- CeO2-catalyzed direct synthesis of dialkylureas from CO2 and amines
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CeO2 showed higher activity for the direct synthesis of 1,3-dibutylurea (DBU) from CO2 and n-butylamine than the metal oxides tested. The solvent largely influenced the reaction over CeO2, and N-methylpyrrolidone (NMP) was preferable among various solvents tested from the viewpoints of activity and selectivity. The catalyst system composed of CeO2 catalyst and NMP solvent (CeO2 in NMP) was applicable to the reactions of various amines such as linear primary alkylamines or branched primary alkylamines, although tert-butylamine afforded low conversion. In contrast, secondary amines and aniline provided no yield of the ureas. The combination of 2-cyanopyridine with CeO2 in NMP (CeO2 in NMP with 2-cyanopyridine) promoted the transformation of the unreactive amines, showing that tert-butylamine and aniline were converted to the corresponding ureas in 82% and 80% yields, respectively. These yields are much higher than those reported in the previous literatures, indicating that CeO2 in NMP with 2-cyanopyridine drastically promoted transformation of amines with low reactivity.
- Tamura, Masazumi,Ito, Kazuki,Nakagawa, Yoshinao,Tomishige, Keiichi
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- Colloid and nanosized catalysts in organic synthesis: XIV. Reductive amination and amidation of carbonitriles catalyzed by nickel nanoparticles
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Hydrogenation of carbonitriles catalyzed by nickel nanoparticles in the presence of primary amines led to the predominant formation of unsymmetrical secondary amines. In the presence of secondary amines hydrogenation of nitrites provided enamines as main products. Hydrogenation of nitriles in the presence of formamide or acetamide afforded formyl or acetyl derivatives of primary amines.
- Popov, Yu. V.,Mokhov,Shcherbakova
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p. 798 - 805
(2016/06/13)
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- Copper(I)-Catalysed Multicomponent Reaction: Straightforward Access to 5-Hydroxy-1H-pyrrol-2(5H)-ones
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A copper-catalysed multicomponent coupling reaction between readily available (Z)-3-iodoacrylic acids, terminal alkynes, and primary amines was developed to smoothly access a small library of 5-hydroxy-1H-pyrrol-2(5H)-ones in good yields. This practical and general process was applied to a short-steps synthesis of the natural product pulchellalactam.
- Mardjan, Muhammad Idham Darussalam,Parrain, Jean-Luc,Commeiras, Laurent
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p. 543 - 548
(2016/02/27)
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- Selective N-methylation of aliphatic amines with CO2 and hydrosilanes using nickel-phosphine catalysts
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A method using CO2 and PhSiH3 for the methylation of primary and secondary aliphatic amines catalyzed by Ni (0) complexes was developed, selectively producing the monomethylated products in moderate to good yields. For that purpose, two catalysts were used: [(dippe)Ni(μ-H)]2 and the commercially available Ni(COD)2/dcype, both of which were rather efficient in this process. With a slight experimental modification, the reaction allowed the production of monomethylated ureas in good yields by using low amounts of PhSiH3. On the basis of the experimental results, we propose a possible reaction mechanism for the formation of the new C-N bond.
- Gonzlez-Sebastin, Lucero,Flores-Alamo, Marcos,Garca, Juventino J.
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p. 763 - 769
(2015/05/12)
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- New synthesis of vanillin by degradation of lignin in presence of functional basic ionic liquid
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The degradation of lignin catalyzed by functional basic ionic liquid was investigated. Higher conversion of lignin and simpler degradation product composition were obtained in the presence of basic ionic liquid, comparing with that under traditional NaOH
- Yi, Fengping,Jiang, Xiaoyan,Niu, Jihua,Zhang, Lirong,Wang, Zhen
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p. 885 - 888
(2015/02/05)
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- A highly efficient sulfur-catalyzed oxidative carbonylation of primary amines and β-amino alcohols
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A highly efficient sulfur-catalyzed oxidative carbonylation of aliphatic amines and aliphatic β-amino alcohols to ureas and 2-oxazolidinones, respectively, was developed. Sodium nitrite was involved in the reoxidation of hydrogen sulfide to sulfur in the catalytic oxidative carbonylation cycle. Georg Thieme Verlag Stuttgart.
- Peng, Xingao,Li, Fuwei,Xia, Chungu
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p. 1161 - 1164
(2007/10/03)
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- A novel PdCl2/ZrO2-SO42- catalyst for synthesis of carbamates by oxidative carbonylation of amines
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At 170°C and ca. 4.0 MPa, oxidative carbonylation of aromatic amines to synthesize corresponding carbamates over a novel PdCl2/ZrO2-SO42- catalyst could proceed with high conversion and selectivity.
- Shi, Feng,Deng, Youquan,SiMa, Tianlong,Yang, Hongzhou
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p. 525 - 528
(2007/10/03)
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- REACTIONS OF α-CHLORO- AND α,α-DICHLORO-β-CARBONYL-SUBSTITUTED ALDEHYDES WITH AMINES
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Depending on the nature of the substrate (the chlorodicarbonyl compound) and the nature of the nucleophilic reagent (the amine), the reaction of α-chloro- and α,α-dichloro-β-carbonyl-substituted aldehydes with amines takes place mainly in three directions i.e., with the formation of enamines or imines or with cleavage of the C-CHO bond of the aldehydes.
- Guseinov, F. I.,Klimentova, G. Yu.,Moskva, V. V.
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p. 530 - 533
(2007/10/02)
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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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p. 2647 - 2651
(2007/10/02)
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- Tellurium-catalyzed Carbonylation of Amines with Carbon Monoxide
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Carbonylation of amines with carbon monoxide was catalyzed by tellurium to produce corresponding urea derivatives, formamides, and molecular hydrogen.The urea formation proceeds according to the equation; 2RNH2+CO->(RNH)2CO+H2.The successful achievement of the catalytic formation of urea derivatives would be due to the thermal instability of hydrogen telluride which decomposes to generate elemental tellurium and hydrogen.The formation of formamides and hydrogen was found to be suppressed by the addition of nitrobenzene which did not affect the urea formation.Effects of the reaction time, temperature, pressure of carbon monoxide, and additives on this carbonylation reaction are discussed.
- Kambe, Nobuaki,Kondo, Kiyoshi,Ishii, Hideo,Sonoda, Noboru
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p. 1460 - 1464
(2007/10/02)
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