109-73-9Relevant articles and documents
Impact of solvent on Co/SiO2 activity and selectivity for the synthesis of n-butylamine from butyronitrile hydrogenation
Segobia,Trasarti,Apesteguía
, p. 62 - 66 (2015)
The impact of solvent on Co(9.8%)/SiO2 activity and selectivity for the synthesis of n-butylamine from butyronitrile hydrogenation was investigated using methanol, benzene, toluene and cyclohexane as solvents. In non-polar solvents, the yield of n-butylamine increased from 60% to 79% following the order cyclohexane toluene benzene. Nevertheless, the highest n-butylamine yield (91%) was obtained in methanol, a protic solvent. The solvent effect on the catalyst performance was interpreted by considering: i) the solvent-catalyst interaction strength and ii) the solvent polarity and its ability for H-bond formation with n-butylamine.
Kinetics of Amine Addition to Benzylidenemalonodialdehyde in 50percent Me2SO-50percent water
Bernasconi, Claude F.,Stronach, Michael W.
, p. 1993 - 2001 (1991)
The kinetics of the reaction of benzylidenemalonodialdehyde with piperidine, morpholine, n-butylamine, 2-methoxyethylamine, glycinamide, glycine ethyl ester, cyanomethylamine, and semicarbazide have been determined in 50percent aqueous Me2SO at 20 deg C.The reaction leads to a zwitterionic adduct, PhCH(RR'NH(1+))C(CHO)2(1-) (TA(+/-)), that is in fast acid-base equilibrium with the anionic adduct, PhCH(RR'N)C(CHO)2(1-) (TA(1-)).With strongly basic amines at high pH there is also attack of the amine on one of the carbonyl groups, which acts as a rapid preequilibrium.Rate constants for the formation of TA(+/-) (k1) and its reverse (k-1), as well as equilibrium constants (K1 = k1/k-1) and the pKa of TA(+/-) were determined for all the amines.Intrinsic rate constants (k0 = k1 = k-1 when K1 = 1) were calculated.The intrinsic rate constants are lower than those for amine addition to benzylidene Meldrum's acid.This is consistent with the greater role played by resonance in stabilizing TA(+/-) derived from benzylidenemalonodialdehyde.However, k0 for piperidine/morpholine addition to benzylidenemalonodialdehyde is much higher than for the reaction of benzylideneacetylacetone with the same amines, indicating that the rate-depressing effect of intramolecular hydrogen bonding in TA(+/-) derived from benzylidenemalonodialdehyde is much smaller than that in TA(+/-) derived from benzylideneacetylacetone.Even though semicarbazide is an α-effect nucleophile, no enhancement of k1 was observed, but K1, estimated on the basis of a structure-reactivity relationship, is larger than expected based on the pKa of the amine.This result is attributed to a low νnucn value.
Dynamic Covalent Switches and Communicating Networks for Tunable Multicolor Luminescent Systems and Vapor-Responsive Materials
Zou, Hanxun,Hai, Yu,Ye, Hebo,You, Lei
, p. 16344 - 16353 (2019)
Molecular switches are an intensive area of research, and in particular, the control of multistate switching is challenging. Herein we introduce a general and versatile strategy of dynamic covalent switches and communicating networks, wherein distinct states of reversible covalent systems can induce addressable fluorescence switching. The regulation of intramolecular ring/chain equilibrium, intermolecular dynamic covalent reactions (DCRs) with amines, and both permitted the activation of optical switches. The variation in electron-withdrawing competition between the fluorophore and 2-formylbenzenesulfonyl unit afforded diverse signaling patterns. The combination of switches in situ further enabled the creation of communicating networks for multistate color switching, including white emission, through the delicate control of DCRs in complex mixtures. Finally, reversible and recyclable multiresponsive luminescent materials were achieved with molecular networks on the solid support, allowing visualization of different types of vapors and quantification of primary amine vapors with high sensitivity and wide detection range. The results reported herein should be appealing for future studies of dynamic assemblies, molecular sensing, intelligent materials, and biological labeling.
Biocatalysed synthesis of chiral amines: continuous colorimetric assays for mining amine-transaminases
Gourbeyre, Léa,Heuson, Egon,Charmantray, Franck,Hélaine, Virgil,Debard, Adrien,Petit, Jean-Louis,de Berardinis, Véronique,Gefflaut, Thierry
, p. 904 - 911 (2021)
In the course of our research aimed at the design of new biocatalytic processes for the enantioselective synthesis of chiral amines, we have developed new continuous assays for the screening of amine-transaminase collections. These assays are based on the use of hypotaurine as an irreversible amine donor. This β-aminosulfinic acid is converted upon transamination into 2-oxoethylsulfinic acid, which instantaneously decomposes into acetaldehyde and sulfite ions that can be easily detected by spectrophotometry using Ellman's reagent. Two complementary assays were developed based on this titration method. Firstly, a direct assay allowed detection of various transaminases able to use hypotaurine as an amino donor. In a second coupled assay,l-alanine is used as a generic donor substrate of amine-transaminases and is regenerated using an auxiliary hypotaurine-transaminase. The powerful and complementary nature of both assays was demonstrated through the screening of a collection of 549 amine-transaminases from biodiversity, thus allowing the discovery of a variety of valuable new biocatalysts for use in synthetic processes.
Kinetic and equilibrium studies of σ-adduct formation and nucleophilic substitution in the reactions of trinitro-activated benzenes with aliphatic amines in acetonitrile
Crampton, Michael R.,Lord, Simon D.
, p. 369 - 376 (1997)
Rate and equilibrium constants are reported for reactions in acetonitrile of butylamine, pyrrolidine and piperidine with 1,3,5-trinitrobenzene, 1, and with ethyl 2,4,6-trinitrophenyl ether, 4a, and phenyl 2,4,6-trinitrophenyl ether, 4b. Rapid nucleophilic attack at unsubstituted ring-positions may yield anionic σ-adducts via zwitterionic intermediates, while slower attack at the 1-position of 4a and 4b may lead to substitution to give 2,4,6-trinitroaniline derivatives. Base catalysis in the substitution reaction reflects rate-limiting proton transfer which may be from the zwitterionic intermediates to amine in the case of 4b, or from a substituted ammonium ion to the ethoxy leaving group in the case of 4a. Comparisons with values in DMSO indicate that values of overall equilibrium constants for adduct formation are ca. 104 lower in acetonitrile, while rate constants for proton transfer are ca. 104 higher. These differences may reflect strong hydrogen-bonding between DMSO and -NH+ protons in ammonium ions and in zwitterions. In acetonitrile homoconjugation of substituted ammonium ions with free amine is an important factor.
SOLVATION OF PRIMARY AMINES: SHORT-RANGE SOLVATION OF PROTON TRANSFER COMPLEXES OF 2,4-DINITROPHENOL, AND n-BUTYLAMINE
Guo, Shuqiong,Scott, Ronald M.
, p. 307 - 313 (1990)
The short range solvation of the proton-transfer complex formed between 2,4-dinitrophenol and n-butylamine was studied in benzene solution containing small amounts of three ethers: n-propylether, tetrahydropyran, and dioxane.In all cases a pattern is observed in which solvation by the ether causes an increase in the equilibrium constant for the formation of the proton transfer complex until a plateau value is reached.This is followed on further increase of the ether concentration by a second rise followed by a second plateau.The equilibrium constants for each of thesolvation events and the number of solvent molecules reacting per amine molecule were calculated.The first step involves two solvent molecules per amine, and the second step involves a larger number.
Charged states of proteins. Reactions of doubly protonated alkyldiamines with NH3: Solvation or deprotonation. Extension of two proton cases to multiply protonated globular proteins observed in the gas phase
Peschke, Michael,Blades, Arthur,Kebarle, Paul
, p. 11519 - 11530 (2002)
The apparent gas-phase basicities (GBapp'S) of basic sites in multiply protonated molecules, such as proteins, can be approximately predicted. An approach used by Williams and co-workers was to develop an equation for a diprotonated system, NH
A new supported rhodium catalyst for selective hydrogenation of nitriles to primary amines
Witte, Peter T.
, p. 468 - 474 (2007)
Nitriles are converted to primary amines with high selectivity using a newly developed alumina-supported rhodium catalyst. The high selectivity is obtained without any additives, which are often used to prevent the formation of higher amines. The catalyst is active under mild conditions In various solvents, which makes it specifically suitable for use in pharmaceutical applications or for other substrates that can react with additives like strong acids or bases.
Electron Spin Resonance Monitoring of Ligand Ejection Reactions Following Solid-State Reduction of Cobalt Globin and Cobalt Protoporphyrin Complexes
Dickinson, L. Charles,Symons, M. C. R.
, p. 917 - 921 (1982)
Cobaltihemoglobin, isolated α and β chains, and cobaltimyoglobin in aqueous solution at neutral pH were irradiated at 77 K with 3 Mrd of 60Co γ-rays.These diamagnetic Co(III) species are converted to paramagnetic Co(II) species in high yield.The EPR spectra are identical with those of authentic six-coordinate cobalt(II) porphyrins.Upon partial annealing of the species, the EPR spectrum transforms irreversibly to that of a five-coordinate species, indicating that at 77 K these cobaltiglobins are cobaltichromes in analogy to the hemichromes of the native iron species.Differences are seen among all of the six-coordinate, reduced protein ligated species.This ejection of the sixth ligand with thermal annealing after addition of one electron to the dz2 orbital of the cobalt porphyrin also occurs in aqueous glasses of cobalt protoporphyrin IX in pyridine, n-butylamine, or quinuclidine.The five-coordinate species in aqueous media are stable with annealing to room temperature.
Selective Transformations of Triglycerides into Fatty Amines, Amides, and Nitriles by using Heterogeneous Catalysis
Jamil, Md. A. R.,Siddiki, S. M. A. Hakim,Touchy, Abeda Sultana,Rashed, Md. Nurnobi,Poly, Sharmin Sultana,Jing, Yuan,Ting, Kah Wei,Toyao, Takashi,Maeno, Zen,Shimizu, Ken-ichi
, p. 3115 - 3125 (2019)
The use of triglycerides as an important class of biomass is an effective strategy to realize a more sustainable society. Herein, three heterogeneous catalytic methods are reported for the selective one-pot transformation of triglycerides into value-added chemicals: i) the reductive amination of triglycerides into fatty amines with aqueous NH3 under H2 promoted by ZrO2-supported Pt clusters; ii) the amidation of triglycerides under gaseous NH3 catalyzed by high-silica H-beta (Hβ) zeolite at 180 °C; iii) the Hβ-promoted synthesis of nitriles from triglycerides and gaseous NH3 at 220 °C. These methods are widely applicable to the transformation of various triglycerides (C4–C18 skeletons) into the corresponding amines, amides, and nitriles.
