- Effect of the catalyst preparation method on the performance of Ni-supported catalysts for the synthesis of saturated amines from nitrile hydrogenation
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The liquid-phase hydrogenation of butyronitrile to saturated amines was studied on silica-supported Ni catalysts prepared by either incipient-wetness impregnation (Ni/SiO2-I) or ammonia (Ni/SiO2-A) methods. A Ni/SiO2-Al2O3-I sample was also used. Ni/SiO2-I was a non-acidic catalyst containing large Ni0 particles of low interaction with the support, while Ni/SiO2-A was an acidic catalyst due to the presence of Ni2+ species in Ni phyllosilicates of low reducibility. Ni/SiO2-I formed essentially butylamine (80%), and dibutylamine as the only byproduct. In contrast, Ni/SiO2-A yielded a mixture of dibutylamine (49%) and tributylamine (45%), being the formation of butylamine almost completely suppressed. The selective formation of secondary and tertiary amines on Ni/SiO2-A was explained by considering that butylamine is not release to the liquid phase during the reaction because it is strongly adsorbed on surface acid sites contiguous to Ni0 atoms, thereby favoring the butylimine/butylamine condensation to higher amines between adsorbed species.
- Segobia,Trasarti,Apesteguía
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- Deoxygenation of amine N-oxides using gold nanoparticles supported on carbon nanotubes
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Deoxygenation of a variety of aromatic and aliphatic amine N-oxides has been carried out in excellent yield using dimethylphenylsilane as the reducing agent under the catalytic influence of a carbon nanotube-gold nanohybrid at room temperature. Low catalyst loading, good TON and TOF values, and recyclability of the catalyst are some of the salient features of our methodology.
- Donck, Simon,Gravel, Edmond,Shah, Nimesh,Jawale, Dhanaji V.,Doris, Eric,Namboothiri, Irishi N. N.
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- Selective deoxygenation of amine N-oxides using borohydride exchange resin-copper sulfate in methanol
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Borohydride exchange resin-copper sulfate in methanol readily deoxygenates quantitatively both tertiary amine N-oxides and heteroaromatic N-oxides at room temperature or under reflux. It tolerates many functional groups such as carbon-carbon double bond, chloride, epoxide, ester, amide, nitrile, sulfoxide, sulfone, and aliphatic disulfide moieties.
- Sim, Tae Bo,Ahn, Jin Hee,Yoon, Nung Min
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- RUTHENIUM CATALYZED N-ALKYLATION OF AMIDES WITH ALCOHOLS.
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Amides reacted with primary alcohols in the presence of a catalytic amount of RuCl//2(PPh//3)//3 at 180 degree C to give the corresponding N-monoalkyl amides in fairly good yields. Thus, benzamide reacted with l-octanol to give N-octylbenzamide in 76% yield with excellent product selectivity. Little esterification of amides with alcohols occurred and selectivity to the N-alkylation was high. Most of the amides gave N-monoalkyl amides but no N,N-dialkyl amides. But formamide reacted with l-butanol to give N,N-dibutylformamide, as well as N-butylformamide, in low yield. RuCl//2(PPh//3)//3 was the most effective catalyst for this reaction and RuHCl(PPh//3)//3 also had some catalytic activity.
- Watanabe,Ohta,Tsuji
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- Iodide-mediated or iodide-catalyzed demethylation and friedel-crafts C-H borylative cyclization leading to thiophene-fused 1,2-oxaborine derivatives
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The first synthesis of dithieno-1,2-oxaborine derivatives was achieved via iodide-mediated or iodide-catalyzed demethylation of 3-methoxy-2,2′-bithiophene and subsequent C-H borylation. A wide variety of thiophene-fused oxaborines could be synthesized by the procedure.
- Shigemori, Keisuke,Watanabe, Momoka,Kong, Julie,Mitsudo, Koichi,Wakamiya, Atsushi,Mandai, Hiroki,Suga, Seiji
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- Hofmann Decomposition of Queternary Ammonium Salts under Phase-transfer Catalytic Conditions
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The known Hofmann degradation of quaternary ammonium salts under basic phase-transfer catalytic conditions has been studied.The base-catalysed isomerization of p-allylanisole to p-methoxy-β-methylstyrene was used as a kinetic probe to find experimentally the rate constant and activation energy of the Hofmann decomposition without isolating the quaternary ammonium basic salt R4N+B- (B- = base anion).Reactions performed at various temperatures showed that the higher the temperature the greater was the initial rate but the lower the final conversion in the isomerization reaction.The quaternary ammonium hydroxide was found to catalyse the isomerization and the Hofmann degradation more effectively than the corresponding alkoxide.This indicates that the former is a stronger base in the non-polar aprotic solvents common in phase-transfer catalysis.
- Zerda, Jaime de la,Neumann, Ronny,Sasson, Yoel
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- Decomposition mechanism of dinitramide onium salts
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Thermal decomposition of dinitramide onium salts proceeds via the dissociative mechanism when pKa of the base is lower than 5.0 and via the monomolecular decay of the anion at pKa > 7.0. On going from the melt to the solid state, the reaction mechanism does not change, and the rate decreases by 1-2 orders of magnitude. No anomalous effects inherent in dinitramide metal salts in the solid phase are observed during decomposition of onium salts.
- Pavlov,Nazin
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- Synthesis of n-butylamine from butyronitrile on Ni/SiO2: Effect of solvent
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The effect of solvent on Ni(10.5percent)/SiO2 activity and selectivity for the liquid-phase hydrogenation of butyronitrile to butylamines was studied at 373 K and 13 bar using ethanol, benzene, toluene and cyclohexane as solvents. In ethanol, a protic solvent, the Ni catalyst yielded n-butylamine (84percent) and dibutylamine (16percent). When non-polar solvents, such as cyclohexane, toluene or benzene, were used, the solvent-catalyst interaction strength determined the selectivity to n-butylamine: the stronger the solvent-catalyst interaction the higher the n-buylamine production. The yield to n-butylamine in non-polar solvents varied between 39percent (cyclohexane) and 63percent (benzene).
- Segobia, Darío J.,Trasarti, Andrés F.,Apesteguía, Carlos R.
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- Electrolytic Reduction of 1,4-Dihalonorbornanes at Mercury Electrodes in Dimethylformamide. Evidence for Propellane as an Intermediate
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Low-temperature (-34 deg C) electrolytic reduction of 1,4-dibromonorbornane at mercury cathodes in dimethylformamide containing tetraalkylammonium perchlorates yields norbornane, bis(1-norbornyl)mercury, and 1,1'-binorbornyl; reduction of 1,4-diiodonorbornane results in the same three products along with 1-iodonorbornane and other minor species.At potentials for which the mass balance is 100percent, norbornane and bis(1-norbornyl)mercury account for 98percent of the electrolysis products and the coulometric n value is precisely three.When tetramethylammonium perchlorate is utilized as the supporting electrolyte at -34 deg C, there is a range of potentials over which a pronounced polarographic current minimun appears; this low-temperature minimum is attributed to adsorbtion upon the electrode of complex species consisting of tetramethylammonium cations and halide ions.Three key observations suggest that propellane is an intermediate in the electrochemical reduction of the 1,4-dihalonorbornanes: (1) norbornane is derived from 1,4-dihalonorbornane via a three-electron process which does not involve 1-halonorbornane as intermediate; (2) bis(1-norbornyl)mercury is produced by electrolytic reduction of 1,4-dihalonorbornane but not by reduction of 1-halonorbornane; and (3) a species apparently obtained by two-electron reduction of 1,4-dihalonorbornanes is capable of undergoing oligomerization.A polarographic wave seemingly attributable to reduction of propellane is observed.
- Carroll, William F.,Peters, Dennis G.
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- ELECTROCHEMICAL REDUCTION OF TRIPHENYL PHOSPHATE
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The electrolytic reduction of triphenyl phosphate proceeds with the participation of tetrabutylammonium cations with the formation of butyl diphenyl phosphate in DMF.It was concluded that the step involving electron transfer to the triphenyl phosphate molecule has retarded character.
- Yanilkin, V. V.,Budnikova, Yu. G.,Kargin, Yu. M.,Gritsenko, E. I.,Strelets, V. V.
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- Catalytic reductive alkylation of secondary amine with aldehyde and silane by an iridium compound
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(Chemical Equation Presented) An efficient methodology for the reductive alkylation of secondary amine with aldehyde and Et3SiH using an iridium complex as a catalyst has been developed. For example, treatment of dibutylamine with butyraldehyde and Et3SiH (a 1:1:1 molar amount of amine, aldehyde, and silane) in 1,4-dioxane at 75°C under the influence of a catalytic amount of [IrCl(cod)]2 gave tributylamine in quantitative yield. In this reaction, no reduction of aldehyde took place. It was found that IrCl3, which is a starting material for preparation of iridium complexes such as [IrCl(cod)]2, acts as an efficient catalyst for the present reductive alkylation of amine. In addition, a cheaper, easy-to-handle, and environmentally friendly reducing reagent such as polymethylhydrosiloxane (PMHS) in place of Et3SiH was also useful. Thus, a variety of secondary amines could be alkylated by allowing them to react with aldehydes and PMHS in the presence of an iridium catalyst to afford the corresponding tertiary amines in good to excellent yields. From the deuterium label experiments, it was revealed that silane and water, generated during the formation of enamine by the reaction of amine and aldehyde, seem to behave as a hydrogen source. The catalytic cycle was discussed.
- Mizuta, Tomoya,Sakaguchi, Satoshi,Ishii, Yasutaka
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- Epoxide as precatalyst for metal-free catalytic transesterification
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Transesterification of methyl esters was accelerated by an in situ-generated metal-free catalyst comprising a quaternary alkylammonium salt and an epoxide. The combination of a quaternary alkylammonium acetate and glycidol is optimal, and various esters were synthesized from methyl esters with alcohols in good to excellent yield. Analysis of the catalyst solution revealed that basic species are generated by the ring-opening reaction of epoxide.
- Tanaka, Shinji,Nakashima, Takuya,Satou,Oono, Hiromi,Kon, Yoshihiro,Tamura, Masanori,Sato, Kazuhiko
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- Scope and post-transformations for the borane-isocyanide multicomponent reactions: Concise access to structurally diverse heterocyclic compounds
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A recently described family of multicomponent reactions (MCRs) involving isocyanides, aldehydes, dipolarophiles and alkylboranes that yield highly substituted aziridines, oxazolidines and pyrrolidines has been studied in detail. In this work the scope of these processes is significantly increased by preparing the borane input through hydroboration of alkenes or organometallic processes, in tandem with the MCR. The aldehyde range is also expanded, and indole-3-carbaldehydes yield reactive imines and bis-indolyloxazolidines, depending on the electron density of the heterocycle. Finally, the obtained adducts constitute an ideal platform to generate structurally diverse compounds using simple post-condensation modifications. In this way, indole imines undergo stereoselective hydrocyanation and oxazolidines are reductively opened to give amino alcohols. Additionally, palladium-, ruthenium- and gold-catalyzed processes lead to a variety of complex heterocycles. The methodology is simple, efficient and highly divergent, leading to an array of interesting scaffolds for medicinal chemistry. Copyright
- Kielland, Nicola,Vicente-Garcia, Esther,Reves, Marc,Isambert, Nicolas,Arevalo, Maria Jose,Lavilla, Rodolfo
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- Hydrogenation of nitriles to primary amines on metal-supported catalysts: Highly selective conversion of butyronitrile to n-butylamine
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The selective liquid-phase hydrogenation of butyronitrile to n-butylamine was studied in a batch reactor on Co(9.8%)/SiO2, Ni(10.5%)/SiO 2, Cu(9.2%)/SiO2, Pt(0.27%)/SiO2, Pd(0.33%)/SiO2, and Ru(1.8%)/SiO2 catalysts. At 373 K and 13 bar (H2), the initial butyronitrile conversion rate (rBN0, mmol/h g) followed the order Ni > Co > Pt > Ru > Cu > Pd. Cu/SiO 2 and Pd/SiO2 did not form n-butylamine and rapidly deactivated during the progress of the reaction. Pt/SiO2 produced mainly dibutylamine and only minor amounts of n-butylamine and tributylamine. In contrast, Ru/SiO2 formed preponderantly n-butylamine but also produced significant amounts of dibutylamine and butylidene-butylamine, an intermediate in the formation pathway of the secondary amine. The highest yield to n-butylamine was obtained on Ni/SiO2 (84%). Co/SiO2 was initially highly selective to n-butylamine but with the progress of the reaction the butylamine concentration in the reaction mixture diminished because it partially reacted with the solvent (ethanol) to form N-ethylbutylamine. In an attempt to reduce the formation of byproducts, Ni/SiO2 and Co/SiO2 catalysts were tested at lower temperatures and higher H 2 pressures. Butyronitrile was selectively converted to n-butylamine on Co/SiO2 at 343 K and 25 bar, yielding 97% of n-butylamine, similarly to the highest yields reported on Raney Co catalysts.
- Segobia,Trasarti,Apesteguía
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- Polyethylene glycol-enhanced chemoselective synthesis of organic carbamates from amines, CO2, and alkyl halides
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An efficient and environmentally benign method for the synthesis of organic carbamates was developed. Amines, CO2, and alkyl halides underwent a three-component reaction with the aid of K2CO3 and polyethylene glycol (PEG, MW=400), affording the organic carbamates under ambient conditions. PEG could presumably act as a solvent and phase-transfer catalyst (PTC). Notably, the presence of PEG could also depress the alkylation of both the amine and the carbamate, thus resulting in enhanced selectivity toward the target carbamate. Supplemental materials are available for this article. Go to the publisher's online edition of Synthetic Communications to view the free supplemental file.
- Kong, De-Lin,He, Liang-Nian,Wang, Jin-Quan
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- Ruthenium-catalyzed deaminative redistribution of primary and secondary amines
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A ruthenium-hydride complex, [Ru(H)(Cl)(CO)(PCy3)2], was found to be active in the highly selective redistribution of primary and secondary amines bearing an α-hydrogen atom. This new deaminative coupling of amines enables the highly selective synthesis of secondary amines from primary amines and of tertiary amines from secondary amines with the evolution of ammonia. A preliminary mechanistic view of this novel reaction based on catalytic experiments using NMR methods confirms the synthetic observations.
- Kostera,Wyrzykiewicz,Pawlu?,Marciniec
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- The synthesis of N-ethyl-n-butylamine by amines disproportionation
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A synthesis of N-ethyl-n-butylamine with simple separation method in a fixed-bed reactor using CuO-NiO-PtO/γ-Al2O3 as the catalyst was proposed and investigated. The present catalytic system gave high activity and good selectivity, and the reaction conditions such as temperature and liquid hourly space velocity were optimized. Since no water was generated, the protocol proved to be easy to separate, and N-ethyl-n-butylamine was collected at 110 °C by distillation. The yield and the purity were 60.7 and 99.5 %, respectively.
- Xu, Lu-Feng,Huang, Jia-Min,Qian, Chao,Chen, Xin-Zhi,Feng, Lie,Chen, Yun-Bin,He, Chao-Hong
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- The electrochemical reduction of succinimide. Reactivity of quaternary ammonium ions under electrolysis conditions
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A solution of succinimide in ether acetonitrile or N, N-dimethylformamide containing tetra-n-butylammonium fluoborate shows a single, irreversible reduction wave at a platimum cathode by cyclic voltammetry. Coulometry demonstrates that a single electron is transferred. The reaction is accompanied by the evolution of hydrogen at a rate such that the passage of one Faraday of charge results in the generation of almost exactly 0.5 mole of hydrogen. The product of these reactions is the succinimide anion which is stable in the electrolysis solution, but reacts with tetra-n-butylammonium ion during vpc analysis or in refluxing N, N-dimethylformamide to form N-n-butylsuccinimide.
- Moore, W.Michael,Finkelstein, Manuel,Ross, Sidney D.
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- Investigation of the stability of quaternary ammonium methyl carbonates
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Quaternary ammonium compounds are used commercially for a variety of applications and some are of interest as ionic liquids. For many years dimethyl carbonate has been touted as a green reagent, including its use for methylation (quaternization) of tertiary amines. In addition, substitution of the methyl carbonate by other anions can be efficiently and cleanly accomplished by reaction with the corresponding acid. How stable are these methyl carbonate quaternary compounds? High field 13C NMR shows that in the presence of water, the methyl carbonate is converted to bicarbonate. Headspace GCMS indicates that the alkylammonium methyl carbonate salts are stable below 170-180 °C while the bicarbonate salts are stable to only about 140 °C. Thermal decomposition occurs by decarboxylation and by dealkylation. AOCS 2011.
- Weisshaar, Duane E.,Earl, Gary W.,Amolins, Michael W.,Mickalowski, Kyle L.,Norberg, Justin G.,Rekken, Brian D.,Burgess, Angela M.,Kaemingk, Bethany D.,Behrens, Katherine C.
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- Oxalate Formation in Electrochemical CO2 Reduction Catalyzed by Rhodium-Sulfur Cluster
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Electrochemical reduction of CO2 catalyzed by a triangular rhodium complex *)3(μ3-S)2>2+ selectively produced formate and oxalate in the presence of Bu4NBF4 and LiBF4, respectively, under the controlled potential electrolysis at -1.50 V (vs.SCE) in CO2-saturated CH3CN.A solution IR spectrum evidenced the adduct formation between *)3(μ3-S)2>0 and CO2 as the possible precursor for the oxalate formation.
- Kushi, Yoshinori,Nagao, Hirotaka,Nishioka, Takanori,Isobe, Kiyoshi,Tanaka, Koji
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- Palladium Promoted Production of Higher Amines from a Lower Amine Feedstock
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Abstract: The catalytic (Pd/Al2O3 and Pd/C; mean Pd size 2.5–3.0?nm from (S)TEM analysis) synthesis of di-butylamine (DBA) and tri-butylamine (TBA) from mono-butylamine (MBA) and DBA, respectively, in continuous gas phase operation is demonstrated. Exclusive production of DBA (from MBA) has been established over both catalysts where 453 ≤ T ≤ 523?K (?Ea = 79?kJ?mol?1). Greater activity for Pd/C is associated with higher levels of surface acidity (from NH3 chemisorption/TPD) and spillover hydrogen (from H2 TPD). Reaction of DBA over both catalysts when configured in series delivered full selectivity to TBA. Our results establish a novel clean alternative route for the continuous production of higher (secondary and tertiary) amines. Graphical Abstract: [Figure not available: see fulltext.]
- Hao, Yufen,Cárdenas-Lizana, Fernando,Keane, Mark A.
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- A Lewis Base Nucleofugality Parameter, NFB, and Its Application in an Analysis of MIDA-Boronate Hydrolysis Kinetics
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The kinetics of quinuclidine displacement of BH3 from a wide range of Lewis base borane adducts have been measured. Parameterization of these rates has enabled the development of a nucleofugality scale (NFB), shown to quantify and predict the leaving group ability of a range of other Lewis bases. Additivity observed across a number of series R′3-nRnX (X = P, N; R′ = aryl, alkyl) has allowed the formulation of related substituent parameters (nfPB, nfAB), providing a means of calculating NFB values for a range of Lewis bases that extends far beyond those experimentally derived. The utility of the nucleofugality parameter is explored by the correlation of the substituent parameter nfPB with the hydrolyses rates of a series of alkyl and aryl MIDA boronates under neutral conditions. This has allowed the identification of MIDA boronates with heteroatoms proximal to the reacting center, showing unusual kinetic lability or stability to hydrolysis.
- García-Domínguez, Andrés,Gonzalez, Jorge A.,Leach, Andrew G.,Lloyd-Jones, Guy C.,Nichol, Gary S.,Taylor, Nicholas P.
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supporting information
(2022/01/04)
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- Degradation of Organic Cations under Alkaline Conditions
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Understanding the degradation mechanisms of organic cations under basic conditions is extremely important for the development of durable alkaline energy conversion devices. Cations are key functional groups in alkaline anion exchange membranes (AAEMs), and AAEMs are critical components to conduct hydroxide anions in alkaline fuel cells. Previously, we have established a standard protocol to evaluate cation alkaline stability within KOH/CD3OH solution at 80 °C. Herein, we are using the protocol to compare 26 model compounds, including benzylammonium, tetraalkylammonium, spirocyclicammonium, imidazolium, benzimidazolium, triazolium, pyridinium, guanidinium, and phosphonium cations. The goal is not only to evaluate their degradation rate, but also to identify their degradation pathways and lead to the advancement of cations with improved alkaline stabilities.
- You, Wei,Hugar, Kristina M.,Selhorst, Ryan C.,Treichel, Megan,Peltier, Cheyenne R.,Noonan, Kevin J. T.,Coates, Geoffrey W.
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supporting information
p. 254 - 263
(2020/12/23)
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- Synthesis process of tetrabutylammonium bromide
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The invention discloses a synthesis process of tetrabutylammonium bromide. The process is characterized by comprising the following steps: (1) taking dibutylamine and n-butyraldehyde as initial raw materials, taking water as a hydrogen source and butanol as a sacrificial reagent under the action of a modified titanium dioxide photocatalyst, and preparing tributylamine by a photocatalytic continuous micro-channel reactor through a reductive amination mechanism; and (2) after concentrating the obtained tributylamine, making the tributylamine directly dissolved in the solvent and mixed with a certain proportion of n-bromobutane, and then enter the next step continuous micro-channel reactor, such that the target product TBAB can be obtained at the high yield after the reaction is performed for3-5 h at the temperature of 60-90 DEG C. Compared with the kettle type reaction, the continuous reaction temperature is low, the reaction time is short, and the process is safe and efficient.
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Paragraph 0048-0053; 0058-0059
(2020/12/06)
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- Selective Synthesis of Secondary and Tertiary Amines by Reductive N-Alkylation of Nitriles and N-Alkylation of Amines and Ammonium Formate Catalyzed by Ruthenium Complex
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A new ruthenium catalytic system for the syntheses of secondary and tertiary amines via reductive N-alkylation of nitriles and N-alkylation of primary amines is proposed. Isomeric complexes 8 catalyze transfer hydrogenation and N-alkylation of nitriles in ethanol to give secondary amines. Unsymmetrical secondary amines can be produced by N-alkylation of primary amines with alcohols via the borrowing hydrogen methodology. Aliphatic amines were obtained with excellent yields, while only moderate conversions were observed for anilines. Based on kinetic and mechanistic studies, it is suggested that the rate determining step is the hydrogenation of intermediate imine to amine. Finally, ammonium formate was applied as the amination reagent for alcohols in the presence of ruthenium catalyst 8. Secondary amines were obtained from primary alcohols within 24 hours at 100 °C, and tertiary amines can be produced after prolonged heating. Secondary alcohols can only be converted to secondary amines with moderate yield. Based on mechanistic studies, the process is suggested to proceed through an ammonium alkoxy carbonate intermediate, where carbonate acts as an efficient leaving group.
- Alshakova, Iryna D.,Nikonov, Georgii I.
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p. 5370 - 5378
(2019/06/14)
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- Synthesis of Symmetric and Unsymmetric Secondary Amines from the Ligand-Promoted Ruthenium-Catalyzed Deaminative Coupling Reaction of Primary Amines
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The catalytic system generated in situ from the tetranuclear Ru-H complex with a catechol ligand (1/L1) was found to be effective for the direct deaminative coupling of two primary amines to form secondary amines. The catalyst 1/L1 was highly chemoselective for promoting the coupling of two different primary amines to afford unsymmetric secondary amines. The analogous coupling of aniline with primary amines formed aryl-substituted secondary amines. The treatment of aniline-d7 with 4-methoxybenzylamine led to the coupling product with significant deuterium incorporation on CH2 (18% D). The most pronounced carbon isotope effect was observed on the α-carbon of the product isolated from the coupling reaction of 4-methoxybenzylamine (C(1) = 1.015(2)). A Hammett plot was constructed from measuring the rates of the coupling reaction of 4-methoxyaniline with a series of para-substituted benzylamines 4-X-C6H4CH2NH2 (X = OMe, Me, H, F, CF3) (ρ = -0.79 ± 0.1). A plausible mechanistic scheme has been proposed for the coupling reaction on the basis of these results. The catalytic coupling method provides an operationally simple and chemoselective synthesis of secondary amine products without using any reactive reagents or forming wasteful byproducts.
- Arachchige, Pandula T. Kirinde,Lee, Hanbin,Yi, Chae S.
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p. 4932 - 4947
(2018/05/08)
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- Colloidal and Nanosized Catalysts in Organic Synthesis: XX. Continuous Hydrogenation of Imines and Enamines Catalyzed by Nickel Nanoparticles
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Nickel nanoparticles on the BAU-A active carbon or NaX zeolite catalyze hydrogenation of imines and enamines in a flow reactor in a gas phase or in a gas–liquid–solid catalyst system. The process occurs at atmospheric pressure of hydrogen and gives secondary or tertiary amines in a high yield.
- Popov, Yu. V.,Mokhov,Latyshova,Nebykov,Panov,Davydova
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p. 2035 - 2038
(2018/12/11)
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- Chemoselective hydrogenation of nitriles to secondary or tertiary amines catalyzed by aqueous-phase catalysts supported on hexagonal mesoporous silica
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The first supported aqueous-phase catalyst for the hydrogenation of nitriles is revealed. The catalyst prepared from Pd(PhCN)2Cl2, water-soluble ligand 2,2′-biquinoline-4,4′-dicarboxylic acid dipotassium salt and mesoporous silica is a highly efficient catalyst for the selective formation of secondary or tertiary amines from aromatic or aliphatic nitriles. The catalytic system is stable and can be recycled and reused three times without loss of activity and selectivity. This environmentally friendly process is, in addition, an attractive alternative to many homogeneous and heterogeneous catalysts because of its easy preparation and the moderate operational conditions under which it is highly active.
- Nait Ajjou, Abdelaziz,Robichaud, André
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- Colloid and nanosized catalysts in organic synthesis: XVII. Reductive amination of carbonitriles in the presence of supported nickel nanoparticles
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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
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p. 2546 - 2551
(2017/12/26)
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- Colloid and nanosized catalysts in organic synthesis: XVI.1 Continuous hydrogenation of carbonitriles catalyzed by nickel nanoparticles applied on a support
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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.
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p. 2276 - 2281
(2017/11/24)
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- An improved and one-pot procedure to the synthesis of symmetric amines by domino reactions of 5-methyl-1,3,4-thiadiazole-2-amine, a new nitrogen atom donor, and alkyl halides
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Abstract: A new one-pot method has been introduced in this work for the synthesis of symmetrical primary, secondary, and tertiary alkyl amines from alkyl halides and 5-methyl-1,3,4-thiadiazole-2-amine as a nitrogen-transfer reagent. In this method, all three types of amines have been successfully prepared after changing the ratio of substrates and base control. In addition to the introduction of a new nitrogen-transfer reagent, other important features of this work include normal atmospheric conditions and excellent yields under mild reaction conditions.
- Soleiman-Beigi, Mohammad,Mohammadi, Fariba
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p. 2123 - 2128
(2017/10/26)
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- Continuous Production of Dialkylamines by Selective Hydrogenation of Nitriles on a Nickel-Zeolite Catalyst
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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.
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p. 1778 - 1782
(2018/03/21)
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- Colloid and Nanosized Catalysts in Organic Synthesis: XVIII.1 Disproportionation and Cross-Coupling of Amines During Catalysis with Immobilized Nickel Nanoparticles
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It has been stated that immobilized nickel nanoparticles catalyze disproportionation and cross-coupling of amines. The influence of the support on the catalysis of these properties in the in plug-flow reactor has been studied. The use of active carbon as the support has been found advantageous for the cross-coupling of amines, whereas alumina was a better support for the disproportionation reaction.
- Popov, Yu. V.,Mokhov,Latyshova,Nebykov,Panov,Davydova
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p. 2757 - 2761
(2018/02/21)
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- Nitrogen: Versus phosphorus nucleophiles-how changing the nucleophilic heteroatom affects ionic liquid solvent effects in bimolecular nucleophilic substitution processes
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A series of nitrogen and phosphorus nucleophiles have been investigated to determine whether the previously established ionic liquid solvent effects on a bimolecular nucleophilic substitution (SN2) reaction vary with the nature of the nucleophilic centre. Reaction of group 15 triphenyl nucleophiles with benzyl bromide showed a different trend in the rate constant with increasing proportions of ionic liquid in the reaction mixture than was observed with pyridine. This result suggests additional interactions are important; a supposition supported by differences in reaction outcome observed when the electrophile was varied in reactions with triphenylphosphine. A novel ionic liquid solvent effect was observed in the reaction of tributylamine with benzyl bromide, with the position of equilibrium varying with the proportions of the ionic liquid present in the reaction mixture. Overall, the work presented demonstrates the importance of considering all possible interactions between an ionic liquid solvent and species along the reaction coordinate and has expanded upon our current predictive framework for ionic liquid solvent effects. Such understanding is important as it allows further development of a predictive framework for the application of ionic liquids in preparative chemistry.
- Schaffarczyk McHale, Karin S.,Hawker, Rebecca R.,Harper, Jason B.
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supporting information
p. 7437 - 7444
(2016/09/12)
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- Alkylation of rhodium porphyrins using ammonium and quinolinium salts
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Alkylation of rhodium(III) porphyrins [RhIII(por)] was achieved under relatively mild conditions in up to 98% yields, where readily available ammonium and quinolinium salts were utilized as the alkylating agents. This transformation tolerates air and water, thus serving as a convenient method to prepare a variety of alkyl- and benzyl-RhIII(por) complexes. Preliminary mechanistic studies support an SN2-like reaction pathway involving a RhI(por) anion intermediate.
- Thompson, Samuel J.,Dong, Guangbin
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supporting information
p. 3757 - 3767
(2014/08/18)
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- Ruthenium-catalyzed N-alkylation of amines with alcohols under mild conditions using the borrowing hydrogen methodology
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Using a simple amino amide ligand, ruthenium-catalyzed one-pot alkylation of primary and secondary amines with simple alcohols was carried out under a wide range of conditions. Using the alcohol as solvent, alkylation was achieved under mild conditions, even as low as room temperature. Reactions occurred with high conversion and selectivity in many cases. Reactions can also be carried out at high temperatures in organic solvent with high selectivity using stoichiometric amounts of the alcohol.
- Enyong, Arrey B.,Moasser, Bahram
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p. 7553 - 7563
(2014/09/17)
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- Thermal decomposition of a molecular material {N(n-C4H 9)4[FeIIFeIII(C2O 4)3]}∞ leading to ferrite: A reaction kinetics study
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A multi-step thermal decomposition of a molecular precursor, {N(n-C 4H9)4[FeIIFeIII(C 2O4)3]}∞ was studied using non-isothermal thermogravimetric (TG) measurements in the temperature range 300 to ≈800 K at multiple heating rates (5, 10 and 20 K min-1). The thermal decomposition of the oxalate-based complex proceeded stepwise through a series of intermediate reactions. Two different isoconversional methods, namely, an improved iterative method and a model-free method were employed to evaluate the kinetic parameters: activation energy and rate of reaction. The most probable reaction mechanism of thermal decomposition was also determined. The different reaction pathways leading to different steps in the TG profile were also explored, which are supplemented by earlier experimental observations. Copyright (C)2013 SCS.
- Bhattacharjee, Ashis,Roy, Debasis,Roy, Madhusudan,Adhikari, Arunabha
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p. 523 - 536
(2013/08/26)
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- An efficient synthesis of tertiary amines from nitriles in aprotic solvents
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Tertiary amines are utilized extensively as non-nucleophilic proton scavengers for a number of organic transformations. Herein we report the efficient syntheses of tertiary alkyl amines from their corresponding alkyl nitriles in the presence of a heterogeneous palladium catalyst and a source of dihydrogen in aprotic solvents. The reaction is atom economic, the conditions are mild, and the isolated yields are virtually quantitative. The degree of amine alkylation shows some solvent dependency; in polar protic solvents such as ethanol or methanol, the reaction affords a mixture of products with the secondary alkyl amine as the major product.
- Shares, Jonathan,Yehl, Jenna,Kowalsick, Amanda,Byers, Philip,Haaf, Michael P.
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experimental part
p. 4426 - 4428
(2012/09/25)
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- A practical and benign synthesis of amines through Pd@mpg-C 3N4 catalyzed reduction of nitriles
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Liquid phase hydrogenation of nitriles is an important method for the production of amines, which find a variety of applications as intermediates in chemical and pharmaceutical industry. In the present work, a highly efficient Pd@mpg-C3N4 catalytic system has been developed for chemoselective reduction of nitriles providing good to excellent conversion with remarkable chemoselectivity (up to 99%) without additives. Compared with homogeneous catalyst systems, the developed protocol is more advantageous due to the use of ambient hydrogen, solvent free and effective catalyst recyclability.
- Li, Yi,Gong, Yutong,Xu, Xuan,Zhang, Pengfei,Li, Haoran,Wang, Yong
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- Shvo's catalyst and [IrCp7z.ast;Cl2(amidine)] effectively catalyze the formation of tertiary amines from the reaction of primary alcohols and ammonium salts
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The reaction of (pentamethylcyclopentadienyl)iridium dichloride dimer, [IrCp*Cl2]2, with bis(2,4,6-trimethylphenyl) formamidine allows the preparation of two new [IrCp*Cl 2(amidine)] and [IrCp*Cl(amidinate)] complexes, which have been fully characterized. Both complexes have been tested in the β-alkylation of 1-phenylethanol with primary alcohols, and in the formation of tertiary amines from the reaction of ammonium salts with primary alcohols, and the results have been compared with those shown by Shvo's catalyst. Our studies demonstrate that both [IrCp*Cl2(amidine)] and Shvo's catalyst are very efficient in both catalytic processes. The high activity of the Ir-amidine complex may be attributed to the presence of the NH group in the amidine ligand. Copyright
- Segarra, Candela,Mas-Marza, Elena,Mata, Jose A.,Peris, Eduardo
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experimental part
p. 2078 - 2084
(2011/10/11)
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- Thiol-isocyanate-ene ternary networks by sequential and simultaneous thiol click reactions
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Thiol-isocyanate-ene ternary networks with systematic variations (100/100/0, 100/80/20, 100/60/40, 100/40/60, 100/20/80, and 100/0/100) were prepared by sequential and simultaneous thiol-ene and thiol-isocyanate click reactions. The thiol-isocyanate coupling reaction was triggered thermally or photolytically to control the sequence with the thiol-ene photopolymerization. Triethyl amine (TEA) and 2,2-dimethoxy-2-phenyl acetophenone (DMPA) were used for the sequential thermally induced thiol-isocyanate coupling and photochemically initiated thiol-ene reaction, respectively. A thermally stable photolatent base catalyst (tributylaminetetraphenylborate salt, TBAHBPh 4) capable of in situ generation of tributylamine by UV light was used with isopropylthioxanthone (ITX) for the simultaneous thiol-isocyanate/ thiol-ene curing systems. The kinetics of the hybrid networks investigated using real-time IR indicate that both thiol-isocyanate and thiol-ene reactions were quantitatively rapid and efficient (>90% of conversion in a matter of minutes and seconds, respectively). The Tg of the thiourethane/thiol-ene hybrid networks progressively increases (-5 to 35 °C by DSC) as a function of the thiourethane content due to the higher extent of hydrogen bonding, also resulting in enhanced mechanical properties. Highly uniform and dense network structures exhibiting narrow full width at half-maximum (～10 °C) were obtained for both the sequential and the simultaneous thiol click reactions, resulting in identical thermal properties that are independent of the sequence of the curing processes.
- Shin, Junghwan,Matsushima, Hironori,Comer, Christopher M.,Bowman, Christopher N.,Hoyle, Charles E.
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scheme or table
p. 2616 - 2625
(2011/11/13)
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- Proton donor acceptor interactions of disubstituted thiovioluric acids with amines bases
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The stability constants of hydrogen bonded ion pair or proton transfer complex formation of N,N'-dimethyl thiovioluric acid [DMTVA], N,N'- di-o-tolyl thiovioluric acid [DOTTVA], N,N'-di-m-tolyl thiovioluric acid [DMTTVA] and N,N'-di-p-tolyl thiovioluric acid [DPTTVA] with methyl amine, dimethyl amine, trimethyl amine, ethyl amine, diethyl amine, triethyl amine, n-butyl amine, dibutyl amine and tributyl amine have been determined spectroscopically in 95% (v/v) ethanol. The composition of the complexes is determined in solution potentiometrically and spectrophotometrically and substantiated by the element analysis and IR spectra of the isolated complexes. The stabilities of the thiovioluric acid-amine complexes have been correlated with the base strength of amines. The correlation between the mode of enolization in the acids and the structure of the proton transfer complex is discussed. The variation in proton transfer constants of acids has been explained on the basis of the changes in the distribution of electron density in the ring.
- Singh,Rani, Babita,Deep, Sorabh Singh
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experimental part
p. 4781 - 4786
(2010/12/18)
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- Cyclic carbonate synthesis catalysed by bimetallic aluminium-salen complexes
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The development of bimetallic aluminium-salen complexes [{Al-(salen)} 2O] as catalysts for the synthesis of cyclic carbonates (including the commercially important ethylene and propylene carbonates) from a wide range of terminal epoxides in the presence of tetrabutylammonium bromide as a cocatalyst is reported. The bimetallic structure of one complex was confirmed by X-ray crystallography. The bimetallic complexes displayed exceptionally high catalytic activity and in the presence of tetrabutylammonium bromide could catalyse cyclic carbonate synthesis at atmospheric pressure and room temperature. Catalyst-reuse experiments demonstrated that one bimetallic complex was stable for over 60 reactions, though the tetrabutylammonium bromide decomposed in situ by a retro-Menschutkin reaction to form tributylamine and had to be regularly replaced. The mild reaction conditions allowed a full analysis of the reaction kinetics to be carried out and this showed that the reaction was first order in aluminium complex concentration, first order in epoxide concentration, first order in carbon dioxide concentration (except when used in excess) and unexpectedly second order in tetrabutylammonium bromide concentration. Further kinetic experiments demonstrated that the tributylamine formed in situ was involved in the catalysis and that addition of butyl bromide to reconvert the tributylamine into tetrabutylammonium bromide resulted in inhibition of the reaction. The reaction kinetics also indicated that no kinetic resolution of racemic epoxides was possible with this class of catalysts, even when the catalyst was derived from a chiral salen ligand. However, it was shown that if enantiomerically pure styrene oxide was used as substrate, then enantiomerically pure styrene carbonate was formed. On the basis of the kinetic and other experimental data, a catalytic cycle that explains why the bimetallic complexes display such high catalytic activity has been developed.
- Clegg, William,Harrington, Ross W.,North, Michael,Pasquale, Riccardo
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supporting information; experimental part
p. 6828 - 6843
(2010/08/07)
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- PRODUCTION OF AMINES
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A process for the hydrogenation of carboxylic acids and/or derivatives, particularly amides, is described. The process includes reacting an acid or derivative such as an amide with a source of hydrogen in the presence of a catalyst system. The catalyst system obtainable by combining: (a) a source of ruthenium, and (b) a phosphine compound of general Formula I: (Formula I). The hydrogenation reaction is carried out in the presence of a low concentration of water or at low pressure or in the presence of a source of ammonia or the hydrogenation reaction is carried out in the absence of water or a combination of these factors is utilised. The invention also relates to the use of ammonia in the production of primary amines by hydrogenation of carboxylic acids and/or derivatives thereof or a process for the production of primary amines generally.
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Page/Page column 24
(2008/06/13)
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- Salt-free synthesis of tertiary amines by ruthenium-catalyzed amination of alcohols
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The amination of secondary alcohols to give tertiary amines in the presence of different in situ generated ruthenium catalysts has been investigated in detail. By applying a combination of [Ru3(CO)12] and N-phenyl-2-(dicyclohexylphosphanyl) pyrrole as the catalyst, cyclic amines can be alkylated with different alcohols in high yield, whereas aliphatic amines gave transalkylation side products. Wiley-VCH Verlag GmbH & Co. KGaA, 2008.
- Tillack, Annegret,Hollmann, Dirk,Mevius, Kathleen,Michalik, Dirk,Baehn, Sebastian,Beller, Matthias
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body text
p. 4745 - 4750
(2009/05/07)
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- Cp*Ir-catalyzed N-alkylation of amines with alcohols. A versatile and atom economical method for the synthesis of amines
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A versatile and highly atom economical catalytic system consisting of [Cp*IrCl2]2/NaHCO3 (Cp*=pentamethylcyclopentadienyl) for the N-alkylation of amines with primary and secondary alcohols as alkylating reagents has been developed. For example, the reaction of equimolar amounts of aniline and benzyl alcohol in the presence of [Cp*IrCl2]2 (1.0 mol % Ir) and NaHCO3 (1.0 mol %) in toluene at 110 °C gives N-benzylaniline in 94% yield. The present catalytic system is applicable to the N-alkylation of both primary and secondary amines, and only harmless water is produced as co-product. A wide variety of secondary and tertiary amines can be synthesized with high atom economy under mild and less-toxic conditions. One-pot sequential N-alkylation leading to tertiary amines bearing three different substituents is also described.
- Fujita, Ken-ichi,Enoki, Youichiro,Yamaguchi, Ryohei
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p. 1943 - 1954
(2008/09/17)
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- The synthesis of amines by the homogeneous hydrogenation of secondary and primary amides
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Amides can be hydrogenated to amines using a catalyst prepared in situ from [Ru(acac)3] and 1,1,1-tris(diphenylphosphinomethyl)ethane; water is required to stabilize the catalyst and primary amines can only be formed (selectivity up to 85%) if ammonia is also present. The Royal Society of Chemistry.
- Nú?ez Magro, Angel A.,Eastham, Graham R.,Cole-Hamilton, David J.
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p. 3154 - 3156
(2008/02/13)
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- Reaction of primary amines with Pt/C catalyst in water under microwave irradiation: A convenient synthesis of secondary amines from primary amines
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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.
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p. 1437 - 1439
(2007/10/03)
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- Alkyl substituent effect on the polarity of phenols-tri-n-alkylamine complexes
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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
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p. 1012 - 1018
(2007/10/03)
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- Unexpected Hofmann elimination in the benzophenone-(phenylthio)acetic tetrabutylammonium salt photoredox system
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The triplet state of benzophenone was quenched by the tetrabutylammonium salt of (phenylthio)acetic acid in acetonitrile solutions. The quenching event, following laser flash photolysis, resulted in the formation of a transient ion pair consisting of the benzophenone radical anion and the tetrabutylammonium cation. Subsequently this ion pair decays with the quaternary ammonium cation undergoing a Hofmann elimination to form butane-1 and tributylamine, which were detected in steady-state irradiation. This appears to be the first report of an ion pair consisting of a benzophenone radical anion and an organic cation (nonradical), in addition to the first report of a photoinduced Hofmann elimination in quaternary ammonium ions. Copyright
- Wrzyszczynski, Andrzej,Pietrzak, Marek,Bartoszewicz, Jarogniew,Kozubek, Halina,Hug, Gordon L.,Marciniak, Bronislaw,Paczkowski, Jerzy
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p. 11182 - 11183
(2007/10/03)
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- Cephalosporin intermediates
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A process and intermediates in the production of cefotiam (hexetil).
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- Fluorinated amino polyhedral borate compounds
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This invention provides a compound comprising fluorinated aminoborate monoanion of the formula: [R1R2R3N—BaHbFc]?1??I methods for preparing the same, and uses thereof, where R1, R2, R3, a, b, and c are those defined herein.
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- The reaction of pentacyanonitrosylferrate(II) with primary amines as a source of stabilized aliphatic diazonium ions: A new route to secondary amines
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Pentacyanonitrosylferrate(II), 1, reacts with n-butylamine to produce di-n-butylamine in high yields (81-95%). The absence of rearranged products indicates that the initially produced diazonium ion is stabilized by coordination to the metal. Benzylamine and 1,4-diaminobutane react with 1 to produce dibenzylamine and piperidine, respectively.
- Doctorovich, Fabio,Trapani, Cecilia
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p. 4635 - 4638
(2007/10/03)
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- Tetraorganylborate salts as convenient precursors for photogeneration of tertiary amines
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Photoreactions of p-(benzoyl)benzyl trisubstituted ammonium tetraorganylborate salts for the generation of tertiary amines in solution and rigid matrices are described. Structural modification of the complexes allows study of the influence of steric and electronic effects on the photogeneration of amines. Flash photolysis, cyclic voltammetry and product analysis indicate that single electron transfer from borate to excited benzophenone is followed by homolytic C-N bond cleavage. Photoliberation of the tertiary amine is controlled by the rate of the electron transfer reaction.
- Sarker, Ananda M.,Lungu, Adrian,Mejiritski, Alexander,Kaneko, Yuji,Neckers, Douglas C.
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p. 2315 - 2331
(2007/10/03)
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- A novel and highly effective halogenation of alkanes with halides on oxidation with m-Chloroperbenzoic acid: Looks old, but new reaction
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The combination of tetraalkylammonium halides (Cl-. Br-) and m-chloroperbenzoic acid in CH3CN effectively halogenated alkanes accompanied by the formation of alkyl m-chlorobenzoate; for which the alkyl halides were formed via a non-photoinduced radical mechanism and the esters were derived from a non-radical process and concomitant with the formation of corresponding trialkylamine.
- Kojima, Takahiko,Matsuo, Hidenobu,Matsuda, Yoshihisa
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p. 1085 - 1086
(2007/10/03)
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- Joint Synthesis of Tertiary Unsymmetrical and Symmetrical Aliphatic Amines
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Tertiary unsymmetrical and symmetrical aliphatic amines were prepared by reaction of higher (C8-C16) and lower (C2-C4) aliphatic alcohols with nitriles containing the same number of carbon atoms as the lower aliphatic alcohols. Reaction conditions ensuring nearly quantitative yields of tertiary amines were determined.
- Kozlov,Tereshko,Basalaeva,Tarasevich
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p. 1095 - 1098
(2007/10/03)
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