cas 527-60-6, 2,4,6-Trimethylphenol | Articles data

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Enhanced Photodecarboxylation of an Aryl Ester in Polyethylene Films
(Matrix presented) Photodecarboxylation is the exclusive photoreaction of 2,4,6-trimethylphenyl (S)-2-methylbutanoate In unstretched high-density polyethylene films. The sole product, (S)-1-(2-methylpropyl)-2,4,6- trimethylbenzene, is formed with complete
Mori, Tadashi,Inoue, Yoshihisa,Weiss, Richard G.
p. 4661 - 4664
(2003)
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Complete memory of chirality upon photodecarboxylation of mesityl alkanoate to mesitylalkane: Theoretical and experimental evidence for cheletropic decarboxylation via a spiro-lactonic transition state
The photodecarboxylation of chiral mesityl alkanoate to mesitylalkane has been studied experimentally/theoretically, and it has been found that the photodecarboxylation proceeds to give the product in > 99% enantiomeric excesses under a variety of conditions, indicating no involvement of any radical intermediates, but that the reaction proceeds through the concerted cheletropic extrusion of CO2 from the energetically less-favored s-cis conformation.
Mori, Tadashi,Saito, Hideaki,Inoue, Yoshihisa
p. 2302 - 2303
(2003)
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Lapkin,Schkljajew,Schkljajewa
(1941)
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AROMATIC HYDROXYLATION WITH PEROXYMONOPHOSPHORIC ACID
Aromatic hydroxylation of mesitylene, phenol and anisole (ArH) with peroxymonophosphoric acid (H3PO5) in acetonitrile has been studied.H3PO5 is shown to be an effective reagent for aromatic hydroxylation, the reactivity being comparable to that with CF3CO3H.Mesitylene gives mesitol (over 70percent).The hydroxylation with H3PO5 is ca 100 fold faster than that with MeCO3H or PhCO3H.The rate equation is: v=k2 instead of our previous one.The oxidation is catalyzed by H2SO4, giving a linear plot of log k2 vs H0 with a slope of 1.26 for phenol and 1.17 for mesitylene.
Ogata, Yoshiro,Sawaki, Yasuhiko,Tomizawa, Kohtaro,Ohno, Takashi
p. 1485 - 1486
(1981)
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Catalytic Activation of Unstrained C(Aryl)-C(Alkyl) Bonds in 2,2′-Methylenediphenols
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.
Dong, Guangbin,Ratchford, Benjamin L.,Xue, Yibin,Zhang, Rui,Zhu, Jun
p. 3242 - 3249
(2022/02/23)

Iodine promoted reduction of aromatic carbonyl compounds with phosphonic acid to access hydrocarbons
A novel method for selective reduction of aromatic carbonyl compounds by phosphorus acid under metal-free conditions is achieved to produce the corresponding reduced products in good to excellent yields. By using H3PO3/I2 system, various aromatic ketones and aldehydes could be reduced to the corresponding hydrocarbons. Diketone compounds could also be reduced to the corresponding Z-alkenes. The protocol is low-cost and easily scaled up, which provides a simple and practical approach to access corresponding hydrocarbons.
Deng, Jinfeng,Xiao, Jing,Wang, Xiaoyi,Luo, Huang,Jia, Zhicheng,Wang, Jie
(2022/04/19)

Selective hydroxylation of aryl iodides to produce phenols under mild conditions using a supported copper catalyst
Owing to the high activity and low-cost, copper-based catalysts are promising candidates for transforming aromatic halides to yield phenols. In this work, we report the selective hydroxylation of aromatic iodides to produce phenols using an atomically dispersed copper catalyst (Cu-ZnO-ZrO2) under mild reaction conditions. The reactions were conducted without the use of additional organic ligands, and the protection of an inert atmosphere environment is not required. The catalyst can be easily prepared, scalable, and is very efficient for a wide range of substrates. The catalytic reactions can be carried out with only 1.24 mol% Cu loading, which shows great potential in mass production.
Auni, Anika,Ding, Guodong,Hao, Leiduan,Li, Tao,Li, Xiaoyu,Xu, Haiping,Zhang, Qiang
p. 25348 - 25353
(2021/08/03)

Reaction of hydroxyl radical with arenes in solution—On the importance of benzylic hydrogen abstraction
The regioselectivity of hydroxyl radical reactions with alkylarenes was investigated using a nuclear magnetic resonance (NMR)-based methodology capable of trapping and quantifying addition and hydrogen abstraction products of the initial elementary step of the oxidation process. Abstraction products are relatively minor components of the product mixtures (15–30 mol%), depending on the magnitude of the overall rate coefficient and the number of available hydrogens. The relative reactivity of addition at a given position on the ring depends on its relation to the methyl substituents on the hydrocarbons under study. The reactivity enhancements for disubstituted and trisubstituted rings are approximately additive under the conditions of this study.
Waggoner, Abygail R.,Abdulrahman, Yahya,Iverson, Alexis J.,Gibson, Ethan P.,Buckles, Mark A.,Poole, James S.
(2021/08/27)

Application of two morphologies of Mn2O3for efficient catalyticortho-methylation of 4-chlorophenol
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.
Gui, Wenying,Liu, Xiaofei,Wang, Zhenlu,Zhang, Chunlei,Zhang, Hongqiang,Zhang, Li,Zhu, Wanchun
p. 20836 - 20849
(2021/07/01)

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)

Synthesis method of substituted phenol
The invention provides a synthesis method of substituted phenol. The target product substituted phenol is prepared by taking substituted benzene as an initial raw material, and the whole synthetic process is high in selectivity, high in yield, convenient to operate and high in atom economy.
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(2020/09/16)

Reductive Aromatization of Quinols with B2pin2 as Deoxidizing Agent
We have demonstrated B2pin2 as superior deoxidizing agent for the reductive deoxygenation of quinol derivatives under basic conditions. A wide range of highly functionalized phenols were obtained in good yields including a complex drug molecule, which revealed the high functional group tolerance of this protocol.
Liu, Bin,Xu, Yin,Luo, Zhibin,Xie, Jimin
supporting information
p. 1022 - 1024
(2020/03/19)

NRTI THERAPIES
Polymer-of-prodrug (POP) materials enable new nucleoside reverse transcriptase inhibitor (NRTI) therapy strategies. The materials are prodrugs of NRTIs in the form of polymers. Suitable materials include products which are polymeric NRTI delivery systems comprising polymeric materials which are capable of degradation after administration to release NRTIs or NRTI prodrugs which themselves are capable of metabolism to the parent NRTIs. The NRTIs may optionally be selected from tenofovir (TFV), emtricitabine (FTC), lamivudine (3TC) and MK-8591 (EFdA). The invention facilitates long-acting (LA) regimens. Constructs of the materials may be in the form of injectable compositions or implants.
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(2020/07/14)

Visible-light-promoted aerobic oxidative hydroxylation of arylboronic acids in water by hydrophilic organic semiconductor
A green and sustainable catalytic system was developed based on perylenediimide (PDI) organic semiconductor for the aerobic oxidative hydroxylation of arylboronic acids in aqueous solution with visible light. By using PDI-SN, a hydrophilic organic semiconductor, which can activate oxygen to produce superoxide radicals in aqueous solution, this reaction proceeds under ambient conditions: water as the solvent and air as the oxidant, giving various phenols as products with high yields. In contrast to methods using organic solvents, this novel process has the potential of green industrial application.
Yu, Kunyi,Zhang, Hanjie,Sheng, Yuqiang,Zhu, Yongfa
supporting information

(2020/06/23)

A scalable and green one-minute synthesis of substituted phenols
A mild, green and highly efficient protocol was developed for the synthesis of substituted phenols via ipso-hydroxylation of arylboronic acids in ethanol. The method utilizes the combination of aqueous hydrogen peroxide as the oxidant and H2O2/HBr as the reagent under unprecedentedly simple and convenient conditions. A wide range of arylboronic acids were smoothly transformed into substituted phenols in very good to excellent yields without chromatographic purification. The reaction is scalable up to at least 5 grams at room temperature with one-minute reaction time and can be combined in a one-pot sequence with bromination and Pd-catalyzed cross-coupling to generate more diverse, highly substituted phenols.
Elumalai, Vijayaragavan,Hansen, J?rn H.
p. 40582 - 40587
(2020/11/18)

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)

Process preparation method of 4-substituted-2, 6-dimethylphenol
The present invention discloses a process preparation method of 4-substituted-2, 6-dimethyl phenol. According to the process preparation method, a preparation route method is improved and optimized, reaction conditions are optimized, post-treatment and purification methods are improved, so that the danger grade of operation and the production cost are reduced; and the requirement for the corrosionresistance grade of reaction container equipment is low, the operation is safe, and the post-treatment is environment-friendly; and the prepared 4-substituted-2, 6-dimethyl phenol has less impurities, thus, the purity and the quality of an intermediate product are greatly improved while the yield is improved as well, the difficulty of process control in the production process of a subsequent rawmaterial medicine product is improved, and the quality and qualification rate of the subsequent raw material medicine product are improved; and the steps of the preparation method is simple to operate, the solvent and the process conditions are safe and easy to achieve, environment-friendly production is achieved, and the preparation method has wide application prospect.
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(2019/07/11)

Deoxyalkylation of guaiacol using haggite structured V4O6(OH)4
When V2O5 is used for the deoxygenation of guaiacol in methanol, it is reduced in situ to haggite structured V4O6(OH)4. Guaiacol prevents further reduction of the haggite phase in methanol and haggite catalyzes the partial deoxygenation of guaiacol. Haggite is a metastable redox catalyst for the deoxygenation of guaiacol, which follows the reverse Mars-van Krevelen mechanism. In addition, haggite is also a Lewis acid catalyst and catalyzes the alkylation of guaiacol with methanol as the alkylation reagent. The main products of the guaiacol deoxyalkylation are 2,6-dimethylphenol, 2-methoxy-6-methylphenol, 2,4,6-trimethylphenol, 2,3,6-trimethylphenol, 2,3,5,6-tetramethylphenol and 6-methyl-2-tert-butylphenol. Oligomerization takes place during the reaction but it is reversible. When the reaction is performed at 300 °C for 6 h, the 83.5% total selectivity for alkylphenols is achieved with a 99.0% conversion.
Yan, Fei,Wen, Zhe,Wu, Kai,Cui, Kai,Mai, Fuhang,Ma, Zewei,Sang, Yushuai,Bai, Yunfei,Chen, Hong,Li, Yongdan
p. 1922 - 1932
(2019/04/29)

Lewis acid-catalyzed annulative partial dimerization of 3-aryloxyacrylates to 4-arylchroman-2-ones: Synthesis of analogues of tolterodine, RORγ inhibitors and a GPR40 agonist
A beguiling annulative partial dimerization of 3-aryloxyacrylates to 4-arylchroman-2-ones catalyzed by Lewis acid (BF3·OEt2) has been developed. The reaction involves two molecules of 3-aryloxyacrylate, resulting in the loss of one propiolate molecule to furnish 4-arylchroman-2-one, an important structural motif found in many natural products. This methodology has been elaborated to synthesize analogues of tolterodine, RORγ inhibitors and a GPR40 agonist.
Kunkalkar, Rupesh A.,Fernandes, Rodney A.
supporting information
p. 2313 - 2316
(2019/02/27)

A Green Alternative for the Conversion of Arylboronic Acids/Esters into Phenols Promoted by a Reducing Agent, Sodium Sulfite
Hydroxylation of arylboronic acids and arylboronic esters using sodium sulfite and oxygen as the source of ultimate oxidant proceeds rapidly in water under transition metal-free conditions. This remarkable mild and environmentally benign protocol represents a green alternative to synthesize phenols using inexpensive starting materials in a simple methodology. This new application for sodium sulfite shows a wide tolerance of functional groups, and it is compatible with oxidizable functionalities.
Castro-Godoy, Willber D.,Schmidt, Luciana C.,Argüello, Juan E.
p. 3035 - 3039
(2019/05/15)

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)

Photoinduced Hydroxylation of Organic Halides under Mild Conditions
Presented in this paper is photoinduced hydroxylation of organic halides, providing a mild access to a range of functionalized phenols and aliphatic alcohols. These reactions generally proceed under mild reaction conditions with no need for a photocatalyst or a strong base and show a wide substrate scope as well as excellent functional group tolerance. This work highlights the unique role of NaI that allows a challenging transformation to proceed under mild reaction conditions.
Cai, Yue-Ming,Xu, Yu-Ting,Zhang, Xin,Gao, Wen-Xia,Huang, Xiao-Bo,Zhou, Yun-Bing,Liu, Miao-Chang,Wu, Hua-Yue
supporting information
p. 8479 - 8484
(2019/10/16)

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)

Synthesis of substituted phenols via hydroxylation of arenes using hydrogen peroxide in the presence of hexaphenyloxodiphosphonium triflate
A mild and efficient protocol for the synthesis of phenols from arenes has been developed using aqueous hydrogen peroxide as an oxidizing agent and hexaphenyloxodiphosphonium triflate as a promoter. The reactions were carried out with the simple procedure in EtOH-H2O at room temperature in short reaction times.
Khodaei, Mohammad Mehdi,Alizadeh, Abdolhamid,Hezarkhani, Hadis Afshar
supporting information
p. 878 - 882
(2018/11/06)

SYSTEMS AND METHODS FOR SYNTHESIS OF PHENOLICS AND KETONES
Embodiments herein relate to apparatus and systems for phenolic and ketone synthesis and methods regarding the same. In an embodiment, a method of producing phenolics and ketones is included. The method can specifically include forming a reaction mixture comprising nanocrystalline cellulose (NCC) and water. The method can also include contacting the reaction mixture with a metal oxide catalyst at a temperature of 350 degrees Celsius or higher and a pressure of at least about 3200 psi to form a reaction product mixture. The reaction product mixture can include at least about 20 wt. % phenolics and at least about 10 wt. % ketones as a percentage of the total mass of nanocrystalline cellulose (NCC). Other embodiments are also included herein.
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Paragraph 0080-0088

(2018/11/21)

Controlled manipulation of selectivity between O- versus C-alkylation in methylation of phenol using ZrO2-WO3- SiO2 catalysts
Anisole and o-cresol are very important chemicals which could prepared from phenol using different catalytic routes favoring either O- or C-alkylation. In the methylation of phenol with methanol, the selectivity to either anisole or o-cresol could be manipulated using a suitable tailor-made catalyst having a proper balance of acidic and basic sites. In the current work, a series of compositions based on zirconium, tungsten and silicon oxides (xZrO2-yWO3-SiO2) were prepared and employed as catalysts in fixed bed methylation of phenol. In the absence of silica as support, methylation of phenol over 20% WO3-ZrO2 and 40% WO3-ZrO2 favored predominantly C-alkylated product o-cresol. Among various combinations 10% ZrO2-30% WO3-SiO2 gave the best results and selectivity to the desired product anisole. Effect of various parameters affecting selectivity to anisole or o-cresol were studied systematically. The mechanism of formation of different products with reference to catalyst structure and functionality was explored in detail. The process parameters could be optimized to get the desired product. Thus, the proper choice can be made to choose the selectivity of O-versus C-alkylation using a single catalyst. The time on stream study was carried out for 16 h to find that the catalyst was stable and could be regenerated.
Bhadra, Kalpesh H.,Yadav, Ganapati D.
p. 67 - 78
(2018/06/08)

Synergistic Photo-Copper-Catalyzed Hydroxylation of (Hetero)aryl Halides with Molecular Oxygen
Photoredox-mediated copper-catalyzed hydroxylation of (hetero)aryl halides (including chlorides, bromides, and iodides) with O2 at room temperature has been developed. Preliminary mechanistic studies indicate no arylcopper intermediate and that aryl radicals are involved in this procedure. 18O-labeling experiments confirm the hydroxyl oxygen atom originated from molecular oxygen.
Zhang, Xin,Wu, Ge,Gao, Wenxia,Ding, Jinchang,Huang, Xiaobo,Liu, Miaochang,Wu, Huayue
supporting information
p. 708 - 711
(2018/02/09)

A mild copper catalyzed method for the selective deprotection of aryl allyl ethers
Copper boryl reagents enable the selective cleavage of aryl allyl ethers to the corresponding phenols in good to moderate yields.
Hemming, David S.,Talbot, Eric P.,Steel, Patrick G.
supporting information
p. 17 - 20
(2016/12/23)

Highly Selective and Efficient Ring Hydroxylation of Alkylbenzenes with Hydrogen Peroxide and an Osmium(VI) Nitrido Catalyst
The OsVI nitrido complex, OsVI(N)(quin)2(OTs) (1, quin=2-quinaldinate, OTs=tosylate), is a highly selective and efficient catalyst for the ring hydroxylation of alkylbenzenes with H2O2 at room temperature. Oxidation of various alkylbenzenes occurs with ring/chain oxidation ratios ranging from 96.7/3.3 to 99.9/0.1, and total product yields from 93 % to 98 %. Moreover, turnover numbers up to 6360, 5670, and 3880 can be achieved for the oxidation of p-xylene, ethylbenzene, and mesitylene, respectively. Density functional theory calculations suggest that the active intermediate is an OsVIII nitrido oxo species.
Kwong, Hoi-Ki,Lo, Po-Kam,Yiu, Shek-Man,Hirao, Hajime,Lau, Kai-Chung,Lau, Tai-Chu
supporting information
p. 12260 - 12263
(2017/09/06)

An Enzymatic Route to α-Tocopherol Synthons: Aromatic Hydroxylation of Pseudocumene and Mesitylene with P450 BM3
Aromatic hydroxylation of pseudocumene (1 a) and mesitylene (1 b) with P450 BM3 yields key phenolic building blocks for α-tocopherol synthesis. The P450 BM3 wild-type (WT) catalyzed selective aromatic hydroxylation of 1 b (94 %), whereas 1 a was hydroxylated to a large extent on benzylic positions (46–64 %). Site-saturation mutagenesis generated a new P450 BM3 mutant, herein named “variant M3” (R47S, Y51W, A330F, I401M), with significantly increased coupling efficiency (3- to 8-fold) and activity (75- to 230-fold) for the conversion of 1 a and 1 b. Additional π–π interactions introduced by mutation A330F improved not only productivity and coupling efficiency, but also selectivity toward aromatic hydroxylation of 1 a (61 to 75 %). Under continuous nicotinamide adenine dinucleotide phosphate recycling, the novel P450 BM3 variant M3 was able to produce the key tocopherol precursor trimethylhydroquinone (3 a; 35 % selectivity; 0.18 mg mL?1) directly from 1 a. In the case of 1 b, overoxidation leads to dearomatization and the formation of a valuable p-quinol synthon that can directly serve as an educt for the synthesis of 3 a. Detailed product pattern analysis, substrate docking, and mechanistic considerations support the hypothesis that 1 a binds in an inverted orientation in the active site of P450 BM3 WT, relative to P450 BM3 variant M3, to allow this change in chemoselectivity. This study provides an enzymatic route to key phenolic synthons for α-tocopherols and the first catalytic and mechanistic insights into direct aromatic hydroxylation and dearomatization of trimethylbenzenes with O2.
Dennig, Alexander,Weingartner, Alexandra Maria,Kardashliev, Tsvetan,Müller, Christina Andrea,Tassano, Erika,Schürmann, Martin,Ruff, Anna Jo?lle,Schwaneberg, Ulrich
p. 17981 - 17991
(2017/11/29)

Experimental Investigation on Upgrading of Lignin-Derived Bio-Oils: Kinetic Analysis of Anisole Conversion on Sulfided CoMo/Al2O3 Catalyst
Kinetics of the hydroprocessing of anisole, a compound representative of lignin-derived bio-oils, catalyzed by a commercial sulfided CoMo/Al2O3, was determined at 8–20 bar pressure and 573–673 K with a once-through flow reactor. The catalyst was sulfided in an atmosphere of H2 + H2S prior to the measurement of its performance. Selectivity-conversion data were used as a basis for determining an approximate, partially quantified reaction network showing that hydrodeoxygenation (HDO), hydrogenolysis, and alkylation reactions take place simultaneously. The data indicate that these reactions can be stopped at the point where HDO is virtually completed and hydrogenation reactions (and thus H2 consumption) are minimized. Phenol was the major product of the reactions, with direct deoxygenation of anisole to give benzene being kinetically almost insignificant under our conditions. We infer that the scission of the Cmethyl–O bond is more facile than the scission of the Caromatic–O bond, so that the HDO of anisole likely proceeds substantially through the reactive intermediate phenol to give transalkylation products such as 2-methylphenol. The data determine rates of formation of the major primary products. The data show that if oxygen removal is the main processing goal, higher temperatures and lower pressures are favored.
Rahimpour, Hamid Reza,Saidi, Majid,Rostami, Parisa,Gates, Bruce C.,Rahimpour, Mohammad Reza
p. 702 - 713
(2016/09/28)

Copper(i) 5-phenylpyrimidine-2-thiolate complexes showing unique optical properties and high visible light-directed catalytic performance
Solvothermal reactions of 5-phenylpyrimidine-2-thiol (5-phpymtH) with equimolar CuBr afforded one hexanuclear cluster [Cu6(μ3-5-phpymt)6] (1) along with a tetranuclear by-product [{(Cu2Br)(μ-5-phpymtH)}(μ3-5-phpymt)]2 (2). A two dimensional (2D) polymer [Cu4(μ5-5-phpymt)2(μ-Br)2]n (3) was isolated from the reaction of 5-phpymtH with two equiv. of CuBr. Analogous reactions of 5-phpymtH with one or four equiv. of CuI produced one tetranuclear cluster [{Cu2(μ-5-phpymtH)(μ-5-phpymt)}(μ3-I)]2 (4) and one 2D polymer [Cu6I2(μ4-I)2(μ4-5-phpymt)2]n (5). Compound 1 possesses a water-wheel-shaped hexameric structure. Compound 2 has an H-shaped tetrameric structure. Compound 3 possesses a 2D network in which unique 1D [Cu8(μ-Br)2(μ5-5-phpymt)4]n chains are connected by μ-Br- ions. Compound 4 has another tetrameric structure in which two {Cu2(μ-5-phpymtH)2(μ-5-phpymt)} fragments are linked by a pair of μ3-I- ions. Compound 5 contains another 2D network in which hexanuclear {Cu6I2(μ4-I)2} units are linked by μ4-5-phpymt bridges. The 5-phpymt ligand shows four coordination modes: μ-κ1(S)-κ1(N) (4), μ3-κ2(S)-κ1(N) (1 and 2), μ4-κ1(N)-κ2(S)-κ1(N′) (5) and μ5-κ1(N)-κ3(S)-κ1(N′) (3). Complex 1 shows strong solvatochromic behaviour and displays reversible luminescence switching upon alternate addition of CF3COOH and Et3N into its CHCl3 solution. Complexes 1-5 exhibit a high photocatalytic activity towards the aerobic oxidative hydroxylation of arylboronic acids to phenols under visible light irradiation. Catalyst 5 can be reused in several cycles without any obvious decay of the catalytic efficiency. These results offer an interesting insight into how the CuX/5-phpymtH molar ratios and X- ions exert great impacts on the coordination modes of the 5-phpymt- ligand, the structures of the final complexes, and the luminescence and catalytic properties.
Zhang, Meng-Juan,Li, Hong-Xi,Li, Hai-Yan,Lang, Jian-Ping
p. 17759 - 17769
(2016/11/17)

MANUFACTURE OF 2,4,6-TRIMETHYLPHENOL
The present invention is directed to a process for the manufacture of 2,4,6-trimethylphenol by reacting phenol or ortho-cresol or 2,6-xylenol with methanol in the gas phase and in the presence of a catalyst, whereby the catalyst comprises Ga2O3 or additionally MgO. Catalysts consisting of Ga2O3 or catalysts consisting of Ga2O3 and MgO may also be used successfully.
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Page/Page column 9

(2016/05/02)

Arene oxidation with malonoyl peroxides
Malonoyl peroxide 7, prepared in a single step from the commercially available diacid, is an effective reagent for the oxidation of aromatics. Reaction of an arene with peroxide 7 at room temperature leads to the corresponding protected phenol which can be unmasked by aminolysis. An ionic mechanism consistent with the experimental findings and supported by isotopic labeling, Hammett analysis, EPR investigations, and reactivity profile studies is proposed.
Dragan, Andrei,Kubczyk, Tomasz M.,Rowley, Julian H.,Sproules, Stephen,Tomkinson, Nicholas C. O.
supporting information
p. 2618 - 2621
(2015/06/16)

Molecular Dynamics Simulations of the Initial-State Predict Product Distributions of Dediazoniation of Aryldiazonium in Binary Solvents
The dediazoniation of aryldiazonium salts in mixed solvents proceeds by a borderline SN1 and SN2 pathway, and product distribution should be proportional to the composition of the solvation shell of the carbon attached to the -N2 group (ipso carbon). The rates of dediazoniation of 2,4,6-trimethylbenzenediazonium in water, methanol, ethanol, propanol, and acetonitrile were similar, but measured product distributions were noticeably dependent on the nature of the water/cosolvent mixture. Here we demonstrated that solvent distribution in the first solvation shell of the ipso carbon, calculated from classical molecular dynamics simulations, is equal to the measured product distribution. Furthermore, we showed that regardless of the charge distribution of the initial state, i.e., whether the positive charge is smeared over the molecule or localized on phenyl moiety, the solvent distribution around the reaction center is nearly the same.
Cruz, Gustavo N.,Lima, Filipe S.,Dias, Luís G.,El Seoud, Omar A.,Horinek, Dominik,Chaimovich, Hernan,Cuccovia, Iolanda M.
p. 8637 - 8642
(2015/09/15)

Computational and Experimental Studies of Phthaloyl Peroxide-Mediated Hydroxylation of Arenes Yield a More Reactive Derivative, 4,5-Dichlorophthaloyl Peroxide
The oxidation of arenes by the reagent phthaloyl peroxide provides a new method for the synthesis of phenols. A new, more reactive arene oxidizing reagent, 4,5-dichlorophthaloyl peroxide, computationally predicted and experimentally determined to possess enhanced reactivity, has expanded the scope of the reaction while maintaining a high level of tolerance for diverse functional groups. The reaction proceeds through a novel "reverse-rebound" mechanism with diradical intermediates. Mechanistic insight was achieved through isolation and characterization of minor byproducts, determination of linear free energy correlations, and computational analysis of substituent effects of arenes, each of which provided additional support for the reaction proceeding through the diradical pathway.
Camelio, Andrew M.,Liang, Yong,Eliasen, Anders M.,Johnson, Trevor C.,Yuan, Changxia,Schuppe, Alex W.,Houk,Siegel, Dionicio
p. 8084 - 8095
(2015/09/01)

Bio-based green solvent for the catalyst free oxidation of arylboronic acids into phenols
A bio-based green solvent, lactic acid, is found to be an efficient reaction medium for the catalyst free oxidation of arylboronic acids into phenols with aqueous hydrogen peroxide. Various substituted arylboronic acids have undergone ipso-hydroxylation smoothly at room temperature to provide corresponding phenols in excellent yields. Remarkably, the oxidation susceptible functional groups such as sulphide, ketone, aldehyde and olefin are tolerated under the reaction conditions. Over all, lactic acid showed higher efficiency as a solvent medium when compared with conventional acetic acid.
Gupta, Surabhi,Chaudhary, Priyanka,Seva, Lavudi,Sabiah, Shahulhameed,Kandasamy, Jeyakumar
p. 89133 - 89138
(2015/11/09)

Ligand- and base-free synthesis of phenols by rapid oxidation of arylboronic acids using iron(III) oxide
Fe2O3 catalyzed rapid oxidation of arylboronic acids to obtain phenols in excellent yields (90-95%) in the presence of atmospheric oxygen under solar VIS-light irradiation using α-Fe2O3 as a catalyst in ligand- and base-free conditions is presented.
Sawant, Sanghapal D.,Hudwekar, Abhinandan D.,Aravinda Kumar,Venkateswarlu, Vunnam,Singh, Parvinder Pal,Vishwakarma, Ram A.
p. 811 - 814
(2015/03/03)

CYCLIC PEROXIDE OXIDATION OF AROMATIC COMPOUND PRODUCTION AND USE THEREOF
The present invention provides a method for converting an aromatic hydrocarbon to a phenol by providing an aromatic hydrocarbon comprising one or more aromatic C-H bonds and one or more activated C-H bonds in a solvent; adding a phthaloyl peroxide to the solvent; converting the phthaloyl peroxide to a di-radical; contacting the di-radical with the one or more aromatic C-H bonds; oxidizing selectively one of the one or more aromatic C-H bonds in preference to the one or more activated C-H bonds; adding a hydroxyl group to the one of the one or more aromatic C-H bonds to form one or more phenols; and purifying the one or more phenols.
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(2014/10/15)

Baeyer-Villiger oxidation of aromatic aldehydes catalysed by zirconium phosphates intercalated with ionic liquids
Crystalline α-zirconium phosphate intercalated with 1-ethyl-3-methylimidazolium chloride or 1-hexyl-3-methylimidazolium chloride, and crystalline γ-zirconium phosphate intercalated with 1-ethyl-3-methylimidazolium chloride were synthesised, characterized and evaluated as selective catalysts in the Baeyer-Villiger oxidation of p-methoxybenzaldehyde, o-methoxybenzaldehyde and 2,4,6-trimethylbenzaldehyde by hydrogen peroxide, in glacial acetic acid or without solvent. The best selectivities of p-methoxyphenol (100 %), o-methoxyphenol (95 %) and 2,4,6-trimethylphenol (55 %) were achieved without solvent and are explained by the properties and structure of each catalyst.
Rocha, Graca M.S.R.O.,Amador, Cristina M.T.
p. 1197 - 1209
(2014/07/21)

One step C-N bond formation from alkylbenzene and ammonia over Cu-modified TS-1 zeolite catalyst
A Cu doped TS-1 zeolite sample was applied to catalyze the formation of C-N bonds on both the ring and the side chain of toluene, as well as other alkylbenzenes. A yield of 3.4% of toluidine was obtained for the amination of toluene, with a 1.0% yield of nitrobenzene. Cyanobenzene was also obtained as the C-N bond product on the side chain with a yield of 1.0%. The selectivity for C-N bond formation was 52.4%. The catalyst promoted the formation of a hydroxylamine intermediate from ammonia and hydrogen peroxide, and then the instantaneously generated amino cation reacted with the substrate to form C-N bonds on both the ring and side chain. Cyanobenzene was produced from the dehydration of benzylamine, formed via the reaction of ammonia and toluene. The formation of C-N bonds on the ring had an ortho-orientation advantage for mono-substituted-benzenes. With the increase in the number of methyl substituents, the yield of the ring products decreased, which might be caused by steric hindrance. the Partner Organisations 2014.
Xia, Sheng,Yu, Tianhua,Liu, Huihui,Li, Guiying,Hu, Changwei
p. 3108 - 3119
(2014/08/18)

Metal-free synthesis of substituted phenols from arylboronic acids in water at room temperature
A convenient, efficient and practical metal-free method for the synthesis of substituted phenols from arylboronic acids has been developed. The protocol uses hydrogen peroxide as a hydroxylating agent, ammonium bicarbonate as an additive, and the reactions were conveniently performed in water at room temperature. The method shows an excellent tolerance of functional groups, so it will find a wide variety of applications in academic and industrial research.
Jiang, Min,Yang, Hai-Jun,Li, Yong,Jia, Zhi-Ying,Fu, Hua
supporting information
p. 715 - 719
(2014/06/09)

A protocol to generate phthaloyl peroxide in flow for the hydroxylation of arenes
A flow protocol for the generation of phthaloyl peroxide has been developed. This process directly yields phthaloyl peroxide in high purity (>95%) and can be used to bypass the need to isolate and recrystallize phthaloyl peroxide, improving upon earlier batch procedures. The flow protocol for the formation of phthaloyl peroxide can be combined with arene hydroxylation reactions and provides a method for the consumption of peroxide as it is generated to minimize the accumulation of large quantities of peroxide.
Eliasen, Anders M.,Thedford, Randal P.,Claussen, Karin R.,Yuan, Changxia,Siegel, Dionicio
supporting information
p. 3628 - 3631
(2014/08/05)

Ligand- and base-free synthesis of phenols by rapid oxidation of arylboronic acids using iron(III) oxide
Fe2O3 catalyzed rapid oxidation of arylboronic acids to obtain phenols in excellent yields (90-95%) in the presence of atmospheric oxygen under solar VIS-light irradiation using α-Fe2O 3 as a catalyst in ligand- and base-free conditions is presented.
Sawant, Sanghapal D.,Hudwekar, Abhinandan D.,Aravinda Kumar,Venkateswarlu, Vunnam,Singh, Parvinder Pal,Vishwakarma, Ram A.
p. 811 - 814
(2014/02/14)

Metal-free UV-Vis-light-induced aerobic oxidative hydroxylation of arylboronic acids in the absence of a photosensitizer
A simple and efficient method has been developed for the metal-free photosynthesis of phenols with UV-Vis (ultraviolet-visible) light in quartz tubes. The protocol uses readily available arylboronic acids as the starting materials, triethylamine as the sacrificial electron donor, and air as the oxidant. The method shows high efficiency, environmental friendliness and mild reaction conditions, without the addition of a photosensitizer. This journal is the Partner Organisations 2014.
Jiang, Min,Li, Yong,Yang, Haijun,Zong, Ruilong,Jin, Yunhe,Fu, Hua
p. 12977 - 12980
(2014/04/03)

Metal-free oxidation of aromatic carbon-hydrogen bonds through a reverse-rebound mechanism
Methods for carbon-hydrogen (C-H) bond oxidation have a fundamental role in synthetic organic chemistry, providing functionality that is required in the final target molecule or facilitating subsequent chemical transformations. Several approaches to oxidizing aliphatic C-H bonds have been described, drastically simplifying the synthesis of complex molecules. However, the selective oxidation of aromatic C-H bonds under mild conditions, especially in the context of substituted arenes with diverse functional groups, remains a challenge. The direct hydroxylation of arenes was initially achieved through the use of strong Bronsted or Lewis acids to mediate electrophilic aromatic substitution reactions with super-stoichiometric equivalents of oxidants, significantly limiting the scope of the reaction. Because the products of these reactions are more reactive than the starting materials, over-oxidation is frequently a competitive process. Transition-metal-catalysed C-H oxidation of arenes with or without directing groups has been developed, improving on the acid-mediated process; however, precious metals are required. Here we demonstrate that phthaloyl peroxide functions as a selective oxidant for the transformation of arenes to phenols under mild conditions. Although the reaction proceeds through a radical mechanism, aromatic C-H bonds are selectively oxidized in preference to activated-H bonds. Notably, a wide array of functional groups are compatible with this reaction, and this method is therefore well suited for late-stage transformations of advanced synthetic intermediates. Quantum mechanical calculations indicate that this transformation proceeds through a novel addition-abstraction mechanism, a kind of 'reverse-rebound' mechanism as distinct from the common oxygen-rebound mechanism observed for metal-oxo oxidants. These calculations also identify the origins of the experimentally observed aryl selectivity.
Yuan, Changxia,Liang, Yong,Hernandez, Taylor,Berriochoa, Adrian,Houk, Kendall N.,Siegel, Dionicio
p. 192 - 196
(2013/08/23)

The rearrangement of tert -butylperoxides for the construction of polysubstituted furans
The Bronsted acid catalyzed rearrangement of tert-butyl peroxides provides a new strategy to construct 2,3-disubstituted furans via 1,2-aryl migration. In addition, tert-butyl peroxides could also be transformed into 2,3,5-trisubstituted or 2,5-disubstituted furans through a sequence of base-catalyzed Kornblum-DelaMare rearrangements and acid-promoted Paal-Knorr reactions.
Zheng, Xiaojian,Lu, Shenglin,Li, Zhiping
supporting information
p. 5432 - 5435
(2013/11/19)

Improved efficiency and product selectivity in the photo-Claisen-type rearrangement of an aryl naphthylmethyl ether using a microreactor/flow system
Ultraviolet (UV) irradiation of 2-[(2,4,6-trimethylphenoxy)methyl]-1- (methoxycarbonyl)naphthalene promotes a photochemical reaction that gives a cyclohexa-2,4-dienone product arising from a photo-Claisen-type ortho-rearrangement and a phenol derivative arising from a meta-rearrangement, along with 1-methoxycarbonyl-2-methylnaphthalene and 1,2-bis[1-(methoxycarbonyl) naphthalen-2-yl]ethane. When this process is carried out in a microreactor/flow system, its efficiency is dramatically enhanced and selectivity of products is improved. The effects on efficiency and product selectivity caused by the microreactor/flow system are attributed to more efficient light absorption and the suppression of secondary reactions.
Maeda, Hajime,Nashihara, Satoshi,Mukae, Hirofumi,Yoshimi, Yasuharu,Mizuno, Kazuhiko
p. 301 - 310
(2013/02/25)

Pd2dba3/Bippyphos: A robust catalyst system for the hydroxylation of aryl halides with broad substrate scope
A mixture of tris(dibenzylideneacetone)dipalladium(0) (Pd 2dba3) and 5-(di-tert-butylphosphino)-1′,3′, 5′-triphenyl-1′H-[1,4′]bipyrazole (Bippyphos) is shown to be a robust and efficient catalyst system for the hydroxylation of structurally diverse (hetero)aryl halides under mild conditions and with broad substrate scope. Included in this reactivity survey is the successful synthesis of substituted benzofurans and related heteroatomic derivatives, which are formed via the hydroxylation of 2-haloalkynylarenes. Notably, a significant number of the reactions reported herein proceed at room temperature, and we have demonstrated that it is possible to conduct reactions on the benchtop under air using unpurified solvents with negligible loss in reactivity versus related transformations conducted under inert atmosphere conditions. We also report herein the first crystallographically characterized (Bippyphos)Pd(II) complex, which confirms the ability of this synthetically useful ligand to adopt a bidentate binding motif in a manner similar to Buchwald's biarylphosphine ligand class. Copyright
Lavery, Christopher B.,Rotta-Loria, Nicolas L.,McDonald, Robert,Stradiotto, Mark
supporting information
p. 981 - 987
(2013/05/08)

Application of SO3H silica gel to deprotection of silyl ethers
A newly developed SO3H silica gel cleaved the O-Si bonds in various aryl and alkyl silyl ethers to give the corresponding phenols and alcohols in good to excellent yield. The crude filtrates contained no silyl residues. The solid phase 29Si NMR analyses of the SO3H silica gel strongly suggested that the silyl residues were captured by silanol groups on the surface of the silica gel. The SO3H silica gel could be recycled at least ten times without any loss of activity. The disappearance of silyl residues in the crude filtrate was observed in even the 10th repetition. Our method provides an easily handled desilylation method that requires no further purification. Our method was also applicable to a selective desilylation reaction of a derivative 5 with different siloxy groups or desilylation of an alkaloid derivative 7.
Fujii, Hideaki,Yamada, Takaaki,Hayashida, Kohei,Kuwada, Miki,Hamasaki, Atom,Nobuhara, Kazunori,Ozeki, Sumio,Nagase, Hiroshi
p. 2685 - 2691
(2013/01/15)

A heterogenized vanadium oxo-aroylhydrazone catalyst for efficient and selective oxidation of hydrocarbons with hydrogen peroxide
A hydrazone Schiff base ligand derived from salicylaldehyde and benzhydrazide has been synthesized and reacted with vanadium(IV) leading to the corresponding vanadium(V) complex. The complex has been anchored on the surface of functionalized silica gel by N,O-coordination to the covalently Si-O bound modified salicylaldiminato ligand. The supported complex has been evaluated as a catalyst for hydrocarbon oxidation with hydrogen peroxide in acetonitrile. The heterogeneous system proved to be an efficient catalyst and was able to activate hydrogen peroxide toward the oxidation of alkenes, alkanes, benzene, and alkylaromatic compounds with more than 2,500 h-1 activity. Springer Science+Business Media B.V. 2011.
Monfared, Hassan Hosseini,Abbasi, Vahideh,Rezaei, Adineh,Ghorbanloo, Massomeh,Aghaei, Alireza
experimental part
p. 85 - 92
(2012/08/28)

Unexpected phenol production from arylboronic acids under palladium-free conditions; Organocatalyzed air oxidation
An intriguing class of quinones that efficiently catalyze the air oxidation (overall hydroxylation) of arylboronic acids to the corresponding phenol is reported. Autocatalysis in the parent system is particularly efficient and leads to rapid, quantitative synthesis of quinones such as 4 from boronic acid 1 at room temperature using air as stoichiometric oxidant. The efficiency results from a balance between two-stage conjugate addition and migration with each step driven by aromatization of a naphthalene fragment.
Cammidge, Andrew N.,Goddard, Victoria H. M.,Schubert, Christopher P. J.,Gopee, Hemant,Hughes, David L.,Gonzalez-Lucas, Daniel
scheme or table
p. 6034 - 6037
(2012/01/06)

Green catalysts derived from agricultural and industrial waste products: The preparation of phenols from CsOH and Aryl iodides using CuO on mesoporous silica
The synthesis of CuO catalysts supported on mesoporous silica derived from rice husks and semiconductor copper from chemical mechanical planarization (Cu-CMP) wastewater is described. These catalysts are active for the coupling reaction of CsOH with aryl iodides. Low catalyst loading (1 mol-%) without the need for ancillary ligands make these very attractive "green" catalysts. The synthesis of CuO catalysts supported on mesoporous silica derived from rice husks and semiconductor copper from chemical mechanical planarization (Cu-CMP) wastewater is described. These catalysts are active for the coupling reaction of CsOH with aryl iodides. Low catalyst loading (1 mol-%) without the need for ancillary ligands make these very attractive "green" catalysts. Copyright
Chan, Chien-Ching,Chen, Yan-Wun,Su, Chi-Shen,Lin, Hong-Ping,Lee, Chin-Fa
experimental part
p. 7288 - 7293
(2012/01/06)

Study of selectivity of metal phosphates and phosphonates in Baeyer-Villiger oxidations
Layered materials including metal phosphates and phosphonates have been widely investigated in several fields acting as good selective catalysts in a great number of oxidative reactions. Zirconium phosphate amorphous [Zr(HPO 4)2?H2O; ZrPA], sodium exchanged zirconium phosphate amorphous [Zr(NaPO4)2; NaZrPA], potassium exchanged zirconium phosphate amorphous [Zr(KPO4)2; KZrPA], zirconium phenylphosphonate amorphous [Zr(O3PC 6H5)2; ZrPPA], zirconium carboxyethylphosphonate [Zr(O3PCH2CH2COOH) 2; ZrCEP] and aluminium carboxyethylphosphonate [Al 3(OH)3(O3PCH2CH2CO 2)2?3H2O; AlCEP] were prepared, characterized and evaluated as selective catalysts in the Baeyer-Villiger oxidation of cyclopentanone, p-methoxybenzaldehyde and 2,4,6- trimethylbenzaldehyde by hydrogen peroxide, in acetic acid. The selectivity of δ-valerolactone, p-methoxyphenol and 2,4,6-trimethylphenol have been found to be strongly related with the properties and structure of each catalyst. Graphical Abstract: The selectivity of zirconium phosphate amorphous [Zr(HPO4)2?H2O; ZrPA], sodium exchanged zirconium phosphate amorphous [Zr(NaPO4)2; NaZrPA], potassium exchanged zirconium phosphate amorphous [Zr(KPO4) 2; KZrPA], zirconium phenylphosphonate amorphous [Zr(O 3PC6H5)2; ZrPPA], zirconium carboxyethylphosphonate [Zr(O3PCH2CH2COOH) 2; ZrCEP] and aluminium carboxyethylphosphonate [Al 3(OH)3(O3PCH2CH2CO 2)2?3H2O; AlCEP] was evaluated in the Baeyer-Villiger oxidation of cyclopentanone, p-methoxybenzaldehyde and 2,4,6-trimethylbenzaldehyde by hydrogen peroxide, in acetic acid. Different selectivities have been found which were correlated with the properties and structure of each compound.
Rocha, Graca M. S. R. O.,Santos, Teresa M.,Bispo, Claudia S. S.
experimental part
p. 100 - 110
(2011/10/05)