105-67-9Relevant articles and documents
Sodium perborate: A convenient reagent for benzylic hydroperoxide rearrangement
Kabalka,Reddy,Narayana
, p. 7667 - 7668 (1993)
Sodium perborate in boron trifluoride etherate has been found to be an effective reagent for the hydroperoxide rearrangement of electron rich and highly substituted benzylic tertiary alcohols to phenols in good yields.
Photochemical reactions of oxygen atoms with toluene, m-xylene, p-xylene, and mesitylene: An infrared matrix isolation investigation
Parker, James K.,Davis, Steven R.
, p. 4108 - 4114 (2000)
The photochemical reactions of oxygen atoms with methylated benzenes (toluene, m-xylene, p-xylene, and mesitylene) were investigated in solid argon matrices at 12 K with UV light of λ ≥ 280 nm, producing ketene functionalities. The toluene/O atom reaction
Application of two morphologies of Mn2O3for efficient catalyticortho-methylation of 4-chlorophenol
Gui, Wenying,Liu, Xiaofei,Wang, Zhenlu,Zhang, Chunlei,Zhang, Hongqiang,Zhang, Li,Zhu, Wanchun
, p. 20836 - 20849 (2021)
Vapor phaseortho-methylation of 4-chlorophenol with methanol was studied over Mn2O3catalyst with two kinds of morphologies. Here, Mn2O3was prepared by a precipitation and hydrothermal method, and showed the morphology of nanoparticles and nanowires, respectively. XRD characterization and BET results showed that, with the increase of calcination temperature, Mn2O3had a higher crystallinity and a smaller specific surface area. N2adsorption/desorption and TPD measurements indicated that Mn2O3nanowires possessed larger external surface areas and more abundant acid and base sites. Simultaneously, in the fixed bed reactor, methanol was used as the methylation reagent for theortho-methylation reaction of 4-chlorophenol. XRD, XPS, TG-MS and other characterizations made it clear that methanol reduced 4-chlorophenol and its methide, which were the main side-reactions. And Mn3+was reduced to Mn2+under the reaction conditions. Changing the carrier gas N2to a H2/Ar mixture further verified that the hydrogen generated by the decomposition of methanol was not the reason for dechlorination of 4-chlorophenol compounds. Here we summarized the progress of 4-chlorophenol methylation based on the methylation of phenol. Also, we proposed a mechanism of the 4-chlorophenol dechlorination effect which was similar to the Meerwein-Ponndorf-Verley-type (MPV) reaction. The crystal phase and carbon deposition were investigated in different reaction periods by XRD and TG-DTA. The reaction conditions for the two kinds of morphologies of the Mn2O3catalyst such as calcination temperature, reaction temperature, phenol-methanol ratio and reaction space velocity were optimized.
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Simons,McArthur
, p. 364 (1947)
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Evaluation of acute toxicity and genotoxicity of liquid products from pyrolysis of Eucalyptus grandis wood
Pimenta,Bayona,Garcia,Solanas
, p. 169 - 175 (2000)
Slow pyrolysis of Eucalyptus grandis wood was performed in an oven laboratory, and smoke was trapped and condensed to yield liquid products. Polycyclic aromatic hydrocarbons (PAHs) and phenolic fractions were isolated from the former liquid products using adsorption column chromatography (ACC) and identified by GC/MS. Concentrations of PAH and phenolic fractions in total pyrolysis liquids were respectively 48.9 μg/g and 8.59% (w/w). Acute toxicity of total samples of pyrolysis liquids and the phenolic fraction was evaluated by means of two bioassays, namely, 24-h immobilization bioassay with Daphnia magna and Microtox(TM) bioassays, the latter employing the luminescent bacteria Photobacterium phosphoreum. Total pyrolysis liquids and the PAH fraction were evaluated for genotoxicity by the Microtox(TM) bioassay conducted using rehydrated freeze-dried dark mutant of the luminescent bacteria Vibrio fisheri strain M169. Total pyrolysis liquids and the phenolic fraction, respectively, in concentrations of 170 and 68 mg/L were able to immobilize 50% (EC50) of the D. magna population following 24-h exposure. Concentrations of 19 and 6 mg/L, respectively, for total pyrolysis liquids and phenolic fraction were the effective concentrations that resulted in a 50% (EC50) reduction in light produced by bacteria in the Microtox(TM) bioassay. Accordingly, the Microtox(TM) bioassay was more sensitive to toxic effects of both kind of samples than the D. magna bioassay, particularly for the phenolic fraction. Regarding to the genotoxicity evaluation, the results achieved by Microtox(TM) bioassay showed that total pyrolysis liquids had no genotoxic effects with and without exogenous metabolic activation using rat liver homogenate (S9). However, the PAH fraction showed toxic effects with rat liver activation and had a dose-response number (DRN) equal to 1.6, being in this way suspected genotoxic. The lowest detected concentration (LDC) of the PAH fraction able to cause genotoxic effects was 375 μg/L.
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Lambooy
, p. 5327 (1950)
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Phenylthioalkylation-Desulphurisation for the C-Alkylation of Phenols
Fleming, Ian,Iqbal, Javed
, p. 937 - 939 (1982)
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Efficient Transformation of Anisole into Methylated Phenols over High-Silica HY Zeolites under Mild Conditions
Meng, Qinglei,Fan, Honglei,Liu, Huizhen,Zhou, Huacong,He, Zhenhong,Jiang, Zhiwei,Wu, Tianbin,Han, Buxing
, p. 2831 - 2835 (2015)
Transformation of anisole (methoxybenzene), a typical component of bio-oil, into phenol and methylated phenols was studied over HY zeolites with framework Si/Al ratios of 5, 15, 25, and 35. It was demonstrated that the amounts of Bronsted acid and Lewis acid sites, the ratio of Lewis acid and Bronsted acid sites, and the textural properties of the zeolites were all crucial parameters that influenced the catalytic performance. The Bronsted acid and Lewis acid sites of the zeolites catalyzed the reaction cooperatively and efficiently promoted the transmethylation. The hierarchical channel system with fully open micropore-mesopore connectivity was favorable to reduce the amount of coke generated.
A new mild deprotecting method for O-benzylsulfonyl phenols and alcohols based on a DTBB-catalyzed lithiation
Alonso, Francisco,Moglie, Yanina,Vitale, Cristian,Radivoy, Gabriel,Yus, Miguel
, p. 1971 - 1976 (2005)
A variety of alcohols and phenols, protected as the corresponding benzylsulfonic esters, were efficiently deprotected by selective reductive cleavage of the sulfur-oxygen bond, using an excess of lithium sand and a catalytic amount (5 mol%) of 4,4′-di-tert-butylbiphenyl (DTBB) as electron carrier, in THF at 0° C. This deprotection system was also efficient at -50 °C and was compatible with a wide range of other functional groups. Georg Thieme Verlag Stuttgart.
Acid-Catalyzed Dehydration of Substituted Dienediols
Wigal, Carl T.,McKinley, Jason D.,Coyle, Jennifer,Porter, Diane J.,Lehman, Daniel E.
, p. 8421 - 8423 (1995)
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ipso-Attack in the Hydroxylation of o- and p-Xylene using bis(trimethylsilyl) Peroxide and Aluminium Chloride
Apatu, Jonas O.,Chapman, David C.,Heaney, Harry
, p. 1079 - 1080 (1981)
Electrophilic hydroxylation of o- and p-xylene using a range of peroxides, including the title compound, in the presence of Lewis acids results in the formation of mixtures of phenols including those derived by ipso-attack followed by rearrangement; ipso-attack by the hydroxyl radical leads to dealkylation.
Improved oxidation of aromatic and aliphatic hydrocarbons using rate enhancing variants of P450Bm3 in combination with decoy molecules
Munday, Samuel D.,Shoji, Osami,Watanabe, Yoshihito,Wong, Luet-Lok,Bell, Stephen G.
, p. 1036 - 1039 (2016)
Enzyme performance can be improved using decoy molecules or engineered variants to accelerate the activity without affecting selectivity. Here we combine a rate accelerator variant of cytochrome P450Bm3 with decoy molecules to enhance the oxidation activity of a range of small organic molecules. This combined approach offers superior biocatalytic efficiency without modifying the product distribution.
Comparison of cresol transformation on USHY and HZSM-5
Imbert,Guisnet,Gnep
, p. 279 - 286 (2000)
In the commercial synthesis of cresols, the most common processes include the alkylation of phenol with methanol. The cresol (methylphenol) transformation on zeolite USHY was studied and compared with HZSM-5 with different pore size, structure, and different acidity in a flow reactor at 380°C and 0.1 bar. The cresol turnover numbers for USHY were pretty similar, whereas on HZSM-5, the cresols reactivities followed the sequence p- ≥ m- > o-cresol. The cresols reacted over the zeolites mainly through two parallel reactions, isomerization and disproportionation, whose relative importance depends on the catalysts characteristics (pore structure and acidity), on the reacting cresol itself, and on the reaction conditions (temperature, total pressure, reactant partial pressure, etc). The USHY selectivity toward the monomolecular isomerization reaction was by far lower than that of HZSM-5, due to its size/shape selectivity. On USHY and HZSM-5 catalysts, the o-cresol showed higher disproportionation selectivity than the other two cresol isomers, this proportionation occurring via diphenylmethane intermediates. The cresol isomerization selectivity was limited by product desorption even on a large pore zeolite like USHY. The cresol isomer composition at high conversions on USHY was 44, 42, and 14% for o-, m-, and p-cresol, respectively. Xylenols underwent a rapid isomerization once formed.
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Harris,Saeman,Bergstrom
, p. 2063,2065 (1949)
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Palladium-catalyzed hydroxylation of aryl and heteroaryl halides enabled by the use of a palladacycle precatalyst
Cheung, Chi Wai,Buchwald, Stephen L.
, p. 5351 - 5358 (2014)
A method for the hydroxylation of aryl and heteroaryl halides, promoted by a catalyst based on a biarylphosphine ligand tBuBrettPhos (L5) and its corresponding palladium precatalyst (1), is described. The reactions allow the cross-coupling of both potassium and cesium hydroxides with (hetero)aryl halides to afford a variety of phenols and hydroxylated heteroarenes in high to excellent yield.
REARRANGEMENT OF DIMETHYLPHENYLACYLATES USING ZEOLITES
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Page/Page column 9-10; 12, (2021/08/14)
The present invention relates to a Fries rearrangement of specific dimethylphenylacylates to form the desired respective hydroxyaryl ketones having two methyl groups bound to the aromatic ring. It has been found that the process is surprisingly very specific in view of the number and position of the methyl group(s) bound to the aromatic ring.
Isotruxene-based porous polymers as efficient and recyclable photocatalysts for visible-light induced metal-free oxidative organic transformations
Zhang, Haowen,Zhang, Xiao,Zheng, Ying,Zhou, Cen
supporting information, p. 8878 - 8885 (2021/11/27)
Two new isotruxene-based porous polymers were prepared and demonstrated to be highly efficient, metal-free heterogeneous photocatalysts for oxidative transformations using air as the mild oxidant under visible-light irradiation. Both catalysts show excellent recyclability. In addition, the reactions can be performed in water, further indicating the greenness of this method. This journal is