23 research outputs found
Access to functionalized quinones via the aromatic oxidation of phenols bearing an alcohol or olefinic function catalyzed by supported iron phthalocyaninew
International audienceThe controlled oxidation at only one position of compounds with several oxidizable sites, while keeping the other sites intact, has been demonstrated for phenols bearing alcohol or olefinic functional groups. Iron tetrasulfophthalocyanine supported on silica was found to be an efficient catalyst for the preparation of functionalized quinones under mild conditions, with tertbutylhydroperoxide as the oxidant. A novel rapid and mild one-pot procedure for the covalent grafting of iron tetrasulfophthalocyanine onto silica has been developed. The supported catalyst was characterized by chemical analysis, a specific surface study, UV-vis spectroscopy and XPS. A non-radical mechanism for this unusual selective oxidation has been revealed by 18O labelling experiments
H2O2-Based oxidation of functionalized phenols containing several oxidizable sites to p-quinones using a mesoporous titanium-silicate catalyst
International audienc
Preparation of 2-methyl-1,4-naphthoquinone (vitamin K3) by catalytic oxidation of 2-methyl-1-naphthol in the presence of iron phthalocyanine supported catalyst
International audienceIron tetrasulfophthalocyanine (FePcS) supported catalyst was prepared by covalent grafting onto amino-modified silica by a novel practical one-pot method using activation of sulfonate groups of FePcS by triphenylphosphine triflate. FePcSeSiO2 in combination with tBuOOH behaved as an efficient catalyst for the oxidation of 2-methyl-1-naphthol to 2-methyl-1,4-naphthoquinone, vitamin K3. To optimise the catalytic system, the influence of different reaction parameters on the efficiency of this oxidation has been studied. Vitamin K3 was obtained with 59% selectivity at 96% conversion of 2-methyl-1-naphthol using only 0.5 mol% of catalyst. 18O labelling experiments indicate a non-radical mechanism for this oxidation
Kinetics and mechanism of the oxidation of alkyl substituted phenols and naphthols with tBuOOH in the presence of supported iron phthalocyanine
BIOVERT+ASO:IVA:OZANon
Mechanistic study on the oxidation of functionalized phenols and naphthols in Ti-MMM-2 / H2O2 and FePcS-SiO2 / tBuOOH systems
internationa
Efficient epoxidation of olefins by H2O2 catalyzed by iron "helmet" phthalocyanines
BIOVERT:RAFFINAGE+ISK:EKU:PAF:ASOHigh yields of epoxides were obtained in the oxidation of a large range of olefins using 1.2-2 equiv. of H2O2 in the presence of iron helmet phthalocyanines. The involvement of high-valent iron oxo species was evidenced using cryospray mass spectrometry
Iron tetrasulfophthalocyanine immobilized on metal organic framework MIL-101: synthesis, characterization and catalytic properties
BIOVERT+ASOInternational audienc
EPR study on the mechanism of H2O2-based oxidation of alkylphenols over titanium single-site catalysts
International audienc