- Identifying the roles of amino acids, alcohols and 1,2-diamines as mediators in coupling of haloarenes to arenes
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Coupling of haloarenes to arenes has been facilitated by a diverse range of organic additives in the presence of KOtBu or NaOtBu since the first report in 2008. Very recently, we showed that the reactivity of some of these additives (e.g., compounds 6 and 7) could be explained by the formation of organic electron donors in situ, but the role of other additives was not addressed. The simplest of these, alcohols, including 1,2-diols, 1,2-diamines, and amino acids are the most intriguing, and we now report experiments that support their roles as precursors of organic electron donors, underlining the importance of this mode of initiation in these coupling reactions.
- Zhou, Shengze,Doni, Eswararao,Anderson, Greg M.,Kane, Ryan G.,Macdougall, Scott W.,Ironmonger, Victoria M.,Tuttle, Tell,Murphy, John A.
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Read Online
- Ureas and amides as dipolar aprotic solvents in highly basic media. The dependence of kinetic basicity on solvent composition
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The basicity of dipolar aprotic solvent water HO systems with amides and ureas as the organic component has been studied kinetically because previous information is not available. excluding some H values measured for aqueous dimethylformamide (DMF) and tetramethylurea (TMU). It was found that the increase in basicity with the mole fraction of organic component is at least of the same magnitude as in aqueous dimethyl sulfoxide (DMSO). For instance, in the detritiation of chloroform-t the slopes of the plots log(k2/mol 1 dm3 s 1) vs. x(urea) varied between 11.4 14.6 (as compared to 11.0 in aqueous DMSO) when TMU and cyclic ureas. 1.3-dimethylimidazolidin-2-one (DMI) and 1.3-dimethyl-3.4.5.6-tetrahydropyrimidin-2(1H)-one (DMPU). were used as the organic component in solvent mixture. In aqueous TMU acidity functions H were extrapolated from kinetic results using linear free energy correlations. Agreement with literature values was evident. This method was also used to extrapolate the H values in aqueous DMPU. On the basis of present work aqueous ureas can be recommended as solvents in highly basic media. The utility of amides. dimethylformamide and dimethylacetamide. is limited by their instability in basic water solutions.
- Kankaanperae, Alpo,Scharlin, Pirketta,Kuusisto, Ilona,Kallio, Riitta,Bernoulli, Emma
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Read Online
- New method for preparing N,N'-dimethylethylenediamine and N,N'-dimethyl-1,3-propanediamine
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The present invention relates to a new method for preparing N,N'-dimethylethylenediamine and N,N'-dimethyl-1,3-propanediamine, wherein 1,3-dimethyl-2-imidazolidinone or 1,3-dimethyl-tetrahydro-2-pyrimidone is used as a raw material, a suitable alkali is added, and a heating ring-opening reaction is perform to prepare N,N'-dimethylethylenediamine and N,N'-dimethyl-1,3-propanediamine. In the prior art, the conventional method performs alkylation by using the amine as the raw material to generate more by-products. According to the present invention, the method completely avoids the problem in theprior art, has characteristics of simple operation, high yield, less three-waste and high product purity, and is suitable for industrial production.
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Paragraph 0009-0014
(2019/10/01)
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- Low-Temperature Reductive Aminolysis of Carbohydrates to Diamines and Aminoalcohols by Heterogeneous Catalysis
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Short amines, such as ethanolamines and ethylenediamines, are important compounds in today's bulk and fine chemicals industry. Unfortunately, current industrial manufacture of these chemicals relies on fossil resources and requires rigorous safety measures when handling explosive or toxic intermediates. Inspired by the elegant working mechanism of aldolase enzymes, a novel heterogeneously catalyzed process—reductive aminolysis—was developed for the efficient production of short amines from carbohydrates at low temperature. High-value bio-based amines containing a bio-derived C2 carbon backbone were synthesized in one step with yields up to 87 C%, in the absence of a solvent and at a temperature below 405 K. A wide variety of available primary and secondary alkyl- and alkanolamines can be reacted with the carbohydrate to form the corresponding C2-diamine. The presented reductive aminolysis is therefore a promising strategy for sustainable synthesis of short, acyclic, bio-based amines.
- Pelckmans, Michiel,Vermandel, Walter,Van Waes, Frederik,Moonen, Kristof,Sels, Bert F.
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p. 14540 - 14544
(2017/10/23)
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- Nitric oxide reactivity of copper(ii) complexes of bidentate amine ligands: Effect of substitution on ligand nitrosation
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Three copper(ii) complexes with bidentate ligands L1, L 2 and L3 [L1, N,N/- dimethylethylenediamine; L2, N,N/-diethylethylenediamine and L3, N,N/-diisobutylethylenediamine], respectively, were synthesized as their perchlorate salts. The single crystal structures for all the complexes were determined. The nitric oxide reactivity of the complexes was studied in acetonitrile solvent. The formation of thermally unstable [CuII-NO] intermediate on reaction of the complexes with nitric oxide in acetonitrile solution was observed prior to the reduction of copper(ii) centres to copper(i). The reduction was found to result with a simultaneous mono- and di-nitrosation at the secondary amine sites of the ligand. All the nitrosation products were isolated and characterized. The ratio of the yield of mono- and di-nitrosation product was found to be dependent on the N-substitution present in the ligand framework.
- Sarma, Moushumi,Mondal, Biplab
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experimental part
p. 2927 - 2934
(2012/04/10)
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- Merging constitutional and motional covalent dynamics in reversible imine formation and exchange processes
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The formation and exchange processes of imines of salicylaldehyde, pyridine-2-carboxaldehyde, and benzaldehyde have been studied, showing that the former has features of particular interest for dynamic covalent chemistry, displaying high efficiency and fast rates. The monoimines formed with aliphatic α,ω-diamines display an internal exchange process of self-transimination type, inducing a local motion of either "stepping-in- place" or "single-step" type by bond interchange, whose rate decreases rapidly with the distance of the terminal amino groups. Control of the speed of the process over a wide range may be achieved by substituents, solvent composition, and temperature. These monoimines also undergo intermolecular exchange, thus merging motional and constitutional covalent behavior within the same molecule. With polyamines, the monoimines formed execute internal motions that have been characterized by extensive one-dimensional, two-dimensional, and EXSY proton NMR studies. In particular, with linear polyamines, nondirectional displacement occurs by shifting of the aldehyde residue along the polyamine chain serving as molecular track. Imines thus behave as simple prototypes of systems displaying relative motions of molecular moieties, a subject of high current interest in the investigation of synthetic and biological molecular motors. The motional processes described are of dynamic covalent nature and take place without change in molecular constitution. They thus represent a category of dynamic covalent motions, resulting from reversible covalent bond formation and dissociation. They extend dynamic covalent chemistry into the area of molecular motions. A major further step will be to achieve control of directionality. The results reported here for imines open wide perspectives, together with other chemical groups, for the implementation of such features in multifunctional molecules toward the design of molecular devices presenting a complex combination of motional and constitutional dynamic behaviors.
- Kovaricek, Petr,Lehn, Jean-Marie
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supporting information; experimental part
p. 9446 - 9455
(2012/07/14)
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- Reversible aminal formation: Controlling the evaporation of bioactive volatiles by dynamic combinatorial/covalent chemistry
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Dynamic mixtures generated by reversible aminal formation efficiently prolong the duration of evaporation of bioactive volatile aldehydes. Secondary diamines used for the generation of dynamic mixtures are obtained by treatment of primary diamines with carbonyl compounds and reduction of the diimines with NaBH4. The reversibilities of the reactions were demonstrated by NMR measurements in buffered aqueous solutions. Kinetic rate constants and equilibrium constants for the formation and hydrolysis of aminals were determined. The performance of dynamic mixtures as delivery systems for perfumery ingredients was tested after deposition onto cotton, and the long-lastingness of fragrance evaporation was investigated by dynamic headspace analysis against a reference sample. The simplicity of the concept together with its excellent performance makes this delivery system highly interesting for applied perfumery. Reversible aminal formation might also be successfully applicable to dynamic combinatorial/covalent chemistry for screening of pharmaceutically or catalytically active ligands and receptors. The evaporation of bioactive volatiles that are emitted from flowers to attract insects and that are used as fragrances in our everyday life is limited in time. Dynamic mixtures obtained by reversible aminal formation of suitably designed diamines with volatile aldehydes prolong the perception of these compounds in functional perfumery.
- Buchsnee Levrand, Barbara,Godin, Guillaume,Trachsel, Alain,De Saint Laumer, Jean-Yves,Lehn, Jean-Marie,Herrmann, Andreas
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experimental part
p. 681 - 695
(2011/03/22)
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- CONTROLLED RELEASE OF ACTIVE ALDEHYDES AND KETONES FROM EQUILIBRATED DYNAMIC MIXTURES
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The present invention concerns a dynamic mixture obtained by combining, in the presence of water, at least one diamine derivative, comprising at least one benzylamine moiety, with at least one active aldehyde or ketone. The invention's mixture is capable of releasing in a controlled and prolonged manner said active compound, in particular perfuming ingredients, in the surrounding environment.
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Page/Page column 31-33
(2008/12/07)
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- METHOD FOR PRODUCING N-MONOALKYL-SUBSTITUTED ALKYLENE AMINE
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PROBLEM TO BE SOLVED: To provide a method for producing an N-monoalkyl-substituted alkylene amine especially useful for uses such as medicine intermediates, agrochemical intermediates, urethane resin-foaming catalysts, surfactants and the like among alkyl-substituted alkylene amine compounds from an alcohol and an alkylene amine as raw materials. SOLUTION: This method for producing the N-monoalkyl-substituted alkylene amine is characterized by reacting the alkylene amine with a ≥2C alkyl alcohol in the presence of a copper-containing oxide catalyst system. The N-monoalkyl-substituted alkylenamine is produced in high conversion and in N-monoalkylation selectivity.
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Page/Page column 8
(2010/02/11)
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- Continuous chemoselective methylation of functionalized amines and diols with supercritical methanol over solid acid and acid-base bifunctional catalysts
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The selective N-methylation of bifunctionalized amines with supercritical methanol (scCH3OH) promoted by the conventional solid acids (H-mordenite, β-zeolite, amorphous silica-alumina) and acid-base bifunctional catalysts (Cs-P-Si mixed oxide and γ-alumina) was investigated in a continuous-flow, fixed-bed reactor. The use of scCH 3OH in the reaction of 2-aminoethanol with methanol (amine/CH 3OH = 1/10.8) over the solid catalysts led to a significant improvement in the chemoselectivity of the N-methylation. Among the catalysts examined, the Cs-P-Si mixed oxide provided the most efficient catalyst performance in terms of selectivity and reactivity at 300 °C and 8.2 MPa; the N-methylation selectivity in the products reaching up to 94% at 86% conversion. The present selective methylation was successfully applied to the synthesis of N-methylated amino alcohols and diamines as well as O-methylated ethylene glycol. Noticeably, ethoxyethylamine was less reactive, suggesting that the hydroxy group of the amino alcohols is a crucial structural factor in determining high reactivity and selectivity, possibly because of the tethering effect of another terminus, a hydroxo group, to the catalyst surface. The magic-angle-spinning NMR spectroscopy and X-ray diffraction analysis of the Cs-P-Si mixed oxide catalyst revealed that the acidic and basic sites originate from P2O5/SiO2 and Cs/SiO2, respectively, and the weak acid-base paired sites are attributed to three kinds of cesium phosphates on SiO2. The weak acid-base sites on the catalyst surface might be responsible for the selective dehydrative methylation.
- Oku, Tomoharu,Arita, Yoshitaka,Tsuneki, Hideaki,Ikariya, Takao
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p. 7368 - 7377
(2007/10/03)
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- Reaction of 1,2-dibromoethane with primary amines: Formation of N,N′-disubstituted ethylenediamines RNH-CH2CH2-NHR and homologous polyamines RNH-[CH2CH2NR]n-H
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The reaction of primary amines RNH2 (R: Me, Et, iPr, tBu and Ph) with 1,2-dibromoethane gave N,N′-disubstituted ethylenediamines R-NH-CH2CH2-NH-R (1) in yields ranging from 10% (1a; R=Me) to 70% (1d, R=tBu; 1e, R=Ph). Pipe
- Denk, Michael K.,Krause, Mike J.,Niyogi, Debyani F.,Gill, Nachhattarpal K.
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p. 7565 - 7570
(2007/10/03)
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- Valency platform molecules comprising carbamate linkages
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This invention pertains generally to valency molecules, such as valency platform molecules which act as scaffolds to which one or more molecules may be covalently tethered to form a conjugate. More particularly, the present invention pertains to valency platform molecules which comprise a carbamate linkage (i.e., —O—C(=O)—N). In one aspect, the present invention pertains to valency platforms comprising carbamate linkages, which molecules have the structure of any one of Formulae I, II, or III, shown in FIG. 1. In one aspect, the present invention pertains to valency platforms comprising carbamate linkages, which molecules have the structure of any one of Formulae IV, V, or VI, shown in FIG. 8. The present invention also pertains to methods of preparing such valency platform molecules, conjugates comprising such valency platform molecules, and methods of preparing such conjugates.
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- Method and apparatus for sunless tanning
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Apparatus for simulating skin tanning comprises a receptacle containing a fluid comprising dihydroxyacetone, a receptacle containing a fluid comprising a secondary polyamine, and dispensing means for simultaneously or sequentially providing desired amounts of dihydroxyacetone and polyamine.
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- Ruthenium catalyzed reactions of ethylene glycol with primary amines: steric factors and selectivity control
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The selectivity of reactions of ethylene glycol with primary amines in the presence of RuCl2(PPh3)3 at 120 deg C is highly dependent on the steric nature of the amine.Selectivity to di-amination is favored by smaller alkyl groups on the amine while large amines cleanly yield ethanolamines.This contrasts with the results obtained with secondary amines at this temperature, in which ruthenium-triphenylphosphine catalyst systems always favor mono-amination.In the case of sec-butyl amine, where almost equal amounts of mono- and di-aminated product are obtained, the selecti vity can be shifted to mono-amination by the addition of excess triphenylphosphine.The steric effects seen in these reactions are consistent with standard steric parameters availble from the literature.
- Marsella, John A.
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- Condensation of Alkanediamines with Formaldehyde; Intramolecular Disproportionation of N-Hydroxymethyl Groups into N-Methyl and N-Formyl Groups
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The condensation of α,ω-alkanediamines NH2(CN2)nNH2 with aqueous formaldehyde has been studied by NMR spectroscopy of isolated products and of product mixtures.The condensation was reversible and gave products of widely different types depending on alkane chain length: bicyclic oxadiaza compounds (n = 2, 3, 4), a tricyclic tetraaza compound (n = 2), a quinquecyclic octaaza compound (n = 3), two-dimensional polymers (n = 4, 5).A slow irreversible rearrangement gave in two cases (n = 3, 4), unicyclic 1-formyl-3-methyl-1,3-diaza compounds.The condensation of N,N'-dimethyl-α,ω-alkandediamines CH3NH(CH2)nNHCH3 with aqueous formaldehyde was also studied.The reversible formation of simple unicyclic diaza compounds was observed in all cases (n = 2, 3, 4), but in one case (n = 2) there was again a slow irreversible rearrangement to the N-formyl-N,N'N'-trimethyl derivative.The rearrangement reaction involves a hydride shift and is strictly intramolecular.The conditions for its occurrence can be understood on a conformational basis.
- Dale, Johannes,Sigvartsen, Turid
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p. 1064 - 1070
(2007/10/02)
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- Selective Reductions of 3-Substituted Hydantoins to 4-Hydroxy-2-imidazolidinones and Vicinal Diamines
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N3-Substituted hydantoins (1) have been shown to undergo LiAlH4 reduction (THF, room temperature, 2 days) to give 4-hydroxy-2-imidazolidinones (3) in good yields.Reduction of 3,5-disubstituted hydantoins in which an aliphatic substituent was present at nitrogen 3 led to the preferential formation of the cis adduct 3.Conversely, disubstituted hydantoins possessing an aryl moiety at nitrogen 3 gave the trans derivative 3 as the major product.Treatment of the N3-substituted hydantoins (1) under more vigorous conditions (THF, reflux, 3 days) led to selective ring opening of 1 to yield N-methylethylenediamines (7).The scope of both of these reductive processes has been explored, and explanations are offered to account for the observed results.Full spectral (infrared, 1H and 13C NMR, and mass spectra) data on all three classes of compounds (1, 3, and 7) have been collected.Together this information provides a consistent data set which is useful in structure elucidation.Moreover, various NMR aids have been discerned for the isomeric cis- and trans-4-hydroxy-2-imidazolidinones (3) which permitted stereochemical assignments for these compounds.
- Cortes, Sergio,Kohn, Harold
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p. 2246 - 2254
(2007/10/02)
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- General-Acid-Catalyzed Imidazolidine Ring Opening. Hydrolysis of Symmetrical and Unsymmetrical 1,3-Imidazolidines of p-Dimethylaminocinnamaldehyde
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Rate constants have been obtained for ring opening of a series of symmetrical and unsymmetrical 1,3-imidazolidines of p-dimethylaminocinnamaldehyde in H2O at 30 deg C.Ring opening of the N,N'-diphenyl derivative is catalyzed by hydronium ion (kH = 2290 M-1 s-1), and gives rise to a cationic Schiff base with λmax 505 nm.The reaction is considerably slower in D2O than in H2O, kH/kD = 3.0.At pH greater than 6 ring opening is pH independent (k0' = 1.8 10-2 s-1).Ring opening of the N,N'-dimethylimidazolidine to a species with λmax 480 nm is hydronium ion catalyzed (kH = 2 109 M-1 s-1) and pH independent at pH values above 11.5.The unsymmetrical N-isopropyl-N'-phenyl derivative opens to give a species with λmax 480 nm and with rate constants that are similar to those for the N,N'-dimethyl substituted compound (kH = 4 107 M-1 s-1).Consequently, this species must be the N-isopropyl Schiff base resulting from breaking of the C-N phenyl bond.General acid catalysis of ring opening was observed in trimethylamine buffer.Only at pH values less than 6 does C-N isopropyl bond breaking become competitive, giving the N-phenyl Schiff base (λmax 512 nm).The interconversion of Schiff bases (480 -> 512 nm) is general acid catalyzed by buffer acids or a kinetic equivalent.Thus, ring-opening reactions of imidazolidines have been directly monitored, and general acid catalysis has been observed.It can be concluded that, in reactions of the neutral species and hydronium ion, or a general acid, the imidazolidine ring opens preferentially to give the most stable carbonium ion with expulsion of the least basic nitrogen.In the reaction of the unsymmetrical imidazolidine at low pH when there are two protons in the transition state, either C-N bond may break, and the C-N phenyl Schiff base is the favored product.These results are discussed in relation to reactions of N5,N10-methylenetetrahydrofolic acid.
- Fife, Thomas H.,Pellino, August M.
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p. 3062 - 3071
(2007/10/02)
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