- Wolff rearrangement of α-diazoketones using in situ generated silver nanoclusters as electron mediators
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We report Wolff rearrangement of α-diazoketones by in situ generated silver nanoclusters (Agn, 2-4 nm) from silver(I) oxide (Ag 2O) involving a nonclassical electron-transfer process. Our results show that Agn+/Agn0 redox couple allows the initial removal of an electron from α-diazoketone and its back-donation after chemical reaction(s). Controlled potential coulometry (CPC) of various α-diazoketones results in the realization of Wolff-rearranged carboxylic acids in excellent yields.
- Sudrik, Surendra G.,Sharma, Jadab,Chavan, Vilas B.,Chaki, Nirmalya K.,Sonawane, Harikisan R.,Vijayamohanan, Kunjukrishna P.
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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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- Practical and green synthesis of combretastatin A-4 and its prodrug CA4P using renewable biomass-based starting materials
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A practical and green protocol for the synthesis of vascular disrupting agent combretastatin A-4 (CA4) and its water soluble prodrug CA4P is described. Starting from the biomass-based compound anethole, which is abundantly and sustainably available from Chinese star anise (Illicium verum Hook. f.), the key intermediate 3-hydroxy-4-methoxyphenylacetic acid can be obtained within five steps. Perkin condensation between this acid and another naturally derived compound 3,4,5-trimethoxybenzaldehyde, followed by decarboxylation gives combretastatin A-4 in good overall yield. The phosphate produrg CA4P can be prepared under simple and mild conditions in a sequential one-pot two-step reaction. Georg Thieme Verlag Stuttgart New York.
- Chen, Yu,Zou, Yong,Sun, Hong-Yi,Liu, Xian-Ke,Xiao, Chun-Fen,Sun, Jie,He, Shu-Jie,Li, Jun
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- AlCl3·6H2O/KI/CH3CN/H 2O: An efficient and versatile system for chemoselective C-O bond cleavage and formation of halides and carbonyl compounds from alcohols in hydrated media
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AlCl3·6H2O/KI/CH3CN/H 2O, an efficient and versatile system, cleaves the C-O bonds of esters, acetals, ethers, and oxathiolanes to the corresponding acids, alcohols, and carbonyl compounds chemoselectively at 80°C in hydrated media with good yields. This system also converts the alcohols (primary/secondary) to halides and oxidizes the alcohols (primary/secondary) to the corresponding carbonyl compounds in the presence of DMSO. Copyright Taylor & Francis Group, LLC.
- Gogoi, Pranjal,Konwar, Dilip,Sharma, Saikat Das,Gogoi, Prodip Kumar
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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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- Silver nanocluster redox-couple-promoted nonclassical electron transfer: An efficient electrochemical wolff rearrangement of α-diazoketones
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In this work we report the unique electrocatalytic role of benzoic acid protected silver nanoclusters (Agn, mean core diameter 2.5 nm) in the Wolff rearrangement (Scheme 1) of α-diazoketones. More specifically, the presence of a Agn0/Agn+ redox couple facilitates a nonclassical electron-transfer process, involving chemical reaction(s) interposed between two electron-transfer steps occurring in opposite directions. Consequently, the net electron transfer between the electron mediator (Agn) and α-diazoketone is zero. In-situ UV-visible studies using pyridine as a nucleophilic probe indicate the participation of α-ketocarbene/ketene as important reaction intermediates. Controlled potential coulometry of α-diazoketones using Agn as the anode results in the formation of Wolff rearranged carboxylic acids in excellent yield, without sacrificing the electrocatalyst.
- Sudrik, Surendra G.,Chaki, Nirmalya K.,Chavan, Vilas B.,Chavan, Sambhaji P.,Chavan, Subhash P.,Sonawane, Harikisan R.,Vijayamohanan
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- The effect of an alkoxy group on the kinetic and thermodynamic acidity of benzene and toluene
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2-, 3- and 4-Methoxytoluene can be selectively metalated at an O-adjacent ortho position when butyllithium or tert-butyllithium in the presence of sodium (potassium) tert-butoxide or N,N,N',N'',N''-pentamethyldiethylenetriamine are employed as reagents. In contrast, lithium diisopropylamide or lithium 2,2,6,6-tetramethylpiperidide deprotonate the benzylic α-position of 2- and 3-methoxytoaluene exclusively and of 4-methoxytoluene preferentially. These relative reactivities can be rationalized by an interplay of transition state stabilizing and destabilizing forces (dipole matching and metal coordination vs. lone pair repulsion).
- Schlosser, Manfred,Maccaroni, Paola,Marzi, Elena
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- Copper-catalyzed oxidation of deoxybenzoins to benzils under aerobic conditions
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A novel copper-catalyzed approach to benzils from readily available deoxybenzoins under neutral conditions using air as the oxidant has been developed. The reaction tolerates a variety of useful substituents including chloro, bromo, iodo, keto, ester, and cyano groups. Georg Thieme Verlag Stuttgart, New York.
- Cacchi, Sandro,Fabrizi, Giancarlo,Goggiamani, Antonella,Iazzetti, Antonia,Verdiglione, Rosanna
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- HETEROCYCLIC COMPOUND, APPLICATION THEREOF, AND COMPOSITION CONTAINING SAME
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A heterocyclic compound represented by formula XI, a pharmaceutically acceptable salt, a solvate, or a solvate of a pharmaceutically acceptable salt thereof, use thereof, and a composition containing the same. The compound is novel in structure and has good STAT5 inhibitory activity.
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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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- 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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- 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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p. 10913 - 10917
(2020/05/25)
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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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- 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 0044-0045
(2020/03/06)
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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 0088-0092
(2019/10/23)
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- Design and evolution of an enzyme with a non-canonical organocatalytic mechanism
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The combination of computational design and laboratory evolution is a powerful and potentially versatile strategy for the development of enzymes with new functions1–4. However, the limited functionality presented by the genetic code restricts the range of catalytic mechanisms that are accessible in designed active sites. Inspired by mechanistic strategies from small-molecule organocatalysis5, here we report the generation of a hydrolytic enzyme that uses Nδ-methylhistidine as a non-canonical catalytic nucleophile. Histidine methylation is essential for catalytic function because it prevents the formation of unreactive acyl-enzyme intermediates, which has been a long-standing challenge when using canonical nucleophiles in enzyme design6–10. Enzyme performance was optimized using directed evolution protocols adapted to an expanded genetic code, affording a biocatalyst capable of accelerating ester hydrolysis with greater than 9,000-fold increased efficiency over free Nδ-methylhistidine in solution. Crystallographic snapshots along the evolutionary trajectory highlight the catalytic devices that are responsible for this increase in efficiency. Nδ-methylhistidine can be considered to be a genetically encodable surrogate of the widely employed nucleophilic catalyst dimethylaminopyridine11, and its use will create opportunities to design and engineer enzymes for a wealth of valuable chemical transformations.
- Burke, Ashleigh J.,Lovelock, Sarah L.,Frese, Amina,Crawshaw, Rebecca,Ortmayer, Mary,Dunstan, Mark,Levy, Colin,Green, Anthony P.
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p. 219 - 223
(2019/06/13)
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- A deprotection procedure using SO3H silica gel to remove non-silyl protecting groups
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Protecting groups are indispensable in organic synthesis and there is a great need for a variety of deprotection methods. Here, we investigated the scope of the application of a deprotection procedure using SO3H silica gel, which we have previously reported as a desilylation procedure. Under these conditions, -OMOM, -OSEM, -OTHP, and -OAc groups and dimethyl acetal were cleaved. Pivaloyloxy, benzyloxy and methoxy carbonyl groups remained intact and selective deprotection of TBS groups in the presence of other protecting groups was accomplished. We succeeded in cleaving an acetyl group on a secondary alcohol in a highly polar nortropine derivative. Our findings here provide another deprotection option and would be helpful in the synthesis of multifunctional compounds.
- Karaki, Fumika,Kuwada, Miki,Tajiri, Saki,Kanda, Misaki,Yanai, Mari,Kamimura, Mitsuhiro,Itoh, Kennosuke,Fujii, Hideaki
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p. 212 - 220
(2019/05/06)
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- Synthesis and biological evaluation of 3-arylcoumarin derivatives as potential anti-diabetic agents
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A variety of substituted 3-arylcoumarin derivatives were synthesised through microwave radiation heating. The method has characteristics of environmental friendliness, economy, simple separation, and purification process, less by-products and high reaction yield. Those 3-arylcoumarin derivatives were screened for antioxidant, α-glucosidase inhibitory and advanced glycation end-products (AGEs) formation inhibitory. Most compounds exhibited significant antioxidant and AGEs formation inhibitory activities. Anti-diabetic activity studies showed that compounds 11 and 17 were equipotent to the standard drug glibenclamide in vivo. According to the experimental results, the target compound 35 can be used as a lead compound for the development of new anti-diabetic drugs. The whole experiment showed that anti-diabetic activity is prevalent in 3-arylcoumarins, which added a new natural skeleton to the development of anti-diabetic active drugs.
- Hu, Yuheng,Wang, Bing,Yang, Jie,Liu, Teng,Sun, Jie,Wang, Xiaojing
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- Synthesis and biological evaluation of 3-arylcoumarins as potential anti-Alzheimer's disease agents
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Alzheimer's disease, a neurodegenerative illness, has the extremely complex pathogenesis. Accumulating evidence indicates there is a close relationship between several enzymes and Alzheimer's disease. Various substituted 3-arylcoumarin derivatives were synthesised, and their in vitro activity, including cholinesterase inhibitory activity, monoamine oxidase inhibitory activity, and antioxidant activity were investigated. Most of the compounds exhibited high activity; therefore 3-arylcoumarin compounds have the potential as drug candidates for the treatment of Alzheimer's disease.
- Yang, Jie,Zhang, Pingping,Hu, Yuheng,Liu, Teng,Sun, Jie,Wang, Xiaojing
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p. 651 - 656
(2019/02/19)
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- Electrogenerated Sm(II)-Catalyzed CO2 Activation for Carboxylation of Benzyl Halides
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Sm(II)-catalyzed carboxylation of benzyl halides is reported through the electrochemical reduction of CO2. The transformation proceeds under mild reaction conditions to afford the corresponding phenylacetic acids in good to excellent yields. This user-friendly and operationally simple protocol represents an alternative to traditional strategies, which usually proceeds through the C(sp3)-halide activation pathway.
- Bazzi, Sakna,Schulz, Emmanuelle,Mellah, Mohamed
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supporting information
p. 10033 - 10037
(2019/12/24)
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- Synthetic method of fatty acid containing nitrogen heterocycle
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The invention discloses a synthetic method of fatty acid containing nitrogen heterocycle. The synthetic method comprises the following steps: (S1) adding a heterocyclic compound with substitution of chloromethyl groups, a catalyst and a solvent DMF into a reaction kettle; (S2) introducing carbon dioxide to lead the pressure in the kettle to be 2-4MPa, adjusting and reacting for 10-16 hours at thetemperature of 40-50 DEG C; (S3) adding diluted hydrochloric acid into the reaction kettle to carry out acidification, using ethyl acetate for extraction, combining organic phases, carrying out rotaryevaporation to remove liquid, and further carrying out vacuum drying, thus obtaining the fatty acid containing nitrogen heterocycle. The synthetic method disclosed by the invention has the beneficialeffects that a one-pot method is adopted, the raw materials are easy to obtain, price is low, aftertreatment of products is also simpler, the universality for a substrate is also very high, and the promotion and application are easy.
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Paragraph 0042
(2018/07/30)
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- Base-promoted ring-closing carbonyl-allene metathesis for the synthesis of 2,4-disubstituted pyrroles
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A base-promoted ring-closing carbonyl-allene metathesis reaction of N-allenyl β-enaminones (generated in situ from N-propargyl β-enaminones) gives 2,4-disubstituted pyrroles with cleavage of the C(sp)-C(sp3) bond. This transition metal-free procedure generates 1 equiv. of acetic acid as the sole byproduct. A preliminary mechanistic study supports a stepwise [2 + 2] cycloaddition/retro [2 + 2] reaction pathway.
- Cheng, Guolin,Lv, Weiwei,Xue, Lulu
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supporting information
p. 4414 - 4417
(2018/10/17)
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- Synthetic method for drug intermediate p-methoxyphenylacetic acid
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The invention discloses a synthetic method for the drug intermediate p-methoxyphenylacetic acid. The synthetic method comprises the following steps: adding 4-methoxy-6-methyl-benzaldehyde and a sodiumnitrate solution into a reaction vessel, controlling the temperature of the obtained solution, controlling a stirring speed, adding an ethylene glycol solution and aluminum isopropoxide, and continuing a reaction; and then adding cobalt chloride powder, raising the temperature to continue the reaction, carrying out cooling, adding an oxalic acid solution to adjust a pH value, carrying out washingwith a potassium sulfate solution, then carrying out washing with a triamylbenzene solution, carrying out recrystallization in a triethylene glycol solution and then carrying out dehydration with a dehydrating agent so as to obtain the finished p-methoxyphenylacetic acid.
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Paragraph 0013; 0016-0027
(2018/07/30)
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- Method for synthesizing p-methoxyphenylacetic acid
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The invention discloses a method for synthesizing p-methoxyphenylacetic acid. The method comprises the following steps: adding malonate, alkali and p-methoxy halobenzene in a solvent, enabling the p-methoxy halobenzene and the malonate to perform alkylation reaction under the alkali condition, adding water to perform quenching reaction after the reaction is finished, directly acidizing and heatingto perform the decarboxylation hydrolysis reaction after concentrating out most solvent, and then cooling to crystallize, filter and dry, namely obtaining the p-methoxyphenylacetic acid. The method disclosed by the invention has the following advantages: 1, the raw materials used by the method of the invention are easier to obtain and convenient for storing, the raw material and operation cost are greatly reduced; 2, the method disclosed by the invention is less in reaction step, the intermediate reaction process is easy to control and easy for scale production; and 3, the three waste (wastewater, waste solid and waste gas) yield is less, the environment pollution is reduced, and the ecological environment is protected. And meanwhile, the prepared product is high in purity, and the purity can achieve 99% or more; the yield is high and can achieve 95% or more.
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Paragraph 0037
(2018/07/28)
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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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- Bromo-tyrosine alkaloidal compound as well as preparation method and application thereof
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The invention belongs to the field of a medical technology, and concretely relates to a bromo-tyrosine alkaloidal compound as well as a preparation method and application thereof. The invention provides the bromo-tyrosine alkaloidal compound as shown in a general formula I and a general formula II, the preparation method thereof, and the application thereof in preparing an antitumor drug for the first time. The bromo-tyrosine alkaloidal compound has good antineoplastic activity, the preparation method is simple and feasible, the yield is better, and the bromo-tyrosine alkaloidal compound has abroad application prospect.
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Paragraph 0067; 0068
(2018/04/03)
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- N-(4-alkyl-5-benzylthiazol-2-yl)phenylalkylamide and application of same as anticancer drug
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The invention relates to N-(4-alkyl-5-benzylthiazol-2-yl)phenylalkylamide with a chemical structural formula I as shown in the specification or a salt thereof. In the formula I, R is selected from a group consisting of C1-C2 alkyl groups and C3-C4 straight-chain or branched-chain alkyl groups; X, X, Y and Y are selected from a group consisting of hydrogen, a methyl group, an ethyl group, a hydroxyl group, a methoxy group, an ethoxy group, fluorine, chlorine, bromine and iodine; X, X, X, Y and Y are selected from a group consisting of hydrogen, a methyl group and an ethyl group; n is one selected from a group consisting of 1, 2 and 3; and the salt is one selected from a group consisting of hydrochloride, hydrobromide, sulfate, phosphate, mesylate, benzene sulfonate and tosilate. The invention also provides application of N-(4-alkyl-5-benzylthiazol-2-yl)phenylalkylamide and the salt thereof to preparation of drugs used for resisting human mammary gland cells MCF-7.
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Paragraph 0020; 0022; 0023; 0024
(2017/07/12)
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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 0040-0043; 0044-0047; 0048-0051; 0052-0053
(2017/08/28)
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- Methoxyphenylacetic acid, intermediate thereof, and preparation method of salt thereof
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The invention discloses methoxyphenylacetic acid, an intermediate thereof, and a preparation method of a salt thereof. The invention provides a preparation method of hydroxyl phenylacetate, wherein the method may be a method (1) or a method (2). The method has high yield, high purity, simple operation process, mild reaction conditions, short reaction time and low demand on equipment. A catalyst in the method is recyclable, so that the method has simple post-treatment. The method is environment-friendly, is low in production cost and is suitable for industrial production.
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- Chlorotrimethylsilane and Sodium Iodide: A Useful Combination for the Regioselective Deoxygenation of Arylalkyl-α-Diketones
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An efficient regioselective deoxygenation of arylalkyl-1,2-diketones by the couple trimethylsilylchloride/sodium iodide has been reported. In all cases, the deoxygenation takes place on the carbonyl group (Cα=O) proximal to the aromatic ring in methylene chloride at room temperature in good yields, furnishing a series of variously functionalized alkylbenzylketones. A large range of functional groups were well tolerated on the ortho-, meta- and para-positions by this mild process regardless of their electronic effects, demonstrating the general character of the present methodology. The trimethylsilylchloride/sodium iodide reducing process was also successfully applied to reduce α-ketoacid and α-ketoester substrates. (Figure presented.).
- Yuan, Ling-Zhi,Zhao, Guangkuan,Hamze, Abdallah,Alami, Mouad,Provot, Olivier
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p. 2682 - 2691
(2017/08/16)
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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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- Synthesis of Ketones and Esters from Heteroatom-Functionalized Alkenes by Cobalt-Mediated Hydrogen Atom Transfer
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Cobalt bis(acetylacetonate) is shown to mediate hydrogen atom transfer to a broad range of functionalized alkenes; in situ oxidation of the resulting alkylradical intermediates, followed by hydrolysis, provides expedient access to ketones and esters. By modification of the alcohol solvent, different alkyl ester products may be obtained. The method is compatible with a number of functional groups including alkenyl halides, sulfides, triflates, and phosphonates and provides a mild and practical alternative to the Tamao-Fleming oxidation of vinylsilanes and the Arndt-Eistert homologation.
- Ma, Xiaoshen,Herzon, Seth B.
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p. 8673 - 8695
(2016/10/17)
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- Modification of an Enzyme Biocatalyst for the Efficient and Selective Oxidative Demethylation of para-Substituted Benzene Derivatives
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The bacterial CYP199A4 enzyme is able to oxidise a narrow range of aromatic acids, which includes 4-methoxybenzoic acid, efficiently. A serine 244 to aspartate variant was identified with enhanced activity for a wide range of para-methoxy-substituted benzenes. Substrates in which the acidic benzoic acid moiety is replaced with a phenol and the amide, aldehyde and bromide analogues were all oxidised with high activity by the S244D mutant (product formation rate >600 nmol nmolCYP ?1 min?1) with turnover numbers of up to 20 000. If the carboxylate moiety was modified to a nitro, ketone, boronic acid, hydroxymethyl or nitrile group, these substrates were also oxidised at a significantly higher activity by S244D than the wild-type enzyme. 3,4-Dimethoxybenzaldehyde was demethylated selectively and oxidatively to 3-methoxy-4-hydroxybenzaldehyde by the S244D mutant 84-fold more rapidly than with the wild-type enzyme. CYP199A4 would have applications in the catalytic regioselective oxidative demethylation of suitably substituted benzene substrates under mild conditions and in the presence of more oxidatively sensitive functional groups, such as an aldehyde.
- Chao, Rebecca R.,Lau, Ian C.-K.,De Voss, James J.,Bell, Stephen G.
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p. 3626 - 3635
(2016/12/14)
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- A method for the preparation of phenylacetic acid derivatives
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The invention discloses a preparation method of a substituted phenylacetic acid derivative. The method comprises the following steps: 1, carrying out a sulfonylation reaction on substituted phenylglycine and sulfuryl chloride under the action of an alkali, and post-processing after completing the reaction to obtain an intermediate; and 2, carrying out a deamination reaction on the intermediate obtained in step 1 under the action of an organic acid and a reducing agent, and post-processing after completing the reaction to obtain the substituted phenylacetic acid derivative. The raw material phenylglycine used in the above route can be very easily purchased from the market, and is cheap and easily available. The preparation method has the advantages of short process route, mild reaction conditions, simple operation, high reaction yield and low total lost.
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Paragraph 0055; 0056; 0057; 0058
(2017/05/30)
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- Method for the preparation of acetic acid to methoxylphenylboronic
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The invention relates to a method for preparation of 4-methoxyphenylacetic acid through hydrogenation reduction reaction on p-methoxymandelic acid. The reaction system includes: a solvent, which is selected from water, monoalkyl acid with a carbon number of 1-6 and a mixture of them; p-methoxymandelic acid; a hydrogen source; a hydrogenation reduction catalyst; and inorganic acid. The 4-methoxyphenylacetic acid finished product prepared by the invention has purity up to 99.8% and yield up to 99.1%. The method provided by the invention has the advantages of high reaction rate, short reaction time, high yield, few by-product, and little environmental pollution, and is suitable for industrial mass production.
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Paragraph 0021; 0022
(2016/12/01)
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- Metal-Free Chemoselective Oxidative Dehomologation or Direct Oxidation of Alcohols: Implication for Biomass Conversion
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A transition metal-free, chemoselective reaction was performed using the sodium tert-butoxide-oxygen (NaOtBu-O2) system, resulting in either oxidative dehomologation or direct oxidation of alcohols. In particular, the newly developed protocol may be used to predict the major product formed, which depends on alkyl chain length of the alcohols and reaction conditions. The rational mechanism of this transformation was also demonstrated by performing an 18O isotopic labelling experiment. This protocol presents a straightforward method for biomass conversion of a lignin model compound to phenol and benzoic acid.
- Kim, Sun Min,Shin, Hun Yi,Kim, Dong Wan,Yang, Jung Woon
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p. 241 - 245
(2016/02/27)
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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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- A new compound and its preparation method (by machine translation)
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The invention provides a new compound and a preparation method thereof. The compound is a new impurity of venlafaxine, and particularly is (+/-)-1-{2-[(4-methoxy phenyl ethyl) (methyl) amino]-1-(4-methoxy phenyl) ethyl} cyclohexanol. The compound and the preparation method thereof provide support for more accurate control of impurities in venlafaxine and acquisition of venlafaxine which is more safe and reliable and has a definite curative effect.
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Paragraph 0049; 0050; 0051
(2016/10/09)
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- Synthesis of 1,3-Amino Alcohols, 1,3-Diols, Amines, and Carboxylic Acids from Terminal Alkynes
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The half-sandwich ruthenium complexes 1-3 activate terminal alkynes toward anti-Markovnikov hydration and reductive hydration under mild conditions. These reactions are believed to proceed via addition of water to metal vinylidene intermediates (4). The functionalization of propargylic alcohols by metal vinylidene pathways is challenging owing to decomposition of the starting material and catalytic intermediates. Here we show that catalyst 2 can be employed to convert propargylic alcohols to 1,3-diols in high yield and with retention of stereochemistry at the propargylic position. The method is also amenable to propargylic amine derivatives, thereby establishing a route to enantioenriched 1,3-amino alcohol products. We also report the development of formal anti-Markovnikov reductive amination and oxidative hydration reactions to access linear amines and carboxylic acids, respectively, from terminal alkynes. This chemistry expands the scope of products that can be prepared from terminal alkynes by practical and high-yielding metal-catalyzed methods.
- Zeng, Mingshuo,Herzon, Seth B.
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p. 8604 - 8618
(2015/09/15)
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- Photogenerated α,n-didehydrotoluenes from chlorophenylacetic acids at physiological pH
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Aromatic diradicals are recognized as promising intermediates for DNA cleavage, but their formation has thus far been limited to the Bergman and Myers-Saito cycloaromatizations. We report here the phototriggered generation of all isomers of the potential DNA-cleaving α,n-didehydrotoluene diradicals at physiological pH, accomplished by the irradiation of chlorophenylacetic acids under mild conditions. The desired diradicals were formed upon photolysis of the chosen aromatic in aqueous phosphate buffer solution (pH = 7.3), with the consecutive elimination of biologically compatible chloride ion and carbon dioxide. Theoretical simulations reveal that the efficient decarboxylation of the primarily generated phenyl cations involves a previously not known diradical structure.
- Ravelli, Davide,Protti, Stefano,Fagnoni, Maurizio
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supporting information
p. 852 - 858
(2015/03/05)
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- Palladium-Catalyzed Carboxylation of Benzyl Chlorides with Atmospheric Carbon Dioxide in Combination with Manganese/Magnesium Chloride
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An efficient direct carboxylation of a series of benzyl chlorides with CO2 catalyzed by Pd(OAc)2/dicyclohexyl (2′,6′-dimethoxy-[1,1′-biphenyl]-2-yl)phosphine (SPhos) was developed to afford the corresponding phenylacetic acids in combination with Mn powder as a reducing reagent and MgCl2 as an indispensable additive. The reaction proceeded smoothly under 1 atm CO2. The application of Mn powder instead of a sensitive reducing reagent represents an operationally simple access to phenylacetic acids. Notably, MgCl2 is able to stabilize the (SPhos)2PdII(Bn)(Cl)(η1-CO2)(MgCl2) adduct and thus facilitates CO2 insertion into the PdII-C bond, which is supported by a DFT study. Specific effect: MgCl2 facilitates the direct insertion of CO2 into the PdII-C bond by stabilizing the PdII-CO2 adduct. With MgCl2 as an indispensable additive, the Pd-catalyzed carboxylation of various benzyl chlorides proceeded smoothly under 1 atm CO2, and the application of Mn powder instead of a sensitive reducing reagent makes this protocol an operationally simple access to phenylacetic acids.
- Zhang, Shuai,Chen, Wei-Qiang,Yu, Ao,He, Liang-Nian
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p. 3972 - 3977
(2016/01/26)
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- Oxidative cleavage of α-sulfonyl ketones to carboxylic acids with Ce(NH4)2(NO3)6
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Tandem oxidative cleavage of α-sulfonyl arylketones 2 with the combination of Ce(NH4)2(NO3)6 and O2 in MeCN afforded carboxylic acids 3 in moderate to good yields. The plausible reaction mechanism has
- Chang, Meng-Yang,Tsai, Chung-Yu
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supporting information
p. 5548 - 5550
(2014/12/11)
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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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- Rhodium-catalyzed oxygenative addition to terminal alkynes for the synthesis of esters, amides, and carboxylic acids
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A gem of a couple: The title reaction of terminal alkynes with O and Nnucleophiles proceeds in the presence of [Rh(cod)Cl}2], P(4-FC 6H4)3, and 4-picoline N-oxide. Alcohols, amines, and water add to the terminal alkynes to give esters, amides, and carboxylic acids, respectively. The reaction involves formation of a rhodium vinylidene, oxidation to a ketene by oxygen transfer, and nucleophilic addition.
- Kim, Insu,Lee, Chulbom
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supporting information
p. 10023 - 10026
(2013/10/01)
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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; 0048; 0049
(2013/11/19)
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- Release of guests from encapsulated masked hydrophobic precursors by a phototrigger
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Examples of release of organic acids from encapsulated p-methoxyphenacyl esters provided here demonstrate the value of a phototrigger strategy to release chemicals of interest in water from hydrophobic precursors. In this study, a photochemical β-cleavage process centered on the p-methoxyphenacyl group is exploited to release the acid of interest from a water-soluble capsule made up of octa acid.
- Jayaraj, Nithyanandhan,Jagadesan, Pradeepkumar,Samanta, Shampa R.,Da Silva, Jose P.,Ramamurthy
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supporting information
p. 4374 - 4377
(2013/09/24)
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- Ni-catalyzed direct carboxylation of benzyl halides with CO2
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A novel Ni-catalyzed carboxylation of benzyl halides with CO2 has been developed. The described carboxylation reaction proceeds under mild conditions (atmospheric CO2 pressure) at room temperature. Unlike other routes for similar means, our method does not require well-defined and sensitive organometallic reagents and thus is a user-friendly and operationally simple protocol for assembling phenylacetic acids.
- León, Thierry,Correa, Arkaitz,Martin, Ruben
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supporting information
p. 1221 - 1224
(2013/03/14)
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- Selective oxoammonium salt oxidations of alcohols to aldehydes and aldehydes to carboxylic acids
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The oxidation of alcohols to aldehydes using stoichiometric 4-acetamido-2,2,6,6-tetramethylpiperidine-1-oxoammonium tetrafluoroborate (1) in CH2Cl2 at room temperature is a highly selective process favoring reaction at the carbinol center best able to accommodate a positive charge. The oxidation of aldehydes to carboxylic acids by 1 in wet acetonitrile is also selective; the rate of the process correlates with the concentration of aldehyde hydrate. A convenient and high yield method for oxidation of alcohols directly to carboxylic acids has been developed.
- Qiu, Joseph C.,Pradhan, Priya P.,Blanck, Nyle B.,Bobbitt, James M.,Bailey, William F.
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supporting information; experimental part
p. 350 - 353
(2012/03/09)
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- Photophysics and photodeprotection reactions of p -methoxyphenacyl phototriggers: An ultrafast and nanosecond time-resolved spectroscopic and density functional theory study
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Time-resolved spectroscopic experiments were performed to investigate the kinetics and mechanisms of the photodeprotection reactions for p-methoxyphenacyl (pMP) compounds, p-methoxyphenacyl diethyl phosphate (MPEP) and diphenyl phosphate (MPPP). The experimental results reveal that compared to the previous reports for the counterpart p-hydroxyphenacyl (pHP) phosphates, the 3nπ/ππ* mixed character triplet of pMP acts as a reactive precursor that leads to the subsequent solvent and leaving group dependent chemical reactions and further affects the formation of photoproducts. The MPPP triplet in H2O/CH3CN and in fluorinated alcohols shows a rapid heterolytic cleavage (τ ≈ 5.4 ns) that results in deprotection and formation of a solvolytic rearrangement product, whereas the MPPP triplet in CH3CN and the MPEP triplet in CH3CN and H2O/CH3CN and fluorinated alcohols decay on a much longer time scale (τ ≈ 100 ns) with little observation of the rearrangement product. The density functional theory (DFT) calculations reveal a substantial solvation effect that is connected with the methoxy versus hydroxyl substitution in accounting for the different deprotection reactivity of pMP and pHP compounds. The results reported here provide new insight in elucidating the solvent and leaving group dependent dual reactivity of pMP compounds on the formation of the rearrangement versus reductive photoproduct.
- An, Hui-Ying,Kwok, Wai Ming,Ma, Chensheng,Guan, Xiangguo,Kan, Jovi Tze Wai,Toy, Patrick H.,Phillips, David Lee
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scheme or table
p. 5837 - 5851
(2010/10/03)
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- Design, synthesis and in vivo hypoglycemic activity of tetrazole-bearing N-glycosides as SGLT2 inhibitors
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Novel tetrazole-bearing N-glycosides have been designed and synthesized as SGLT2 inhibitors via a conventional protocol starting from substituted phenylacetic acids and two monosaccharides, D-glucose and D-galactose, and their hypoglycemic activity has been tested in vivo by mice oral glucose tolerance test (OGTT). Two compounds are found to be more potent than the positive control Dapagliflozin. The structure-activity relationship has also been investigated.
- Gao,Zhao,Liu,Shao,Wang,Tang,Wang
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experimental part
p. 1499 - 1508
(2011/02/22)
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- MgCl2-accelerated addition of functionalized organozinc reagents to aldehydes, ketones, and carbon dioxide
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Figure Presented Pump it up! The sluggish reactivity of organozinc reagents in additions to aldehydes, ketones, and CO2 can be increased by MgCl2, which is usually generated in the preparation of the zinc reagent. The direct reaction with CO2, in particular, opens an expeditious route to phenylacetic acid derivatives, as demonstrated in a short synthesis of ibuprofen (see scheme).
- Metzger, Albrecht,Bernhardt, Sebastian,Manolikakes, Georg,Knochel, Paul
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supporting information; experimental part
p. 4665 - 4668
(2010/08/19)
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- Novel hybrids from lamellarin D and combretastatin A 4 as cytotoxic agents
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A new series of hybrids of lamellarin D and combretastatin A 4, 1,2-diphenyl-5,6-dihydropyrrolo [2,1-a] isoquinolines, were designed as cytotoxic agents based on principles of combination in medicinal chemistry and taking the parent compounds' different anti-proliferative mechanisms into consideration. Twenty-two novel hybrids were synthesized through a convenient route, with a key step of core pyrrole formation and evaluated for their anti-proliferative activities in vitro against K-562, A-549, SMMC-7721, SGC-7901 and HCT-116 cancer cell lines. The results showed that some hybrids had good anti-proliferative activities in low IC50 ranges.
- Shen, Li,Yang, Xiaochun,Yang, Bo,He, Qiaojun,Hu, Yongzhou
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scheme or table
p. 11 - 18
(2010/03/03)
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- 1, 2 DISUBSTITUTED HETEROCYCLIC COMPOUNDS
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1,2-disubstituted heterocyclic compounds which are inhibitors of phosphodiesterase 10 are described. Also described are processes, pharmaceutical compositions, pharmaceutical preparations and pharmaceutical use of the compounds in the treatment of mammals, including human(s) for central nervous system (CNS) disorders and other disorders which may affect CNS function. Among the disorders which may be treated are neurological, neurodegenerative and psychiatric disorders including, but not limited to, those associated with cognitive deficits or schizophrenic symptoms.
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Page/Page column 61
(2010/01/30)
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- A new access to 16-membered macrocycles: Synthesis of the model c-o-d ring system of vancomycin
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A simple methodology for construction of the C-O-D diphenyl ether 16-membered ring system present in vancomycin by an intramolecular O-arylation reaction of arylboronic acid with substituted phenol for formation of the macrocyclic biaryl ether is described.
- Ghosh, Samir,Kumar, A. Sanjeev,Mehta,Soundararajan
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scheme or table
p. 3322 - 3326
(2010/02/28)
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