- Iron-catalyzed AlkylAlkyl negishi coupling of organoaluminum reagents
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The first iron-catalyzed cross-coupling reaction of alkyl halides with alkylaluminum reagents (alkylalkyl Negishi coupling) is developed using an iron/bisphosphine catalyst system. The reaction shows high functional group tolerance: various primary alkyl halides possessing a non-protected indole, carboxyl, or hydroxy group are coupled with primary alkylaluminum reagents in good yields. Potassium fluoride plays a key role to promote the reaction by generating an aluminate species, which facilitates the transmetalation between the organoaluminum and the iron catalyst.
- Agata, Ryosuke,Kawamura, Shintaro,Isozaki, Katsuhiro,Nakamura, Masaharu
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- Efficient oxidative cleavage of olefins to carboxylic acids with hydrogen peroxide catalyzed by methyltrioctylammonium tetrakis(oxodiperoxotungsto)phosphate(3-) under two-phase conditions. Synthetic aspects and investigation of the reaction course
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The oxidative cleavage of alkenes to carboxylic acids with 40% w/v aqueous hydrogen peroxide catalyzed by methyltrioctylammonium tetrakis(oxodiperoxotungsto)phosphate(3-) (1a) is reported to occur in high yields and selectivities under two-phase conditions in the absence of organic solvents. On the basis of a study of the reaction, two main reaction pathways leading to acids have been recognized, the first one involving the perhydrolysis and the second one the hydrolysis of the epoxide initially formed. The "perhydrolytic" reaction pathway appears to play a primary role in the oxidation of medium- and long-chain alkenes to acids, while it intervenes to a rather limited extent in the oxidation of arylalkenes and C5-C7 cycloalkenes. The occurrence of this pathway has been proved by the isolation of the intermediate β-hydroperoxy alcohols and their transformation into acids with H2O2 and la. The course of this transformation, involving an initial oxidation (to α-oxo hydroperoxide) or decomposition (to carbonyl compounds) of the β-hydroperoxy alcohol intermediate, is described. The primary oxidation products, α-hydroperoxy ketones, have been isolated in the case of internal β-hydroperoxy alcohols, whereas their presence has been evidenced with terminal β-hydroperoxy alcohols bearing a secondary hydroxy group. Hydrogen peroxide concentration appears to exert a remarkable influence on medium acidity, and its effects on the reaction efficiency are shown.
- Antonelli, Ermanno,D'Aloisio, Rino,Gambaro, Mario,Fiorani, Tiziana,Venturello, Carlo
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- Determination of Key Hydrocarbon Autoxidation Products by Fluorescence
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Hydroperoxides and carboxylic acids are key primary products that arise in the autoxidation of hydrocarbons. We have developed a simple approach to rapidly and simultaneously determine both types of products using hydroperoxide- and acid-sensitive moieties conjugated to nonpolar coumarin- and BODIPY-based fluorophores. The coumarin- and BODIPY-conjugated amine probes described here undergo 38- and 8-fold enhancement, respectively, upon protonation in a solvent system compatible with heavy hydrocarbons. The latter can be used directly with our previously described hydroperoxide-sensitive coumarin-conjugated phosphine probe to enable rapid quantification of both carboxylic acids and hydroperoxides in hydrocarbon samples. The utility of the approach is illustrated by the ready determination of the differing relative rates of hydroperoxide and acid formation with changes in hydrocarbon structure (e.g., n-hexadecane vs 1-hexadecene vs a lubricant base stock). The method offers significant versatility and automation compared with common but laborious titration approaches, and greatly improves screening efficiency and accuracy for the identification of novel radical-trapping antioxidants for high temperature applications. This application was demonstrated by the automated analysis of hydroperoxides and carboxylic acids (by microplate reader) in samples from 24 inhibited autoxidations of a lubricating oil, which were carried out on a parallel synthesizer at 160 °C in triplicate in a single day.
- Shah, Ron,Pratt, Derek A.
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- Enantioselective α-hydroperoxylation of long-chain fatty acids with crude enzyme of marine green alga Ulva pertusa
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When palmitic acid was incubated with crude enzyme of marine green alga Ulva pertusa, (R)-2-hydroperoxyhexadecanoic acid was formed in high enantiomeric purity (>99%ee).
- Akakabe,Matsui,Kajiwara
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- Release of nicotinamide from fatty acid-nicotinamide equimolar complexes
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The release behavior of nicotinamide (NAA) from fatty acid (FA)-NAA equimolar complexes was examined in a JP XI dissolution test apparatus in JP XI disintegration test medium No. 1 (pH 1.2) at 37°C where the carbon number of FA is 14-18. The time required for 50% or 80% of NAA to release (T50 or T80) was measured, and the effect of the constituent FA on T50 or T80 was investigated. The values of T50 or T80 for FA-NAA formed with odd-numbered FA were larger than those for FA-NAA formed with even-numbered FA whose alkyl chain length is one more carbon number longer, though the values of T50 of T80 increased rather regularly with an increase of the alkyl chain length for only even-numbered or odd-numbered FA. The values of T50 and T80 for FA-NAA formed with heptadecanoic acid (C17-NAA) were about 36 and 102 min, respectively, suggesting that C17-NAA may be applicable to the preparaton of a sustained-release drug formulation.
- Yokoyama,Ueda,Fujie
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- A Comprehensive Study on Metal Triflate-Promoted Hydrogenolysis of Lactones to Carboxylic Acids: From Synthetic and Mechanistic Perspectives
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Direct hydrogenolysis of lactone to carboxylic acid (i.e., hydrogenolysis of the Calkoxy-O bond with the carbonyl group untouched) is generally difficult, as the current strategies employing Br?nsted acids as the catalyst usually require harsh conditions such as a high temperature and a high H2 pressure. Herein, we report a developed solvent-free catalytic transformation, in which W(OTf)6 is believed to promote the hydrogenolysis process. This strategy could efficiently hydrogenate lactones to carboxylic acids under extra mild conditions (e.g., a reaction temperature of 2) and showed a broad substrate scope. In addition, the catalytic protocol can be further applied to the hydrogenolysis of polyhydroxyalkanoate, as a renewable polymer, to the corresponding straight-chain carboxylic acids. An extensive mechanistic study was subsequently performed, and the density functional theory calculations revealed a reaction pattern, including the complete cleavage of the C=O bond with the assistance of the W(OTf)6 catalyst. Moreover, the key intermediate created in the mechanism, as an oxonium with an OTf moiety, was successfully detected by electrospray ionization mass spectra. Through a comparison with the Br?nsted acid-catalyzed system, the study confirmed that the existence of the OTf moiety can significantly lower the barriers associated with the rearrangement and elimination processes. Meanwhile, emphasis was placed on the critical role that the anion plays, as well as the fact that the anion effect is directly related to the chemoselectivity.
- Zhu, Rui,Jiang, Ju-Long,Li, Xing-Long,Deng, Jin,Fu, Yao
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- New 19α-hydroxyursane-type triterpenes from the leaves of Meyna spinosa (= Vangueria spinosa), Rubiaceae
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Two new 19α-hydroxyursane-type triterpenes, 2α,3α, 19α,24,28-pentahydroxyurs-12-ene (1) and meyanthic acid, 3β-acetoxy-2β,19α,23-trihydroxyurs-12-en-28-oic acid (2) along with one new aliphatic ester, myricyl pentadecanoate (3) and five known compounds, 1
- Rudrapaul, Prasenjit,Das, Niranjan,De, Utpal Chandra,Dinda, Biswanath
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- Release kinetics of nicotinamide from fatty acid-nicotinamide equimolar complexes. I. Release characteristics of fatty acid complexes
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The rates of release of nicotinamide (NAA) from fatty acid (FA)-NAA complexes, FA-NAA, were determined in a JP XI dissolution test apparatus in 500 ml of JP XI disintegration test medium No. 1 at 37°C. The release rate constant (k) and the activation Gibbs energy (ΔG+) for the release of NAA from FA-NAA were estimated. The results obtained for FA-NAA were compared with previous results obtained for the thiamine disulfide (TDS) complex, (FA)6-(TDS). The plots of log k against the carbon number of the constituent FA (n) presented a zig-zag line which indicates a downward convex at an odd-numbered position. The plots of ΔG+ against n showed a zig-zag line with an upward convex at an odd-numbered position, though the positive value of ΔG± increased rather regularly with an increase of n for either even-numbered or odd-numbered FA. The phenomena that the plots of log k vs. n and ΔG+ vs. n show zig-zag lines due to the difference between even- and odd-numbered FA were the same as observed previously for the release of TDS from (FA)6 (TDS).
- Yokoyama,Ueda,Fujie
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- 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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- Preparation method of carboxylic acid compound
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The invention provides a preparation method of a carboxylic acid compound. The preparation method comprises the following step of taking a lactone component to react with hydrogen in the presence of a compound catalyst to obtain the carboxylic acid compound. The compound catalyst comprises a hydrogenation catalyst and Lewis acid. In the presence of the compound catalyst comprising the hydrogenation catalyst and the Lewis acid, the lactone component is subjected to hydrogenation ring-opening reaction to obtain the carboxylic acid compound. The preparation method has the advantages of moderate reaction conditions and high yield; compared with a traditional method, less byproducts are generated, green and chemical requirements are met and the industrial value is better.
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Paragraph 0113; 0131-0133
(2017/08/29)
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- Cp2TiCl2-Catalyzed Regioselective Hydrocarboxylation of Alkenes with CO2
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Cp2TiCl2-catalyzed regioselective hydrocarboxylation of alkenes with CO2 to give carboxylic acids in high yields has been developed in the presence of iPrMgCl. The reaction proceeds with a wide range of alkenes under mild conditions. Styrene and its derivatives can transform to α-aryl carboxylic acids, and aliphatic alkenes can transform to form alkanoic acids.
- Shao, Peng,Wang, Sheng,Chen, Chao,Xi, Chanjuan
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supporting information
p. 2050 - 2053
(2016/06/01)
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- Silver(I)-Catalyzed deprotection of p -methoxybenzyl ethers: A mild and chemoselective method
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The p-methoxybenzyl protecting group (PMB) on various alcohols and an acid was efficiently and selectively cleaved by the action of a catalytic amount of silver(I) hexafluoroantimonate combined with 0.5 equiv of 1,3,5- trimethoxybenzene in dichloromethane at 40 °C.
- Kern, Nicolas,Dombray, Thomas,Blanc, Aurelien,Weibel, Jean-Marc,Pale, Patrick
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p. 9227 - 9235,9
(2012/12/12)
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- Synthesis and reactions of nitro derivatives of hydrogenated cardanol
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3-n-Pentadecylphenol (hydrogenated cardanol) and its derivative 5-n-pentadecyl-2-tert-butylphenol can be nitrated using nitric acid in acetonitrile or methanol to give mono, di or trinitro products. 5-n-Pentadecyl-2-nitrophenol undergoes reductive carbonylation to give a benzoxazole-2-one derivative. An efficient catalytic oxidation reaction in the presence of MeReO3 has also been studied.
- Attanasi, Orazio A.,Berretta, Stefano,Fiani, Cinzia,Filippone, Paolino,Mele, Giuseppe,Saladino, Raffaele
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p. 6113 - 6120
(2007/10/03)
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- Oxidative photo-decarboxylation in the presence of mesoporous silicas
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FSM-16, a mesoporous silica, was found to catalyze oxidative photo-decarboxylation of α-hydroxy carboxylic acid, phenyl acetic acid derivatives and N-acyl-protected α-amino acids to afford the corresponding carbonyl compounds. Furthermore, FSM-16 proved to be re-usable by re-calcination at 450°C after the reaction.
- Itoh, Akichika,Kodama, Tomohiro,Masaki, Yukio,Inagaki, Shinji
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p. 1571 - 1575
(2007/10/03)
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- Pentadecanoic acid β-D-glucoside from Clerodendrum inerme
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A new aliphatic glucoside, isolated from the hexane extract of aerial parts of Clerodendrum inerme, has been characterized as pentadecanoic acid-β-D-glucoside, on the basis of spectral data analyses and chemical studies. Stigmasterol glucoside was also isolated from the same extract for the first time from this plant species. The butanol extract afforded acacetin and apigenin.
- Pandey,Verma,Gupta
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p. 2161 - 2163
(2007/10/03)
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- INHIBITORS OF YEAST FILAMENTOUS GROWTH AND METHOD OF THEIR MANUFACTURE
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The invention broadly relates to the use of α, β-unsaturated fatty acids to inhibit the filamentous growth of fungi and yeasts and to a method for producing same. In particular the invention relates to the use of optionally substituted C8 to C15 α, β-unsaturated fatty acids or salts, esters or amides thereof for inhibiting or retarding the yeast-to-mycelium transition of organisms having a dimorphic life cycle.
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Page/Page column 12-14
(2008/06/13)
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- TMS Triflate-Catalyzed Cleavage of Prenyl (3-Methylbut-2-enyl) Ester
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(Matrix Presented) Prenyl (3-methylbut-2-enyl) ester is catalytically cleaved by TMS triflate affording carboxylic acid and isoprene in high yield under mild conditions with high chemoselectivity without causing epimerization of the neighboring chiral cen
- Nishizawa, Mugio,Yamamoto, Hirofumi,Seo, Ken,Imagawa, Hiroshi,Sugihara, Takumichi
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p. 1947 - 1949
(2007/10/03)
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- Oxidative photodecarboxylation of α-hydroxycarboxylic acids and phenylacetic acid derivatives with FSM-16
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(Formula Presented) FSM-16, a mesoporous silica, was found to catalyze oxidative photodecarboxylation of α-hydroxy carboxylic acid and phenyl acetic acid derivatives to afford the corresponding carbonyl compounds. Furthermore, FSM-16 proved to be reuseable by recalcination at 450 °C after the reaction.
- Itoh, Akichika,Kodama, Tomohiro,Inagaki, Shinji,Masaki, Yukio
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p. 331 - 333
(2007/10/03)
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- Ion-induced specificity change in polymer-catalyzed solvolyses of p-nitrophenyl alkanoates
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Spheres, rods, or vesicles are formed by the polymer 1, depending on the added salt (tris(hydroxymethyl)methylammonium chloride (TrisCl) or NaCl) and its concentration. Consequently, ion-induced substrate specificity occurs in the 1-catalyzed solvolysis o
- Wang,Fife
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p. 1543 - 1545
(2007/10/03)
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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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- Hair growth composition containing citric acid esters
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Triesters of citric acid are used for inducing, maintaining or increasing hair growth. Compositions for topical application to mammalian hair or scalp comprise an effective amount of from 1% to 99% by weight of an ester of citric acid having the structure (1): where, R1, R2 and R3 each independently represent a branched or unbranched alkyl, alkenyl, aryl, alkylaryl or arylalkyl group, each said group having from 1 to 18 carbon atoms, R4 represents -H, or a branched or unbranched saturated or unsaturated acyl, alkyl, aryl, alkylaryl or aylalkyl group having from 1 to 18 carbon atoms, in the presence of a cosmetically acceptable vehicle for the citric acid ester and in the absence of solid absorbent for the ester;, said effective amount of said ester being sufficient to increase hair growth in the rat, when said composition is applied topically thereto over a period of no more than three months, by at least 10% more than that obtainable using a control composition from which the said ester has been omitted, in accordance with the Rat Hair Growth Test.
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- THE INVENTION OF RADICAL REACTIONS. PART XVIII. DECARBOXYLATIVE RADICAL ADDITION TO ARSENIC, ANTIMONY, AND BISMUTH PHENYLSULPHIDES - A NOVEL SYNTHESIS OF NOR-ALCOHOLS FROM CARBOXYLIC ACIDS
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Carbon centered radicals obtained by decarboxylative transformation of suitable thiohydroxamate esters react with group Va trisphenylsulphides to give intermediates of general formula R-M(SPh)2 (M= As, Sb, Bi).These react spontaneously with air to give the corresponding alcohols.This procedure is especially useful in the case where M=Sb.It is thus sufficient to stir the thiohydroxamate ester with tris(phenylthio)antimony under air to obtain the nor alcohol directly and in high yield.The intermediate organometalloid could also be oxidised with nitrogen dioxide to give the expected nitroalkane albeit in only modest yield.The corresponding organobismuth intermediate derived from 3,3-diphenylpropionic acid could actually be isolated thereby providing strong evidence for the proposed mechanism.
- Barton, Derek H. R.,Bridon, Dominique,Zard, Samir Z.
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p. 2615 - 2626
(2007/10/02)
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- REACTION OF ALKOXYHYDROPEROXIDES WITH METAL SALTS. ALKYL HALIDE PREPARATION
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A synthesis is described of alkyl chlorides by reaction of methoxy hydroperoxides, prepared from 1-alkenes by ozonisation in methanol, with ferric chloride: RCH=CH2 --> RCH(OOH)OCH3 --> R. --> RCl.Yields of 1-chlorotetradecane were about 60percent; those of other halides from 38 to 57percent.
- Cardinale, G.,Grimmelikhuysen, J. C.,Laan, J. A. M.,Lier, F. P. van,Steen, D. van der,Ward, J. P.
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p. 5971 - 5978
(2007/10/02)
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- SELECTIVE MIXED COUPLING OF CARBOXYLIC ACIDS (II). -PHOTOLYSIS OF UNSYMMETRICAL DIACYLPEROXIDES WITH ALKENYL-, HALO-, KETO-, CARBOXYL-GROUPS AND A CHIRAL α-CARBON. COMPARISON WITH THE MIXED KOLBE ELECTROLYSIS.
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- Alkenoyl and functionalized alkanoyl dodecanoyl peroxides are prepared in 70 to 97 percent yield and photolyzed at -78 deg C.Thereby 4- to 10-alkenoyl and 4-alkynoyl peroxides afford good yields (56 - 68 percent) of unsymmetrical coupling products.Similarly α- to δ-haloalkanoyl, cholanoyl or 3- and 4-carboxyalkanoyl peroxides can be coupled (40 - 70 percent).The α-chiral diacyl peroxide 1s undergoes the photochemical coupling reaction with 80 percent retention of its configuration.The photolysis of diacyl peroxides at -78 deg C proves to be a favorable supplement of the Kolbe-electrolysis in cases, where the electrolysis fails or produces low yields.
- Feldhues, Michael,Schaefer, Hans J.
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p. 4213 - 4236
(2007/10/02)
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- Nitrosochlorination and Azidoiodination of Methyl 4-Oxo-trans-2-octadecenoate
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Nitrosochlorination of methyl 4-oxo-trans-2-octadecenoate (I) gives 2(3)-chloro-3(2)-nitroso-4-oxooctadecanoate (II) along with the cleavage products, pentadecanoic (III) and 2-oxo-hexadecanoic (IV) acids, and the isomerised methyl 2(3)-hydroxy-3(2)-oximi
- Khan, Mushfiquddin,Ahmad, Suhail,Ahmad, M. S.,Osman, S. M.
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p. 1043 - 1046
(2007/10/02)
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- Photosensitive Monolayers. Photochemistry of Long-Chain Diazo and Azide Compounds at the Air-Water Interface
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The photochemistry of a number of surface-active diazo and azide compounds was investigated in monolayers at the air-water boundary.Irradiation of long-chain α-diazo ketones with ultraviolet light leads to rapid loss of nitrogen.The resulting ketenes react with the subphase to generate carboxylic acids (photochemical Arndt-Eistert reaction) and dimerize to give β-lactones as side-products.A long-chain diester of 2-diazopropanedioic acid loses nitrogen and adds water, yielding the diester of 2-hydroxypropanedioic acid. α-Azido ketones split off nitrogen and the resulting isocyanates react with water (photoche mical Curtius reaction) and undergo further degradation to give complex product mixtures.These reactions lead to pronounced changes in the spreading behavior of the monolayers.Depending on functional group, chain length, substrate pH, and temperature it is possible to achieve changes in compressibility and collapse pressure, disappearance of expanded phases, collapse of monolayers to give oily films, or disappearance of monolayers by dissolution in the subphase.
- Holden, David A.,Ringsdorf, Helmut,Haubs, Michael
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p. 4531 - 4536
(2007/10/02)
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- SYNTHETIC APPLICATION OF PHENYLTHIO- AND PHENYLSULFONYLMETHYL ETHERS TO ALDEHYDES, METHYLALS, CARBOXYLIC ACIDS, AND ENOL OR DIENOL ETHERS
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Novel synthetic application of the title compounds to aldehydes, methylals, carboxylic acids, and enol or dienol ethers has been newly developed.
- Mandai, Tadakatsu,Hara, Kiyomi,Nakajima, Tsukasa,Kawada, Mikio,Otera, Junzo
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p. 4993 - 4996
(2007/10/02)
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- NEW CONCEPTS IN THE MECHANISM OF THE THERMAL DECOMPOSITION OF OZONIDES
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The mechanism for the thermal decomposition of ozonides which postulates the formation of the bipolar ion RC+H-OO- as an unstable intermediate is not in accordance with experiments on the decomposition of ozonides in methanol.A study
- Yur'ev, Yu. N.
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p. 1020 - 1024
(2007/10/02)
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- Preparation of acids
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A method of preparing carboxylic acids is provided by heating an acylhydroximyl halide in an aqueous medium at elevated temperatures.
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