- 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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- Development of a general non-noble metal catalyst for the benign amination of alcohols with amines and ammonia
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The N-alkylation of amines or ammonia with alcohols is a valuable route for the synthesis of N-alkyl amines. However, as a potentially clean and economic choice for N-alkyl amine synthesis, non-noble metal catalysts with high activity and good selectivity are rarely reported. Normally, they are severely limited due to low activity and poor generality. Herein, a simple NiCuFeOx catalyst was designed and prepared for the N-alkylation of ammonia or amines with alcohol or primary amines. N-alkyl amines with various structures were successfully synthesized in moderate to excellent yields in the absence of organic ligands and bases. Typically, primary amines could be efficiently transformed into secondary amines and N-heterocyclic compounds, and secondary amines could be N-alkylated to synthesize tertiary amines. Note that primary and secondary amines could be produced through a one-pot reaction of ammonia and alcohols. In addition to excellent catalytic performance, the catalyst itself possesses outstanding superiority, that is, it is air and moisture stable. Moreover, the magnetic property of this catalyst makes it easily separable from the reaction mixture and it could be recovered and reused for several runs without obvious deactivation. Copyright
- Cui, Xinjiang,Dai, Xingchao,Deng, Youquan,Shi, Feng
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supporting information
p. 3665 - 3675
(2013/03/29)
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- Tertiary amines as synthetic equivalents of vinyl cations: Zinc bromide promoted coupling of propargylamines with α-isocyanoacetamides to give 2,4,5-trisubstituted oxazoles initiated by an internal redox process
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Crabee interrupted: Propargylamines 1 react with α-isocyanoacetamides 2 in the presence of zinc bromide to afford vinyl oxazoles 3. The transformation, wherein the propargylamine acts as a vinyl cation synthetic equivalent, involves a domino sequence incorporating a 1,5-hydride shift, intermolecular trapping/cyclization, and a 1,6-elimination (see scheme). Copyright
- Odabachian, Yann,Wang, Qian,Zhu, Jieping
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supporting information
p. 12229 - 12233
(2013/09/23)
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- Formation of secondary or tertiary aliphatic amines in aqueous media
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Secondary and tertiary amines can be easily obtained from primary and secondary amines, respectively, in completely aqueous media, in the presence of a bicatalytic system formed of cheap commercial aluminum (Al) powder and 5% rhodium (Rh) or ruthenium (Ru) deposed on charcoal.
- Marieta Simion, Alina,Arimura, Takashi,Miyazawa, Akira,Simion, Cristian,Surya Prakash,Olah, George A.,Tashiro, Masashi
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scheme or table
p. 2859 - 2865
(2009/12/03)
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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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- Method for producing amines by homogeneously catalyzed reductive amination of carbonyl compounds
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The invention relates to the preparation of chiral or achiral amines by reaction of aldehydes or ketones with ammonia or primary or secondary amines in the presence of hydrogen and in the presence of homogeneous metal catalysts under mild conditions. Metal catalysts which can be used are complexes of late transition metals with chiral or achiral phosphorus-containing ligands.
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Page/Page column 10
(2010/02/11)
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- Microwave-assisted direct transformation of amines to ketones using water as an oxygen source
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Retro-reductive animations, direct transformations of amines to ketones, were catalyzed by Pd/C in water under microwave irradiation. The Royal Society of Chemistry 2005.
- Miyazawa, Akira,Tanaka, Kan,Sakakura, Toshiyasu,Tashiro, Masashi,Tashiro, Hideki,Surya Prakash,Olah, George A.
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p. 2104 - 2106
(2007/10/03)
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- About selenidostannates. I: Synthesis, structure, and properties of [Sn2Se6]4-, [Sn4Se10]4-, and [Sn3Se7]2-
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The selenidostannates [(C4H9)2NH2]4Sn 2Se6·H2O (I), [(C4H9)2NH2]4Sn 4Se10·2H2O (II) und [(C3H7)3NH]2-Sn3Se 7 (III) were prepared by hydrothermal syntheses from the elements and the amines. I crystallizes in the monoclinic spacegroup P21/n (a = 1262.9(3) pm, b = 1851.3(4) pm, c = 2305.2(4) pm, β = 104.13(3)° and Z = 4). The [Sn2Se6]4- anion consists of two edge-sharing tetrahedra. II crystallizes in the orthorhombic spacegroup Pna21 (a = 2080.3(4) pm, b = 1308.2(3) pm, c = 2263.5(5) pm and Z = 4). The anion is formed from four SnSe4 tetrahedra which are joined by common corners to the adamantane cage [Sn4Se10]4-. III crystallizes in the orthorhombic spacegroup Pbcn (a = 1371.1(3) pm, b = 2285.4(5) pm, c = 2194.7(4) pm and Z = 8). The anion is a chain, built from edge-sharing [Sn3Se5Se4/2]2- units, in which two corner sharing tetrahedra are connected to a trigonal bipyramid by an edge of one and a corner of the other tetrahedron. The results of the TG/DSC measurements and of temperature dependent X-ray diffractograms reveal that I and II decompose at first by release of minor quantities of triethylammonium to compounds with layer structure and larger cell dimensions. At still higher temperature the rest of triethylammonium and H2Se is evolved, leaving SnSe2 and Se in the bulk. The former decomposes partially at the highest temperature to SnSe. In the measurements of III the complex intermediate compound was not observed. III decomposes directly to SnSe2. Wiley-VCH Verlag GmbH, 2001.
- Fehlker, Andreas,Blachnik, Roger
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p. 411 - 418
(2008/10/08)
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- Phenylureas. Part 2. Mechanism of the acid hydrolysis of phenylureas
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The mechanism of the hydrolytic decomposition of phenylureas in acid media is investigated. It includes, in part, knowledge already present in the literature. Over the investigated pH range the occurrence of a rate maximum in the pH curves due to the strongly reduced water activity at higher acid strengths is observed. An addition-elimination mechanism with rate-determining attack of water at the N-protonated substrate is proposed. The reversion of the substituent influence on the reaction rate with increasing acidity of the reaction medium points to a change of the hydrolytic decomposition mechanism in strongly acidic media.
- Laudien, Robert,Mitzner, Rolf
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p. 2230 - 2232
(2007/10/03)
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- Preparation of amines
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A process for preparing an amine by catalytic reaction of an olefin with ammonia or a primary or secondary amine by contacting a mixture of the reactants in a reactor at 200° to 400° C. and an elevated pressure up to 700 bar in the presence of a catalyst consisting essentially of an X-ray amorphous (non-crystalline) mesoporous catalyst, some of which may have a microporous non-crystalline content. The catalyst has the composition where Q is at least one of the trivalent elements aluminum, boron, chromium, iron or gallium, and M is at least one of the tetravalent elements silicon, titanium or germanium. The molar ratio of a:b is from 0.5:1 to 1000:1 and the molar ratio of c:b is from 0 to 2:1. As prepared and used in the process, this non-crystalline catalyst has a specific BET surface area of from 200 to 1000 m2 /g.
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- Amination of butenes over protonic zeolites
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The reaction of 1-butene and isobutene with ammonia has been investigated, far from thermodynamic equilibrium, in the pressure range 1-6 MPa over a series of acidic zeolites. The kinetics are compatible with a Langmuir-Hinshelwood mechanism involving adsorbed species. The rates of amination increase with the Si/Al ratio of the solid. A small influence of the zeolite structure is noticed on the relative adsorption coefficients in the case of 1-butene but not in that of isobutene. The catalytic activity calculated per proton is higher on MFI than on BEA or HY zeolites, but this effect of the structure is less than an order of magnitude. Under the conditions of reaction used in this work large pore zeolites show a good resistance to deactivation. It is proposed that deactivation is mainly due to the formation of strongly basic polyalkylamines and not to coke.
- Lequitte,Figueras,Moreau,Hub
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p. 255 - 261
(2007/10/03)
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- Unimolecular Reactions of the Isolated Immonium Ions CH3CH=NH+C4H9, CH3CH2CH=NH+C4H9 and (CH3)2C=NH+C4H9
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The reactions of ten metastable immonium ions of general structure R1R2C=NH+C4H9 (R1 = H, R2 = CH3, C2H5; R1 = R2 = CH3) are reported and discussed.Elimination of C4H8 is usually the dominant fragmentation pathway.This process gives rise to a Gaussian metastable peak; it is interpreted in terms of a mechanism involving ion-neutral complexes containing incipient butyl cations.Metastable immonium ions containing an isobutyl group are unique in undergoing a minor amount of imine (R1R2C=NH) loss.This decomposition route, which also produces a Gaussianmetastable peak, decreases in importance as the basicity of the imine increases.The correlation between imine loss and the presence of an isobutyl group is rationalized by the rearrangement of the appropriate ion-neutral complexes in which there are isobutyl cations to the isomeric complexes containing the thermodynamically more stable tert-butyl cations.A sizeable amount of a third reaction, expulsion of C3H6, is observed for metastable n-C4H9+NH=CR1R2 ions; in contrast to C4H8 and R1R2C=NH loss, C3H6 elimination occurs with a large kinetic energy release (40-48 kJ mol-1) and is evidenced by a dish-topped metastable peak.This process is explained using a two-step mechanism involving a 1,5-hydride shift, followed by cleavage of the resultant secondary open-chain cations, CH3CH+CH2CH2NHCHR1R2.
- Bowen, Richard D.,Colburn, Alex. W.,Derrick, Peter J.
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p. 509 - 516
(2007/10/02)
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