F:Flammable;107-10-8Relevant academic research and scientific papers
Spectroscopy of Hydrothermal Reactions, Part 26: Kinetics of Decarboxylation of Aliphatic Amino Acids and Comparison with the Rates of Racemization
Li, Jun,Brill, Thomas B.
, p. 602 - 610 (2003)
The kinetics of decarboxylation of six α-amino acids (glycine, alanine, aminobutyric acid, valine, leucine, and isoleucine) and β-aminobutyric acid were studied in aqueous solution at 310-330 deg C and 275 bar over the pH25 range 1.5-8.5 by using an in situ FT-IR spectroscopy flow reactor. Based on the rate of formation of CO2, the first-order or pseudo-first-order rate constants were obtained along with the Arrhenius parameters. The decarboxylation rates of amino acids follow the order Gly > Leu ca. Ile ca. Val > Ala > α-Aib > β-Aib. Differences in the concentration between 0.05 and 0.5 m had only a minor effect on the decarboxylation rate. The effect of the position of the amino group on the decarboxylation rate was investigated for α-, β-, and γ-aminobutyric acid and the order was found to be α > β >> γ. Although the pH dependence is complex, the decarboxylation rates of α-amino acids qualitatively have the inverse trend of the racemization rates.
Merging constitutional and motional covalent dynamics in reversible imine formation and exchange processes
Kovaricek, Petr,Lehn, Jean-Marie
, p. 9446 - 9455 (2012)
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.
N,N-Bis(trimethylsilyl)methoxymethylamine as a Convenient Synthetic Equivalent for +CH2NH2: Primary Aminomethylation of Organometallic Compounds
Morimoto, Toshiaki,Takahashi, Toshio,Sekiya, Minoru
, p. 794 - 795 (1984)
The introduction of the primary aminomethyl unit at carbon through N,N-bis(trimethylsilyl)aminomethylation of Grignard and organolithium compounds can be achieved in good yield using N,N-bis(trimethylsilyl)methoxymethylamine (1).
Water-soluble platinum and palladium nanoparticles modified with thiolated β-cyclodextrin
Alvarez, Julio,Liu, Jian,Roman, Esteban,Kaifer, Angel E.
, p. 1151 - 1152 (2000)
Pt and Pd nanoparticles can be modified with surface-attached cyclodextrin receptors leading to water-soluble materials that exhibit catalytic activity for the hydrogenation of allylamine.
Rice husk-SiO2supported bimetallic Fe-Ni nanoparticles: as a new, powerful magnetic nanocomposite for the aqueous reduction of nitro compounds to amines
Ghadermazi, Mohammad,Moradi, Setareh,Mozafari, Roya
, p. 33389 - 33400 (2020)
This paper reports a novel green procedure for immobilization of bimetallic Fe/Ni on amorphous silica nanoparticles extracted from rice husk (RH-SiO2). The heterogeneous nanocomposite (Fe/Ni?RH-SiO2) was identified using SEM, EDX, TEM, BET, H2-TPR, TGA, XRD, VSM, ICP-OES, and FT-IR analyses. The Fe/Ni?RH-SiO2nanocomposite was applied as a powerful catalyst for the reduction of structurally diverse nitro compounds with sodium borohydride (NaBH4) in green conditions. This procedure suggests some benefits such as green chemistry-based properties, short reaction times, non-explosive materials, easy to handle, fast separation and simple work-up method. The catalyst was separated by an external magnet from the reaction mixture and was reused for 9 successive cycles with no detectable changes of its catalytic efficiency.
Reduced reactivity of amines against nucleophilic substitution via reversible reaction with carbon dioxide
Mohammed, Fiaz S.,Kitchens, Christopher L.
, (2016)
The reversible reaction of carbon dioxide (CO2) with primary amines to form alkyl-ammonium carbamates is demonstrated in this work to reduce amine reactivity against nucleophilic substitution reactions with benzophenone and phenyl isocyanate. The reversible formation of carbamates has been recently exploited for a number of unique applications including the formation of reversible ionic liquids and surfactants. For these applications, reduced reactivity of the carbamate is imperative, particularly for applications in reactions and separations. In this work, carbamate formation resulted in a 67% reduction in yield for urea synthesis and 55% reduction for imine synthesis. Furthermore, the amine reactivity can be recovered upon reversal of the carbamate reaction, demonstrating reversibility. The strong nucleophilic properties of amines often require protection/de-protection schemes during bi-functional coupling reactions. This typically requires three separate reaction steps to achieve a single transformation, which is the motivation behind Green Chemistry Principle #8: Reduce Derivatives. Based upon the reduced reactivity, there is potential to employ the reversible carbamate reaction as an alternative method for amine protection in the presence of competing reactions. For the context of this work, CO2 is envisioned as a green protecting agent to suppress formation of n-phenyl benzophenoneimine and various n-phenyl-n-alky ureas.
Supramolecular solid-gas complexes: A thermodynamic approach
Grechin, Alexander G.,Buschmann, Hans-Juergen,Schollmeyer, Eckhard
, p. 6499 - 6501 (2007)
(Table Presented) Phasing up to complex problems: A thermodynamic approach based on solution data has been proposed for the determination of the stability of gas complexes and elucidation of the selectivity of gas binding. Stability constants, reaction enthalpies, and entropies for the complexation of gaseous guests (n-alkylamines) by solid macrocyclic hosts (β-cyclodextrin, cucurbit[6]uril) were calculated by using the Born-Haber type cycle (see picture).
Insight into the mechanism of hydrogenation of amino acids to amino alcohols catalyzed by a heterogeneous MoOx-modified Rh catalyst
Tamura, Masazumi,Tamura, Riku,Takeda, Yasuyuki,Nakagawa, Yoshinao,Tomishige, Keiichi
, p. 3097 - 3107 (2015)
Hydrogenation of amino acids to amino alcohols is a promising utilization of natural amino acids. We found that MoOx-modified Rh/SiO2 (Rh-MoOx/SiO2) is an efficient heterogeneous catalyst for the reaction at low temperature (323 K) and the addition of a small amount of MoOx drastically increases the activity and selectivity. Here, we report the catalytic potential of Rh-MoOx/SiO2 and the results of kinetic and spectroscopic studies to elucidate the reaction mechanism of Rh-MoOx/SiO2 catalyzed hydrogenation of amino acids to amino alcohols. Rh-MoOx/SiO2 is superior to previously reported catalysts in terms of activity and substrate scope. This reaction proceeds by direct formation of an aldehyde intermediate from the carboxylic acid moiety, which is different from the reported reaction mechanism. This mechanism can be attributed to the reactive hydride species and substrate adsorption caused by MoOx modification of Rh metal, which results in high activity, selectivity, and enantioselectivity.
Catalytic Reductions and Tandem Reactions of Nitro Compounds Using in Situ Prepared Nickel Boride Catalyst in Nanocellulose Solution
Prathap, Kaniraj Jeya,Wu, Qiong,Olsson, Richard T.,Dinér, Peter
, p. 4746 - 4749 (2017)
A mild and efficient method for the in situ reduction of a wide range of nitroarenes and aliphatic nitrocompounds to amines in excellent yields using nickel chloride/sodium borohydride in a solution of TEMPO-oxidized nanocellulose in water (0.01 wt %) is described. The nanocellulose has a stabilizing effect on the catalyst, which increases the turnover number and enables low loading of nickel catalyst (0.1-0.25 mol % NiCl2). In addition, two tandem protocols were developed in which the in situ formed amines were either Boc-protected to carbamates or further reacted with an epoxide to yield β-amino alcohols in excellent yields.
Amination of alcohols with ammonia in water over Rhin catalyst
Takanashi, Tsukasa,Nakagawa, Yoshinao,Tomishige, Keiichi
, p. 822 - 824 (2014)
Amination of various C3 alcohols such as 1,2-propanediol with ammonia was catalyzed by RhIn/C in water while Rh/C was totally inactive. Activated carbon FAC-10 was the best support in terms of activity and resistance to metal leaching. In the amination of 1,2-propanediol, RhIn/C produced amino alcohols in 68% total selectivity and 38% conversion. XRD and TEM measurements showed that RhIn alloy particle with size of 34 nm was formed on the carbon support.
