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Aqueous-Phase Oxidation of N-Substituted N-PhosphonomethylGlycines into Glyphosate with Hydrogen Peroxide in the Presence of Carbon-Supported Gold Catalysts. / Pyrjaev, Pavel A.; Yushchenko, Dmitry Yu; Moroz, Boris L. и др.
в: ChemistrySelect, Том 4, № 36, 30.09.2019, стр. 10756-10764.Результаты исследований: Научные публикации в периодических изданиях › статья › Рецензирование
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TY - JOUR
T1 - Aqueous-Phase Oxidation of N-Substituted N-PhosphonomethylGlycines into Glyphosate with Hydrogen Peroxide in the Presence of Carbon-Supported Gold Catalysts
AU - Pyrjaev, Pavel A.
AU - Yushchenko, Dmitry Yu
AU - Moroz, Boris L.
AU - Pai, Zinaida P.
AU - Bukhtiyarov, Valerii I.
N1 - Publisher Copyright: © 2019 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
PY - 2019/9/30
Y1 - 2019/9/30
N2 - The catalytic performance of carbon-supported gold nanoparticles has been studied for the oxidative dealkylation of a series of N-substituted N-phosphonomethyl glycines into N-phosphonomethyl glycine (“glyphosate”) using dilute (0.11 m) aqueous H2O2 solution as oxidant. It was shown that the electron-donating inductive (+I) effect of the hydrocarbon substituent at the nitrogen atom greatly influences both the substrate reactivity and product distribution. Gold nanoparticles of 1.5-2.5 nm in diameter synthesized by “cationic adsorption” technique on the mesoporous Sibunit carbons, which are pre-oxidized with HNO3 and containing a lot of surface acidic groups, were found to catalyze the formation of glyphosate from N-isopropyl-N-phosphonomethyl glycine at 70 °C with selectivity up to 94% at 98% substrate conversion. Oxidation of other substrates containing the substituents with a weaker +I effect than that of iPr group resulted a large amount of undesirable N-decarboxymethylation product in addition to glyphosate. Considering the literature data and our own experimental results, assumptions about the reaction mechanism and causes of the observed trends are made.
AB - The catalytic performance of carbon-supported gold nanoparticles has been studied for the oxidative dealkylation of a series of N-substituted N-phosphonomethyl glycines into N-phosphonomethyl glycine (“glyphosate”) using dilute (0.11 m) aqueous H2O2 solution as oxidant. It was shown that the electron-donating inductive (+I) effect of the hydrocarbon substituent at the nitrogen atom greatly influences both the substrate reactivity and product distribution. Gold nanoparticles of 1.5-2.5 nm in diameter synthesized by “cationic adsorption” technique on the mesoporous Sibunit carbons, which are pre-oxidized with HNO3 and containing a lot of surface acidic groups, were found to catalyze the formation of glyphosate from N-isopropyl-N-phosphonomethyl glycine at 70 °C with selectivity up to 94% at 98% substrate conversion. Oxidation of other substrates containing the substituents with a weaker +I effect than that of iPr group resulted a large amount of undesirable N-decarboxymethylation product in addition to glyphosate. Considering the literature data and our own experimental results, assumptions about the reaction mechanism and causes of the observed trends are made.
KW - glyphosate synthesis
KW - gold
KW - N-substituted glyphosates
KW - oxidation
KW - supported catalysts
KW - SURFACE-PROPERTIES
KW - SELECTIVE OXIDATION
KW - H2O2
KW - NANOPARTICLES
KW - ACTIVATED CARBON
KW - AMINES
KW - KINETICS
KW - AU/AL2O3
KW - GENERATION
KW - AU/CARBON
UR - http://www.scopus.com/inward/record.url?scp=85073226179&partnerID=8YFLogxK
U2 - 10.1002/slct.201902625
DO - 10.1002/slct.201902625
M3 - Article
AN - SCOPUS:85073226179
VL - 4
SP - 10756
EP - 10764
JO - ChemistrySelect
JF - ChemistrySelect
SN - 2365-6549
IS - 36
ER -
ID: 21856343