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Efficiency of sulfonic cation-exchange resins used in para-tert-butylphenol production: A comparison based on the kinetics of transalkylation in the phenol-tert-butylphenols system
The kinetics of transalkylation in the phenol-tert-butylphenols system in the presence of Amberlyst 36 Dry sulfonic cation-exchange resin has been investigated at 353-403 K in the tert-Bu/Ar = 0.10-0.55 mol/mol range. Kinetic characteristics of the o-tert-butylphenol + phenol ai p-tert-butylphenol + phenol (I) and 2,4-di-tert-butylphenol + phenol ai 2p-tert-butylphenol (II) reactions have been determined. The chemical equilibrium in the presence of Amberlyst 36 Dry is reached much sooner than in the presence of KU-23 10/60, a cation-exchange resin used at present. On passing from Amberlyst 36 Dry to KU-23 10/60, the preexponential factor for reaction (I) increases by a factor of 10 and that for reaction (II) increases by a factor of 2000. Thermodynamic characteristics of reaction (I) between 353 and 523 K have been calculated from experimental data and data available from the literature. The thermodynamic characteristics of reaction (II) have been determined experimentally. The enthalpy and entropy of reaction (I) are equal to those of reaction (II). The difference between the equilibrium constants of these reactions is explained. It is recommended that Amberlyst 36 Dry, which proved more efficient than KU-23 10/60, be used in the industrial production of p-tert-butylphenol.
Voronin,Nesterova,Strelchik,Zhuravskii
p. 705 - 711
(2014)
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Smith,Rodden
p. 2353
(1937)
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Hydroperoxide method for the synthesis of p-tert-butylphenol
The results of studies related to the development of a highly selective three-stage method for the synthesis of p-tert-butylphenol along with acetone are presented. The alkylation of isopropylbenzene with tert-butyl alcohol in the presence of concentrated sulfuric acid makes it possible to obtain only the para-isomer of tert-butylcumene. For the liquid-phase aerobic oxidation of p-tert-butylcumene in the presence of the phthalimide catalysts, the hydrocarbon conversion reaches 45% with a selectivity of hydroperoxide formation of 90–95%. The process of acid decomposition of p-tert-butylcumene hydroperoxide to p-tert-butylphenol and acetone was studied. Conditions providing the production of p-tert-butylphenol in a yield of 90% were found.
Frolov, A. S.,Korshunova, A. I.,Koshel’, G. N.,Kurganova, E. A.,Yarkina, E. M.
p. 1951 - 1956
(2021/11/05)

Increasing the steric hindrance around the catalytic core of a self-assembled imine-based non-heme iron catalyst for C-H oxidation
Sterically hindered imine-based non-heme complexes4and5rapidly self-assemble in acetonitrile at 25 °C, when the corresponding building blocks are added in solution in the proper ratios. Such complexes are investigated as catalysts for the H2O2oxidation of a series of substrates in order to ascertain the role and the importance of the ligand steric hindrance on the action of the catalytic core1, previously shown to be an efficient catalyst for aliphatic and aromatic C-H bond oxidation. The study reveals a modest dependence of the output of the oxidation reactions on the presence of bulky substituents in the backbone of the catalyst, both in terms of activity and selectivity. This result supports a previously hypothesized catalytic mechanism, which is based on the hemi-lability of the metal complex. In the active form of the catalyst, one of the pyridine arms temporarily leaves the iron centre, freeing up a lot of room for the access of the substrate.
Frateloreto, Federico,Capocasa, Giorgio,Olivo, Giorgio,Abdel Hady, Karim,Sappino, Carla,Di Berto Mancini, Marika,Levi Mortera, Stefano,Lanzalunga, Osvaldo,Di Stefano, Stefano
p. 537 - 542
(2021/02/09)

Aromatic C?H Hydroxylation Reactions with Hydrogen Peroxide Catalyzed by Bulky Manganese Complexes
The oxidation of aromatic substrates to phenols with H2O2 as a benign oxidant remains an ongoing challenge in synthetic chemistry. Herein, we successfully achieved to catalyze aromatic C?H bond oxidations using a series of biologically inspired manganese catalysts in fluorinated alcohol solvents. While introduction of bulky substituents into the ligand structure of the catalyst favors aromatic C?H oxidations in alkylbenzenes, oxidation occurs at the benzylic position with ligands bearing electron-rich substituents. Therefore, the nature of the ligand is key in controlling the chemoselectivity of these Mn-catalyzed C?H oxidations. We show that introduction of bulky groups into the ligand prevents catalyst inhibition through phenolate-binding, consequently providing higher catalytic turnover numbers for phenol formation. Furthermore, employing halogenated carboxylic acids in the presence of bulky catalysts provides enhanced catalytic activities, which can be attributed to their low pKa values that reduces catalyst inhibition by phenolate protonation as well as to their electron-withdrawing character that makes the manganese oxo species a more electrophilic oxidant. Moreover, to the best of our knowledge, the new system can accomplish the oxidation of alkylbenzenes with the highest yields so far reported for homogeneous arene hydroxylation catalysts. Overall our data provide a proof-of-concept of how Mn(II)/H2O2/RCO2H oxidation systems are easily tunable by means of the solvent, carboxylic acid additive, and steric demand of the ligand. The chemo- and site-selectivity patterns of the current system, a negligible KIE, the observation of an NIH-shift, and the effectiveness of using tBuOOH as oxidant overall suggest that hydroxylation of aromatic C?H bonds proceeds through a metal-based mechanism, with no significant involvement of hydroxyl radicals, and via an arene oxide intermediate. (Figure presented.).
Masferrer-Rius, Eduard,Borrell, Margarida,Lutz, Martin,Costas, Miquel,Klein Gebbink, Robertus J. M.
p. 3783 - 3795
(2021/03/09)

Alkylation of Phenol with tert-Butanol in a Draining-Film Reactor
The alkylation of phenol with tert-butanol in a displacement draining-film reactor on a heterogeneous catalyst, Beta zeolite, was evaluated. Optimum process conditions ensuring the maximal p-tert-butylphenol yield were determined: phenol:tert-butanol molar ratio (3–3.5):1, superficial liquid velocity 1.0–1.5 m3 m–2 h–1, and temperature 100°C–110°C. A procedure ensuring 100% conversion of tert-butanol and isobutylene (a by-product formed from tert-butanol) was observed.
Maksimov, A. L.,Mel’chakov, I. S.,Terekhov, A. V.,Zanaveskin, L. N.
p. 569 - 575
(2021/07/26)

Catalyst-free rapid conversion of arylboronic acids to phenols under green condition
A catalyst-free and solvent-free method for the oxidative hydroxylation of aryl boronic acids to corresponding phenols with hydrogen peroxide as the oxidizing agent was developed. The reactions could be performed under green condition at room temperature within very short reaction time. 99% yield of phenol could be achieved in only 1 min. A series of different arenes substituted aryl boronic acids were further carried out in the hydroxylation reaction with excellent yield. It was worth nothing that the reaction could completed within 1 min in all cases in the presence of ethanol as co-solvent.
Dong, Zhenhua,Liu, Mengmeng,Pan, Hongguo
(2021/09/06)

The graphite-catalyzed: ipso -functionalization of arylboronic acids in an aqueous medium: metal-free access to phenols, anilines, nitroarenes, and haloarenes
An efficient, metal-free, and sustainable strategy has been described for the ipso-functionalization of phenylboronic acids using air as an oxidant in an aqueous medium. A range of carbon materials has been tested as carbocatalysts. To our surprise, graphite was found to be the best catalyst in terms of the turnover frequency. A broad range of valuable substituted aromatic compounds, i.e., phenols, anilines, nitroarenes, and haloarenes, has been prepared via the functionalization of the C-B bond into C-N, C-O, and many other C-X bonds. The vital role of the aromatic π-conjugation system of graphite in this protocol has been established and was observed via numerous analytic techniques. The heterogeneous nature of graphite facilitates the high recyclability of the carbocatalyst. This effective and easy system provides a multipurpose approach for the production of valuable substituted aromatic compounds without using any metals, ligands, bases, or harsh oxidants.
Badgoti, Ranveer Singh,Dandia, Anshu,Parewa, Vijay,Rathore, Kuldeep S.,Saini, Pratibha,Sharma, Ruchi
p. 18040 - 18049
(2021/05/29)

Electrochemical-induced hydroxylation of aryl halides in the presence of Et3N in water
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.
Ke, Fang,Lin, Chen,Lin, Mei,Long, Hua,Wu, Mei,Yang, Li,Zhuang, Qinglong
supporting information
p. 6417 - 6421
(2021/08/03)

Nickel-catalyzed deallylation of aryl allyl ethers with hydrosilanes
An efficient and mild catalytic deallylation method of aryl allyl ethers is developed, with commercially available Ni(COD)2 as catalyst precursor, simple substituted bipyridine as ligand and air-stable hydrosilanes. The process is compatible with a variety of functional groups and the desired phenol products can be obtained with excellent yields and selectivity. Besides, by detection or isolation of key intermediates, mechanism studies confirm that the deallylation undergoes η3-allylnickel intermediate pathway.
Ding, Guangni,Fan, Sijie,Wang, Jingyang,Wang, Yu,Wu, Xiaoyu,Xie, Xiaomin,Yang, Liqun,Zhang, Zhaoguo
supporting information

(2021/09/28)

Substituent and Surfactant Effects on the Photochemical Reaction of Some Aryl Benzoates in Micellar Green Environment?
In this study, we carried out preparative and mechanistic studies on the photochemical reaction of a series of p-substituted phenyl benzoates in confined and sustainable micellar environment. The aim of this work is mainly focused to show whether the nature of the surfactant (ionic or nonionic) leads to noticeable selectivity in the photoproduct formation and whether the electronic effects of the substituents affect the chemical yields and the rate of formation of the 5-substituted-2-hydroxybenzophenone derivatives. Application of the Hammett linear free energy relationship (LFER) on the rate of formation of benzophenone derivatives, on the lower energy band of the UV-visible absorption spectra of the aryl benzoates and 5-substituted-2-hydroxybenzophenone derivatives allows a satisfactory quantification of the substituent effects. Furthermore, UV-visible and 2D-NMR (NOESY) spectroscopies have been employed to measure the binding constant Kb and the location of the aryl benzoates within the hydrophobic core of the micelle. Finally, TD-DFT calculations have been carried out to estimate the energies of the absorption bands of p-substituted phenyl benzoates and 5-substituted-2-hydroxybenzophenone derivatives providing good linear correlation with those values measured experimentally.
Siano, Gastón,Crespi, Stefano,Bonesi, Sergio M.
p. 1298 - 1309
(2021/05/07)

Aryl phenol compound as well as synthesis method and application thereof
The invention discloses a synthesis method of an aryl phenol compound shown as a formula (3). All systems are carried out in an air or nitrogen atmosphere, and visible light is utilized to excite a photosensitizer for catalyzation. In a reaction solvent, ArNR1R2 as shown in a formula (1) and water as shown in a formula (2) are used as reaction raw materials and react under the auxiliary action of acid to obtain the aryl phenol compound as shown in a formula (3). The ArNR1R2 in the formula (1) can be primary amine and tertiary amine, can also be steroid and amino acid derivatives, and can also be drugs or derivatives of propofol, paracetamol, ibuprofen, oxaprozin, indomethacin and the like. The synthesis method has the advantages of cheap and easily available raw materials, simple reaction operation, mild reaction conditions, high reaction yield and good compatibility of substrate functional groups. The fluid reaction not only can realize amplification of basic chemicals, but also can realize amplification of fine chemicals, such as synthesis of drugs propofol and paracetamol. The invention has wide application prospect and use value.
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Paragraph 0036-0041

(2021/05/12)

Catalytic SNAr Hydroxylation and Alkoxylation of Aryl Fluorides
Nucleophilic aromatic substitution (SNAr) is a powerful strategy for incorporating a heteroatom into an aromatic ring by displacement of a leaving group with a nucleophile, but this method is limited to electron-deficient arenes. We have now established a reliable method for accessing phenols and phenyl alkyl ethers via catalytic SNAr reactions. The method is applicable to a broad array of electron-rich and neutral aryl fluorides, which are inert under classical SNAr conditions. Although the mechanism of SNAr reactions involving metal arene complexes is hypothesized to involve a stepwise pathway (addition followed by elimination), experimental data that support this hypothesis is still under exploration. Mechanistic studies and DFT calculations suggest either a stepwise or stepwise-like energy profile. Notably, we isolated a rhodium η5-cyclohexadienyl complex intermediate with an sp3-hybridized carbon bearing both a nucleophile and a leaving group.
Kang, Qi-Kai,Li, Ke,Li, Yuntong,Lin, Yunzhi,Shi, Hang,Xu, Lun
supporting information
p. 20391 - 20399
(2021/08/13)

Method for hydrolyzing diarylether compound to generate aryl phenol compound
The invention discloses a method for hydrolyzing a diarylether compound to generate an arylphenol compound. According to the method, visible light is utilized to excite a photosensitizer for catalysis. In a reaction solvent, the raw material in the formula (1) breaks a C (sp2)-O bond under the auxiliary action of acid, and hydrolysis is performed to obtain the bimolecular aryl phenol compounds in the formula (3) and the formula (4). The method can catalyze the reaction at room temperature, is green and environment-friendly, and is easy to operate; the universality is wide, the reaction yield is relatively high, and the tolerance of functional groups is strong; the synthesis method not only can realize small-scale hydrolysis conversion of various diarylether compounds, but also can realize hydrolysis of herbicidal ether, triclosan and a lignin template substrate, and even can realize large-scale hydrolysis of triclosan and the lignin template substrate to realize gram-level degradation. A new strategy is provided for recovering phenol derivatives through lignin hydrolysis, degrading pesticides and purifying wastewater containing a degerming agent or herbicide. The method has wide application prospect and use value.
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Paragraph 0050-0053

(2021/09/29)

Method for synthesizing heteroatom- substituted aromatic compound from styrene compound
The invention discloses a method for synthesizing a heteroatom-substituted aromatic compound from a styrene compound, which comprises the following steps of: mixing a styrene compound with a general formula (I) and a heteroatom-containing compound with a general formula (II), and reacting in the presence of an acid additive and an organic solvent to obtain a heteroatom-substituted compound with ageneral formula (III). According to the synthesis method disclosed by the invention, a large amount of styrene compounds are used as raw materials and react to generate aromatic amine or phenol compounds under the action of no metal catalysis; and compared with the traditional aromatic amine and phenol synthesis method, the method has the advantages of high yield, simple conditions, low waste discharge amount, no metal participation, simple reaction equipment, easiness in industrial production and the like.
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Paragraph 0330-0333

(2021/02/06)

Photohomolysis and Photoheterolysis in Aryl Sulfonates and Aryl Phosphates
The photochemical behaviour of selected aryl sulfonates and phosphates (ArOX) in polar and nonpolar media has been investigated by laser flash photolysis (LFP) experiments. Two main pathways have been identified, namely the photohomolysis of the ArO?X bon
Bonesi, Sergio,Protti, Stefano,Fagnoni, Maurizio
p. 6315 - 6323
(2021/03/16)

Mechanistic study of carboxylic acid and phosphate ester cleavage by oximate metal complexes surpassing the limiting reactivity of highly basic free oximate anions
Two tridentate and one tetradentate new ligands containing the terminal oxime group separated from secondary amino and pyridine groups as additional binding sites by two or three methylene groups have been prepared. Their acid-base properties, as well as the composition and stability of their complexes with Zn(ii) and Cd(ii) ions, were determined by potentiometric and spectrophotometric titrations. The X-ray structure of a Cd(ii) complex of a related tridentate oxime ligand previously studied in solution was determined. All oximate complexes show high reactivity in the cleavage of aryl acetates, paraoxon, parathion and 4-nitrophenyl diphenyl phosphate, with rate constants significantly surpassing the limiting rate constants observed for highly basic free oximate anions. The second-order rate constants for individual oximate complexes in solution are assigned to each ligand, metal cation and substrate. The results of the cleavage of 4-substituted phenyl acetates were analyzed in terms of Br?nsted correlations with the leaving group pKa, which demonstrated a change in the rate determining step from the nucleophilic attack to the leaving group departure upon an increase in the leaving group basicity. The zero slope of the Br?nsted correlation for the nucleophilic attack indicates transition state stabilization through electrophilic assistance by the metal ion. This interpretation is supported by metal selectivity in the relative efficiency of the cleavage of paraoxon and parathion. The existence of the alpha-effect in ester cleavage by coordinated oximates is confirmed by an analysis of the Br?nsted correlations with the nucleophile basicity for metal bound oximate and alkoxo or hydroxo nucleophiles. The very high reactivity of the oximate complexes of the new ligands is attributed to transition state stabilization and to the removal of the solvational imbalance of oximate anions that impedes the expected increase in the reactivity of highly basic free anions.
Flores-Alamo, Marcos,Gómez-Tagle, Paola,Lugo-González, José Carlos,Yatsimirsky, Anatoly K.
supporting information
p. 2452 - 2467
(2020/03/05)

Easy Synthesis of a Self-Assembled Imine-Based Iron(II) Complex Endowed with Crown-Ether Receptors
Herein we report that an imine-based iron complex decorated with crown-ether moieties self-assembles in CH3CN solution from three building blocks (namely Fe(CH3CN)2(OTf)2, 2-picolylamine and aldehyde 6a) added in the proper molar ratio (1:2:2, respectively). Aldehyde 6a, endowed with a benzocrown-ether receptor, can be prepared in two steps from commercial materials with high yields (79 percent) and no need of chromatographic separations. The self-assembled complex is highly stable in CH3CN solution. The complex has been tested as catalyst for the oxidation of aromatic compounds endowed with primary ammonium anchoring group with H2O2. An unexpected yet moderate selectivity for remote meta over ortho hydroxylation was obtained, which is mainly due to the steric hindrance of the catalyst.
Capocasa, Giorgio,Di Berto Mancini, Marika,Di Stefano, Stefano,Frateloreto, Federico,Lanzalunga, Osvaldo,Olivo, Giorgio
(2020/06/10)

Clean production method of 2,4-di-tert-butylphenol
The invention provides a clean production method of 2,4-di-tert-butylphenol, wherein the clean production method comprises the steps: A) mixing phenol and a catalyst, stirring, heating, adding isobutene, and carrying out a reaction to obtain 2,4-di-tert-butylphenol, wherein the catalyst is a transition metal oxide doped molecular sieve, the transition metal oxide is La2O3 and CeO2, the molecular sieve is an X-type molecular sieve and/or a Y-type molecular sieve, and the mass fraction of the transition metal oxide in the catalyst is 6-20%; and B) mixing the used catalyst with a new catalyst, adding phenol and isobutene, carrying out a reaction again, repeating for several times, extracting and recovering the catalyst by using an organic solvent, and then drying and calcining to finish regeneration and recycling of the catalyst. The molecular sieve catalyst doped with the transition metal is used for alkylation reaction of phenol and isobutene, the catalytic activity is high, byproductsgenerated by reaction of a target product and isobutene molecules can be reduced, and the reaction selectivity is improved.
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Paragraph 0040-0057

(2020/06/16)

Palladium-Catalyzed Hydroxylation of Aryl Halides with Boric Acid
Boric acid, B(OH)3, is proved to be an efficient hydroxide reagent in converting (hetero)aryl halides to the corresponding phenols with a Pd catalyst under mild conditions. Various phenol products were obtained in good to excellent yields. This transformation tolerates a broad range of functional groups and molecules, including base-sensitive substituents and complicated pharmaceutical (hetero)aryl halide molecules.
Song, Zhi-Qiang,Wang, Dong-Hui
supporting information
p. 8470 - 8474
(2020/11/18)

Benzylic C?H Functionalisation by [Et3SiH+KOtBu] leads to Radical Rearrangements in o-tolyl Aryl Ethers, Amines and Sulfides
Reaction of Et3SiH+KOtBu with diaryl ethers, sulfides and amines that feature an ortho alkyl group leads to rearrangement products. The rearrangements arise from formation of benzyl radicals, likely formed through hydrogen atom abstraction by triethylsilyl radicals. The rearrangements involve cyclisation of the benzyl radical onto the partner arene, which, from computation, is the rate determining step. In the case of diaryl ethers, Truce-Smiles rearrangements arise from radical cyclisations to form 5-membered rings, but for diarylamines, cyclisations to form dihydroacridines are observed. (Figure presented.).
Arokianathar, Jude N.,Kolodziejczak, Krystian,Bugden, Frances E.,Clark, Kenneth F.,Tuttle, Tell,Murphy, John A.
p. 2260 - 2267
(2020/05/06)

Trinuclear Mn2+/Zn2+based microporous coordination polymers as efficient catalysts foripso-hydroxylation of boronic acids
Two microporous coordination polymers based on hourglass trinuclear building units, [Mn3(bpdc)3(bpy)]·2DMF and [Zn3(bpdc)3(bpy)]·2DMF·4H2O (bpdc = 4,4′-biphenyl dicarboxylic acid, bpy = 4,4′-bipyridine), have been synthesized under solvothermal conditions employing DMF as the solvent. Each structure consists of two crystallographically distinct M2+(M1 and M2) centers that are connectedviacarboxylate bridges from six bpdc ligands, generating a trinuclear metal cluster, [M3(bpdc)3(bpy)]. Cluster representation of the structure resulted in an interpenetrated net of rarehextopological type. Catalytic activities of the CPs have been assessed for the oxidative hydroxylation of phenylboronic acids (PBAs) using aqueous hydrogen peroxide (H2O2). Various substituted aryl/hetero-arylboronic acids RB(OH)2[R = phenyl, 2,4-difluorophenyl, 4-aminophenyl, 2-thiopheneetc.] underwentipso-hydroxylation smoothly at room temperature to generate the corresponding phenols in excellent yields. The main advantages of this protocol are the aqueous medium reaction, heterogeneous catalytic system, and short reaction time with excellent yield.
Bora, Sanchay J.,Dutta, Anurag,Goswami, Shyam,Guha, Ankur K.,Paul, Rima,Thakur, Ashim J.
p. 5454 - 5462
(2020/05/16)

Rongalite-promoted metal-free aerobic ipso-hydroxylation of arylboronic acids under sunlight: DFT mechanistic studies
A novel rongalite-promoted metal-free aerobic ipso-hydroxylation of arylboronic acids has been developed. This method employs low-cost rongalite as a radical initiator and O2 as a green oxidizing agent for ipso-hydroxylation. This protocol is compatible with a wide variety of functional groups with good to excellent yields at room temperature. Furthermore, mechanistic insight into the role of superoxide radical anions in C-B cleavage has also been provided based on DFT studies.
Golla, Sivaparwathi,Poshala, Soumya,Pawar, Ravinder,Kokatla, Hari Prasad
supporting information

(2019/12/27)

Strong Visible-Light-Absorbing Cuprous Sensitizers for Dramatically Boosting Photocatalysis
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.
Chen, Kai-Kai,Guo, Song,Li, Xiyou,Liu, Heyuan,Lu, Tong-Bu,Zhang, Zhi-Ming
supporting information
p. 12951 - 12957
(2020/05/29)

Reticular Synthesis of tbo Topology Covalent Organic Frameworks
The metal-organic framework (MOF) HKUST-1 with a tbo topology serves as an archetypal tunable and isoreticular framework platform for targeting desired applications, but the design and synthesis of tbo-covalent organic frameworks (COFs) remains a formidable challenge. Here we demonstrate the successful use of reticular chemistry as an appropriate strategy for the design and deliberate construction of COFs with a tbo topology. The judicious selection of the perquisite planar building blocks, 4-connected square tetramine of porphyrin and 3-connected trigonal trialdehydes of triphenylamine, allows the condensation of two tbo-COFs, the first examples of COFs with a tbo topology. The resulting COFs both crystallize in the cubic Pm3ˉ space group and adopt a non-interpenetrated open framework, in which each tritopic linker connects to three square units forming a truncated Td-octahedron and occupies the alternating triangular faces of the truncated octahedron. Owing to the presence of two different types of photoredox-active moieties, the two COFs can be efficient heterogeneous photocatalysts for the oxidative hydroxylation of arylboronic acids and the reductive defluoroalkylation of trifluoromethyl aromatics with alkenes. The present finding will provide an impetus to examine the potential of tbo-COFs as a new platform for engineering multifunctional materials via expansion and functionalization of building blocks.
Kang, Xing,Han, Xing,Yuan, Chen,Cheng, Cheng,Liu, Yan,Cui, Yong
supporting information
p. 16346 - 16356
(2020/10/26)

Method for synthesizing phenol or derivative thereof in aqueous phase by photocatalytic one-pot method
The invention discloses a method for synthesizing phenol or a derivative thereof in an aqueous phase by a photocatalytic one-pot method. The method comprises the following steps: by taking a compoundaryl halide shown in formula (I) as a raw material and water as a solvent, adding a catalyst and an auxiliary agent, and carrying out reacting under the conditions of alkali and visible light to obtain the phenol or the derivative (II) thereof. Compared with the prior art, the method is applicable to a large number of functional groups, high in yield, few in byproducts, simple and safe to operate,low in cost and environmentally friendly, wherein R is selected from substituted or non-substituted phenyl, pyridyl, quinolyl or pyrimidinyl; X is selected from halogen; the substituted phenyl is substituted by C1-C4 alkyl, C1-C4 alkoxy, hydroxyl, halogen, cyano, aldehyde group, nitro, amino, acetyl or carboxyl; and the substituted pyridyl, quinolyl or pyrimidinyl is pyridyl, quinolyl or pyrimidinyl substituted by C1-C4 alkyl.
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Paragraph 0032-0033; 0046-0047; 0085-0106

(2020/12/08)

Method for preparing alcohol and phenol through aerobic hydroxylation reaction of boric acid derivative in absence of photocatalyst
The invention discloses a method for preparing alcohol and phenol through aerobic hydroxylation reaction of a boric acid derivative in the absence of a photocatalyst, wherein the boric acid derivativeis aryl boronic acid or alkyl boronic acid, and the corresponding target compounds are respectively a phenol-based compound and an alcohol-based compound. According to the method, by using a boric acid derivative as a reaction substrate, an additive is added under a solvent condition, and a hydroxylation reaction is performed under aerobic and illumination conditions to obtain a corresponding target compound. According to the invention, the new strategy is provided for the synthesis of phenols through aerobic hydroxylation of aryl boronic acid without a photocatalyst; the catalyst-free aerobic hydroxylation method for photocatalysis of aryl boronic acid or alkyl boronic acid by using triethylamine as an additive is firstly disclosed; and the new method has advantages of photocatalyst-freecondition, wide substrate range and good functional group compatibility.
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Paragraph 0025-0028; 0030-0032

(2020/01/25)

Nickel-catalyzed removal of alkene protecting group of phenols, alcohols via chain walking process
An efficient nickel-catalyzed removal of alkene protection group under mild condition with high functional group tolerance through chain walking process has been established. Not only phenolic ethers, but also alcoholic ethers can be tolerated with the retention of stereocenter adjacent to hydroxyl group. The new reaction brings the homoallyl group into a start of new type of protecting group.
Meng, Chenkai,Niu, Haolin,Ning, Juehan,Wu, Wengang,Yi, Jun
(2020/02/04)

Mild environment-friendly oxidative debenzylation of N-benzylanilines using DMSO as an oxidant
Oxidative debenzylation of N-benzyl aromatic amines using DMSO as a non-toxic oxidant and catalyzed by TsOH gave Nphenylimines, which were spontaneously hydrolyzed to form anilines and benzaldehydes in good yields. This reaction employs mild, metal-free conditions. The conditions are also suitable for the debenzylation of benzylphenylethers.
Yoshinaga, Tatsuro,Iwata, Takayuki,Shindo, Mitsuru
p. 191 - 194
(2020/02/25)

Green preparation process of M-tert-butylphenol
The invention discloses a preparation process of m-tert-butylphenol. The method includes the steps of: (1) adopting phenol and tert-butyl chloride as the raw materials, taking acidic clay and concentrated sulfuric acid as the catalyst, carrying out alkylation reaction to obtain the main product m-tert-butylphenol and the byproduct p-tert-butylphenol by one step, and performing separation; and (2)taking unreacted phenol and the p-tert-butylphenol by-product obtained in the step (1) as the raw materials, and taking acidic clay and aluminum trichloride as the catalyst, and carrying out rearrangement reaction to obtain m-tert-butylphenol in one step. Compared with the prior art, the preparation process of m-tert-butylphenol provided by the invention has the advantages of cheap and easily available raw materials, simple technology, good atom economy, greenness and environmental protection, is suitability for industrial production, and has important practical significance for improvement ofthe economic and social benefits of the tert-butylphenolation industry.
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Paragraph 0023-0024; 0027-0028; 0030-0031

(2020/04/02)

Thermal Stability Study of 4-tert-Butylphenol
Abstract: The thermal stability of 4-tert-butylphenol has been studied in the temperature range of 673–738?K, the components of the thermolysis reaction mixture have been identified, a kinetic model of the process has been proposed, and the rate constants and parameters of the Arrhenius equation have been calculated for all of the reactions considered. The predominant role of 4-tert-butylphenol isomerization transformations has been established. Information on the 4-tert-butylphenol thermal stability facilitates to a more substantiated approach to its use as an additive that increases the oxidative stability of fuels and lubricants, as well as an antioxidant for polymer compositions.
Shakun,Nesterova,Naumkin
p. 120 - 127
(2019/04/27)

Alkylation of Phenols with tert-Butanol Catalyzed by H-Form of Y Zeolites with a Hierarchical Porous Structure
tert-Butyl-substituted phenols have been synthesized via the reaction of phenol, o-, m-, and p-cresols with tert-butanol under the action of CBr4-promoted Y-zeolites in the H-form with a hierarchical porous structure.
Bayguzina,Makhiyanova,Khazipova,Khusnutdinov
p. 1554 - 1559
(2019/10/14)

Trichloroacetonitrile as an efficient activating agent for the: Ipso -hydroxylation of arylboronic acids to phenolic compounds
A metal-free and base-free Cl3CCN mediated method was developed for the ipso-hydroxylation of aryl boronic acids to their corresponding phenols, which was promoted by a key unstable Lewis adduct intermediate. This transformation has broad functional group tolerance, and late-stage functionalization was successful as well. After simple investigation, two pathways (radical/ionic mechanism) were suggested, and the beneficial action of blue light needs to be further studied.
Fang, Yuanding,Zhao, Rong,Yao, Yuan,Liu, Yang,Chang, Denghu,Yao, Ming,Shi, Lei
p. 7558 - 7563
(2019/08/20)

Cellulose as recyclable organocatalyst for ipso-hydroxylation of arylboronic acids
Cellulose catalyzed oxidative hydroxylation of aryl and hetero-arylboronic acids to the corresponding phenols under metal and base free strategy has been demonstrated. The sustainable ipso-hydroxylation takes place using hydrogen peroxide as an oxidant in water under mild condition in shorter period of time. Interestingly, easy recovery and reusability of heterogeneous catalyst without significant loss in catalytic yield makes the protocol environmentally benign.
Laskar, Khairujjaman,Paul, Subham,Bora, Utpal
(2019/08/26)

A practical method for preparation of phenols from arylboronic acids catalyzed by iodopovidone in aqueous medium
A novel and efficient strategy for the ipso-hydroxylation of arylboronic acids to phenols has been developed using inexpensive, readily available, air-stable water-soluble povidone iodine as catalyst and aqueous hydrogen peroxide as oxidizing agent. The reactions were performed at room temperature under metal-, ligand- and base-free condition in a short reaction time. The corresponding substituted phenols were obtained in moderate to good yields by oxidative hydroxylation of arylboronic acids in aqueous medium.
Dong, Bin,Ke, Yanxiong,Lu, Guangying,Ren, Jiangmeng,Ren, Yaoyao,Zeng, Bu-Bing,Zhou, Bin
(2019/09/06)

Photoinduced hydroxylation of arylboronic acids with molecular oxygen under photocatalyst-free conditions
Photoinduced hydroxylation of boronic acids with molecular oxygen under photocatalyst-free conditions is reported, providing a green entry to a variety of phenols and aliphatic alcohols in a highly concise fashion. This new protocol features photocatalyst-free conditions, wide substrate scope and excellent functional group compatibility.
Xu, Yu-Ting,Li, Chen-Yuan,Huang, Xiao-Bo,Gao, Wen-Xia,Zhou, Yun-Bing,Liu, Miao-Chang,Wu, Hua-Yue
supporting information
p. 4971 - 4975
(2019/09/30)

Catalyst- And solvent-free: Ipso -hydroxylation of arylboronic acids to phenols
A catalyst-free method for the hydroxylation of arylboronic acids to form the corresponding phenols with sodium perborate as the oxidant was developed using water as the solvent. Under the reaction conditions, the yield of phenol reached 92% at only 5 min. Moreover, the reaction could be conducted without a catalyst under the solvent-free condition, the efficiency of which was as high as that of a liquid-phase reaction. Using a microcalorimeter, the reaction was found to be an exothermic reaction. The reaction mechanism was investigated and understood via DFT calculations, which revealed that it was a nucleophilic reaction.
Yang, Xiufang,Jiang, Xulu,Wang, Weitao,Yang, Qi,Ma, Yangmin,Wang, Kuan
p. 34529 - 34534
(2019/11/13)

Multifunctional Tubular Organic Cage-Supported Ultrafine Palladium Nanoparticles for Sequential Catalysis
The imine condensation reaction of 5,5′-(benzo[c][1,2,5]thiadiazole-4,7-diyl)diisophthalaldehyde with cyclohexanediamine resulted in a shape-persistent multifunctional tubular organic cage (MTC1). It exhibits selective fluorescence sensing towards divalent Pd ions with a very low detection limit (38 ppb), suggesting effective complexation between these two species. Subsequent reduction of MTC1 and Pd(OAc)2 with NaBH4 afforded a cage-supported catalyst with well-dispersed ultrafine Pd nanoparticles (NPs) in a narrow size distribution (1.9±0.4 nm), denoted as Pd?MTC1-1/5. Such ultrafine Pd NPs in Pd?MTC1-1/5, in cooperation with photocatalytically active MTC1, enable efficient sequential reactions involving visible light-induced aerobic hydroxylation of 4-nitrophenylboronic acid to 4-nitrophenol and the following hydride reduction with NaBH4. This is the first example of a multifunctional organic cage capable of sensing, directing nanoparticle growth, and catalyzing sequential reactions.
Sun, Nana,Wang, Chiming,Wang, Hailong,Yang, Le,Jin, Peng,Zhang, Wei,Jiang, Jianzhuang
supporting information
p. 18011 - 18016
(2019/11/14)

Selectivity in the photo-fries rearrangement of some aryl benzoates in green and sustainable media. Preparative and mechanistic studies
Irradiation of a series of p-substituted aryl benzoates under N2 atmosphere in homogeneous and micellar media was investigated by means of steady-state condition and of time-resolved spectroscopy. A notable selectivity in favor of the 2-hydroxybenzophenone derivatives was observed in micellar media. The benzophenone derivatives were the main photoproduct. On the other hand, in homogeneous media (cyclohexane, acetonitrile, and methanol) the observed product distribution was entirely different, viz. substituted 2-hydroxybenzophenones, p-substituted phenols, benzyl and benzoic acid were found. The binding constants in the surfactant were also measured and NOESY experiments showed that the aryl benzoates were located in the hydrophobic core of the micelle. Laser flash photolysis experiments led to the characterization of both p-substituted phenoxy radical and substituted 2-benzoylcyclohexadienone transients in homogeneous and micellar environment.
Siano, Gastón,Bonesi, Sergio M.,Crespi, Stefano,Mella, Mariella
p. 4338 - 4352
(2019/05/01)

Synthesis of Ti-Al binary oxides and their catalytic application for C-H halogenation of phenols, aldehydes and ketones
Traditional C–H halogenation of organic compounds often requires corrosive agent or harsh condition, and current researches are focused on the use of noble metals as catalyst. In order to give an efficient, benign, activity-adjustable and cost-effective system for halogenation, a series of Ti-Al mixed oxides are prepared as catalyst through sol-gel in this work. Characterizations reveal all catalysts contain more aluminum than titanium, but preparative conditions affect their composition and crystallinity. Monitoring of particle size, zeta potential and UV–vis of preparative solution reveals that formation of catalyst colloids undergoes chemical reaction, affecting catalyst morphology. In halogenation, all catalysts show moderate to high activities, copper chloride proves to be an effective halogen source rather than sodium chloride. The chlorination and bromination are better than iodization, phenol and ketone appear to be more appropriate substrates than aldehyde. Additionally, oxide backbone of catalyst is more durable than its organic components during recycling. This study may provide new catalytic materials for progress of C–H activation.
Su, Peigen,Fan, Chao,Yu, Heng,Wang, Wanqin,Jia, Xin,Rao, Qifan,Fu, Chenxi,Zhang, Donghua,Huang, Benhua,Pan, Cheng,Zheng, Aqun,Sun, Yang
(2019/06/13)

Cu-Catalyzed Couplings of Heteroaryl Primary Amines and (Hetero)aryl Bromides with 6-Hydroxypicolinamide Ligands
A family of 6-hydroxypicolinamide ligands have been identified as effective supporting ligands for Cu-catalyzed couplings of heteroaryl bromides and chlorides with heteroaryl primary amines. The C-N couplings are carried out at 80-120 °C in DMSO or sulfolane using K2CO3 or K3PO4 as the base with 2-10 mol % CuI and supporting ligand. The strength of the base was found to have an impact on the chemoselectivity and rate. The use of K2CO3 as the base enabled selective C-N coupling of aryl bromides over aryl chlorides with 2-5 mol % Cu at 80-120 °C. With K3PO4 as the base, aryl chlorides are capable of undergoing C-N coupling, though 5-10 mol % Cu is required at 120-130 °C. Members of the ligand family are straightforward to prepare in one step from 6-hydroxypicolinic acid and the corresponding anilines.
Bernhardson, David J.,Widlicka, Daniel W.,Singer, Robert A.
p. 1538 - 1551
(2019/09/04)

Method of removing protective groups of olefins under catalytic action of nickel
The invention relates to a method of removing protective groups of olefins under the catalytic action of nickel. The method comprises following steps: dissolving olefin containing compounds into an organic solvent, carrying out reactions in the presence of a catalyst, organic ligands, bis(pinacolato)diboron, alkalis, alcohols, and water, wherein the catalyst contains nickel; after reactions, adding excess hydrochloric acid solution (1M) to adjust the pH to the acidic region, stirring the solution until the solution becomes clear; adding water and ethyl acetate to carry out extraction; washing the organic phase by saturated brine, drying the organic phase by anhydrous sodium sulfate, carrying out condensation, and adopting a 200-300 mesh silica gel column to carry out chromatographic separation to obtain compounds that contains alcohols or phenol. The provide method has the advantages that the adopted chemical reagents are common, the primary alkyl halide protective groups of olefins can be removed efficiently, and the method has a good application prospect in the field of organic synthesis and good industrial potential.
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Paragraph 0189-0193

(2019/10/04)

Thermal Stability of 4-tert-Butyl Diphenyl Oxide
Abstract: In the temperature range of 703–763 K, the thermal stability of 4-tert-butyl diphenyl oxide (4?TBDPO) has been studied, the components of the thermolysis reaction mass have been identified, a kinetic model of the process has been proposed, and the rate constants and parameters of the Arrhenius equation for all reactions under consideration have been calculated. The predominant role of isomerization transformations of 4-TBDPO has been found. A mechanism for the radical isomerization of the tert-butyl substituent has been proposed.
Shakun,Nesterova,Tarazanov,Spiridonov
p. 2123 - 2130
(2019/11/11)

Aerobic Liquid-Phase Oxidation of Para-tert-Butylcumene to Hydroperoxide
Abstract: The reaction of aerobic liquid-phase oxidation of para-tert-butylcumene (PTBC) in the presence of N-hydroxyphthalimide has been studied. It has been found that the selectivity for the tertiary hydroperoxide of PTBC is over 95–98% up to a hydrocarbon conversion of 35–50%. The reasonability of the use of this reaction in the process of joint production of PTBC and acetone is shown. The mechanism of the process is discussed.
Yarkina,Kurganova,Frolov,Lebedeva,Koshel’
p. 1245 - 1248
(2019/11/21)

Acid Decomposition of p-tert-Butylcumene Hydroperoxide to p-tert-Butylphenol and Acetone
p-tert-Butyphenol is a valuable product of basic organic synthesis, widely used in various branches of industry. The relationships of acid decomposition of p-tert-butylcumene hydroperoxide to p-tert-butylphenol and acetone as one of the key steps of the alternative method for p-tert-butylphenol synthesis were studied. The influence exerted by temperature, catalyst concentration, and initial concentration of p-tert-butylcumene hydroperoxide on its acid decomposition was examined. Conditions ensuring preparation of p-tert-butylphenol in 92% yield were found. A kinetic model of the acid decomposition of p-tert-butylcumene hydroperoxide in the presence of concentrated sulfuric acid was constructed; it adequately describes the experimental data and allows substantiation of the reaction mechanism.
Yarkina,Kurganova,Frolov,Koshel’,Denisova
p. 1524 - 1530
(2020/01/03)

Synthesis method of o-tert-butyl cyclohexyl acetate essence
The invention discloses a synthesis method of o-tert-butyl cyclohexyl acetate essence, which includes the following steps: a) successively adding petroleum ether and phenol to a three-neck glass flask, and adding TiO2-supported phosphotungstic acid catalyst, dropwise adding tert-butyl alcohol at 10 - -15 DEG C, and layering a reaction liquid mixture, generated in the glass flask, of o-tert-butyl phenol and p-tert-butyl phenol; b) washing an oil layer successively with alkali and water, and performing a hydrogenation reaction under a Pd/C catalyst, collecting o-tert-butyl cyclohexanol, adding acetic anhydride and p-toluenesulfonic acid, recovering the acetic acid, and alkali-washing, water-washing and evaporating the oil layer to prepare the o-tert-butyl cyclohexyl acetate essence. The method employs easy-to-obtained raw materials and is high in yield, wherein final product content can reach more than 98.5% and content of cis-isomers in the product can reach more than 85%. The ssence has a pure and mellow fragrance and satisfies the demand of essence and perfumes in flavor blending.
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Paragraph 0010; 0011

(2018/04/26)

Production method of iris ester synthetic essence
The invention discloses a production method of an iris ester synthetic essence, which relates to the technical field of fine chemical production. The phenol and tert-butyl alcohol are taken as initialraw materials for an alkylation reaction, after hydrogenation, the materials and acetic anhydride are subjected to an acetylation reaction to generate iris ester, the raw materials are easily available, and yield is high; petroleum ether is taken as an organic solvent of the alkylation reaction and a hydrogenation reaction, the disadvantages that the reaction is incomplete during a hydrogenationprocess and a catalyst is inactivated after application can be overcome, and a distillation technology step employed in the alkylation reaction by employing dichloroethane as a solvent is simultaneously omitted; a boiling point of petroleum ether is low, and the petroleum ether is easily recovered and applied, so that environment pollution due to discharge of the organic solvent in waste water canbe avoided, and production cost is reduced.
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Paragraph 0047; 0048; 0049; 0050; 0051; 0052-0054; 0068

(2018/05/03)

Synthesis of Cyclic Enones by Allyl-Palladium-Catalyzed α,β-Dehydrogenation
The use of allyl-palladium catalysis for the one-step α,β-dehydrogenation of ketones via their zinc enolates is reported. The optimized protocol utilizes commercially available Zn(TMP)2 as base and diethyl allyl phosphate as oxidant. Notably, this transformation operates under salt-free conditions and tolerates a diverse scope of cycloalkanones.
Huang, David,Zhao, Yizhou,Newhouse, Timothy R.
supporting information
p. 684 - 687
(2018/02/09)

Dimethylglyoxime as an efficient ligand for copper-catalyzed hydroxylation of aryl halides
The CuI/dimethylglyoxime (CuI/DMG) catalyzed direct hydroxylation of aryl iodides with CsOH takes place at 120°C in a mixed solvent system (DMSO–H 2O ,1:1), afforded the corresponding phenols in good to excellent yield. Aryl bromides are found to be less reactive than aryl iodides under these reaction conditions. Graphical Abstract: SYNOPSIS. (CuI/DMG) catalyzed synthesis of phenol from aryl iodide and aryl bromide in presence of mixed solvents (H 2O : DMSO) is reported in this paper. This protocol is general, economical, easy and convenient for transformation of aryl iodides and bromides to substituted phenols under mild reaction conditions. [Figure not available: see fulltext.].
Shendage, Suresh S
(2018/02/14)

Hierarchical ZSM-5 nanocrystal aggregates: Seed-induced green synthesis and its application in alkylation of phenol with: Tert -butanol
Hierarchical ZSM-5 zeolite aggregates were synthesized in an organic-template-free system via seed-induced crystallization. The obtained samples were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron mi
Chen, Li,Xue, Teng,Wu, Haihong,Wu, Peng
p. 2751 - 2758
(2018/02/06)

A PROCESS FOR THE PREPARATION OF TERTIARY BUTYL PHENOL
The present invention disclosed a process for the preparation of tertiary butyl phenol by reaction of phenol with tertiary butanol using phosphorus pentoxide as catalyst.
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Page/Page column 7-8

(2018/05/16)

Synthesis of phenols and aryl silyl ethers via arylation of complementary hydroxide surrogates
Two transition-metal-free methods to access substituted phenols via the arylation of silanols or hydrogen peroxide with diaryliodonium salts are presented. The complementary reactivity of the two nucleophiles allows synthesis of a broad range of phenols without competing aryne formation, as illustrated by the synthesis of the anesthetic Propofol. Furthermore, silyl-protected phenols can easily be obtained, which are suitable for further transformations.
Reitti, Marcus,Gurubrahamam, Ramani,Walther, Melanie,Lindstedt, Erik,Olofsson, Berit
p. 1785 - 1788
(2018/04/14)