T:Toxic;
106-44-5Relevant articles and documents
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Cerny,Malek
, p. 1739 (1969)
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CoMo sulfide-catalyzed hydrodeoxygenation of lignin model compounds: An extended reaction network for the conversion of monomeric and dimeric substrates
Jongerius, Anna L.,Jastrzebski, Robin,Bruijnincx, Pieter C.A.,Weckhuysen, Bert M.
, p. 315 - 323 (2012)
In the present work, extensive hydrodeoxygenation (HDO) studies with a commercial sulfided CoMo/Al2O3 catalyst were performed on a library of lignin model compounds at 50 bar hydrogen pressure and 300 °C in dodecane, using a batch autoclave system. The catalyst was activated under hydrogen atmosphere prior to the reaction, and the spent catalyst was analyzed using thermogravimetric analysis. An extended reaction network is proposed, showing that HDO, demethylation, and hydrogenation reactions take place simultaneously. HDO of mono-oxygenated substrates proved to be difficult at the applied conditions. Starting from most positions in the network, phenol, and cresols are therefore the main final products, suggesting the possibility of convergence on a limited number of products from a mixture of substrates. HDO of dimeric model compounds mimicking typical lignin linkages revealed that coumaran alkyl ethers and β-O-4 bonds can be broken, but 5-5′ linkages not.
Characteristic Effect of Pyridine on the NIH Shift and Selectivity in the Monooxygenation of Aromatic Compounds Catalyzed by a Nonheme Iron Complex/Hydroquinones/O2 System
Funabiki, Takuzo,Toyoda, Takehiro,Yoshida, Satohiro
, p. 1279 - 1282 (1992)
The high values of the NIH and Me-NIH shifts were observed in the hydroxylation of aromatic compounds such as toluene and xylenes with O2 by the catalytic system in the title.The pyridine concentration greatly affected not only the NIH shift, but the selectivity to form phenols by hydroxylation of the aromatic ring and to form aldehydes by oxidation of the methyl group.
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Kaeding et al.
, p. 805,806 (1961)
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Aerobic homocoupling of phenylboronic acid on Mg-Al mixed-oxides-supported Au nanoparticles
Wang, Liang,Wang, Hong,Zhang, Wei,Zhang, Jian,Lewis, James P.,Meng, Xiangju,Xiao, Feng-Shou
, p. 186 - 197 (2013)
Au nanoparticles are highly dispersed on Mg-Al mixed oxides by anion exchange (Au/MAO-AE) and homogeneous deposition-precipitation (Au/MAO-HDP). The XRD, UV-visible, and XPS spectra demonstrate that the Au species on both samples are present as metallic Au. The Au nanoparticles are directly confirmed by the transmission electron microscopy images. Very importantly, both Au/MAO-AE and Au/MAO-HDP catalysts show superior catalytic activity, selectivities, and recyclabilities in the aerobic homocoupling of phenylboronic acid, yielding biphenyl and phenol. During this reaction, H2O molecules from the system and hydroxyl groups on Mg-Al mixed oxides strongly influence the catalytic performance. Based on the catalytic data and XPS characterizations, a mechanism for aerobic homocoupling of phenylboronic on metallic Au nanoparticles is proposed. These catalytic data are in good agreement with those obtained from theoretical calculations.
One step phenol synthesis from benzene catalysed by nickel(ii) complexes
Muthuramalingam, Sethuraman,Anandababu, Karunanithi,Velusamy, Marappan,Mayilmurugan, Ramasamy
, p. 5991 - 6001 (2019)
Nickel(ii)complexes of N4-ligands have been synthesized and characterized as efficient catalysts for the hydroxylation of benzene using H2O2. All the complexes exhibited Ni2+ → Ni3+ oxidation potentials of around 0.966-1.051 V vs. Ag/Ag+ in acetonitrile. One of the complexes has been structurally characterized and adopted an octahedral coordination geometry around the nickel(ii) center. The complexes catalysed direct benzene hydroxylation using H2O2 as an oxygen source and afforded phenol up to 41% with a turnover number (TON) of 820. This is unprecedentedly the highest catalytic efficiency achieved to date for benzene hydroxylation using 0.05 mol% catalyst loading and five equivalents of H2O2. The benzene hydroxylation reaction possibly proceeds via the key intermediate bis(μ-oxo)dinickel(iii) species, which was characterized by HR-MS, vibrational and electronic spectral methods, for almost all complexes. The formation constant of the key intermediate was calculated to be 5.61-9.41 × 10-2 s-1 by following the appearance of an oxo-to-Ni(iii) LMCT band at around 406-413 nm. The intermediates are found to be very short-lived (t1/2, 73-123 s). The geometry of one of the catalytically active intermediates was optimized by DFT and its spectral properties were calculated by TD-DFT calculations, which are comparable to experimental spectral data. The kinetic isotope effect (KIE) values (0.98-1.05) support the involvement of nickel-bound oxygen species as an intermediate. The isotope-labeling experiments using H218O2 showed 92.46% incorporation of 18O, revealing that H2O2 is the key oxygen supplier to form phenol. The catalytic efficiencies of complexes are strongly influenced by the geometrical configuration of intermediates, and stereoelectronic and steric properties, which are fine-tuned by the ligand architecture.
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Baddeley
, (1944)
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Synthesis and antiradical activity of hybrid antioxidants based on isobornylphenols
Chukicheva, I. Yu.,Sukrusheva,Mazaletskaya,Kuchin
, (2016)
Alkylation of isobornylphenols with allylbenzene in the presence of homogeneous and heterogeneous catalysts of different nature has been studied. The maximum yield of phenols containing isobornyl and 1-phenylpropyl moieties has been achieved in the presen
Kinetics of Electron-transfer Reactions of para-Substituted Phenols p-C6H4(X)OH with 3+ (phen = 1,10-phenantroline) and with 2- in Aqueous Acidic Solutions: Correlation between the Hammett Constant of X and the One-electron Redox Potential of p-C6H4(X)OH
Kimura, Masaru,Kaneko, Yukari
, p. 341 - 343 (1984)
Kinetic Studies of the electron-transfer reactions of p-C6H4(X)OH (X= H, OCH3, OH, NH2, or NH3+ with tris(1,10-phenanrtoline)iron(III), 3+, and with hexachloroiridate(IV), 2-, have been made in aqueous acidic solutions.The second-order rate constants (k0) follow the rate law -d/dt = k0, where A is the one-electron acceptor 3+ or 2-, and were determined at an ionic strength of 1.0 mol dm-3 and 25 deg C.The order of the forward rate constants (kf) for the one-electron transfer step, which are defined as k0 = 2kf for the other X, was H + 3+ and 1 : 150 : 75 : 4x1E4 : 7.2x1E4 : 1.0x1E8 in the case of the 2- reactions.By applying Marcus theory to kf, standard redox potentials for the radical cations p-C6H4(X)OH.+ were estimated and found to be well correlated with the Hammett constants (?p) for the para substituents X.
Strong Visible-Light-Absorbing Cuprous Sensitizers for Dramatically Boosting Photocatalysis
Chen, Kai-Kai,Guo, Song,Li, Xiyou,Liu, Heyuan,Lu, Tong-Bu,Zhang, Zhi-Ming
, p. 12951 - 12957 (2020)
Developing strong visible-light-absorbing (SVLA) earth-abundant photosensitizers (PSs) for significantly improving the utilization of solar energy is highly desirable, yet it remains a great challenge. Herein, we adopt a through-bond energy transfer (TBET) strategy by bridging boron dipyrromethene (Bodipy) and a CuI complex with an electronically conjugated bridge, resulting in the first SVLA CuI PSs (Cu-2 and Cu-3). Cu-3 has an extremely high molar extinction coefficient of 162 260 m?1 cm?1 at 518 nm, over 62 times higher than that of traditional CuI PS (Cu-1). The photooxidation activity of Cu-3 is much greater than that of Cu-1 and noble-metal PSs (Ru(bpy)32+ and Ir(ppy)3+) for both energy- and electron-transfer reactions. Femto- and nanosecond transient absorption and theoretical investigations demonstrate that a “ping-pong” energy-transfer process in Cu-3 involving a forward singlet TBET from Bodipy to the CuI complex and a backward triplet-triplet energy transfer greatly contribute to the long-lived and Bodipy-localized triplet excited state.
Catalytic activity of the anaerobic tyrosine lyase required for thiamine biosynthesis in Escherichia coli
Challand, Martin R.,Martins, Filipa T.,Roach, Peter L.
, p. 5240 - 5248 (2010)
Thiazole synthase in Escherichia coli is an αβ heterodimer of ThiG and ThiH. ThiH is a tyrosine lyase that cleaves the Cα-Cβ bond of tyrosine, generating p-cresol as a by-product, to form dehydroglycine. This reactive intermediate acts as one of three substrates for the thiazole cyclization reaction catalyzed by ThiG. ThiH is a radical S-adenosylmethionine (AdoMet) enzyme that utilizes a [4Fe-4S]+ cluster to reductively cleave AdoMet, forming methionine and a 5′-deoxyadenosyl radical. Analysis of the time-dependent formation of the reaction products 5′- deoxyadenosine (DOA) and p-cresol has demonstrated catalytic behavior of the tyrosine lyase. The kinetics of product formation showed a pre-steady state burst phase, and the involvement of DOA in product inhibition was identified by the addition of 5′-methylthioadenosine/S-adenosylhomocysteine nucleosidase to activity assays. This hydrolyzed the DOA and changed the rate-determining step but, in addition, substantially increased the uncoupled turnover of AdoMet. Addition of glyoxylate and ammonium inhibited the tyrosine cleavage reaction, but the reductive cleavage of AdoMet continued in an uncoupled manner. Tyrosine analogues were incubated with ThiGH, which showed a strong preference for phenolic substrates. 4-Hydroxyphenylpropionic acid analogues allowed uncoupled AdoMet cleavage but did not result in further reaction (Cα-Cβ bond cleavage). The results of the substrate analogue studies and the product inhibition can be explained by a mechanistic hypothesis involving two reaction pathways, a product-forming pathway and a futile cycle.
Cresol Izomerization in the Presence of Acid Catalysts
Tarasov,Dunaev,Kustov
, p. 262 - 264 (2018)
It is shown for toluene oxidation with nitrous oxide that modifying HZSM-5 zeolite with zinc oxide nanoparticles considerably improves the selectivity and yield of cresols. It is found that a 2% ZnO/HZSM-5 composite catalyst also exhibits enhanced and stable activity at high temperatures. For the o-cresol isomerization reaction, this modification of HZSM-5 zeolite greatly reduces the contribution from disproportionation and cracking reactions proceeding with formation of phenol, C6–C9 aromatic hydrocarbons, and xylenols. The regularities of their formation in the presence of the studied catalysts are determined using the results from thermodynamic calculations for the equilibrium concentrations of cresol isomers.
MCM-41-supported phosphotungstic acid-catalyzed cleavage of C-O bond in allyl aryl ethers
Sakate, Sachin S.,Kamble, Sumit B.,Chikate, Rajeev C.,Rode, Chandrashekhar V.
, p. 4943 - 4949 (2017)
Removal of the protecting allyl group from allyl aryl ethers in the presence of other oxygen protecting groups was successfully achieved using a solid acid supported on the high surface area material MCM-41. The catalyst showed excellent activity in the presence of various electron withdrawing, electron donating, and oxidizable functional groups. The methodology is also very useful for the removal of protecting allyl groups of various natural products such as vanillin, isovanillin, and other oxygen functionalized aldehydes and ketones.
Nickel-catalyzed cross-coupling of aryl grignard reagents with aromatic alkyl ethers: An efficient synthesis of unsymmetrical biaryls
Dankwardt, John W.
, p. 2428 - 2432 (2004)
New substrates for biaryl synthesis: aromatic ethers undergo nickel-catalyzed cross-coupling with aryl Grignard reagents to give unsymmetrical biaryls in excellent yields (see scheme). Both the nature of the nickel catalyst and the choice of solvent are crucial for reaching high levels of conversion.
Effects of ascorbic acid on arenediazonium salts reactivity: Kinetics and mechanism of the reaction
Costas-Costas, Ugo,Gonzalez-Romero, Elisa,Bravo-Diaz, Carlos
, p. 632 - 648 (2001)
We have examined the kinetics and mechanism of dediazoniation of o-, m- and p-methylbenzenediazonium (ArN2-) tetrafluoroborate in the presence of ascorbic acid (H2A) at different pHs by combining spectophotometric (VIS-UV), high performance liquid chromatography (HPLC), and polarographic measurements. Kinetic data show that, at low pH, observed rate constants increase linearly with increasing ascorbic acid concentration, but the saturation kinetics observed at higher pH suggest the formation of a transient diazo-ether complex preceding the slow step of the reaction. Experimental evidence for the formation of such a complex was obtained from a competitive coupling reaction with the Na salt of '2-naphthol-6-sulfonic acid' and by titration of ascorbic acid (H2A) with the arenediazonium ions (electrochemical measurements). HPLC Analysis of dediazoniation products indicates that, in the absence of H2A, only the heterolytic phenol derivative, ArOH, is formed quantitatively, in keeping with the predictions of the DN+AN mechanism. In the pH 2-4 range and in the presence of H2A, reduction products (ArH) are obtained in addition to heterolytic products (ArOH), corroborating that certain biological reducing agents like ascorbate (HA-) are capable of inducing reductive fragmentation of ArN2- into aryl radicals. All evidence is consistent with two competitive reaction pathways, the thermal decomposition of ArN2+, and a rate-limiting decomposition of the transient diazo ether 'complex', formed during the reaction of ArN2+ with HA- in a rapid pre-equilibrium step.
A MODEL FOR METABOLIC ACTIVATION OF DIALKYLNITROSAMINES. OXIDATIVE DEALKYLATION OF N-NITROSO-2-(ALKYLAMINO)ACETONITRILE BY FLAVIN MIMIC IN AQUEOUS SOLUTION
Yano, Yumihiko,Yokoyama, Takeshi,Yoshida, Kitaro
, p. 5121 - 5124 (1986)
Oxidation-active flavin mimic, benzodipteridine (BDP), is found to react with N-nitroso-2-(alkylamino)acetonitrile via oxidative dealkylation in aqueous solution.From the kinetic investigations, the oxidation mechanism is proposed.
Comparison of neurotoxic effects and potential risks from oral administration or ingestion of tricresyl phosphate and jet engine oil containing tricresyl phosphate
Mackerer, Carl R.,Barth, Mary L.,Krueger, Andrew J.,Chawla, Birbal,Roy, Timothy A.
, p. 293 - 328 (1999)
Neurotoxicity of tricresyl phosphates (TCPs) and jet engine oil (JEO) containing TCPs were evaluated in studies conducted in both rat and hen. Results for currently produced samples ('conventional' and 'low-toxicity') were compared with published findings on older samples to identify compositional changes and relate those changes to neurotoxic potential. Finally, a human risk assessment for exposure by oral ingestion of currently produced TCPs in JEO at 3% (JEO + 3%) was conducted. TCPs and certain other triaryl phosphates administered as single doses inhibited brain neuropathy target esterase (B-NTE; neurotoxic esterase) in the rat and the hen (hen 3.25 times as sensitive), and both species were deemed acceptable for initial screening purposes. Neither rat nor hen was sensitive enough to detect statistically significant inhibition of B-NTE after single doses of JEO + 3% 'conventional' TCP. Subacute administration of 2 g/kg/d of JEO + 3% 'conventional' TCP to the hen produced B-NTE inhibition 132%), which did not result in organophosphorus-induced delayed neurotoxicity (OPIDN). Subchronic administration of JEO + 3% TCP but not JEO + 1% TCP at 2 g/kg/d produced OPIDN. Thus, the threshold for OPIDN was between 20 and 60 mg 'conventional' TCP/kg/d in JEO for 10 wk. The current 'conventional' TCPs used in JEO and new 'low-toxicity' TCPs now used in some JEO are synthesized from phenolic mixtures having reduced levels of ortho-cresol and ortho-xylenols resulting in TCPs of very high content of meta- and para-substituted phenyl moieties; this change in composition results in lower toxicity. The 'conventional' TCPs still retain enough inhibitory activity to produce OPIDN, largely because of the presence of ortho-xylyl moieties; the 'low-toxicity' TCPs are largely devoid of ortho substituents and have extremely low potential to cause OPIDN. The TCP produced in the 1940s and 1950s were more than 400 times as toxic as the 'low-toxicity' TCPs produced today. Analysis of the doses required to produce OPIDN in a subchronic hen study suggests that the minimum toxic dose of 'conventional' TCP for producing OPIDN in a 70-kg person would be 280 mg/d, and for JEO containing 3% TCP, 9.4 g/d. Food products could be inadvertently contaminated with neat 'conventional' TCP but it is unlikely that food such as cooking oil would be contaminated with enough JEO + 3% TCP to cause toxicity. Further, at the dosage required for neurotoxiciy, it would be virtually impossible for a person to receive enough JEO + 3% TCP in the normal workplace (or in an aircraft) to cause such toxicity. There is no record of a JEO formulated with the modern 'conventional' TCP causing human neurotoxicity.
Retentive Solvolysis. 15. Salt Effect ion the Retentive Phenolyses of 1-(p-Substituted phenyl)ethyl p-Nitrobenzoates. The Pattern of Salt Effect and the Number of Ion-Pair Intermediates in the SN1 Solvolysis
Kinoshita, Tomomi,Shibayama, Koichi,Ikai, Keizo,Okamoto, Kunio
, p. 2917 - 2922 (1988)
The salt effect of sodium phenoxide on the polarimetric (kp) and titrimetric rate constants (kt) has exhibited pattern B for the phenolysis of optically active 1-(p-methylphenyl)ethyl p-nitrobenzoate (ROPNB; (1)) in pure phenol.The other patterns A, C, and D were previously observed for the phenolyses of 1-phenylethyl p-nitrobenzoates with p-MeO- (2), p-H- (3), and p-NO2-substituents (4), respectively.Thus, the kp-kt pattern changes in the order A -> B -> C -> D as the stability of the intermediate decreases in the order of 2 > 1 > 3 > 4.All the kp-kt patterns can be correlated with the ion-pair stage for product formation, i.e., the pattern A with the second ion-pair intermediate and the patterns B, C, and D with the first one.The pattern of salt effect on the product distribution (percent of ROPh, o- and p-RC6H4OH, and p-MeC6H4CH=CH2) for 1 is also compatible with the kp-kt pattern B.
One-pot synthesis of cresols from toluene and hydroxylamine catalyzed by ammonium molybdate
Zhang, Dongsheng,Gao, Liya,Wang, Yanji,Xue, Wei,Zhao, Xinqiang,Wang, Shufang
, p. 1109 - 1112 (2011)
One-pot synthesis of cresols from toluene and hydroxylamine catalyzed by ammonium molybdate was investigated under mild conditions. The hydroxylation reaction was strongly dependent on reaction medium, temperature, the amount of catalyst and hydroxylamine. Moreover, the reaction took place more efficiently in a closed system than in open air. High toluene conversion (72.9%) and cresol selectivity (79.4%) were obtained at 80 °C in water-acetic acid-sulfuric acid medium.
Efficient hydroxylation of aromatic compounds catalyzed by an iron(II) complex with H2O2
Wang, Xiao,Zhang, Tianyong,Li, Bin,Yang, Qiusheng,Jiang, Shuang
, p. 666 - 672 (2014)
A mononuclear iron(II) complex, Et4N[Fe(C10H 6NO2)3], coordinated by three 1-nitroso-2-naphtholate ligands in a fac-N3O3 geometry, was initiated to catalyze the direct hydroxylation of aromatic compounds to phenols in the presence of H2O2 under mild conditions. Various reaction parameters, including the catalyst dosage, temperature, mole ratio of H2O2 to benzene, reaction time and solvents which could affect the hydroxylation activity of the catalyst, were investigated systematically for benzene hydroxylation to obtain ideal benzene conversion and high phenol distribution. Under the optimum conditions, the benzene conversion was 10.2% and only phenol was detected. The catalyst was also found to be active towards hydroxylation of other aromatic compounds with high substrate conversions. The hydroxyl radical formed due to the reaction of the catalyst and H2O2 was determined to be the crucial active intermediate in the hydroxylation. A rational pathway for the formation of the hydroxyl radical was proposed and justified by the density functional theory calculations. Copyright
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Huang
, p. 3084,3087 (1954)
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Visible-Light Photoredox Borylation of Aryl Halides and Subsequent Aerobic Oxidative Hydroxylation
Jiang, Min,Yang, Haijun,Fu, Hua
, p. 5248 - 5251 (2016)
Efficient and practical visible-light photoredox borylation of aryl halides and subsequent aerobic oxidative hydroxylation were developed. The protocols use readily available aryl halides and bis(pinacolato)diboron as the starting materials, fac-Ir(ppy)3 as the photocatalyst, and corresponding arylboronic esters and phenols were obtained in good yields. The methods show some advantages including simple equipment, mild conditions, easy operation, and wide substrate scope. Therefore, they should provide a valuable strategy for chemical transformations.
The complex synergy of water in metal/bromide autoxidations. Part II. Effect of water and catalyst on the aerobic oxidation of benzaldehydes and the effect of water on the elementary catalytic pathways
Partenheimer, Walt
, p. 580 - 590 (2005)
All of the rates of the elementary steps in the Co/Br and Co/Mn/Br homogeneous, liquid-phase catalyzed reactions decrease with increasing water concentration in acetic acid. The step-wise replacement of the acetic acid ligands by water ligands in the coordination sphere of the catalyst metals may be responsible for this behavior. The non-catalyzed and metal-catalyzed (Co, Co/Mn/Br and Co/Mn) aerobic oxidations of benzaldehyde and 4-methylbenzaldehyde are reported. The non-catalyzed autoxidations are quite vigorous reactions in acetic acid/water mixtures but by-products from the Baeyer-Villiger reaction, the thermal decomposition of the peroxy acid, and over-oxidation to carbon dioxide limit the yield to the aromatic carboxylic acids. As the concentration of a Co or Co/Mn/Br catalyst increases these by-products are first reduced and then eliminated probably due to the very fast, selective reaction of [Co(II)]2 with the peroxy acid. A Co/Mn catalyst completely inhibits the autoxidation of the benzaldehydes. There is a gradual change in the yield of terephthaldicarboxaldehyde from 4-methylbenzaldehyde with increasing Co/Mn/Br concentration suggesting that the non-catalyzed steps are being replaced by catalyzed ones. The autoxidation of heptaldehyde generates about 500 times more carbon monoxide than does benzaldehyde using a Co/Mn/Br catalyst and gives only a 50% yield to heptanoic acid consistent with excessive amounts of decarbonylation with aliphatic aldehydes.
Effects of salt, acid and base on the decomposition of 2-chlorophenol in supercritical water
Lee, Geun-Hee,Nunoura, Teppei,Matsumura, Yukihiko,Yamamoto, Kazuo
, p. 1128 - 1129 (2001)
The effect of salt, acid and base as additives on the decomposition of 2-chlorophenol (2CP) in supercritical water was investigated. Four additives were selected, NaCl as a salt, HCl and H2SO4 as acids, and KOH as a base. The addition of salts and acids had a little effect on the decomposition of 2CP in supercritical water (SCW), but that of bases showed a significant effect to enhance the decomposition rate.
Catalytic cleavage of ether C-O bonds by pincer iridium complexes
Haibach, Michael C.,Lease, Nicholas,Goldman, Alan S.
, p. 10160 - 10163 (2014)
The development of efficient catalytic methods to cleave the relatively unreactive C-O bonds of ethers remains an important challenge in catalysis. Building on our group's recent work, we report the dehydroaryloxylation of aryl alkyl ethers using pincer iridium catalysts. This method represents a rare fully atom-economical method for ether C-O bond cleavage.
Catalytic Activation of Unstrained C(Aryl)-C(Alkyl) Bonds in 2,2′-Methylenediphenols
Dong, Guangbin,Ratchford, Benjamin L.,Xue, Yibin,Zhang, Rui,Zhu, Jun
supporting information, p. 3242 - 3249 (2022/02/23)
Catalytic activation of unstrained and nonpolar C-C bonds remains a largely unmet challenge. Here, we describe our detailed efforts in developing a rhodium-catalyzed hydrogenolysis of unstrained C(aryl)-C(alkyl) bonds in 2,2′-methylenediphenols aided by removable directing groups. Good yields of the monophenol products are obtained with tolerating a wide range of functional groups. In addition, the reaction is scalable, and the catalyst loading can be reduced to as low as 0.5 mol %. Moreover, this method proves to be effective to cleave C(aryl)-C(alkyl) linkages in both models of phenolic resins and commercial novolacs resins. Finally, detailed experimental and computational mechanistic studies show that with C-H activation being a competitive but reversible off-cycle reaction, this transformation goes through a directed C(aryl)-C(alkyl) oxidative addition pathway.
Electrochemical-induced hydroxylation of aryl halides in the presence of Et3N in water
Ke, Fang,Lin, Chen,Lin, Mei,Long, Hua,Wu, Mei,Yang, Li,Zhuang, Qinglong
supporting information, p. 6417 - 6421 (2021/08/03)
A thorough study of mild and environmentally friendly electrochemical-induced hydroxylation of aryl halides without a catalyst is presented. The best protocol consists of hydroxylation of different aryl iodides and aryl bromides by water solution in the presence of Et3N under air, affording the target phenols in good isolated yields. Moreover, aryl chlorides were successfully employed as substrates. This methodology also provides a direct pathway for the formation of deoxyphomalone, which displayed a significant anti-proliferation effect.
REARRANGEMENT OF DIMETHYLPHENYLACYLATES USING ZEOLITES
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Page/Page column 9-10; 15, (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.
