- Synthesis of Carboxylic Acids by Palladium-Catalyzed Hydroxycarbonylation
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The synthesis of carboxylic acids is of fundamental importance in the chemical industry and the corresponding products find numerous applications for polymers, cosmetics, pharmaceuticals, agrochemicals, and other manufactured chemicals. Although hydroxycarbonylations of olefins have been known for more than 60 years, currently known catalyst systems for this transformation do not fulfill industrial requirements, for example, stability. Presented herein for the first time is an aqueous-phase protocol that allows conversion of various olefins, including sterically hindered and demanding tetra-, tri-, and 1,1-disubstituted systems, as well as terminal alkenes, into the corresponding carboxylic acids in excellent yields. The outstanding stability of the catalyst system (26 recycling runs in 32 days without measurable loss of activity), is showcased in the preparation of an industrially relevant fatty acid. Key-to-success is the use of a built-in-base ligand under acidic aqueous conditions. This catalytic system is expected to provide a basis for new cost-competitive processes for the industrial production of carboxylic acids.
- Sang, Rui,Kucmierczyk, Peter,Dühren, Ricarda,Razzaq, Rauf,Dong, Kaiwu,Liu, Jie,Franke, Robert,Jackstell, Ralf,Beller, Matthias
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supporting information
p. 14365 - 14373
(2019/09/06)
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- Use of ethyl (benzothiazol-2-ylsulfonyl)acetate for malonic ester-type syntheses of carboxylic acids and esters
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A new methodology for the synthesis of substituted carboxylic acids is described. Alkylation of either ethyl (benzothiazol-2-ylsulfonyl)acetate or ethyl 2-(benzothiazol-2-ylsulfonyl)propionate was achieved with alkyl halides and 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) in dichloromethane solution. These products were then desulfinated and hydrolysed in one-pot under mild conditions to give substituted acetic acids in good-to-excellent yields.
- Hussein, Waleed M.,McGeary, Ross P.
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p. 1222 - 1227
(2014/10/16)
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- Nickel-butadiene catalytic system for the cross-coupling of bromoalkanoic acids with alkyl grignard reagents: A practical and versatile method for preparing fatty acids
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The knights who say Ni: A practical and convenient synthetic route to fatty acids involves the Ni-catalyzed alkyl-alkyl cross-coupling of bromoalkanoic acids and alkyl Grignard reagents in the presence of 1,3-butadiene as an additive (see scheme). Copyright
- Iwasaki, Takanori,Higashikawa, Kiyokazu,Reddy, Vutukuri P.,Ho, Willbe W. S.,Fujimoto, Yukari,Fukase, Koichi,Terao, Jun,Kuniyasu, Hitoshi,Kambe, Nobuaki
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supporting information
p. 2956 - 2960
(2013/03/28)
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- New molecular markers for prostate tumor imaging: A study on 2-methylene substituted fatty acids as new AMACR inhibitors
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The development of prostate carcinoma is associated with alterations in fatty acid metabolism. α-Methylacyl-CoA racemase (AMACR) is a peroxisomal and mitochondrial enzyme that catalyses interconversion between the (S)/(R)-isomers of a range of α-methylacyl-CoA thioesters. AMACR is involved in the β-oxidation of the dietary branched-chain fatty acids and bile acid intermediates. It is highly expressed in prostate (more than 95 %), colon (92 %), and breast cancers (44 %) but not in the respective normal or hyperplastic tissues. Thus, targeting of AMACR could be a new strategy for molecular imaging and therapy of prostate and some other cancers. Unlabeled 2-methylenacyl-CoA thioesters (12 a-c) were designed as AMACR binding ligands. The thioesters were tested for their ability to inhibit the AMACR-mediated epimerization of (25R)-THC-CoA and were found to be strong AMACR inhibitors. Radioiodinated (E)-131I-13-iodo-2-methylentridec-12-enoic acid ( 131I-7 c) demonstrated preferential retention in AMACR-positive prostate tumor cells (LNCaP, LNCaP C4-2wt and DU145) compared with both AMACR-knockout LNCaP C4-2 AMACR-siRNA and benign BPH1 prostate cell lines. A significant protein-bound radioactive fraction with main bands at 47 (sum of molecular weights of AMACR plus 12 c), 70, and 75 kDa was detected in LNCaP C4-2 wt cells. Copyright
- Morgenroth, Agnieszka,Urusova, Elizaveta A.,Dinger, Cornelia,Al-Momani, Ehab,Kull, Thomas,Glatting, Gerhard,Frauendorf, Holm,Jahn, Olaf,Mottaghy, Felix M.,Reske, Sven N.,Zlatopolskiy, Boris D.
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p. 10144 - 10150
(2011/10/09)
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- Inhibitors of Acyl-CoA:cholesterol acyltransferase. I. Identification and structure-activity relationships of a novel series of fatty acid anilide hypocholesterolemic agents
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A series of fatty acid anilides was prepared, and compounds were tested for their ability to inhibit the enzyme acyl-CoA:cholesterol acyltransferase (ACAT) in vitro and to lower plasma total cholesterol and elevate high- density lipoprotein cholesterol in cholesterol-fed rats in vivo. The compounds reported were found to fall into two subclasses with different anilide SAR. For nonbranched acyl analogues, inhibitory potency was found to be optimal with bulky 2,6-dialkyl substitution. For α-substituted acyl analogues, there was little dependence of in vitro potency on anilide substitution and 2,4,6-trimethoxy was uniquely preferred. Most of the potent inhibitors (IC50 50 nM) were found to produce significant reductions in plasma total cholesterol in cholesterol-fed rats. Additionally, in vivo activity could be improved significantly by the introduction of α,α- disubstitution into the fatty acid portion of the molecule. A narrow group of α,α-disubstituted trimethoxyanilides, exemplified by 2,2-dimethyl-N-(2,4,6- trimethoxyphenyl)dodecanamide (39), was found to not only lower plasma total cholesterol (-60%) in cholesterol-fed rats but also elevate levels of high- density lipoprotein cholesterol (+94%) in this model at the screening dose of 0.05% in the diet (ca. 50 mg/kg).
- Roth,Blankley,Hoefle,Holmes,Roark,Trivedi,Essenburg,Kieft,Krause,Stanfield
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p. 1609 - 1617
(2007/10/02)
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- The Copper(I)-Catalyzed Decarboxylation of Malonic Acids; A New Mild and Quantitative Method
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A novel catalytic decarboxylation of malonic acids under mild conditions is proposed.This simple copper(I)-catalyzed reaction affords the corresponding monocarboxylic acids in good purity and nearly quantitative yields.
- Toussaint, Olivier,Capdevielle, Patrice,Maumy, Michel
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p. 1029 - 1031
(2007/10/02)
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