grignard reagents or sodium borohydride on easily available N,N-dialkyl-N-amines (1) or tris(benzotriazolylmethyl)amine (7), on bis(benzotriazolylmethyl)amines (3), (5), and (6), and on N,N-bis(benzotriazolylmethyl)hydroxylamine (4), respectively.
- Katritzky, Alan R.,Yannakopoulou, Konstantina,Lue, Ping,Rasala, Danuta,Urogdi, Laszlo
-
p. 225 - 233
(2007/10/02)
-
- Preparation of trialkylamines
-
Trialkylamines are prepared by reacting primary alcohols with ammonia or a primary alkylamine in the presence of a hydrogenation/dehydrogenation catalyst and in the presence of hydrogen by (a) operating in liquid phase (b) using the alcohol in a stoichiometric excess of from 1 to 15 moles per mole of ammonia or primary alkylamine, (c) carrying out the reaction in the presence of the water formed in the course of the reaction, and (d) using a hydrogenation/dehydrogenation catalyst which substantially contains only copper as the catalytically hydrogenating/dehydrogenating metal.
- -
-
-
- FORMATION OF SULFUR COMPOUNDS IN THE HYDRODENITROGENATION OF PIPERIDINE, PYRIDINE, 1-PENTYLAMINE AND 1-PENT-4-ENYLAMINE ON A NICKEL-TUNGSTEN CATALYST IN THE PRESENCE OF HYDROGEN SULFIDE
-
Hydrogenations of piperidine, pyridine, 1-pentylamine, and 1-pent-4-enylamine were carried out in an autoclave at 300 deg C on a sulfidized nickel-tungsten catalyst using either pure hydrogen or a mixture of hydrogen with hydrogen sulfide.Hydrogen sulfide was found to raise the degree of conversion of the starting substances and accelerate the hydrodenitrogenation by formation of sulfur compounds; 1-pentanethiol, di(1-pentyl)sulfide, 2-methylthiacyclopentane, thiacyclohexane and other sulfur compounds were detected in the reaction mixtures in the presence of hydrogensulfide.A reaction pathway is suggested of the hydrodenitrogenation of piperidine in the presence of hydrogen sulfide, accounting for the favourable effect of the latter on the hydrodenitrogenation of nitrogen compounds.
- Cerny, Mirko
-
p. 928 - 935
(2007/10/02)
-
- Oxidation of thiols employing cobalt molybdate/triethylamine catalyst
-
A thiol is oxidized to a corresponding disulfide employing a supported cobalt molybdate catalyst in combination with a liquid tertiary amine. 2-propanethiol is converted to diisopropyl disulfide with conversions of the order of 94% and selectivities of the order of 98%.
- -
-
-