- The importance of the ortho effect in the solvolyses of 2,6-difluorobenzoyl chloride
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The ortho effect of the chloro substituents in 2,6-dichlorobenzoyl chloride sufficiently hindered attack on the acyl carbon such that an ionization mechanism was observed over the full range of solvents studied. We now compare this behavior with that of 2,6-difluorobenzoyl chloride. The smaller fluoro substituents allow the dominant pathway to be addition-elimination (association-dissociation) in all solvents except those rich in fluoroalcohol, where ionization is dominant. Ranges of operation for both mechanisms had previously been observed for the parent benzoyl chloride but with a wider ionization range than for the 2,6-difluoro derivative. This indicates that, relative to the parent, the electronic destabilizing influence of the fluorines on acyl cation formation outweighs the steric retardation to attack because of the presence of the two ortho-fluorine atoms. An extended (two-term) Grunwald-Winstein equation treatment of the solvolyses of 2,6-difluorobenzoyl chloride is reported. Copyright
- Park, Kyoung-Ho,Kevill, Dennis N.
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Read Online
- Hydrogen Bond Directed Photocatalytic Hydrodefluorination and Methods of Use Thereof
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Methods of synthesizing compounds comprising fluorinated aryl groups are disclosed, wherein said methods utilize hydrogen bond directed photocatalytic hydrodefluorination.
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Paragraph 0180-0181
(2021/01/22)
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- Nickel-Catalyzed Esterification of Amides Under Mild Conditions
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Abstract: The use of ligands to adjust the catalytic activity of the catalyst for esterification of amides is challenge in organic chemistry. In this paper, Nickel(II)-NHC-catalyzed the esterification reaction between N,N-di-Boc amide and alcohols at room temperature have been demonstrated. The imidazolium salt bearing a hydroxyl functionalized side arm showed high effective catalytic activity in the activation of the amide N–C bond in air atmosphere. Graphic Abstract: [Figure not available: see fulltext.].
- Li, Jun-Fei,Wang, Yao-Fang,Wu, Yuan-Yuan,Liu, Wen-Jing,Wang, Jun-Wen
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p. 874 - 880
(2019/11/13)
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- A biocatalytic method for the chemoselective aerobic oxidation of aldehydes to carboxylic acids
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Herein, we present a study on the oxidation of aldehydes to carboxylic acids using three recombinant aldehyde dehydrogenases (ALDHs). The ALDHs were used in purified form with a nicotinamide oxidase (NOx), which recycles the catalytic NAD+ at the expense of dioxygen (air at atmospheric pressure). The reaction was studied also with lyophilised whole cell as well as resting cell biocatalysts for more convenient practical application. The optimised biocatalytic oxidation runs in phosphate buffer at pH 8.5 and at 40 °C. From a set of sixty-one aliphatic, aryl-Aliphatic, benzylic, hetero-Aromatic and bicyclic aldehydes, fifty were converted with elevated yield (up to >99%). The exceptions were a few ortho-substituted benzaldehydes, bicyclic heteroaromatic aldehydes and 2-phenylpropanal. In all cases, the expected carboxylic acid was shown to be the only product (>99% chemoselectivity). Other oxidisable functionalities within the same molecule (e.g. hydroxyl, alkene, and heteroaromatic nitrogen or sulphur atoms) remained untouched. The reaction was scaled for the oxidation of 5-(hydroxymethyl)furfural (2 g), a bio-based starting material, to afford 5-(hydroxymethyl)furoic acid in 61% isolated yield. The new biocatalytic method avoids the use of toxic or unsafe oxidants, strong acids or bases, or undesired solvents. It shows applicability across a wide range of substrates, and retains perfect chemoselectivity. Alternative oxidisable groups were not converted, and other classical side-reactions (e.g. halogenation of unsaturated functionalities, Dakin-Type oxidation) did not occur. In comparison to other established enzymatic methods such as the use of oxidases (where the concomitant oxidation of alcohols and aldehydes is common), ALDHs offer greatly improved selectivity.
- Knaus, Tanja,Tseliou, Vasilis,Humphreys, Luke D.,Scrutton, Nigel S.,Mutti, Francesco G.
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p. 3931 - 3943
(2018/09/11)
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- Protein kinase inhibitor and its composition and use thereof
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The invention relates to compounds as shown in the general formula (I), pharmaceutical compositions containing the compounds, a method for treating diseases and disease symptoms related to abnormal activity of protein kinase by using the compounds, and medicinal use of the compounds.
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Paragraph 0147-0149
(2017/08/02)
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- Two Routes to 4-Fluorobenzisoxazol-3-one in the Synthesis of a 5-HT4 Partial Agonist
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A potent 5-HT4 partial agonist, 1 (PF-04995274), targeted for the treatment of Alzheimer's disease and cognitive impairment, has been prepared on a multi-kilogram scale. The initial synthetic route, that proceeded through a 4-substituted 3-hydroxybenzisoxazole core, gave an undesired benzoxazolinone through a Lossen-type rearrangement. Route scouting led to two new robust routes to the desired 4-substituted core. Process development led to the efficient assembly of the API on a pilot plant scale under process-friendly conditions with enhanced throughput. In addition, crystallization of a hemicitrate salt of the API with pharmaceutically beneficial properties was developed to enable progression of clinical studies.
- Widlicka, Daniel W.,Murray, John C.,Coffman, Karen J.,Xiao, Chunguang,Brodney, Michael A.,Rainville, Joseph P.,Samas, Brian
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p. 233 - 241
(2016/03/04)
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- Synthesis and biological evaluation of novel resveratrol-oxadiazole hybrid heterocycles as potential antiproliferative agents
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A novel class of resveratrol-oxadiazole hybrid compounds was synthesized to screen for their in vitro antiproliferative activity against three human cancer cell lines. All the compounds showed superior antiproliferative activity than the reference compound resveratrol. The most promising active compounds in this series were 1g, 2g, 1c, 2c, 2i and 1a (GI50 0.1 μM), endowed with excellent antiproliferative activity. Thus, we believe that resveratrol-oxadiazole hybrid compounds may possibly be used as a good leads for the development of new antiproliferative agents. Structures of newly synthesized compounds were confirmed by NMR and IR spectral data.
- Murty,Penthala, Raju,Polepalli, Sowjanya,Jain
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p. 627 - 643
(2016/03/08)
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- KINASE MODULATING COMPOUNDS, COMPOSITIONS CONTAINING THE SAME AND USE THEREOF
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The invention provides a compound represented by formula (I) which may modulate a kinase, and a pharmaceutical composition thereof, as well as the method for preventing or treating a protein kinase mediated disease or condition.
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Page/Page column 25
(2013/06/05)
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- Synthesis of 2,6-difluoro-N-(3-[11C]methoxy-1H-pyrazolo[3,4-b] pyridine-5-yl)-3-(propylsulfonamidio)benzamide as a new potential PET agent for imaging of B-RafV600E in cancers
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The authentic standard 2,6-difluoro-N-(3-methoxy-1H-pyrazolo[3,4-b] pyridine-5-yl)-3-(propylsulfonamidio)benzamide was synthesized from 2,6-difluorobenzoic acid and 3-amino-5-hydroxypyrazole in 9 steps with 1% overall chemical yield. Direct desmethylation
- Wang, Min,Gao, Mingzhang,Miller, Kathy D.,Zheng, Qi-Huang
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p. 1017 - 1021
(2013/03/13)
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- Continuous flow oxidation of alcohols and aldehydes utilizing bleach and catalytic tetrabutylammonium bromide
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We report a method for the oxidation of a range of alcohols and aldehydes utilizing a simple flow system of alcohols in EtOAc with a stream of 12.5% NaOCl and catalytic Bu4NBr. Secondary alcohols are oxidized to ketones, aldehydes are oxidized directly to methyl esters in the presence of methanol, and benzylic alcohols are oxidized to either benzaldehydes or methyl esters, depending on the conditions used. The reaction conditions are mild and generally provide complete conversion in 5-30 min.
- Leduc, Andrew B.,Jamison, Timothy F.
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supporting information; experimental part
p. 1082 - 1089
(2012/08/27)
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- Facile preparation of aromatic esters from aromatic bromides with ethyl formate or DMF and molecular iodine via aryllithium
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Various aromatic bromides were treated with n-BuLi and subsequently with ethyl formate, followed by the reaction with ethanol and molecular iodine in the presence of K2CO3 to provide the corresponding aromatic ethyl esters in good yields. Moreover, aromatic bromides could be transformed into the corresponding aromatic methyl esters in good yields by the treatment with n-BuLi and subsequently with DMF, followed by the reaction with methanol, molecular iodine, and K2CO3. Some aromatics could be also converted into the corresponding aromatic esters in good yields by the treatment with n-BuLi, and subsequently with ethyl formate or DMF, followed by the reaction with molecular iodine and K2CO3. The present reactions offer a novel route for the transition-metal-free, carbon-monoxide-free, and therefore environmentally benign one-pot conversion of aromatic bromides and aromatics into aromatic esters.
- Ushijima, Sousuke,Moriyama, Katsuhiko,Togo, Hideo
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experimental part
p. 4701 - 4709
(2012/07/28)
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- BENZENE SULFONAMIDE THIAZOLE AND OXAZOLE COMPOUNDS
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The present invention provides thiazole sulfonamide and oxazole sulfonamide compounds, compositions containing the same, as well as processes for the preparation and methods for their use as pharmaceutical agents.
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Page/Page column 101-102
(2011/06/16)
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- Novel C-C bond cleavage under mild, neutral conditions: Conversion of electron-deficient aryl alkyl ketones to aryl carboxylic esters
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A novel, unique way to cleave the carbon-carbon bond in aryl alkyl ketones under mild, neutral conditions is described. Treatment of aryl alkyl ketones in a refluxing mixture of N,N-dimethylformamide dimethyl acetal and methanol for 16 h provided aryl car
- Zhang, Nan,Vozzolo, Joseph
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p. 1703 - 1704
(2007/10/03)
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- The basicity gradient-driven migration of iodine: Conferring regioflexibility on the substitution of fluoroarenes
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Six different fluoroarenes were submitted to the same transformations. Direct deprotonation with alkyllithium or lithium dialkylamide as reagents and subsequent carboxylation afforded the acids 1, 6, 11, 16, 18, and 23. If the aryllithium intermediate was trapped with iodine rather than with dry ice, an iodofluoroarene (2, 7, 12, 17, 19, and 24) was formed. This, upon treatment with lithium diisopropylamide, underwent deprotonation and iodine migration. The resulting new aryllithium species was intercepted either by carboxylation, to give the acids 3, 8, 13, 20, and 25, or by neutralization, to produce the iodofluoroarenes 4, 9, 14, 21, and 26. The latter family of compounds was converted into another set of acids 5, 10, 15, 22, and 27 by subsequent treatment with butyllithium or isopropylmagnesium chloride and carbon dioxide. ( Wiley-VCH Verlag GmbH, 69451 Weinheim, Germany, 2002).
- Rausis, Thierry,Schlosser, Manfred
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p. 3351 - 3358
(2007/10/03)
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- KINETICS OF METHANOLYSIS OF 1-(2-HALOGENO AND 2,6-DIHALOGENOBENZOYL)-3-(4-CHLOROPHENYL)UREAS
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The methanolysis kinetics has been measured of 1-(2,6-difluorobenzoyl)-3-(4-chlorophenyl)urea (a larvicidal insecticide Dimilin) and of four other mono- and dihalogenobenzoyl derivatives.Polar and steric effects of halogen on the rate and dissociation constants is discussed.
- Kavalek, Jaromir,Kacetl, Lubomir,Kavalkova, Marcela
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p. 1363 - 1369
(2007/10/02)
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- Palladium Catalysed Alkoxycarbonylation of Phenols to Benzoate Esters
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The methoxycarbonylation of aryl trifluoromethanesulphonates with CO and aliphatic alcohols is catalysed by Pd(OAc)2-1,3-bis(diphenylphosphino)propane in high yield at 70 deg C and ambient CO pressure.
- Dolle, Roland E.,Schmidt, Stanley J.,Kruse, Lawrence I.
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p. 904 - 905
(2007/10/02)
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