- Phosphorous acid-catalyzed alkylation of phenols with alkenes
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A H3PO3-catalyzed alkylation of phenols with alkenes is achieved in a facile, efficient, and selective manner. The reaction shows a unique selectivity, i.e., excellent regioselectivity, thorough suppression of overalkylation, without alkylation of a simple phenyl ring, and can selectively provide ortho-, meta-, or para-alkylated phenol derivatives in good to excellent yields. This feature along with mild reaction conditions, sensitive functional group tolerance, and scale-up synthesis and late modification of phenolic bioactive compounds make it an ideal and practical alternative for the modification of phenols.
- Wu, Shaofeng,Dong, Jianyu,Zhou, Dan,Wang, Wan,Liu, Long,Zhou, Yongbo
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p. 14307 - 14314
(2020/01/31)
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- New approach to the generation of aryldifluoroboranes–prospective acid catalysts of organic reactions
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A new approach for preparation of aromatic and fluoroaromatic difluoroboranes via the interaction between corresponding aryltrifluoroborates and ionic liquids containing tetrachloroaluminate-anion and aluminum chloride has been developed. Catalytic properties of obtained aryldifluoroboranes have been investigated in model reactions of phenols alkylation. The dependence of catalytic properties on both the nature of solvent used and the type of substituents in the aromatic ring of difluoroborane has been established.[Figure presented]
- Shmakov, Mikhail M.,Prikhod'ko, Sergey A.,Bardin, Vadim V.,Adonin, Nicolay Yu.
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p. 369 - 371
(2018/08/10)
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- Metal-Free C-O Bond Functionalization: Catalytic Intramolecular and Intermolecular Benzylation of Arenes
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A catalytic, metal-free intramolecular rearrangement of benzyl phenyl ethers using nitrosonium salt as a catalyst is described. The optimized reaction conditions enabled a catalytic and metal-free Friedel-Crafts alkylation reaction with benzylic alcohols, producing water as the stoichiometric byproduct. A comprehensive scope (>50 examples) for both approaches and application in drug synthesis were demonstrated. Mechanistic studies suggest a Lewis acid-based mechanism for the metal-free Friedel-Crafts reaction.
- Bering, Luis,Jeyakumar, Kirujan,Antonchick, Andrey P.
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supporting information
p. 3911 - 3914
(2018/07/22)
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- Efficient catalyst for hydroarylation reaction of styrene with phenol to obtain high DSP selectivity in mild condition
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Background: Technical mixture of styrenated phenols including mono-, di-, and tristyrenated phenol, has been commonly applied for industrial materials such as rubber or plastic stabilizer, antioxidant, and nonionic surfactant, etc. Among these styrenated phenols, di-styrenated phenol should be most effective as rubber and plastic stabilizers. Although a number of catalysts for the synthesis of styrenated phenols have been explored, researches on the synthesis of styrenated phenol generally have been focused on selective preparation of mono-styrenated phenol MSP, rather than distyrenated phenol DSP. In this paper, we have investigated the hydroarylation reaction of styrene with phenol to find the optimal catalyst, including single catalysts and mixed catalysts, to get high selectivity to DSP under mild reaction conditions. Method: Hydroarylation reactions of styrene with phenol using various single catalysts, such as inorganic acids, organic acids, Lewis acids, and metal salt catalysts, have been conducted. To optimize the reaction conditions, hydroarylation reactions of styrene with phenol employing InCl3 catalyst were carried out with a variety of styrene amount, catalyst amount, reaction time, and reaction temperature. Halogenpromoted hydroarylation reactions of styrene with phenol were investigated in the presence of NBS or I2 as a halogen source and a variety of metal halides as a Lewis acid catalyst. Br-promoted hydroarylation reactions of styrene with phenol were accomplished using InCl3 along with NBS under a variety of NBS amount and reaction temperature. To explore the scope of Br-promoted hydroarylation, the reactions of various styrene derivatives with phenol were carried out using NBS and InCl3. Results: Hydroarylation reactions of styrene with phenol using various single catalysts, such as inorganic acids, organic acids, Lewis acids, and metal salt catalysts, have been conducted. Among 19 catalysts used, best results in both high conversion of phenol and high DSP selectivity are obtained with InCl3 catalyst. Using InCl3, total yield of styrenated phenols is 98% and product selectivity MSP/DSP/ TSP is 20/65/13. When InCl3 as an optimal catalyst was applied for the hydroarylation reactions of styrene with phenol under various reaction conditions, the optimal reaction conditions for obtaining a high yield, high DSP, and low MSP are as follows: styrene/phenol = 2 molar ratio, catalyst/phenol = 0.1 molar ratio, reaction time 6 hours, reaction temperature 120°C. In the halogen-promoted hydroarylation reactions of styrene with phenol in the presence of NBS or I2 as a halogen source and various metal halides as a Lewis acid catalyst, best yield (99%) and DSP selectivity (MSP/DSP/ TSP=13/42/41) were obtained using NBS and InCl3. The optimal reaction condition for Br-promoted hydroarylation reaction was found to be phenol 1 eq., styrene 2 eq., InCl3 0.04 eq., NBS 1 eq., 4 hours reaction time, room temperature. For the reactions of various styrene derivatives with phenol using NBS and InCl3, the best DSP selectivity was observed for the CH3-substituted styrene derivative. Conclusion: We have developed hydroarylation reaction of styrene with phenol for obtaining a high yield and a high DSP selectivity even at room temperature. Using NBS as a Br source and InCl3 as a catalyst at room temperature, Br-promoted hydroarylation reaction of styrene with phenol yields good results with respect to both yield and DSP selectivity.
- Kim, Vicna,Ju Shin, Eun,Ahn, Hogeun,Chung, Minchul,Jung, Sunghun,Kwak, Wonbong
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p. 139 - 146
(2018/03/06)
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- METHOD OF PREPARING FOR SELECTIVE DI-STYRENATED PHENOL USING ZIRCONIUM OXIDE SOLID ACID CATALYST MANUFACTURED BY BEING IMPREGNATED ZIRCONIUM HYDROXIDE IN SULFURIC ACID AQUEOUS SOLUTION
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The present invention relates to a selective preparation method of di-styrenated phenol represented by chemical formula 1 obtained by making a phenol compound represented by chemical formula 2 react with a styrene monomer in the presence of a zirconium oxide solid acid catalyst prepared by impregnating zirconium hydroxide with an aqueous sulfuric acid solution. In chemical formulas 1 and 2, R_1 and R_2 are each independently selected from hydrogen, a C_1-C_20 alkyl group, a C_1-C_20 alkoxyl group, a C_3-C_30 cycloalkyl group, and a C_6-C_30 aryl group. The selective preparation method according to the present invention can minimize the amount of an unreacted residual material and can dramatically increase selectivity of di-styrenated phenol by exhibiting a high reactivity in the presence of the zirconium oxide solid acid catalyst prepared by impregnating zirconium hydroxide with the aqueous sulfuric acid solution.COPYRIGHT KIPO 2018
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Paragraph 0104; 0105; 0127; 0133; 0137
(2018/04/12)
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- METHOD OF PREPARING FOR SELECTIVE DI-STYRENATED PHENOL USING TITANIUM DIOXIDE SOLID ACID CATALYST
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The present invention relates to a method for producing di-styrenated phenol. More specifically, the present invention relates to a method for selectively producing di-styrenated phenol at high yield using solid titanium dioxide acid catalyst. According to the present invention, since the method for producing di-styrenated phenol ensures high reactivity in the presence of solid titanium dioxide acid catalyst, the method for producing di-styrenated phenol can minimize an amount of unreacted residues while remarkably increasing selectivity of di-styrenated phenol.(AA) Titanium dioxide (Powder form, 20 g)(BB) Titanium dioxide + Sulfuric acid + Distilled water (500 ml)(CC) Stir (Room temperature and 3 hours)(DD) Dry (110anddeg;C, and 12 hours)(EE) Sintering (600anddeg;C, 2 hours, and air atmosphere)(FF) Titanium dioxide solid acid catalyst (SO_4^2-/TiO_2) (Sulfuric acid : 5 wt%)COPYRIGHT KIPO 2017
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Paragraph 0030-0031; 0113-0114; 0117
(2017/05/16)
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- METHOD FOR MANUFACTURING STYRENATED PHENOL
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The present invention relates to a method for producing styrenated phenol which is represented by chemical formula 1. According to an embodiment of the present invention, provided is a method for producing styrenated phenol, which comprises the following steps: a step (a) for carrying out a reaction between a phenol compound and a styrene compound in the presence of a first acid catalyst; and a step (b) for carrying out a reaction after additionally inserting a styrene compound into a product obtained in the step (A) in the presence of a second acid catalyst. In the chemical formula 1, n refers to an integer of 1-3.COPYRIGHT KIPO 2017
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Paragraph 0065-0067
(2017/06/20)
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- Synthesis and catalytic reactivity of mononuclear substituted tetramethylcyclopentadienyl molybdenum carbonyl complexes
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The reactions of five dinuclear carbonyl complexes [(η 5-C5Me4R)Mo(CO)3]2 [R = allyl, n Bu, t Bu, Ph, Bz] with I2 in chloroform solution gave the corresponding mononuclear substituted tetramethylcyclopentadienyl molybdenum carbonyl complexes [(η 5-C5Me4R)MoI(CO)3] [R = allyl (1), n Bu (2), t Bu (3), Ph (4), Bz (5)]. The molecular structures of complexes 2, 3 and 5 were determined by X-ray diffraction analysis. The results show that the substituent in the ring can directly affect the Mo-I bond distances; the more sterically hindered the substituent, the longer the Mo-I bond. Friedel-Crafts reactions of aromatic compounds with a variety of alkylation reagents catalyzed by the complexes showed that all of these mononuclear molybdenum carbonyl complexes have catalytic activity in Friedel-Crafts alkylation reactions. Indeed, compared with traditional catalysts, these mononuclear metal carbonyl complexes have obvious advantages such as higher activities, mild reaction conditions, high selectivity, simple post-processing, and environmentally friendly chemistry.
- Ma, Zhi-Hong,Lv, Lin-Qian,Wang, Hong,Han, Zhan-Gang,Zheng, Xue-Zhong,Lin, Jin
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p. 225 - 233
(2016/02/20)
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- STYRENATED PHENOLIC COMPOSITION, AND PRODUCTION METHOD THEREFOR
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PROBLEM TO BE SOLVED: To provide a styrenated phenolic composition having high content of tristyrenated phenolic compound and low content of impurities such as a styrene oligomer, and a production method therefor. SOLUTION: There are provided the styrenated phenolic composition containing a specific monostyrenated phenolic compound, a specific distyrenated phenolic compound and a specific tristyrenated phenolic compound and the production method for the styrenated phenolic composition. The styrenated phenolic compound has total content of the monostyrenated phenolic compound, the distyrenated phenolic compound and tristyrenated phenolic compound of 98 mass% or more per 100 mass% of an organic product. The content of the tristyrenated phenolic compound in the styrenated phenolic composition is 80 mass% or more and the content of accessory components is 2 mass% or less including 0. SELECTED DRAWING: Figure 1 COPYRIGHT: (C)2017,JPOandINPIT
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Paragraph 0034-0040
(2017/05/12)
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- Microwave-assisted hydroarylation of styrenes catalysed by transition metal oxide nanoparticles supported on mesoporous aluminosilicates
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Abstract The addition of phenols to styrene to form ortho and para-(1-phenylethyl) phenols was catalysed by a range of metal oxide nanoparticles supported on mesoporous aluminosilicates (M/Al-SBA-15 catalysts) under microwave irradiation. Moderate to excellent yields to products could be obtained at short times of reaction (typically 10 min). 0.5%Fe/Al-SBA-15 as readily available, environmentally friendly and cheap catalysts exhibited remarkable improvements in yield as compared to the majority of utilized catalysts. The heterogeneous catalyst can be reused at least three times without a significant loss in activity.
- Hosseinpour, Reza,Pineda, Antonio,Garcia, Angel,Romero, Antonio A.,Luque, Rafael
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- Organocatalytic asymmetric synthesis of 1,1-diarylethanes by transfer hydrogenation
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A new organocatalytic transfer hydrogenation strategy for the asymmetric synthesis of 1,1-diarylethanes is described. Under mild conditions, a range of 1,1-diarylethanes substituted with an o-hydroxyphenyl or indole unit could be obtained with excellent efficiency and enantioselectivity. We also extended the protocol to an unprecedented asymmetric hydroarylation of 1,1-diarylalkenes with indoles for the synthesis of a range of highly enantioenriched 1,1,1-triarylethanes bearing acyclic all-carbon quaternary stereocenters. These diaryl- and triarylethanes exhibit impressive cytotoxicity against a number of human cancer cell lines. Preliminary mechanistic studies combined with DFT calculations provided important insight into the reaction mechanism.
- Wang, Zhaobin,Ai, Fujin,Wang, Zheng,Zhao, Wanxiang,Zhu, Guangyu,Lin, Zhenyang,Sun, Jianwei
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supporting information
p. 383 - 389
(2015/01/30)
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- Hydroarylation of styrenes with electron-rich arenes over acidic ion-exchange resins
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A series of acidic cation-exchange resins were used for the hydroarylation of resorcinol with styrene, in which resin D072 exhibited the excellent catalytic performance in this reaction with 99% conversion of styrene and 90% selectivity of 4-(1-phenylethyl)resorcinol. It was applied to the hydroarylation of various electron-rich arenes with styrenes, and the hydroarylated products were quantitatively obtained. This catalyst could be used for four consecutive runs with slight decrease in activity. The hydroarylation of resorcinol with styrene over resin D072 in a fixed bed was completed effectively with 94% selectivity and 99% conversion, and this green continuous process is potentially applicable to large-scale productions.
- Wen, Jingyun,Qi, Haofei,Kong, Xiangjin,Chen, Ligong,Yan, Xilong
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p. 1893 - 1903
(2014/07/07)
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- Iron-catalyzed arylation of aromatic ketones and aldehydes mediated by organosilanes
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A simple and efficient iron-catalyzed method for arylation of aromatic carbonyl compounds is reported. The use of 4-% FeCl3 or Fe(acac) 3 as the catalyst, in combination with a slight excess of chlorotrimethylsilane and triethylsilane, chlorination of benzylic ketones and aldehydes with subsequent Friedel-Crafts alkylation of arenes is achieved. Although the method is limited by the general constraints associated with Friedel-Crafts alkylation reactions, robust applications for the synthesis of pharmaceutical intermediates and so on can be envisioned. A robust one-pot, iron-catalyzed chlorination Friedel-Crafts alkylation reaction of benzylic carbonyl compounds, mediated by chlorotrimethylsilane and triethylsilane, has been developed to yield substituted diaryl and triaryl building blocks. Copyright
- Savela, Risto,Majewski, Marcin,Leino, Reko
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p. 4137 - 4147
(2014/07/08)
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- Cationic Iron(III) porphyrin catalyzed dehydrative friedel-crafts reaction of alcohols with arenes
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Alcohols react with arenes in the presence of cationic iron(III) porphyrin catalyst. The reaction involves the formation of the C-C bond via dehydration, which is formal Lewis acid catalyzed Friedel-Crafts reaction. Georg Thieme Verlag Stuttgart, New York.
- Teranishi, Satoru,Kurahashi, Takuya,Matsubara, Seijiro
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supporting information
p. 2148 - 2152
(2013/10/21)
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- Synthesis of diarylmethanes via metal-free reductive cross-coupling of diarylborinic acids with tosyl hydrazones
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This paper describes a practical and efficient procedure that takes advantage of diarylborinic acids as a cost-effective alternative to arylboronic acids for synthesis of diarylmethanes through metal-free reductive cross-coupling with N-tosylhydrazones of aromatic aldehydes and ketones. The procedure tolerates hydroxyl, halide, amine, and allyl functionality, complementary to the transition-metal catalyzed cross-coupling techniques.
- Li, Xijing,Feng, Yuanyuan,Lin, Lin,Zou, Gang
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p. 10991 - 10995
(2013/02/22)
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- H-β-zeolite-catalysed hydroarylation of styrenes
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The hydroarylation of styrenes with various arene(heteroarene) compounds using H-β-zeolite as a green and recyclable heterogeneous catalyst under mild reaction conditions has been developed. The catalyst showed versatility and high selectivity (up to 100a€‰%) of desired 1,1-diarylalkanes in cyclohexane as solvent under the conditions studied. The catalyst could be reactivated by simple treatment with mineral acid at room temperature for better catalytic activity. Hydroarylation of styrenes with variousarene(heteroarene) compounds using H-β-zeolite as a green, heterogeneous and reusable catalyst under mild conditions is reported.
- Mohan, Darapaneni Chandra,Patil, Rajendra D.,Adimurthy, Subbarayappa
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experimental part
p. 3520 - 3525
(2012/07/30)
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- Iron(iii)-based ionic liquid-catalyzed regioselective benzylation of arenes and heteroarenes
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An easily prepared Fe(iii)-derived Lewis acid ionic liquid ([C 4mim][FeCl4]), being comprised of 1-butyl-3-methyl imidazolium cation and tetrachloroferrate anion, was found to be an efficient, recyclable catalyst for benzylation of various arenes/heteroarenes into the diarylmethanes derivatives under mild reaction conditions without utilization of additional organic solvent. Interestingly, the acidity of [C 4mim][FeCl4] could account for its catalytic activity in promoting the Lewis acid-catalyzed alkylation. Notably, this type of Fe(iii)-based ionic liquid (IL) shows excellent stability, and could be easily recovered, and reused for five times without significant loss of its catalytic activity.
- Gao, Jian,Wang, Jin-Quan,Song, Qing-Wen,He, Liang-Nian
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supporting information; experimental part
p. 1182 - 1186
(2011/06/25)
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- Microwave-accelerated alkylation of arenes/heteroarenes with benzylic alcohols using antimony(III) chloride as catalyst: Synthesis of O-heterocycles
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An efficient protocol for alkylation of electron-rich arenes/heteroarenes with benzylic alcohols under microwave irradiation using antimony(III) chloride as catalyst has been developed. The mild reaction conditions, high yields, operational simplicity, and applicability to various substrates render the approach a useful route for the synthesis of diaryl/triarylalkane. In addition, a new route for the conversion of ortho-alkenylated phenols into functionalized O-heterocycles has been accomplished. Georg Thieme Verlag Stuttgart ? New York.
- Shukla, Prashant,Choudhary, Manoj K.,Nayak, Sandip K.
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supporting information; experimental part
p. 1585 - 1591
(2011/08/03)
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- Simple and efficient metal-free hydroarylation and hydroalkylation using strongly acidic ion-exchange resin
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Higly efficient hydroarylation and hydroalkylation of styrenes with various arenes and 1,3-dicarbonyl compounds respectively have been developed using Amberlyst-15 as a heterogeneous catalyst. The excellent yields, short reaction times, and high selectivity are the advantages of this method. The C-H functionalization has been achieved here under metal-free conditions. Copyright
- Das, Biswanath,Krishnaiah, Martha,Laxminarayana, Keetha,Damodar, Kongara,Kumar, D. Nandan
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experimental part
p. 42 - 43
(2009/12/02)
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- A simple catalyst for the efficient benzylation of arenes by using alcohols, ethers, styrenes, aldehydes, or ketones
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The compound [IrCp* (OTf)2(InBu)] (I nBu = 1,3-di-n-butyl-imidazolylidene) is an effective catalyst in the benzylation of arenes with different benzylating agents, such as alcohols, ethers and styrenes, representing an unprecedented highly versatile catalyst for this type of process. The same compound also catalyses a remarkable tandem process that allows the use of aldehydes and ketones as benzylating agents, through the base-free hydrogenation of C=O bonds with iPrOH and further use of the resulting primary or secondary alcohols as benzylating agents.
- Prades, Amparo,Corberan, Rosa,Poyatos, Macarena,Peris, Eduardo
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experimental part
p. 4610 - 4613
(2009/12/26)
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- A novel InCl3/SiO2-catalyzed hydroarylation of arenes with styrenes under solvent-free conditions
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A novel InCl3/SiO2-catalyzed hydroarylation of various styrenes with arenes has been developed. The reaction can be carried out under solvent-free conditions to afford a series of 1,1-diarylalkanes in high yields and with good regioselectivities. The catalyst can be reused six times without obvious loss of catalytic activity. Georg Thieme Verlag Stuttgart.
- Sun, Gaojun,Sun, Huayin,Wang, Zhiyong,Zhou, Ming-Ming
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experimental part
p. 1096 - 1100
(2009/04/04)
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- Highly efficient iodine-catalyzed hydroarylation of arenes with styrenes
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Iodine mediates the hydroarylation of styrenes with arenes and heteroarenes to afford 1,1-diarylalkanes in good to high yields. Details regarding the substrate scope and selectivity of this hydroarylation reaction are discussed.
- Chu, Cheng-Ming,Huang, Wan-Ju,Liu, Ju-Tsung,Yao, Ching-Fa
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p. 6881 - 6885
(2008/02/12)
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- A convenient FeCl3-catalyzed hydroarylation of styrenes
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(Chemical Equation Presented) 1,1-Diarylalkanes are easily synthesized by CH-functionalization reactions of electron-rich arenes and heteroarenes with styrenes in the presence of FeCl3 as catalyst.
- Kischel, Jette,Jovel, Irina,Mertins, Kristin,Zapf, Alexander,Beller, Matthias
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- An efficient and general iron-catalyzed arylation of benzyl alcohols and benzyl carboxylates
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(Chemical Equation Presented) Green grow the diarylmethanes: Substituted arenes and heteroarenes can be easily benzylated in the presence of inexpensive and relatively nontoxic metal salts such as FeCl3 (see scheme). This arylation method with benzyl alcohols is a state-of-the-art green route to diarylmethanes as water is the only by-product.
- Iovel, Irina,Mertins, Kristin,Kischel, Jette,Zapf, Alexander,Beller, Matthias
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p. 3913 - 3917
(2007/10/03)
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- BENZYLPHENOL DERIVATIVES AS ANTIOXIDANTS FOR AUTOXIDATION OF TETRALIN.
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A series of 4-benzylphenols, 2-methyl-4-benzylphenols, 4-methyl-2-benzylphenols and 4-methoxy-2-benzylphenols have been prepared and evaluated as antioxidants for tetralin at 60 degree C by means of an oxygen-absorption method. Very good activities have been observed with a series of 4-methoxy-2-benzylphenols. The electrochemical oxidation potentials of these compounds were determined using linear-sweep voltammetry. The antioxidative activities were found to correlate with both the **1**3C NMR chemical shifts ( delta ) of the ipsocarbon of the OH substituents and their peak potentials (E//p).
- Yamada,Nishiyama,Suzuura,Yamamura
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p. 115 - 119
(2007/10/02)
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- Products of reaction between styrene and some radicals with 2,2-diphenyl-1-picrylhydrazyl
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Addition of 2,2-diphenyl-1-picrylhydrazyl DPPH to styrene at 75 deg C results in little change in the amounts of cis- and trans-1,2-diphenylcyclobutane and 1,2,3,4-tetrahydro-1-phenylnaphthalene, in a slightly smaller amount of 1-phenylnaphthalene, and in a considerable increase in the amount of 1,2-dihydro-1-phenylnaphthalene that are formed.Formation of the styrene trimer 1,2,3,4-tetrahydro-1-phenyl-4-(1-phenylethyl)naphthalene is eliminated completely.Products derived from DPPH are 1-(4-nitrophenyl)-1-phenyl-2-picrylhydrazine 9 and 1--2,2-diphenylhydrazine, 10.DPPH intercepts the thermally formed Diels-Alder dimer of styrene as soon as it is formed to give the 1,2,3,4-tetrahydro-4-phenyl-1-naphthyl radical.Thermolysis of bis(1,2,3,4-tetrahydro-4-phenyl-1-naphthyl)diazene in the presence of DPPH yields 20percent of 10, 10percent of 1--2-(4-nitrophenyl)-2-phenylhydrazine and 9 while thermolysis of 1,2-bis(1-phenylethyl)diazene in the presence of DPPH yields 9 and 44percent of 1--2,2-diphenylhydrazine showing that substituted benzyl radicals efficiently displace the 4-nitro group of DPPH.The nitro group is transferred to an unsubstituted phenyl group of DPPH.
- Kopecky, Karl R.,Hall, Michael C.
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p. 3095 - 3104
(2007/10/02)
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- Process for the production of 2-aryl-2H-benzotriazoles
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A process for the production of 2-aryl-2H-benzotriazoles comprises reducing and cyclizing the corresponding o-nitroazobenzenes with hydrogen at a temperature in the range of about 20° C. to about 100° C. and at a pressure in the range of about 15 psia (1 atmosphere) to about 1000 psia (66 atmospheres) in an alkaline medium at a pH over 10 in the presence of a nickel catalyst, preferably molybdenum-promoted Raney nickel. High yields of pure product are obtained directly with a concomitant reduction of undesired by-product and a reduction in effluent pollution problems.
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- Process for the production of 2-aryl-2H-benzotriazoles
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A process for the production of 2-aryl-2H-benzotriazoles comprises reducing and cyclizing the corresponding o-nitroazobenzenes with carbon monoxide at a temperature in the range of about 20° C. to about 150° C. and at a pressure in the range of about 15 psia (1 atmosphere) to about 1000 psia (66 atmospheres) in an alkaline medium at a pH over 10 in the presence of a copper-amine complex catalyst. High yields of pure product are obtained with a concomitant reduction of undesired by-products and a reduction in effluent pollution problems.
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- Process for the production of 2-aryl-2H-benzotriazoles
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An improved process for the production of 2-aryl-2H-benzotriazoles by the reduction of o-nitroazobenzene intermediates with zinc in alkaline medium comprises employing a ratio of moles of alkali to moles of o-nitroazobenzene intermediate in the range of 0.2-1.7/1 in the presence of less than 150 ppm of iron based on zinc used. The improved process results in higher yields of high purity products with a concomitant reduction in the amount of undesired cleavage amine by-products and a reduction in effluent pollution problems. The process is carried out in a polar/non-polar solvent mixture.
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