- 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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- Synthetic method of prasugrel intermediate o-fluorophenylacetic acid
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The invention discloses a synthetic method of prasugrel intermediate o-fluorophenylacetic acid. The reaction process comprises the steps that (1) 2-fluorotoluene, N-halosuccinimide, an initiator and asolvent S1 are mixed uniformly, protective gas is introduced, the pressure is controlled to be 1.5-2 atmospheric pressure, the temperature is controlled to be 90-120 DEG C, stirring reaction is conducted for 1-2 h, and a mixture M1 is obtained; (2) a catalyst is mixed uniformly with a cyanide aqueous solution, the pressure is controlled to be 2-3 atmospheric pressure, the temperature is controlled to be 80-100 DEG C, the mixture M1 is added into a reaction system, then conditions are maintained to continue the reaction for 1-2 h, still standing and layering are conducted, organic phase is collected and concentrated to 1/2 of the original volume, and a mixture M2 is obtained; and (3) the mixture M2 is mixed uniformly with hydrochloric acid and glacial acetic acid, refluxing is conducted for 40-55 min, the mixture is poured into crushed ice after cooling, a solvent S2 is added for extraction, and after the organic phase is dried by a drying agent, a product is obtained by concentratingby a rotary evaporator. According to the synthetic method, safety and reliability are achieved, the production cost is low, three wastes are basically avoided, and the synthetic method is suitable forindustrial production.
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Paragraph 0029; 0037; 0038; 0046; 0047; 0055-0068
(2020/02/19)
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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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- 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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- 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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- 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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- Electrochemical direct carboxylation of benzyl alcohols having an electron-withdrawing group on the phenyl ring: One-step formation of phenylacetic acids from benzyl alcohols under mild conditions
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Electrochemical direct carboxylation of benzyl alcohols having an electron-withdrawing group on the phenyl ring was successfully carried out by constant current electrolysis using an undivided cell equipped with a platinum plate cathode and a magnesium rod anode in DMF in the presence of carbon dioxide. Reductive cleavage of the C-O bond followed by fixation of carbon dioxide efficiently took place at the benzylic position without any additive to give the corresponding phenylacetic acids in good yields in one step under neutral and mild conditions.
- Senboku, Hisanori,Yoneda, Kenji,Hara, Shoji
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p. 6772 - 6776
(2016/01/30)
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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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- 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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- AN IMPROVED PROCESS FOR THE PREPARATION OF PRASUGREL HYDROCHLORIDE AND ITS INTERMEDIATES
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The present invention provides an improved process for the preparation of prasugrel and its pharmaceutical acceptable salt. Prasugrel chemically known as 2-acetoxy-5-(a- cyclopropylcarbonyl-2-fluorobenzyl)-4,5,6,7-tetrahydrothieno[3,2-c]-pyridine or 5-[2- cyclopropyl-l-(2-fluorophenyl)-2-oxoethyl]-4,5,6,7-tetrahydrothieno[3,2,-c]pyridine- 2yl acetate and having the structural formula (I) and its pharmaceutically acceptable salts. The present invention also provides an improved process for the preparation of cyclopropyl 2-fluorobenzyl ketone, 2-Fluoro-a-cyclopropyl carbonylbenzyl bromide, 5,6,7,7a Tetrahydro-4H- theino-[3,2-c]- pyridone-2 p-toluenesulfonate and its hydrochloride salt.
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Page/Page column 15
(2012/01/14)
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- Controlled anion migrations with a mixed metal Li/K-TMP amide: General application to benzylic metalations
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A general method is described for benzylic metalation of o-, m-, and p-substituted toluenes using a mixed metal amide base generated from BuLi/KOtBu/TMP at -78 °C in THF. The excellent selectivity achieved can be rationalized by the ability of the mixed metal amide base to facilitate an anion migration from the kinetic (o-aryl) to the benzylic metalation site. Remarkably, this controlled anion migration is achievable with catalytic amounts of TMP at -78 °C.
- Fleming, Patricia,Oshea, Donal F.
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supporting information; experimental part
p. 1698 - 1701
(2011/04/17)
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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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- 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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- Spiro(2h-1-benzopyran-2,4-piperidine)derivatives as glycine transport inhibitors
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The present invention relates to spiro[2H-1-benzopyran-2,4′-piperidine] derivatives having general formula (I), wherein the substituents R1, R2, X and Y are ase defined in the claims or a pharmaceutically acceptable salt thereof. The invention also relates to pharmaceutical compositions comprising said derivatives, as well as to the use of these spiro[2H-1-benzopyran-2,4′-piperidine] derivatives in therapy, more specifically for the treatment of CNS disorders.
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