6407-34-7Relevant academic research and scientific papers
Reviving electrocatalytic reductive amination: A sustainable route from biogenic levulinic acid to 1,5-dimethyl-2-pyrrolidone
Holzh?user, F. Joschka,Kurig, Nils,Mürtz, Sonja D.,Palkovits, Regina
, p. 8428 - 8433 (2021/11/17)
The electrocatalytic reductive amination offers a green pathway to N-containing platform and fine chemicals by using water as a hydrogen source and benign reaction conditions. However, systematic studies about suitable reaction conditions and application to biogenic substrates are rare. Here, we present the electrochemical transformation of levulinic acid to 1,5-dimethyl-2-pyrrolidone. Data from Smirnov et al. for the amination of conventional ketones were validated and extended by systematically investigating the impact of electrode material, substrate concentration, current density, solvent, electrolyte, and pH value. High substrate concentrations in an aqueous electrolyte with a high pH value enable imine formation and copper is identified as the most selective cathode material at current densities lower than 40 mA cm-2. The application of optimized reaction conditions to levulinic acid, followed by a short heating procedure for dehydrative ring closure, led to 1,5-dimethyl-2-pyrrolidone in 78% yield. The systematic approach of this work presents the first example of an electrochemical levulinic acid amination and provides a methodology for the benign synthesis of other N-containing species. This journal is
Bis(β-ketoiminate) dioxo tungsten(VI) complexes as precursors for growth of WOx by aerosol-assisted chemical vapor deposition
Su, Xiaoming,Panariti, Persi,Abboud, Khalil A.,McElwee-White, Lisa
, p. 219 - 227 (2019/06/05)
Bis(β-ketoiminate) dioxo tungsten(VI) complexes WO2L2 (L = acNac, acNacMe, acNacEt) have been synthesized and characterized. The thermal behaviors and possible decomposition mechanisms of these dioxo compounds were studied by TGA, MS and thermolysis. The performance of WO2(acNacMe)2 as an AACVD precursor was evaluated at growth temperatures of 250–550 °C using nitrogen as the carrier gas. The elemental compositions of the as-deposited and sputtered tungsten oxide films were determined by XPS. The morphology and stoichiometry of the as-deposited films were studied by SEM and XRD.
Characterization of three novel enzymes with imine reductase activity
Gand,Müller,Wardenga,H?hne
, p. 126 - 132 (2015/02/19)
Imine reductases (IRED) are promising catalysts for the synthesis of optically pure secondary cyclic amines. Three novel IREDs from Paenibacillus elgii B69, Streptomyces ipomoeae 91-03 and Pseudomonas putida KT2440 were identified by amino acid or structural similarity search, cloned and recombinantly expressed in E. coli and their substrate scope was investigated. Besides the acceptance of cyclic amines, also acyclic amines could be identified as substrates for all IREDs. For the IRED from P. putida, a crystal structure (PDB-code 3L6D) is available in the database, but the function of the protein was not investigated so far. This enzyme showed the highest apparent E-value of approximately Eapp = 52 for (R)-methylpyrrolidine of the IREDs investigated in this study. Thus, an excellent enantiomeric purity of >99% and 97% conversion was reached in a biocatalytic reaction using resting cells after 24 h. Interestingly, a histidine residue could be confirmed as a catalytic residue by mutagenesis, but the residue is placed one turn aside compared to the formally known position of the catalytic Asp187 of Streptomyces kanamyceticus IRED.
Reactions of N, N-dichloroalkylamines with solid base as studied by FTIR combined with DFT calculations
Egawa,Ito,Konaka
, p. 337 - 344 (2007/10/03)
Products of vacuum gas-solid reactions of N, N-dichloroalkylamines with KOH have been identified by FTIR spectroscopy and DFT calculations. It has been found that the reactions consist of elimination of two Cl atoms accompanied with migration of an H atom, a ring carbon or a methyl group from the α-carbon to the N atom and unstable imines with a C=N double bond are formed.
Thermolysis of 5-Alkylidene-1,4-dihydro-5H-tetrazoles
Quast, Helmut,Bieber, Lothar,Regnat, Dieter
, p. 1739 - 1747 (2007/10/02)
In benzene solution at 100 deg C, the isopropylidenedihydrotetrazole 1a decomposes mainly (80percent) into molecular nitrogen and the aziridinimines (E)- and (Z)-2a which are thermally unstable and afford methyl isocyanide and the imine 3a.In addition, the novel spirocyclic tetrahydropyrimidine 7a is formed (18percent yield) in a cycloaddition of 1a and the hypothetical intermediate 1,3-diazabutadiene 19a generated from 1a through a hydrogen shift and loss of molecular nitrogen.The thermolysis of the neopentylidenedihydrotetrazole 1b at 100 deg C is more complex.Only small amounts of the aziridinimines (E)- and (Z)-2b and their decomposition products 3b and methyl isocyanide are observed.A major product is the spirocyclic tetrahydropyrimidine 7b which exhibits moderate thermal stability.Slow thermolysis of 7b affords the tetrahydropyrimidinimine 8b and methyl azide.The latter reacts with 1b in a cycloaddition furnishing the spiro compound 5b which partially decomposes into the amino-1,2,3-triazole 16, thus regenerating methyl azide.This catalyzed isomerization 1b -> 16 which is initiated through the thermal cycloreversion of 7b involves a total of 19percent of 1b.The structures of the products are elucidated by means of mass spectra and high-field NMR spectra.The mechanism of formation of the 1,3-diazabutadienes 19 from 1 is discussed.
THE PHOTOCHEMISTRY OF 1,4-DIHYDRO-5H-TETRAZOLE DERIVATIVES ISOLATED IN LOW-TEMPERATURE MATRICES
Dunkin, Ian R.,Shields, Charles J.
, p. 259 - 268 (2007/10/02)
Six 1,4-dihydro-5H-tetrazole (tetrazoline) derivatives have been photolysed in Ar and N2 matrices at 12 K.The dimethyltetrazolinone (1a) gave as the major product the same diaziridinone obtained previously from solution photolysis, but it also underwent a novel cleavage to MeNCO and, presumably, methyl azide.Iminotetrazolines (3a) and (3b) gave the corresponding carbodiimides (5a) and (5b), and iminodiaziridines (4a) and (4b); while the tetrazolinethiones (7a) and (7b) gave carbodiimides (8a) and (8b), respectively.Photolysis of the vinyl substituted tetrazolinone (9) proceeded differently in inert ambient-temperature solutions and low-temperature matrices.In the former an imidazolone (10) was the sole isolable product, while in the latter formation of diaziridinone (15) competed with an alternative cleavage giving t-butyl isocyanate and vinyl azide.THese results are best interpreted on the basis of an intermediate biradical, which, however, could not be detected directly by matrix ir. spectroscopy.
Electronic Structure and Gas-Phase Thermolysis of Substituted Tetrazolines Studied by Photoelectron Spectroscopy
Rademacher, Paul,Carboni, Bertrand,Carrie, Robert,Heymanns, Peter,Poppek, Rainer
, p. 1213 - 1218 (2007/10/02)
The electronic structures and the gas-phase thermolyses of terazolines 1-5 have been studied by photoelectron spectroscopy.For compounds 1-4 cyclorevision to imine and methyl azide is observed, whereas compound 5 is contracted to give the respective diaziridine.To assign the PE spectra, MNDO calculations were performed for compounds 1, 2, 4, and 5; some conformational properties of 5 have been studied by AM1 calculations.
ELECTRONIC STRUCTURES AND THERMOLYSES OF CYCLIC 2-TETRAZENES
Rademacher, P.,Heymanns, P.,Carrie, R.,Carboni, B.
, p. 423 - 428 (2007/10/02)
The electronic structures of 2-tetrazenes 1-4 have been studied by UV photoelectron spectroscopy and MNDO calculations.Gas-phase thermolyses of these compounds were investigated by variable temperature PES.We found that the relative stabilities of cyclic 2-tetrazenes strongly depend on ring-size.The total bond order of the N=N bonds can be correlated with the energy differences of the respective first and second ionization potential.
Synthesis and Reactions of N-Alkyl-O-diphenylphosphinylhydroxylamines and N-Alkyl-N-diphenylphosphinylhydroxylamines
Masse, Guy,Sturtz, Georges
, p. 904 - 907 (2007/10/02)
Reaction of a series of primary amines with bis(diphenylphosphinyl)peroxide conveniently leads to N-alkyl-O-diphenylphosphinylhydroxylamines.These compounds rearrange on heating to the thermodynamically more stable N-phosphinylated derivatives, the N-alkyl-N-diphenylphosphinylhydroxylamines (N-alkyldiphenylphosphinohydroxamic acids).
