Catalytic activity of Cu ion-exchanged Na·MCM-41 in the liquid-phase oxidation of 2,6-di-tert-butylphenol

Kohara, Ichitaroh; Fujiyama, Hirofumi; Iwai, Koji; Nishiyama, Satoru; Tsuruya, Shigeru

doi:10.1016/s1381-1169(99)00306-4

Cited by 23 publications

(17 citation statements)

References 24 publications

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“…zeolite, demonstrating advantages of mesoporous materials for oxidation of the bulky DTBP molecule [107,108].…”

Section: Coppermentioning

confidence: 99%

“…Although the catalytic activity was rather low (TOF = 0.4 h -1 ), the catalyst could be readily recovered and reused.Copper (II) was introduced into mesostructured silicates of the MCM-41 type having a hexagonal arrangement of mesopores-channels with uniform diameter of ca. 3.5 nm by impregnation[107] or ion exchange[108] procedures. The Cu(II)-impregnated and Cu(II)-ionexchanged MCM-41 materials showed activity in the liquid-phase oxidation of DTBP with molecular oxygen[107,108].…”

mentioning

confidence: 99%

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Recent advances in transition-metal-catalyzed selective oxidation of substituted phenols and methoxyarenes with environmentally benign oxidants

Kholdeeva

Zalomaeva

2016

Coordination Chemistry Reviews

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“…zeolite, demonstrating advantages of mesoporous materials for oxidation of the bulky DTBP molecule [107,108].…”

Section: Coppermentioning

confidence: 99%

mentioning

confidence: 99%

Recent advances in transition-metal-catalyzed selective oxidation of substituted phenols and methoxyarenes with environmentally benign oxidants

Kholdeeva

Zalomaeva

2016

Coordination Chemistry Reviews

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“…The oxidation reaction of DTBP carried out under different condition led to DTBQ and PQ mixture (table 4). In general, during the oxidation with the complex CuL, PQ appeared to be predominant product, similarly to the reaction catalysed by Cu(II) ions-amine systems [12,13,[15][16][17][18][19][25][26][27]. for Cu(II) uptake resulted in a greater yield of PQ than DTBQ.…”

Section: Resultsmentioning

confidence: 92%

“…Japanese authors [15,16] reported that liquid-phase catalytic oxidation of DTBP was performed on Cu ionexchanged Na MCM-41 support. They found that in a basic medium or in the presence of alkali metal, DTBP was easy deprotonated to phenolate anion.…”

Section: Introductionmentioning

confidence: 99%

Oxidation of 2,6-di-tert-butylphenols to Diphenoquinones Catalysed by Schiff Base-Cu(II) Systems Immobilized on Polymer Support

2006

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Benzoquinone, diphenoquinones and its derivatives are important intermediates for industrial synthesis of a wide variety of special chemicals, such as pharmaceuticals, dyes and agricultural chemicals. The useful catalyst were obtained by aminolysis of vinylbenzyl chloride/divinylbenzene copolymer with ethylenediamine (1) or urotropine (2) and then modification by salicylaldehyde (1A, 2A) or picolinaldehyde (1B, 2B). The catalytic activity of Cu(II) complexes with Schiff base immobilized on the synthesized supports were tested in the oxidation reaction of 2,6-di-tert-butylphenol (DTBP) to diphenoquinone (PQ) with tertbutylhydroperoxide. The best oxidation degree of DTBP (60-70%) and the selectivity towards PQ (80%) is revealed by Cu(II) complexes with long Schiff base ligands derived from salicylaldimine (1A), which have CuL structure (EPR measurement).

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“…This reaction has been studied well in both heterogeneous 5 and homogeneous 6 systems, as well as in scCO 2 . 7 DTBP is converted to a mixture of 2,6-di-tert-butyl-1,4-benzoquinone (DTBQ) and the related product of radical coupling, 3,5,3A,5A-tetra-tert-butyl-4,4A-diphenoquinone (TTDBQ).…”

Section: Introductionmentioning

confidence: 99%

Autoxidation of 2,6-di-tert-butylphenol with cobalt Schiff base catalysts by oxygen in CO2-expanded liquids

et al. 2004

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CO 2 -expanded acetonitrile and methylene chloride have been used in this first detailed study of catalytic O 2 oxidations in these remarkably effective reaction media. The autoxidation of 2,6-di-tert-butylphenol (DTBP) with the cobalt Schiff-base (Co(salen*) in these so-called CO 2 -expanded liquids (CXLs) has been extensively studied using precisely controlled and monitored batch reactions. The dependence of conversion, selectivity and turn-over-frequency on various reaction parameters, including temperature, [O 2 ], [catalyst], and solvent composition has been evaluated. The rates of O 2 -oxidation in CXLs are typically 1-2 orders of magnitude greater than those obtained with either the neat organic solvent or supercritical CO 2 as reaction media. In keeping with the proposed mechanism, the dependence of both the selectivity and conversion on O 2 concentration and catalyst concentration indicates that the O 2 adduct, and not free O 2 , serves as oxidant in two critical steps in these systems. The increase in conversion with increasing temperature supports formation of the phenoxy radical as the rate determining step. In contrast, the temperature independence of selectivity is as expected for two competing radical coupling reactions. The balance between O 2 solubility and mixed-solvent dielectric constant determines some of the benefits of the CXLs. Because of the greatly increased solubility of O 2 in CXLs, the conversion in those media is substantially greater than that in either scCO 2 or the neat organic solvent. However, conversion eventually decreases with increasing CO 2 content of the solvent because of the decreasing dielectric constant of the medium. The solubilities of O 2 and Co(salen*) have been determined in CXLs based on methylene chloride.

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Catalytic activity of Cu ion-exchanged Na·MCM-41 in the liquid-phase oxidation of 2,6-di-tert-butylphenol

Cited by 23 publications

References 24 publications

Recent advances in transition-metal-catalyzed selective oxidation of substituted phenols and methoxyarenes with environmentally benign oxidants

Recent advances in transition-metal-catalyzed selective oxidation of substituted phenols and methoxyarenes with environmentally benign oxidants

Oxidation of 2,6-di-tert-butylphenols to Diphenoquinones Catalysed by Schiff Base-Cu(II) Systems Immobilized on Polymer Support

Autoxidation of 2,6-di-tert-butylphenol with cobalt Schiff base catalysts by oxygen in CO2-expanded liquids

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