- Rational control of enzymatic enantioselectivity through solvation thermodynamics
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The enantioselectivity of cross-linked crystals of γ-chymotrypsin in the transesterification of the medicinally important compound methyl 3-hydroxy-2-phenylpropionate (1) with propanol has been examined in a variety of organic solvents. The (k(cat)/K(M))(
- Wescott, Charles R.,Noritomi, Hidetaka,Klibanov, Alexander M.
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Read Online
- Pyrrolidine integrin regulator and application thereof
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Disclosed are a compound as represented by formula I, and a racemate, a stereoisomer, a tautomer, an isotopic marker, a nitrogen oxide, a solvate, a polymorph, a metabolite, an ester, and a prodrug thereof or a pharmaceutically acceptable salt thereof, and a pharmaceutical composition comprising same, a preparation method therefor, and the medical use thereof. The structure of formula I is as follows:
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Paragraph 0572-0576
(2021/09/08)
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- Green Esterification of Carboxylic Acids Promoted by tert-Butyl Nitrite
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In this work, the green esterification of carboxylic acids promoted by tert-butyl nitrite has been well developed. This transformation is compatible with a broad range of substrates and exhibits excellent functional group tolerance. Various drugs and substituted amino acids are applicable to this reaction under near neutral conditions, with good to excellent yields.
- Cheng, Xionglve,Jiang, Gangzhong,Li, Xingxing,Tao, Suyan,Wan, Xiaobing,Zhao, Yanwei,Zheng, Yonggao
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supporting information
p. 2713 - 2718
(2021/06/25)
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- 3,3′-Disubstituted Oxindoles Formation via Copper-Catalyzed Arylboration and Arylsilylation of Alkenes
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Arylboration and arylsilylation reactions of N-(2-iodoaryl)acrylamides with bis(pinacolato)-diboron (B2pin2) or PhMe2Si-Bpin are developed by using simple CuOAc as the sole catalyst. A range of boron-or silane-bearing 3,3′-disubstituted oxindoles are obtained in moderate to excellent yields. The reaction is proposed to proceed via a domino sequence involving intermolecular olefin borylcupration or silylcupration followed by intramolecular coupling of an alkyl-Cu intermediate with aryl iodide.
- Liang, Ren-Xiao,Chen, Ru-Yi,Zhong, Chao,Zhu, Jia-Wen,Cao, Zhong-Yan,Jia, Yi-Xia
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supporting information
p. 3215 - 3218
(2020/04/10)
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- Synthesis method of 3-hydroxy-2-phenylpropionic acid
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The invention discloses a synthetic method of 3-hydroxyl-2-phenylpropionic acid. The method comprises the following steps: mixing dimethyl sulfoxide, paraformaldehyde, potassium carbonate powder and methyl phenylacetate, heating to 85-95 DEG C, carrying out gas phase monitoring reaction, and cooling to room temperature when the GC content of the product methyl tropine is more than or equal to 70%;adjusting the pH value to be neutral, and performing reduced pressure distillation for desolvation; then adding methanol into the desolventized mixture, dropwise adding a sodium hydroxide solution, and reacting to obtain a mixed solution containing sodium tropine salt; adjusting the pH value of the mixed solution to 2-3, and completely reacting to obtain a crude product; and finally, recrystallizing the crude product sequentially by using methylbenzene of which the ratio of m product to m methylbenzene is 1: (4-6), methylbenzene/water of which the ratio of m product to m methylbenzene to m water is 1: (1-2): (4-6), and water of which the ratio of m product to m water is 1: (4-6) to obtain a pure product of 3-hydroxyl-2-phenylpropionic acid. According to the method, GC is adopted to monitor the reaction, control points are judged quickly and accurately, purification of methyl tropinate is not needed, operation procedures are reduced, and production cost is reduced. According to the method, the purity of the prepared 3-hydroxyl-2-phenylpropionic acid reaches 99% or above while the yield is ensured to reach 76.5% or above.
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Paragraph 0024-0026; 0030-0032; 0036-0038
(2019/12/25)
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- Study on the synthesis and biological activities of α-substituted arylacetates derivatives
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Anisodamine was isolated from the medicinal herb, it was used in the treatment of gastrointestinal smooth muscle spasm, infective toxic shock and organophosphorus intoxication. But there is no report about anisodamine with α-glucosidase inhibitory activity. In order to find novel α-glucosidase inhibitors, a series of α-substituted arylacetates derivatives have been synthesized based on the active unit of anisodamine. In α-glucosidase assay, compound 9 in Schiff base form and compound 22 in ester form show strong inhibition against α-glucosidase with IC50value of 46.81?μM and 83.76?μM, respectively. Compounds 9 and 22 exhibit comparable good antidiabetic activities as commercial drug Glimepiride. In addition, Schiff bases of α-substituted arylacetates show antitumor activities against human cancer cell lines, where compound 9 with thiourea moiety performs the best antitumor activity. We anticipate that our research will provide potential candidate scaffolds for antidiabetic drug design.
- Liu, Jinbing,Chen, Changhong,Wu, Fengyan,Tang, Junyuan
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supporting information
p. 1715 - 1719
(2016/07/27)
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- Chemoselective esterification of α-hydroxyacids catalyzed by salicylaldehyde through induced intramolecularity
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A new, direct and chemoselective esterification of α-hydroxyacids was developed using a reversible covalent-binding strategy. By taking advantage of acetal chemistry, simple aldehydes can be used to efficiently catalyze the esterification of α-hydroxy carboxylic acids in the presence of β-hydroxyacid moieties or other carboxylic acids in amounts equal to or in excess of the alcohols. A diverse array of α-aryl, α-alkyl, α-heteroaryl, and functionalized α-hydroxyacids were smoothly esterified with 1° and 2° alcohols catalyzed by 10 mol% inexpensive and commercially available salicylaldehyde, furnishing the resultant esterification products in 83-95% yields after a simple basic aqueous workup to remove the unreacted hydroxyacids. In addition, the salicylaldehyde can be recovered through vacuum distillation or silica gel purification, thereby meeting the standards of green chemistry. A mechanistic study proved that the formation of covalent adduct III during our proposed catalytic cycle (Scheme 1A) is responsible for the real catalysis.
- Weng, Shiue-Shien,Li, Hsin-Chun,Yang, Teng-Mao
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p. 1976 - 1986
(2013/03/13)
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- Kinetic resolution of racemic α-arylalkanoic acids with achiral alcohols via the asymmetric esterification using carboxylic anhydrides and acyl-transfer catalysts
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A variety of optically active carboxylic esters are produced by the kinetic resolution of racemic α-substituted carboxylic acids using achiral alcohols, aromatic or aliphatic carboxylic anhydrides, and chiral acyl-transfer catalysts. The combination of 4-methoxybenzoic anhydride (PMBA) or pivalic anhydride with the modified benzotetramisole-type catalyst ((S)-β-Np-BTM) is the most effective for promotion of the enantioselective coupling reaction between racemic carboxylic acids and a novel nucleophile, bis(α-naphthyl) methanol, to give the corresponding esters with high ees. This protocol was successfully applied to the production of nonracemic nonsteroidal anti-inflammatory drugs from racemic compounds utilizing the transacylation process to generate the mixed anhydrides from the acid components with the suitable carboxylic anhydrides.
- Shiina, Isamu,Nakata, Kenya,Ono, Keisuke,Onda, Yu-Suke,Itagaki, Makoto
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supporting information; experimental part
p. 11629 - 11641
(2010/10/04)
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- Anionic, in situ generation of formaldehyde: A very useful and versatile tool in synthesis
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(Chemical Equation Presented) A very simple, safe and powerful method for the in situ generation of formaldehyde at low temperature in anhydrous conditions is described. This new tool avoids the use of gaseous formaldehyde and is suitable for basic carbon nucleophiles which cannot be generated in aqueous reaction media. Various substrates, including organolithium reagents and enolates, underwent smooth hydroxymethylation showing the versatility of this process. A Wittig reaction was also carried out in high yield.
- Deguest, Geoffrey,Bischoff, Laurent,Fruit, Corinne,Marsais, Francis
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p. 1165 - 1167
(2007/10/03)
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- ARYLOXYALKYLAMINE NK-1/SSRI INHIBITORS
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The invention encompasses compounds of Formula I, including pharmaceutically acceptable salts and solvates, their pharmaceutical compositions, and their use in treating disorders associated with an excess or imbalance of tachykinins or serotonin or both.
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Page/Page column 9
(2010/02/15)
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- Anomalous fluorinations of 3-aryl-2-hydroxypropanoic esters by diethylaminosulfur trifluoride (DAST)
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Treatment of 3-aryl-2-hydroxypropanoic esters 8 with diethylaminosulfur trifluoride (DAST) gives considerable amounts of rearranged 2-aryl-3-fluoropropanoic esters 12 together with the expected products 11. The extent of rearrangement is dependent on solv
- Haigh, David,Jefcott, Lee J.,Magee, Katherine,McNab, Hamish
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p. 2895 - 2900
(2007/10/03)
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- Process for the preparation of 2-aryl-1,3-propanediols
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Process for the production of 2-aryl-1,3-propanediols from a tropate ester and novel intermediate compounds produced thereby.
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- Process for the preparation of 2-aryl-1,3-propanediols
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Process for the production of 2-aryl-1,3-propanediols and novel intermediate compounds produced thereby.
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- TRANSFORMATIONS OF 1,1-DIMETHOXY-2-PHENYLCYCLOPROPANE UNDER THE INFLUENCE OF PROTIC ACIDS
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Under the influence of protic acids 1,1-dimethoxy-2-phenylcyclopropane undergoes opening of the three-membered ring, the direction of which does not depend on the strength or the nature of the acid but varies with the polarity of the solvent.In acid-solvent systems which exhibit oxidizing characteristics the compound can undergo oxidative cleavage of the cyclopropane ring directly.
- Novokreshchennykh, V. D.,Lukashova, E. A.,Mochalov, S. S.,Shabarov, Yu. S.
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p. 2022 - 2027
(2007/10/02)
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- Dehydrative Decarboxylation of 2,3-Disubstituted 3-Hydroxycarboxylic Acids with Dimethylformamide Acetals - Mechanistic Studies and Preparative Applicability
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Dimethylformamide dimethylacetal (2a) converts the threo-3-hydroxycarboxylic acids 4 smoothly into the (E)/(Z)-olefins 7/6 only if R2 is an aryl or vinyl substituent.Althougt the reaction exhibits a distinct (E)-selectivity it cannot be considered as a stereo-controlled olefin synthesis.If R2 is alkyl, 2a generates the methyl esters 10 from 4.The erythro-acids 5 react with 2a to give 43 - 95percent of >98percent sterically pure 7.As the key tranformation on the multistep way from 4/5 to 6/7 the fragmentation of the zwitterionic intermediate 11/20 is postulated.
- Mulzer, Johann,Bruentrup, Gisela
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p. 2057 - 2075
(2007/10/02)
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- Enantiotopically Selective Oxidation of α,ω-Diols with the Enzyme Systems of Microorganisms
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Gluconobacter were found to be capable of oxidizing prochiral diols such as 2-substituted propane-1,3-diols 1 and 3-substituted pentane-1,5-diols 4 with distinction of pro-R and pro-S sites of the molecules, in that (-)-(R)-α-substituted β-hydroxypropionic acids 2 and (+)-(3S)-3-substituted δ-valerolactones 5 were obtained, respectively.Oxidation of 3-methylpentane-1,3,5-triol 11 afforded unnatural (+)-(S)-mevalonolactone 12.The steric bulkiness of the substituents on the prochiral center and the distance from the hydroxy group greatly affected the rate and the enantioselectivity of the reaction.
- Ohta, Hiromichi,Tetsukawa, Hatsuki,Noto, Naoko
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p. 2400 - 2404
(2007/10/02)
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