- Asymmetric Catalytic Alkylation of 4-Chlorophenylacetic Acid
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Using N-(monoalkyl)-α,β-diphenyl-β-hydroxy ethylamine as chiral ligands, 46.2percent enantiomeric excess was obtained in the asymmetric catalytic alkylation of 4-chlorophenylacetic acid.
- Mi, A. Q.,Wang, Z. Y.,Jiang, Y. Z.
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Read Online
- α-thiocyanation of carbonyl and β-dicarbonyl compounds using (dichloroiodo)benzene-lead(II) thiocyanate
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The combination reagent (dichloroiodo)benzene and lead(II) thiocyanate in dichloromethane effects oxidation of various enol silyl ethers, ketene silyl acetals, and β-dicarbonyl compounds, thereby providing an efficient and convenient method for α-thiocyanation of carbonyl and β-dicarbonyl compounds.
- Prakash,Kaur,Batra,Rani,Singh,Moriarty
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Read Online
- Visible-Light-Enabled Carboxylation of Benzyl Alcohol Derivatives with CO2 Using a Palladium/Iridium Dual Catalyst
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A highly efficient carboxylation of benzyl alcohol derivatives with CO2 using a palladium/iridium dual catalyst under visible-light irradiation was developed. A wide range of benzyl alcohol derivatives could be employed to provide benzylic carboxylic acids in moderate to high yields. Mechanistic studies indicated that the oxidative addition of benzyl alcohol derivatives was possibly the rate-determining-step. It was also found that a switchable site-selective carboxylation between benzylic C?O and aryl C?Cl moieties could be achieved simply by changing the palladium catalyst.
- Iwasawa, Nobuharu,Jin, Yushu,Toriumi, Naoyuki
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- Alkali-modified heterogeneous Pd-catalyzed synthesis of acids, amides and esters from aryl halides using formic acid as the CO precursor
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To establish an environmentally friendly green chemical process, we minimized and resolved a significant proportion of waste and hazards associated with conventional organic acids and molecular gases, such as carbon monoxide (CO). Herein, we report a facile and milder reaction procedure, using low temperatures/pressures and shorter reaction time for the carboxyl- and carbonylation of diverse arrays of aryl halides over a newly developed cationic Lewis-acid promoted Pd/Co3O4catalyst. Furthermore, the reaction proceeded in the absence of acid co-catalysts, and anhydrides for CO release. Catalyst reusability was achievedviascalable, safer, and practical reactions that provided moderate to high yields, paving the way for developing a novel environmentally benign method for synthesizing carboxylic acids, amides, and esters.
- Fapojuwo, Dele Peter,Maqunga, Nomathamsanqa Prudence,Meijboom, Reinout,Mogudi, Batsile M.,Molokoane, Pule Petrus,Onisuru, Oluwatayo Racheal,Oseghale, Charles O.
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p. 26937 - 26948
(2021/08/17)
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- Method for preparing carboxylic acid by one-pot method
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The invention discloses a method for preparing carboxylic acid by a one-pot method, which comprises the steps of carrying out a Corey-Fuchs process on 1,1-dibromo olefin under the action of n-butyllithium, reacting with isopropanol pinacol borate, quenching with hydrogen chloride, oxidizing with an oxidant, separating and purifying to obtain carboxylic acid. The method disclosed by the invention is a one-pot preparation method, is simple and convenient to operate, does not need to use metal catalysis, uses cheap and easily available reagents for reaction, is green and environment-friendly, hasmild reaction conditions and wide substrate applicability, and provides a new way for rapidly preparing a series of carboxylic acids containing different functional groups.
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Paragraph 0051-0055
(2021/01/29)
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- Desulfonylative Electrocarboxylation with Carbon Dioxide
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Electrocarboxylation of organic halides is one of the most investigated electrochemical approaches for converting thermodynamically inert carbon dioxide (CO2) into value-added carboxylic acids. By converting organic halides into their sulfone derivatives, we have developed a highly efficient electrochemical desulfonylative carboxylation protocol. Such a strategy takes advantage of CO2as the abundant C1 building block for the facile preparation of multifunctionalized carboxylic acids, including the nonsteroidal anti-inflammatory drug ibuprofen, under mild reaction conditions.
- Zhong, Jun-Song,Yang, Zi-Xin,Ding, Cheng-Lin,Huang, Ya-Feng,Zhao, Yi,Yan, Hong,Ye, Ke-Yin
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supporting information
p. 16162 - 16170
(2021/09/02)
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- Pd(OH)2/C, a Practical and Efficient Catalyst for the Carboxylation of Benzylic Bromides with Carbon Monoxide
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A simple, efficient, cheap, and broadly applicable system for the carboxylation of benzylic bromides with carbon monoxide and water is reported. Upon simple reaction with only 2.5 wt % of Pearlman's catalyst and 10 mol % of tetrabutylammonium bromide in tetrahydrofuran at 110 °C for 4 h, a range of benzylic bromides can be smoothly converted to the corresponding arylacetic acids in good to excellent yields after simple extraction and acid-base wash. The reaction was found to be broadly applicable, scalable, and could be successfully extended to the use of ex situ-generated carbon monoxide and applied to the synthesis of the nonsteroidal anti-inflammatory drug diclofenac.
- Wakuluk-Machado, Anne-Marie,Dewez, Damien F.,Baguia, Hajar,Imbratta, Miguel,Echeverria, Pierre-Georges,Evano, Gwilherm
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p. 713 - 723
(2020/02/04)
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- Oxidation of Alkynyl Boronates to Carboxylic Acids, Esters, and Amides
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A general efficient protocol was developed for the synthesis of carboxylic acids, esters, and amides through oxidation of alkynyl boronates, generated directly from terminal alkynes. This protocol represents the first example of C(sp)?B bond oxidation. This approach displays a broad substrate scope, including aryl and alkyl alkynes, and exhibits excellent functional group tolerance. Water, primary and secondary alcohols, and amines are suitable nucleophiles for this transformation. Notably, amino acids and peptides can be used as nucleophiles, providing an efficient method for the synthesis and modification of peptides. The practicability of this methodology was further highlighted by the preparation of pharmaceutical molecules.
- Li, Chenchen,Li, Ruoling,Zhang, Bing,Zhao, Pei,Zhao, Wanxiang
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supporting information
p. 10913 - 10917
(2020/05/25)
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- Method for converting benzyl borate compounds into phenylacetic acid and derivatives thereof by carbon dioxide
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The invention discloses a method for converting benzyl borate compounds into phenylacetic acid and derivatives thereof by carbon dioxide. The method comprises the steps: dissolving the benzyl borate compounds and an alkali in an organic solvent in the absence of a metal catalyst, introducing carbon dioxide into the reaction system, carrying out a reaction at the temperature of 50-150 DEG C for 3-72 hours, and acidifying to obtain phenylacetic acid or the derivatives thereof. The method is a green, simple and efficient method for synthesizing phenylacetic acid and the derivatives thereof, greenhouse gas carbon dioxide is used as a carbon source in the reaction, no transition metal catalyst is used, and the method is environmentally friendly, economical and high in efficiency.
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Paragraph 0036-0037
(2020/03/06)
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- BF3·OEt2-promoted tandem Meinwald rearrangement and nucleophilic substitution of oxiranecarbonitriles
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Tandem Meinwald rearrangement and nucleophilic substitution of oxiranenitriles was realized. Arylacetic acid derivatives were readily synthesized from 3-aryloxirane-2-carbonitriles with amines, alcohols, or water in the presence of boron trifluoride under microwave irradiation, and the designed synthetic strategy includes introducing a cyano leaving group into arylepoxides and capturing the in situ generated toxic cyanide with boron trifluoride, making the reaction efficient, safe, and environmentally benign. The reaction occurs through an acid-promoted Meinwald rearrangement, producing arylacetyl cyanides, followed by an addition-elimination process with nitrogen or oxygen-containing nucleophilic amines, alcohols or water. The current method provides a new application of the tandem Meinwald rearrangement.
- Xu, Chuangchuang,Xu, Jiaxi
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p. 127 - 134
(2019/12/26)
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- Preparation method of phenylacetic acid type compound
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The invention discloses a preparation method of a phenylacetic acid type compound. The preparation method of the phenylacetic acid type compound I comprises the following steps that in a solvent and aCO gas phase system, a benzyl halide type compound II, pyridine-2-cobalt carboxylate, palladium acetate and alkaline neutralizers take carbonylation reaction to obtain the phenylacetic acid type compound I. A mixed catalytic system has a synergistic effect; the whole use quantity of catalysts is greatly reduced. When the mixed catalyst is used, a better catalytic effect can be achieved; the characteristics of easily obtaining the catalyst, avoiding the production safety risk of toxic three wastes and the like, reducing the reaction pressure, realizing mild reaction conditions, reducing the production risk, facilitating the production and the like are realized. The formulas are shown in description.
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Paragraph 0070-0082; 0095-0103
(2019/02/21)
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- Carboxylation of benzylic and aliphatic C-H bonds with CO2 induced by light/ketone/nickel
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A photoinduced carboxylation reaction of benzylic and aliphatic C-H bonds with CO2 is developed. Toluene derivatives capture gaseous CO2 at the benzylic position to produce phenylacetic acid derivatives when irradiated with UV light in the presence of an aromatic ketone, a nickel complex, and potassium tert-butoxide. Cyclohexane reacts with CO2 to furnish cyclohexanecar-boxylic acid under analogous reaction conditions. The present photoinduced carboxylation reaction provides a direct access from readily available hydrocarbons to the corresponding carboxylic acids with one carbon extension.
- Ishida, Naoki,Masuda, Yusuke,Imamura, Yuuya,Yamazaki, Katsushi,Murakami, Masahiro
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supporting information
p. 19611 - 19615
(2019/12/24)
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- Preparation method of acid with different substituent groups
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The invention discloses a preparation method of an acid with different substituent groups. A terminal alkyne is lithiated with n-butyllithium, and then reacts with isopropoxyboronic acid pinacol ester, hydrogen chloride is added to achieve quenching, then the obtained reaction product is oxidized by an oxidizing agent, and the oxidized reaction product is separated and purified to obtain the acid.The method of the invention has the advantages of simplicity in operation, one-pot process preparation, no metal catalysis, nontoxic reagents, greenness, environmental friendliness and high atomic utilization rate, and provides a novel and quick way for preparing the acid with different substituent groups; and the obtained acid is an important fine chemical product, and can be widely used in fields of medicines, pesticides, spices and other industries.
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Paragraph 0139-0143
(2019/10/23)
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- An improved method for the synthesis of phenylacetic acid derivatives via carbonylation
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2,4-Dichlorophenylacetic acid is synthesized in high yield via the carbonylation of 2,4-dichlorobenzyl chloride, and various experimental conditions are evaluated. Xylene, bistriphenylphosphine palladium dichloride, tetraethylammonium chloride and sodium hydroxide in solution are added to the reaction system and held at 80 °C under a CO atmosphere. 2,4-Dichlorophenylacetic acid is obtained in a maximum yield of 95percent, and a mechanism for 2,4-dichlorobenzyl chloride carbonylation is proposed. The reaction system provides a mild, effective and novel means by which to prepare phenylacetic acid derivatives from their corresponding benzyl chloride derivatives.
- Li, He,Zhang, Yijun,Liu, Dinghua,Liu, Xiaoqin
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p. 548 - 552
(2019/11/13)
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- A General, Activator-Free Palladium-Catalyzed Synthesis of Arylacetic and Benzoic Acids from Formic Acid
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A new catalyst for the carboxylative synthesis of arylacetic and benzoic acids using formic acid (HCOOH) as the CO surrogate was developed. In an improvement over previous work, CO is generated in situ without the need for any additional activators. Key to success was the use of a specific system consisting of palladium acetate and 1,2-bis((tert-butyl(2-pyridinyl)phosphinyl)methyl)benzene. The generality of this method is demonstrated by the synthesis of more than 30 carboxylic acids, including non-steroidal anti-inflammatory drugs (NSAIDs), under mild conditions in good yields.
- Wang, Lin,Neumann, Helfried,Beller, Matthias
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supporting information
p. 6910 - 6914
(2018/06/04)
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- Ruthenium-catalyzed umpolung carboxylation of hydrazones with CO2
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The first ruthenium-catalyzed umpolung carboxylation of hydrazones with CO2 to generate important aryl acetic acids is reported. Besides aldehyde hydrazones, a variety of ketone hydrazones, which have not been successfully applied in previous umpolung reactions with other reactive electrophiles, also show high reactivity and selectivity under mild conditions. Moreover, this operationally simple protocol features good functional group tolerance, is readily scalable, and offers easy derivation of important structures, including bioactive felbinac and adiphenine. Computational studies reveal that this umpolung reaction proceeds through the generation of a Ru-nitrenoid followed by concerted [4 + 2] cycloaddition with CO2.
- Yan, Si-Shun,Zhu, Lei,Ye, Jian-Heng,Zhang, Zhen,Huang, He,Zeng, Huiying,Li, Chao-Jun,Lan, Yu,Yu, Da-Gang
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p. 4873 - 4878
(2018/06/07)
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- Microchannel reactor-based cyano hydrolysis reaction method
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The invention discloses a microchannel reactor-based cyano compound hydrolysis reaction method, and particularly, a compound comprising a cyano group in the molecule has the cyano hydrolysis reactionby using a microchannel reactor under the action of alkaline or acid-alkaline substances. By using the microchannel reactor in the process, the raw material is instantaneously evenly mixed and efficiently transfers heat; the most important danger of rushing of the material in the production process, caused by hydrolysis of the cyano compound through the alkali, is avoided; meanwhile, the equivalence ratio of the raw material in the reaction process is also reduced; the side reaction is reduced; the reaction time is shortened to dozens of minutes or even dozens of seconds. In a word, the process improves the operation safety of the reaction, the safe enlarged production of the cyano compound is realized, the time for the hydrolysis reaction of the cyano compound is shortened, the reaction selectivity and the reaction efficiency are improved, the energy consumption of the production is reduced, the use ratio of the raw material is increased, the production process is more environmentallyfriendly, the production cost is low, meanwhile, the used equipment occupies a small area, the production capacity of the equipment is high, and the production efficiency and the production capacityare greatly improved.
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Paragraph 0089-0098
(2018/08/04)
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- A phenylacetic acid compound preparation method (by machine translation)
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The invention relates to the field of chemical synthesis, in particular relates to a preparation method of the compound of phenylacetic acid. The present invention provides a preparation method of the compound of phenylacetic acid, the acid compounds of the structural formula states the benzene second grade shown in formula I, the preparation method comprises the following steps: (1) diazo addition reaction: formula II compound containing vinylidene chloride, acid, diazotization reagent, phase transfer catalyst and a copper catalyst in the system of the formula III compound: (2) hydrolysis reaction: the compound of formula III in the presence of acid hydrolysis of formula I compounds. The present invention provides a preparation method of and is simple, easy operation, low cost of raw materials, mild reaction conditions, low risk, does not need to use expensive noble metal catalyst and complex industrial operation means, the product quality is stable, therefore easy achievement of large-scale industrial production. (by machine translation)
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Paragraph 0104
(2018/03/01)
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- Preparation method of phenylacetic acid compound
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The invention provides a preparation method of a phenylacetic acid compound. The method includes the steps of: subjecting a benzyl chloride compound to carbonylation under an assistant condition; and then adjusting the pH value to obtain a phenylacetic acid compound. Compared with other methods, the method provided by the invention has the advantages of easily available and cheap raw materials, high production efficiency, greatly alleviated environmental pollution and low cost, also improves the conversion rate, can acquire high purity product (with GC being greater than 99%), and the yield is about 90%. Therefore, the preparation method is convenient for industrial production.
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Paragraph 0072-0075; 0076-0079; 0080-0083; 0084-0087
(2017/08/28)
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- Regio- and Stereoselective Oxidation of Styrene Derivatives to Arylalkanoic Acids via One-Pot Cascade Biotransformations
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Green and selective oxidation methods are highly desired in chemical synthesis and manufacturing. In this work, we have developed a biocatalytic method for the regio- and stereoselective oxidation of styrene derivatives into arylacetic and (S)-2-arylpropionic acids via a one-pot epoxidation–isomerization–oxidation sequence. This was done via the engineering of Escherichia coli (StyABC-EcALDH) coexpressing styrene monooxygenase (SMO), styrene oxide isomerase (SOI) and aldehyde dehydrogenase (EcALDH) as an active and easily available whole-cell catalyst. Regioselective oxidation of styrene and 11 substituted styrenes using the E. coli cells was performed in a one-pot set-up, producing 12 phenylacetic acids in both high conversion and high yield. Engineering of E. coli (StyABC-ADH9v1) coexpressing SMO, SOI and ADH9v1 (a mutated alcohol dehydrogenase) led to biocatalysts capable of regio- and stereoselective oxidation of α-methylstyrene derivatives to the corresponding chiral acids. One-pot asymmetric synthesis of 4 (S)-2-arylpropionic acids was achieved in good conversion and excellent ee with the E. coli cells. This is a new type of asymmetric alkene oxidation to give chiral acids with no chemical counterpart thus far. The cascade bio-oxidation operates under mild conditions, uses molecular oxygen, exhibits very high regio- and enantioselectivity, and gives high conversion, thus providing a green and efficient method for the synthesis of arylacetic acids and (S)-2-arylpropionic acids directly from easily available styrenes. (Figure presented.).
- Wu, Shuke,Zhou, Yi,Seet, Daniel,Li, Zhi
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p. 2132 - 2141
(2017/06/23)
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- Metal-free, catalytic regioselective oxidative conversion of vinylarenes: A mild approach to phenylacetic acid derivatives
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A new synthetic approach towards the synthesis of phenylacetic acids from aromatic alkenes has been developed for the first time under mild conditions by employing non-toxic reagents such as molecular iodine and oxone. This metal-free catalytic regioselective oxygenation of vinylarenes proceeds via tandem iodofunctionalization/de-iodination induced rearrangement.
- Kodumuri, Srujana,Peraka, Swamy,Mameda, Naresh,Chevella, Durgaiah,Banothu, Rammurthy,Nama, Narender
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p. 6719 - 6723
(2016/02/03)
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- Palladium-catalyzed silver-mediated α-arylation of acetic acid: A new approach for the α-arylation of carbonyl compounds
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A new approach for the α-arylation of acetic acid through Pd-catalyzed silver-mediated direct C-H arylation of acetic acid with aryl iodides was developed. This protocol provided a straightforward method for the synthesis of a diverse set of α-phenylacetic acids. Palladium served on a silver platter: A new approach for the α-arylation of acetic acid through Pd-catalyzed silver-mediated direct C-H arylation of acetic acid with aryl iodides is presented. This protocol provides a straightforward method for the synthesis of a diverse set of α-phenylacetic acids. Deuteration experiments are performed to help elucidate the reaction mechanism.
- Wu, Guo-Jie,Guan, Jing,Han, Fu-She,Zhao, Yu-Long
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p. 1589 - 1593
(2014/06/24)
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- Proton-exchanged montmorillonite-mediated reactions of methoxybenzyl esters and ethers
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Proton-exchanged montmorillonite (H-mont) was found to be an eco-friendly and cost-effective catalyst for the generation of O-methylated quinone methides (QM) from the corresponding p or o-methoxybenzyl esters and ethers. Nucleophilic trapping of the O-methylated QM with arenes, alcohols, 1,3-dicarbonyl compounds, silyl enol ethers, and allylsilanes has been carried out, respectively, leading to eco-friendly benzylation reactions. Using this protocol, H-mont-mediated deprotection of PMB-protected esters and ethers have been realized for the first time. This work would pave the way for further exploration in O-alkylated QM that are of chemical and biological significance.
- Chen, Dongyin,Xu, Chang,Deng, Jie,Jiang, Chunhuan,Wen, Xiaoan,Kong, Lingyi,Zhang, Ji,Sun, Hongbin
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p. 1975 - 1983
(2014/03/21)
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- An efficient one pot method for synthesis of carboxylic acids from nitriles using recyclable ionic liquid [bmim]HSO4 Dedicated to my mentor Professor (Mrs.) Krishna Misra on her 76th birthday
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Environmentally benign ionic liquid [bmim]HSO4 was found suitable for conversion of nitriles into carboxylic acids under mild conditions with excellent purity.
- Kumar, Satyanand,Dixit, Sandeep Kumar,Awasthi, Satish Kumar
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supporting information
p. 3802 - 3804
(2014/07/07)
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- PROCESS FOR SYNTHESIZING PHENYLACETIC ACID BY CARBONYLATION OF TOLUENE
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A production process for substituted phenylacetic acids or ester analogues thereof is disclosed. In this process toluene or toluene substituted with various substituents, an alcohol, an oxidant and carbon monoxide are used as raw materials to obtain compounds comprising structure of phenylacetic acid ester or analogues thereof by catalysis of the complex catalyst formed from transition metal and ligand, and such compounds are hydrolyzed to obtain various substituted phenylacetic acid based compounds. This type of compounds and their derivatives serve as important fine chemicals used widely in the industries of pharmaceuticals, pesticides, perfume and the like.
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Paragraph 0018; 0062; 0063
(2013/11/19)
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- Highly efficient and selective deprotection method for prenyl, geranyl, and phytyl ethers and esters using borontrifluoride-etherate
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An efficient, simple, and practical method has been developed for the deprotection of prenyl, geranyl, and phytyl ethers and esters of aromatic and aliphatic compounds using borontrifluoride-etherate (BF3· OEt2) at room temperature in good to excellent yields for the first time. Supplemental materials are available for this article. Go to the publisher's online edition of Synthetic Communications to view the free supplemental file. Copyright Taylor & Francis Group, LLC.
- Narender,Venkateswarlu,Madhur,Reddy, K. Papi
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- An efficiently cobalt-catalyzed carbonylative approach to phenylacetic acid derivatives
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A highly efficient cobalt-catalyzed carbonylative approach to phenylacetic acid derivatives under one atmosphere pressure is reported. This methodology represents a useful extension of benzimidazole used as ligand in metal catalysis, and the catalytic mechanism has been proved by computer simulation. Notably, this new cobalt precatalyst, which promotes the carbonylation reaction dramatically and has already been used for scale-up experiment of phenylacetic acid derivatives.
- She, Meng-Yao,Xiao, Da-Wei,Yin, Bing,Yang, Zheng,Liu, Ping,Li, Jian-Li,Shi, Zhen
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p. 7264 - 7268
(2013/08/23)
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- The first synthetic agonists of FFA2: Discovery and SAR of phenylacetamides as allosteric modulators
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Free fatty acid receptor 2 (FFA2) is a G-protein coupled receptor for which only short-chain fatty acids (SCFAs) have been reported as endogenous ligands. We describe the discovery and optimization of phenylacetamides as allosteric agonists of FFA2. These novel ligands can suppress adipocyte lipolysis in vitro and reduce plasma FFA levels in vivo, suggesting that these allosteric modulators can serve as pharmacological tools for exploring the potential function of FFA2 in various disease conditions.
- Wang, Yingcai,Jiao, Xianyun,Kayser, Frank,Liu, Jiwen,Wang, Zhongyu,Wanska, Malgorzata,Greenberg, Joanne,Weiszmann, Jennifer,Ge, Hongfei,Tian, Hui,Wong, Simon,Schwandner, Ralf,Lee, Taeweon,Li, Yang
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scheme or table
p. 493 - 498
(2010/04/26)
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- Pd-catalyzed deoxygenation of mandelate esters
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(Chemical Equation Presented) A new approach to the synthesis of phenylacetic acids and esters has been developed via the palladium-catalyzed deoxygenation of mandelate esters.
- Milne, Jacqueline E.,Murry, Jerry A.,King, Anthony,Larsen, Robert D.
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supporting information; experimental part
p. 445 - 447
(2009/04/10)
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- Development of a one-pot method for the homologation of aldehydes to carboxylic acids
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A highly efficient method is described for the one-carbon homologation of aldehydes to carboxylic acid derivatives employing the reaction of a 1,1-bis-dimethylphosphonate derivative with the aldehyde and controlled acid hydrolysis of the derived α-phosphonoenamine intermediate.
- McNulty, James,Das, Priyabrata
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experimental part
p. 7794 - 7800
(2009/12/26)
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- Exceptionally simple catalytic system for the carbonylation of benzyl halides
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A ligand-less catalytic system, Pd(OAc)2 immobilized in NBu4Hal melt is suggested for the synthesis of arylacetic acids by the carbonylation of benzyl bromides.
- Lapidus, Albert L.,Eliseev, Oleg L.,Bondarenko, Tatyana N.,Chau, Nguen H.,Kazantsev, Ruslan V.
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scheme or table
p. 256 - 257
(2010/01/18)
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- Study of the microwave-assisted hydrolysis of nitriles and esters and the implementation of this system in rapid microwave-assisted Pd-catalyzed amination
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Microwave-assisted hydrolysis of benzonitriles and methyl benzoates has been studied using a toluene/concd aq KOH two phase system in the presence and absence of phase transfer catalyst. Conditions to allow and avoid smooth hydrolysis could be identified. Based on the latter, the first microwave protocol which allows the rapid Pd-catalyzed amination of aliphatic amines with chlorobenzenes containing sensitive functional groups has been developed.
- Van Baelen, Gitte,Maes, Bert U.W.
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p. 5604 - 5619
(2008/09/21)
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- An improved synthesis of α-phosphonoenamines based on a modified Peterson olefination
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An efficient, stereoselective method for the synthesis of α-phosphonoenamines based on a modified Peterson olefination is described. The carbanion derived from isolatable intermediate 2 reacts with aromatic or aliphatic aldehydes selectively eliminating in Peterson fashion to deliver functionally rich α-phosphonoenamines 3. The synthetic utility of these enamines is demonstrated by their hydrolysis yielding the homologous carboxylic acids in good yield.
- McNulty, James,Das, Priyabrata,Gosciniak, Don
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p. 281 - 285
(2008/03/30)
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- 5-SUBSTITUTED QUINAZOLINONE DERIVATIVES AND COMPOSITIONS COMPRISING AND METHODS OF USING THE SAME
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Provided are 5-substituted quinazolinone compounds, and pharmaceutically acceptable salts, solvates, clathrates, stereoisomers, and prodrugs thereof. Methods of use, and pharmaceutical compositions of these compounds are disclosed.
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Page/Page column 66-67
(2010/11/30)
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- Kinetics of Ru(III) catalysed oxidation of phenethyl alcohol and para-substituted phenethyl alcohols by Ce(IV) in aqueous nitric acid medium
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A simple, rapid and sensitive spectroscopic method for the kinetics of Ru(III) catalysed oxidation of phenthyl alcohol(PA) by Ce(IV) in aqueous nitric acid medium has been reported under varying conditions. The reaction is followed spectrophotometrically by measuring the decrease in absorbance of Ce(IV) at 350 nm. The rates show first order dependence on [Ce(IV)] and the rate constants evaluated at different [Ce(IV)] are found to be almost the same. Increase in [Ru(III)] has linear relation with the rate of oxidation and order in [Ru(III)] has been found to be fractional. Variation in ionic strength of the medium has significant effect on the rate of reaction. The rates of the reaction have been measured at different temperatures and the activation parameters for all the substrates computed. The rates decrease in the order - OCH3> -CH3 > -H>-Cl>-NO2 of para substituted phenethyl alcohols. Hammett's plot of log kobs versus σ is found to be valid. The correlation between enthalapies and free energies of activation is reasonably linear with an isokinetic temperature of 425K. The rate constant k obeys corresponding equation, k=Q.e-ΔE#RT,e ΔS#/R Ea increases with introduction of electron-withdrawing groups into the benzene ring. The introduction of electron-releasing groups lowers the Ea for the reaction. Similarly, logA decreases with substitution of electron-withdrawing groups and increases with substitution of electron-releasing groups. A plausible mechanism consistent with the experimental results has been proposed.
- Rao, N. Vijaya Bhaskar,Rao, M. Anand
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- A novel method for synthesis of arylacetic acids from aldehydes, N-(2,3,4,6-tetra-O-pivaloylated-D-glucopyranosyl)amine and trimethylsilylcyanide
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A novel synthetic approach for the preparation of arylacetic acids via the reaction of aldehydes, N-(2,3,4,6-tetra-O-pivaloylated-D-glucopyranosyl)amine and trimethylsilylcyanide was developed, in which the N-(2,3,4,6-tetra-O- pivaloylated-D-glucopyranosyl)amine can be recycled conveniently and reused efficiently.
- Zhou, Guo-Bin,Zhang, Peng-Fei,Pan, Yuan-Jiang
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p. 5671 - 5677
(2007/10/03)
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- A facile synthesis of phenylacetic acids via Willgerodt-Kindler reaction under PTC condition
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Phenylacetic acids are efficiently synthesized from acetophenones via thiomorpholides under Phase Transfer Catalytic (PTC) condition. The reaction proceeds efficiently by using triethyl benzyl ammonium chloride (TEBA) as PTC and the reaction time decreased dramatically upto 1/5th (24-5) to afford pure products in good to excellent yield.
- Alam, Mujahid,Adapa, Srinivas R.
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- An efficient method for one-carbon elongation of aryl aldehydes via their dibromoalkene derivatives
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Various aryl aldehydes were efficiently converted into one-carbon extended aryl acetamides or aryl acetic acids through the reaction of their dibromoalkene derivatives with pyrrolidine in the presence of water under very mild conditions.
- Huh, Dal Ho,Jeong, Ji Sang,Lee, Hee Bong,Ryu, Hoejin,Kim, Young Gyu
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p. 9925 - 9932
(2007/10/03)
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- Microwave-assisted rapid hydrolysis and preparation of thioamides by Willgerodt-Kindler reaction
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Aldehydes and aryl alkyl ketones were efficiently transformed to thioamides with the same number of carbon atoms via Willgerodt-Kindler reaction under microwave irradiation in solvent-free conditions. The thioamides obtained were hydrolyzed to corresponding carboxylic acids with microwave dielectric heating in one minute. Both reactions are very fast and the yields are excellent.
- Matloubi Moghaddam,Ghaffarzadeh
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p. 317 - 321
(2007/10/03)
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- Synthesis, selective aldose reductase inhibitory profile and antihyperglycaemic potential of certain parabanic acid derivatives
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Synthesis and aldose reductase inhibitory profile of certain parabanic acid derivatives 1a-p is described. Also, the antihyperglycaemic potential of these compounds was studied. The most active inhibitors in this series were compounds 1 g, 1p, and 1o which showed inhibitory activity, 36.6, 90 and 91% respectively, at concentration 1 × 10-4. Their IC50 were 2 × 10-6, 7.5 × 10-8 and 5 × 10-8, respectively. Compound 1o exhibited pronounced antihyperglycaemic effect.
- Nabil Aboul-Enein,El-Azzounya,Maklad,Attia,Wiese
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p. 329 - 350
(2007/10/03)
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- Induced thermolysis of tert-butyl phenylperacetates by thiophenol: Simultaneous occurrence of homolysis and single electron transfer
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Thermolysis of tert-butyl phenylperacetates in the presence of thiophenol takes place via dual mechanism. The two-bond homolysis indicates ρH+ = -1.16, testifying to polar transition states. The single electron transfer yields a radical anion intermediate which undergoes fragmentation with ρET = 1.01.
- Sung Soo Kim,Tuchkin,Chun Soo Kim
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p. 7738 - 7740
(2007/10/03)
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- Study of interactive free-energy relationships on ruthenium(III) catalyzed oxidation of phenyl styryl ketone and its substituted analogues by V(V) in acid medium
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Kinetics of Ru(III) catalyzed oxidation of phenyl styryl ketone (PSK) and its substituted analogues by V(V) has been investigated in aqueous acetic acid-sulphuric acid medium in the temperature range 298-313 K. First-order dependence each on [V(V)], [PSK], and [Ru(III)] was observed. Inverse first-order dependence was observed for [V(IV)]. The rate decreased with the increase in dielectric constant (D) of the medium. The rates were enhanced by electron-donating substituents in both the phenyl rings and decreased by electron-with-drawing substituents. Linear Hammett's plots were obtained for various substituents in benzaldehyde moiety of PSK for a given substituent in acetophenone moiety and vice versa. The mechanism proposed envisages formation of Ru(IV) from V(V)+Ru(III) reaction followed by the attack on C double bond O by Ru(IV). Applicability of interactive free-energy relationship has been tested. The cross-interaction constants qx and qy have been determined at different temperatures and possible interpretations discussed.
- Annapoorna,Prasad Rao,Sethuram
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p. 581 - 588
(2007/10/03)
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- Synthesis of phenylacetic acids under rhodium-catalyzed carbonylation conditions
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Benzyl halides are efficiently carbonylated to phenylacetic acids in the presence of a catalytic amount of the dimer of chloro(1,5-cyclooctadiene)rhodium(I) in formic acid. Under these reaction conditions, sensitive functionalities such as esters and nitriles are tolerated and the phenylacetic acids are obtained in good to high yields. (C) 2000 Elsevier Science Ltd.
- Giroux,Nadeau,Han
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p. 7601 - 7604
(2007/10/03)
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- Quinolones as gonadotropin releasing hormone (GnRH) antagonists: Simultaneous optimization of the C(3)-aryl and C(6)-substituents
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A series of 3-arylquinolones was prepared and evaluated for their ability to act as gonadotropin releasing hormone (GnRH) antagonists. A variety of substitution patterns of the 3-aryl substituent are described. The 3,4,5-trimethylphenyl substituent (23h) was found to be optimal. (C) 2000 Elsevier Science Ltd. All rights reserved.
- Young, Jonathan R.,Huang, Song X.,Chen, Irene,Walsh, Thomas F.,DeVita, Robert J.,Wyvratt Jr., Matthew J.,Goulet, Mark T.,Ren, Ning,Lo, Jane,Yang, Yi Tien,Yudkovitz, Joel B.,Cheng, Kang,Smith, Roy G.
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p. 1723 - 1727
(2007/10/03)
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- Media controlled photo - Favorskii type rearrangement of α-chloro acetophenones: Synthesis of phenylacetic acids
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Photolysis of substituted α-chloro acetophenones has been studied in different solvent systems wherein 1,2-aryl migration is found to be media controlled. Effect of substituents on the migratory aptitude and a direct access to phenylacetic acids, in practical yields, has been described.
- Dhavale, Dilip D.,Mali, Vasant P.,Sudrik, Surendra G.,Sonawane, Harikisan R.
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p. 16789 - 16794
(2007/10/03)
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- An in-depth study of the biotransformation of nitriles into amides and/or acids using Rhodococcus rhodochrous AJ270
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A variety of aliphatic, aromatic and heterocyclic nitriles have been readily hydrolysed into the corresponding amides and/or acids under very mild conditions using Rhodococcus sp. AJ270. The nitrile hydratase involved in this novel nitrile-hydrolysing microorganism efficiently hydrates most nitriles tested, irrespective of the electronic and steric effects of the substituents, to form the amides. Conversion of amides into acids catalysed by the associated amidase is rapid and efficient in most cases. Substrates bearing an adjacent substituent (which may be an ortho substituent on an aromatic nitrile, an adjacent heteroatom in a heterocyclic ring or a geminal substituent in an α,β-unsaturated nitrile) undergo slow hydrolysis of the amides allowing efficient amide isolation. The scope, limitations and reaction mechanism of this enzymatic process have been systematically studied. A molecular size of >7 A diameter and the presence of functions capable of metal complexation near to the nitrile inhibit hydrolysis.
- Meth-Cohn, Otto,Wang, Mei-Xiang
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p. 1099 - 1104
(2007/10/03)
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- Rat hepatic microsomal aldehyde dehydrogenase. Identification of 3- and 4-substituted aromatic aldehydes as substrates of the enzyme
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The rat hepatic microsomal aldehyde dehydrogenase (mALDH) metabolizes aliphatic and aromatic aldehydes to the corresponding acids with NAD as the optimal cofactor. However, dehydrogenation of the aliphatic compounds is substantially more efficient. In the present study, a series of aromatic aldehydes was evaluated as substrates of the purified mALDH so that the physicochemical factors that contribute to substrate affinity could be evaluated. Substitution of the aromatic system in the 3- and 4-positions produced relatively good substrates, but 2-substituted congeners did not undergo dehydrogenation. However, aldehydes with hydrophilic substituents in the 3- or 4-positions and those with extremely bulky substituents at both positions (e.g., 3,4-dibenzyloxy) were also poor substrates for the enzyme and dehydrogenation was undetectable. A quantitative structure-activity relationship was determined that related the logarithm of the Michaelis constants for 27 substituted aromatic aldehydes with the zero-order connectivity function of the molecule (0χ), the shapes of the 3-and 4-substituents (κ), and the electronic nature of the 4-substituent (σ). In this equation, 81% of the data variance was explained. From a consideration of the dimensions of 3-phenoxybenzaldehyde, which was a relatively good substrate, the mALDH possesses a narrow cleft within the active site that is at least 7.5 A wide and extends at least 12 A from the the catalytic residue (probably cysteine). Previously established relationships between connectivity functions and molecular polarizability suggest that dipolar interactions within the active site, as well as dispersion forces, may play a role in substrate specificity. Although optimal shapes for carbocyclic substituents were not provided by the analysis, the unfavorable effect on dehydrogenation from hydrophilic and large substituents suggests that the active site of the mALDH is relatively rigid and that the orientation of the substrate in relation to the catalytic cysteine and the cofactor binding site is critical.
- Martini, Robert,Murray, Michael
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p. 268 - 276
(2007/10/03)
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- Dihydropyridazinones, pyridazinones and related compounds as fungicides
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This invention relates to substituted dihydropyridazinones, pyridazinones and related compounds, of the formula STR1 wherein A, Q, D and R1 are as defined within, compositions containing these compounds and methods of controlling agricultural and mammalian fungal diseases.
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- Electronic Substituent Effects in the Nitrilase-Catalyzed Hydrolysis of Para-Substituted Benzyl Cyanides
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The initial rates of the nitrilase (Novo)-catalyzed hydrolysis of a series of para-substituted benzyl cyanides (R = NO2, Cl, OCH3, OH, NH2) were found to be susceptible to the nature of the para-substituent of the substrate and a Hammett-type linear free energy correlation was observed with ρ = 0.96.In a separate study, effective solubilization of substituted benzyl cyanide substrates having electron-donating groups (OH, NH2, OCH3) was achieved upon mixing with β-cyclodextrin to form 1:1 mol ratio inclusion complexes, but para-substituted benzyl cyanides with electron-withdrawing groups (Cl, NO2) were not fully solubilized under the same conditions.In addition, it was shown that the presence of β-cyclodextrin not only had no inhibitory effect on the enzyme activity, but it actually increased the initial rate of hydrolysis of the unsubstituted benzyl cyanide:β-cyclodextrin inclusion complex.However, the initial rates of hydrolysis were observed to be smaller when β-cyclodextrin was added to the para-substituted benzyl cyanides.
- Geresh, Shimona,Giron, Yakir,Gilboa, Ygal,Glaser, Robert
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p. 10099 - 10102
(2007/10/02)
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- A Practical O2-Oxidation of Functionalized Alcohols Producing Carboxylic Acids Catalyzed by the Pd-C/Pb(OAc)2 System
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The Pd-C/Pb(OAc)2 system catalyzes selective O2-oxidation of ArCH(R)CH2OH to ArCH(R)COOH (useful intermediates for drug synthesis) in high yields without contamination of ArCOOH.The turnover number (substrate/Pd) is improved to 85 and > 1800 by recycling the catalyst and using a special reactor, respectively.Alkanols are also efficiently oxidized to alkanoic acids by the title catalyst system.
- Akada, Mitsuo,Nakano, Shinji,Sugiyama, Toshiyuki,Ichitoh, Kazumoto,Nakao, Hiroki,et al.
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p. 1511 - 1515
(2007/10/02)
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