- Asymmetric Synthesis of Optically Active 3-Cyclohexene-1-carboxylic Acid Utilizing Lactic Ester as a Chiral Auxiliary in the Diastereoselective Diels–Alder Reaction
-
The optically active 3-cyclohexene-1-carboxylic acid was synthesized through a TiCl4-catalyzed diastereoselective Diels–Alder reaction utilizing lactic acid ester as a chiral auxiliary, which can be removed by washing with H2O. The (S)- and (R)-isomers were both derived from easily available ethyl l-lactate.
- Ochiai, Hidenori,Hayashi, Wakana,Nishiyama, Akira,Fujita, Ryunosuke,Kubota, Shunichi,Sasagawa, Miwa,Nishi, Tatsuya
-
supporting information
p. 1002 - 1009
(2022/02/09)
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- Selective α,δ-hydrocarboxylation of conjugated dienes utilizing CO2and electrosynthesis
-
To date the majority of diene carboxylation processes afford the α,δ-dicarboxylated product, the selective mono-carboxylation of dienes is a significant challenge and the major product reported under transition metal catalysis arises from carboxylation at the α-carbon. Herein we report a new electrosynthetic approach, that does not rely on a sacrificial electrode, the reported method allows unprecedented direct access to carboxylic acids derived from dienes at the δ-position. In addition, the α,δ-dicarboxylic acid or the α,δ-reduced alkene can be easily accessed by simple modification of the reaction conditions. This journal is
- Buckley, Benjamin R.,Elmorsy, Saad S.,Malkov, Andrei V.,Mashaly, Mohammad A.,Said, Samy B.,Sheta, Ahmed M.
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p. 9109 - 9114
(2020/09/17)
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- Organocatalyzed Aerobic Oxidation of Aldehydes to Acids
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The first example organocatalyzed aerobic oxidation of aldehydes to carboxylic acids in both organic solvent and water under mild conditions is developed. As low as 5 mol % N-hydroxyphthalimide was used as the organocatalyst, and molecular O2 was used as the sole oxidant. No transition metals or hazardous oxidants or cocatalysts were involved. A wide range of carboxylic acids bearing diverse functional groups were obtained from aldehydes, even from alcohols, in high yields.
- Dai, Peng-Fei,Qu, Jian-Ping,Kang, Yan-Biao
-
supporting information
p. 1393 - 1396
(2019/02/26)
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- Zinc Oxide-Catalyzed Dehydrogenation of Primary Alcohols into Carboxylic Acids
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Zinc oxide has been developed as a catalyst for the dehydrogenation of primary alcohols into carboxylic acids and hydrogen gas. The reaction is performed in mesitylene solution in the presence of potassium hydroxide, followed by workup with hydrochloric acid. The transformation can be applied to both benzylic and aliphatic primary alcohols and the catalytically active species was shown to be a homogeneous compound by a hot filtration test. Dialkylzinc and strongly basic zinc salts also catalyze the dehydrogenation with similar results. The mechanism is believed to involve the formation of a zinc alkoxide which degrades into the aldehyde and a zinc hydride. The latter reacts with the alcohol to form hydrogen gas and regenerate the zinc alkoxide. The degradation of a zinc alkoxide into the aldehyde upon heating was confirmed experimentally. The aldehyde can then undergo a Cannizzaro reaction or a Tishchenko reaction, which in the presence of hydroxide leads to the carboxylic acid.
- Monda, Fabrizio,Madsen, Robert
-
supporting information
p. 17832 - 17837
(2018/11/23)
-
- Preparation method of cycloalkene carboxylic acid
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The invention discloses a preparation method of cycloalkene carboxylic acid. The preparation method of cycloalkene carboxylic acid represented as the molecular formula I comprises steps as follows: unsaturated fatty acid represented as the molecular formula II and 1,3-butadiene are subjected to polymerization reaction for 1-3 h in a pressure vessel at the temperature of 120-300 DEG C with aqueousphase serving as a solvent in an inert environment with nitrogen pressurized gauge pressure being 1.0-5.0 MPa, then a synthesis liquid is transferred into a distillation kettle for distillation underthe negative-pressure condition, and cycloalkene carboxylic acid represented as the molecular formula I is obtained. Overall, the preparation method has the advantages as follows: reaction speed is high, reaction period is short, the reaction is performed in the aqueous phase, purification of cycloalkene carboxylic acid is facilitated, operation is simple and convenient, continuous production canbe executed, product quality is effectively improved, and use value is quite high.
- -
-
Paragraph 0017; 0018; 0019; 0020
(2018/05/16)
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- An Efficient Aerobic Oxidation Protocol of Aldehydes to Carboxylic Acids in Water Catalyzed by an Inorganic-Ligand-Supported Copper Catalyst
-
A method for the aerobic oxidation of aldehydes to carboxylic acids in water by using an inorganic-ligand-supported copper catalyst was developed. This method was performed with the use of atmospheric oxygen as the sole oxidant under extremely mild aqueous conditions, and furthermore, a wide range of aldehydes with various functional groups were tolerated. The copper catalyst could be recycled and used in successive reactions at least six times without any appreciable degradation in performance. This method is operationally simple and avoids the use of high-costing, toxic, air/moisture-sensitive, and commercially unavailable organic ligands. The generality of this method gives it potential to be used on the industrial scale.
- Yu, Han,Ru, Shi,Zhai, Yongyan,Dai, Guoyong,Han, Sheng,Wei, Yongge
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p. 1253 - 1257
(2018/02/16)
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- Method for preparing acid through oxidating alcohols or aldehydes by oxygen
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The invention provides a method for preparing acid through oxidating alcohols or aldehydes by using oxygen or oxygen in air as an oxidant. The method comprises the steps: oxidating the alcohols or aldehydes to produce the acid at room temperature in an organic solvent in a manner of taking ferric nitrate (Fe(NO3)3.9H2O), 2,2,6,6-tetramethylpiperidyl nitrogen oxide (TEMPO) and an inorganic halide as catalysts and taking the oxygen or air as an oxidant, and oxidating diols to produce lactone; or, carrying out a reaction on the aldehydes, which serve as a raw material, under neutral conditions by taking ferric nitrate as a catalyst, and oxidating the aldehydes to produce the acid and peroxy acid. The method has the advantages that the method is environmentally friendly, the cost is low, the yield is high, the atomic economical efficiency is high, the compatibility of substrate functional groups is good, the reaction conditions are mild, a reaction scale can be enlarged, and the like, so that the method is suitable for being applied to industrial production.
- -
-
Paragraph 0051; 0052; 0053; 0054; 0094; 0095; 0096
(2017/09/29)
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- Silver-Catalyzed Dehydrogenative Synthesis of Carboxylic Acids from Primary Alcohols
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A simple silver-catalyzed protocol has been developed for the acceptorless dehydrogenation of primary alcohols into carboxylic acids and hydrogen gas. The procedure uses 2.5 % Ag2CO3 and 2.5–3 equiv of KOH in refluxing mesitylene to afford the potassium carboxylate which is then converted into the acid with HCl. The reaction can be applied to a variety of benzylic and aliphatic primary alcohols with alkyl and ether substituents, and in some cases halide, olefin, and ester functionalities are also compatible with the reaction conditions. The dehydrogenation is believed to be catalyzed by silver nanoparticles that are formed in situ under the reaction conditions.
- Ghalehshahi, Hajar Golshadi,Madsen, Robert
-
p. 11920 - 11926
(2017/09/07)
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- BORON-BASED CYCLOADDITION CATALYSTS AND METHODS FOR THE PRODUCTION OF BIO-BASED TEREPHTHALIC ACID, ISOPHTHALIC ACID AND POLY (ETHYLENE TEREPHTHALATE)
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Methods for producing cycloaddition products comprising: reacting a diene with a dienophile in the presence of one or more boron-based catalysts of Formula I or Formula II are provided. In particular, the methods can be used to prepare 4-methyl-3-cyclohexene- 1-carboxylic acid and 3-methyl-3-cyclohexene-l-carboxylic acid, including bio-based versions thereof. The cycloaddition products can be advantageously used in the production of terephthalic acid and isophthalic acid, and ultimately, poly(ethylene terephthalate), and bio-based versions thereof. Formula I Formula II
- -
-
Paragraph 00171; 00187
(2017/04/11)
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- An Efficient Iron(III)-Catalyzed Aerobic Oxidation of Aldehydes in Water for the Green Preparation of Carboxylic Acids
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The first example of a heterogeneous iron(III)-catalyzed aerobic oxidation of aldehydes in water was developed. This method utilizes 1 atmosphere of oxygen as the sole oxidant, proceeds under extremely mild aqueous conditions, and covers a wide range of various functionalized aldehydes. Chromatography is generally not necessary for product purification. Its operational simplicity, gram-scale oxidation, and the ability to successively reuse the catalyst, make this new methodology environmentally benign and cost effective. The generality of this methodology gives it the potential to be used on an industrial scale.
- Yu, Han,Ru, Shi,Dai, Guoyong,Zhai, Yongyan,Lin, Hualin,Han, Sheng,Wei, Yongge
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p. 3867 - 3871
(2017/03/27)
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- Enhancing the catalytic activity of Ru NPs deposited with carbon species in yolk-shell nanostructures
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The synthesis of metal NPs with a well-defined size, shape and composition provides opportunities for tuning the catalytic performance of metal NPs. However, the presence of a stabilizer on the metal surface always blocks the active sites of metal NPs. Herein, we report an efficient method to remove the stabilizer on the metal surface via H2 pyrolysis with Ru-poly(amindoamine) encapsulated in silica-based yolk-shell nanostructures as an example. The CO uptake amount of Ru NPs increases sharply after H2 pyrolysis, indicating that the exposure degree of Ru NPs is increased. No aggregation of the colloidal Ru NPs occurs after H2 pyrolysis, which could be mainly assigned to the protection effect of C and N species formed on Ru NPs. The overall activity of Ru NPs in the yolk-shell nanostructure after the pyrolysis could reach as high as 20 300 mmol per mmol Ru per h in the hydrogenation of toluene, which is much higher than that of most reported Ru-based solid catalysts. It was found that the yolk-shell nanostructure could efficiently prevent the leaching of Ru NPs during the catalytic process. Ru NPs in the yolk-shell nanostructure could also catalyze the hydrogenation of benzoic acid and Levulinic acid with high activity and selectivity.
- Guo, Miao,Lan, Guojun,Peng, Juan,Li, Mingrun,Yang, Qihua,Li, Can
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p. 10956 - 10963
(2016/07/21)
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- Iron Catalysis for Room-Temperature Aerobic Oxidation of Alcohols to Carboxylic Acids
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Oxidation from alcohols to carboxylic acids, a class of essential chemicals in daily life, academic laboratories, and industry, is a fundamental reaction, usually using at least a stoichiometric amount of an expensive and toxic oxidant. Here, an efficient and practical sustainable oxidation technology of alcohols to carboxylic acids using pure O2 or even O2 in air as the oxidant has been developed: utilizing a catalytic amount each of Fe(NO3)3·9H2O/TEMPO/MCl, a series of carboxylic acids were obtained from alcohols (also aldehydes) in high yields at room temperature. A 55 g-scale reaction was demonstrated using air. As a synthetic application, the first total synthesis of a naturally occurring allene, i.e., phlomic acid, was accomplished.
- Jiang, Xingguo,Zhang, Jiasheng,Ma, Shengming
-
supporting information
p. 8344 - 8347
(2016/07/26)
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- Palladium- and ruthenium-catalyzed cycloisomerization of enynamides and enynhydrazides: A rapid approach to diverse azacyclic frameworks
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I want to ride my azacycle: The title reaction of enynamides affords a wide diversity of azacycles. The reactions are high-yielding, highly stereoselective, and proceed rapidly under mild reaction conditions. Equivalent transformations using enynhydrazides offer new routes to pyrazole and indazole scaffolds. Boc=tert-butoxycarbonyl, EWG=electron-withdrawing group, Ns=4-nitrobenzenesulfonyl, Ts=4-toluenesulfonyl. Copyright
- Walker, P. Ross,Campbell, Craig D.,Suleman, Abid,Carr, Greg,Anderson, Edward A.
-
supporting information
p. 9139 - 9143
(2013/09/12)
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- Cooperative N-Heterocyclic Carbene (NHC) and Ruthenium Redox Catalysis: Oxidative Esterification of Aldehydes with Air as the Terminal Oxidant
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The paper describes a cooperative NHC (N-heterocyclic carbene) and ruthenium-based redox catalysis for the mild aerobic oxidative esterification of various aromatic and heteroaromatic aldehydes. The ruthenium(II) complex Ru(bpz)3(PF6)2 (bpz=2,2′-bipyrazine) as catalyst is shown to be compatible with free NHCs. The NHC is used in these cascade reactions for the umpolung of the aldehyde to form the corresponding Breslow intermediate which in turn gets oxidized to an acylazolium ion by the ruthenium redox catalyst. Air is used as a terminal oxidant for oxidation (regeneration) of the ruthenium catalyst. In addition, we will show that in the absence of the ruthenium redox catalyst and alcohol, NHC-catalyzed aerobic oxidation of aldehydes delivers the corresponding acids in good to excellent yields. Mechanistic studies and DFT calculations supporting our suggested mechanisms are provided. Copyright
- Zhao, Junfeng,Mueck-Lichtenfeld, Christian,Studer, Armido
-
supporting information
p. 1098 - 1106
(2013/05/21)
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- PROCESS FOR PRODUCING OPTICALLY ACTIVE CARBOXYLIC ACID
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It has been demanded to provide a process for industrially producing an intermediate for a compound that exhibits an inhibitory effect on activated blood coagulation factor X and is useful as a preventive and/or therapeutic agent for thrombotic diseases. The present invention provides a process for producing the (R-α-phenylethylamine salt of (S)-3-cyclohexene-1-carboxylic acid, comprising reacting 3-cyclohexene-1-carboxylic acid and (R)-α-phenylethylamine using a mixed solvent of water and acetone or a mixed solvent of water and ethyl acetate as a solvent.
- -
-
Page/Page column 13
(2011/10/12)
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- HYDROGENATION OF ESTERS WITH RU/TETRADENTATE LIGANDS COMPLEXES
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The present invention relates to the field of catalytic hydrogenation and, more particularly, to the use of Ru complexes with tetradentate ligands having at least one amino or imino coordinating group and at least one phosphino coordinating group in hydrogenation processes for the reduction of esters or lactones into the corresponding alcohol or diol respectively.
- -
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Page/Page column 9
(2008/06/13)
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- A high-performance selective oxidation system for the facile production of fine chemicals
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MnIIIAlPO-5 and CrVIAlPO-5 redox (microporous) catalysts are effective, in the presence of dissolved acetylperoxyborate (APB) under mild conditions (333-373 K), and much superior to the titanosilicate, TS-1 (also a single-site heterogeneous catalyst), in the selective oxidation of primary, secondary, benzylic and other unsaturated alcohols, p-cymene, methyl cyclohexene and other speciality organics which are of value in the fine-chemical and pharmaceutical industries. The Royal Society of Chemistry.
- Raja, Robert,Thomas, John Meurig,Greenhill-Hooper, Mike,Doukova, Violeta
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p. 1924 - 1926
(2008/02/09)
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- HYDROGENATION OF ESTERS WITH RU/TETRADENTATE LIGANDS COMPLEXES
-
The present invention relates to the field of catalytic hydrogenation and, more particularly, to the use of Ru complexes with tetradentate ligands, having at least one amino or imino coordinating group and at least one phosphino coordinating group, in hydrogenation processes for the reduction of esters or lactones into the corresponding alcohol or diol respectively.
- -
-
Page/Page column 18-19
(2008/06/13)
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- Method for preparing cyclohexyl phenyl ketone from 1,3- butadiene and acrylic acid
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Disclosed is a synthesis method of cyclohexyl phenyl ketone with a high selectivity and a high yield from 1,3-butadiene and acrylic acid in the presence or absence of benzene or a non-aromatic organic solvent in the same reaction without a step of separating or purifying intermediates, the synthesis method including sequentially carrying out a [2+4] Diels-Alder reaction, a hydrogenation reaction, a chlorination reaction and a Friedel-Crafts reaction in the presence/absence of benzene or a non-aromatic organic solvent without separation of intermediates.
- -
-
-
- Catalytic osmium-assisted oxidative cleavage of olefins
-
An osmium-assisted process for the oxidative cleavage of oxidizable organic compounds such as unsaturated organic compounds, including alkenes and olefins into aldehydes, carboxylic acids, esters, or ketones. The process uses a metal catalyst comprising osmium and a peroxy compound selected from the group consisting of peroxymonosulfuric acid and salts thereof to oxidatively cleave the oxidizable organic compound. In particular, the process enables aldehydes, carboxylic acids, esters, or ketones to be selectively produced from the corresponding mono-, 1,1-di-, 1,2-di-, tri-, or tetra-substituted olefins in a reaction that produces the result of ozonolysis but with fewer problems. The present invention further provides a process for oxidizing an aldehyde alone or with the osmium in an interactive solvent to produce an ester or carboxylic acid.
- -
-
-
- Facile oxidation of aldehydes to acids and esters with Oxone
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(Matrix presented) A highly efficient, mild, and simple protocol is presented for the oxidation of aldehydes to carboxylic acids utilizing Oxone as the sole oxidant. Direct conversion of aldehydes in alcoholic solvents to their corresponding ester products is also reported. These reactions may prove to be valuable alternatives to traditional metal-mediated oxidations.
- Travis, Benjamin R.,Sivakumar, Meenakshi,Hollist, G. Olatunji,Borhan, Babak
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p. 1031 - 1034
(2007/10/03)
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- A practical new chiral controller for asymmetric Diels-Alder and alkylation reactions
-
(formula presented) The enantiomerically pure hydroxy sulfones (+)- and (-)-2 have been prepared from 1,2-epoxycyclohexane by a simple and practical procedure. The acrylate esters of these alcohols undergo BCl3-catalyzed Diels-Alder reactions with a variety of dienes at -78 to -55°C in CH2Cl2 or C7H8 with high dienophile face selectivity (Table 1). The chiral esters so formed are readily cleaved with recovery of the controllers (+)- or (-)-2. Esters of (+)- and (-)-2 can be converted to Z-polassium enolates and alkylated with high face selectivity.
- Sarakinos, Georgios,Corey
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p. 1741 - 1744
(2008/02/11)
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- Crystal structure of molecular complex (R)-(+)-3-cyclohexene-1-carboxylic acid with brucine
-
The 3-cyclohexene-1-carboxylic acid was prepared and resolved with brucine. Absolute configuration of (R)-(+)-3-cyclohexene-1-carboxylic acid was confirmed by X-ray diffraction methods.
- Krajewski,Ciunik
-
p. 1687 - 1696
(2007/10/03)
-
- Antiparasitic agents
-
The invention provides novel compounds having the formula: STR1 wherein R when taken individually is H; R1 when taken individually is H or OH; R and R1 when taken together represent a double bond; R2 is an alpha-branched C3 -C8 alkyl, alkenyl, alkynyl, alkoxyalkyl or alkylthioalkyl group; a C3 -C8 cycloalkyl, C5 -C8 cycloalkenyl or C5 -C8 cycloalkylalkyl group, any of which may be substituted by methylene or one or more C1 -C4 alkyl groups or halo atoms; or a 3 to 6 membered oxygen or sulphur containing heterocyclic ring which may be substituted by one or more C1 -C4 alkyl groups or halo atoms; R3 is hydrogen or methyl; R4 is H or 4'-(alpha-L-oleandrosyl)-alpha-L-oleandrosyloxy with the proviso that when R2 is alkyl it is not isopropyl or sec-butyl; when R4 is H, each of R and R1 is H, and R2 is not methyl or ethyl; and when R4 is H, R is H, R1 is OH, and R2 is not 2-buten-2-yl, 2-penten-2-yl or 4-methyl-2-penten-2-yl. The compounds are broad spectrum antiparasitic agents having utility as anthelmintics, ectoparasiticides, insecticides and acaricides. The invention also provides a process for producing the novel avermectin and milbemycin derivatives by adding a carboxylic acid or derivative thereof to a fermentation of an avermectin or milbemycin producing organism.
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-
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- Electrooxidative C-S cleavages as a neutral deprotection for carbocxylic acids
-
C-S Bond cleavages of S-t-butyl thioates (1) and 4-methoxyphenylthiomethyl esters (2) are achieved electrochemically in an indirect and direct manner, respectively, in aqueous acetonitrile, affording an efficient method for deprotection of carboxylic acids under neutral conditions.
- Kimura,Matsubara,Yamamoto,Sawaki
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p. 867 - 876
(2007/10/02)
-
- Factors Influencing Conformational Preferences in Cyclohexenes
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Conformational preferences have been measured for the first time for 4-substituted cyclohexenes in a solvent of low polarity.Measurements were made for the substituents Cl, Br, I, OH, OSiMe3, and CN and were compared with conformational preferences in cyclohexyl and exo-methylenecyclohex-3-yl.In the nearly nonpolar solvent CF2Cl2, in which intramolecular interactions are maximized, there is a much larger axial population for cyclohexen-4-yl than in cyclohexyl or exo-methylenecyclohex-3-yl.In particular, the dipolar interaction of the endocyclic double bond is reduced from that of the exocyclic double bond.This observation is confirmed by the almost negligible effect of symmetrizing the endocyclic double bond through 1,2-dimethyl substitution, in contrast with the large effect of symmetrizing the exocyclic double bond through 7,7-dimethyl substitution.Polar solvents increase the proportion of the axial conformer to a smaller extent for the endocyclic than for the exocyclic system, again in agreement with a lower dipolar effect in the endocyclic case.These results emphasize the anisotropic nature of the steric effects of double bonds.
- Lambert, Joseph B.,Marko, Dale E.
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p. 7978 - 7982
(2007/10/02)
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- Oxo Complexes of Ruthenium(VI) and (VII) as Organic Oxidants
-
Oxidation of a variety of saturated and unsaturated primary and secondary alcohols by tetraoxoruthenate(VI), 2-, tetraoxoruthenate(VII), -, barium trans-trioxodihydroxoruthenium(VI), trans-Ba, dioxotrichlororuthenate(VI), -, and dioxodichlorobipyridylruthenate(VI),, has been studied; 2- may be used catalytically in conjunction with 2- under basic aqueous conditions.For some of these systems, the oxidation of several aldehydes and amines were also examined.Both 2- and - oxidise primary alcohols to carboxylic acids and secondary alcohols to ketones; the reactivity of these reagents towards unsaturated alcohols was studied in particular.The new species and also cleanly oxidise a wide range of alcohols to aldehydes and ketones without attack of double bonds.Ba functions as a heterogeneous oxidant in dichloromethane, oxidising only the most reactive alcohols to aldehydes.
- Green, Graham,Griffith, William P.,Hollinshead, David M.,Ley, Steven V.,Schroeder, Martin
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p. 681 - 686
(2007/10/02)
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- Conversion of Aliphatic Amides into Amines with benzene. Scope of the Reaction
-
The reagent benzene, PIFA, brings about the facile oxidative rearrangement of aliphatic amides to amines in mildly acidic (pH 1-3) mixed aqueous-organic solvents.Aromatic amines are further oxidized by the reagent and therefore cannot be prepared by this method.The rearrangement, which is in effect an "Hofmann rearrangement", occurs with complete retention of configuration in the migrating group, and the rate of the reaction follows approximately the migratory aptitudes of the migrating groups determined for other similar reactions.Isocyanates are intermediates in the rearrangement but are rapidly hydrolyzed to the product amines under the mildly acidic conditions.The acidic conditions protect the product amines from reacting with the isocyanate intermediates and forming ureas.The reaction is accelerated by addition of pyridine to a pH of approximately 3.The scope of the reaction is discussed.
- Loudon, G. Marc,Radhakrishna, A. S.,Almond, Merrick R.,Blodgett, James K.,Boutin, Raymond H.
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p. 4272 - 4276
(2007/10/02)
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- CHEMOSELECTIVE OXIDATION WITH MOLYBDENIUM CATALYST-t-BUTYL HYDROPEROXIDE
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Benzyltrimethylammonium tetrabromooxomolybdate is an excellent chemoselective catalyst to oxidize secondary alcohols to ketones, primary alcohols to esters, and aldehydes to acids or esters with t-butyl hydroperoxide.
- Masuyama, Yoshiro,Takahashi, Masato,Kurusu, Yasuhiko
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p. 4417 - 4420
(2007/10/02)
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- Pulsed Infrared Laser Inducement of Multiple Reaction Channels in Ethyl 3-Cyclohexene-1-carboxylate
-
The pulsed CO2 laser-induced reaction of ethyl 3-cyclohexenecarboxylate, a large organic ester with two reaction channels differing by ca. 13 kcal mol-1 in threshold energies, was studied over the 0.02-0.20-torr pressure range.The absorbed laser energy and the reaction probabilities were measured as functions of laser energy, laser intensity, and added bath gas.The reaction product ratio was very dependent on the incident laser energy but almost independent of the laser pulse duration (intensity) at constant fluence.The dependence of the product ratio on the absorbed energy was satisfactorily explained for low fractional reaction by a postpulse model using RRKM rate constants and a broad distribution function (simulated as a Boltzmann distribution) with mean energy equal to the absorbed laser energy.In addition to implying that the internal energy is randomly distributed prior to reaction, the model implies that all, or nearly all, of the molecules absorb the laser energy.Addition of bath gas significantly lowered the reaction probability but had only a minor influence on the product partitioning ratio; these results were also interpreted satisfactorily by the model calculations.The laser-driven secondary reaction of the ethyl acrilate product, even for single-pulse experiments, is important.
- Setser, D. W.,Nguyen, Hanh H.,Danen, Wayne C.
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p. 408 - 417
(2007/10/02)
-
- SYNTHESIS OF CYCLOHEXENYL-SUBSTITUTED ACRYLIC AND 3-HYDROXYPROPIONIC ACIDS AND THEIR HOMOLOGS
-
The corresponding 3-cyclohexenyl-substituted Z- and E-acrylic and 3-hydroxypropionic acids were synthesized from 3-cyclohexene-1-carbaldehyde and its methyl derivatives.Dehydration of the products under various conditions leads to the formation of the E isomers of the substituted acrylic acid and also isomerization, aromatization, and cyclization products.
- Gramenitskaya, V. N.,Inozemtseva, L. V.,Koz'mina, E. A.,Vul'fson, N. S.
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p. 2260 - 2267
(2007/10/02)
-
- Protonated cyclopropanes in α-aminoketone deamination
-
Deamination of 2-amino-4,4-dideuterio-6,6-dimethylcyclohexanone, 2-exo-amino- and 2-endo-amino-norbornane-3-one, 2-diazo-norbornan-3-one, 2-exo-amino-5,6-exo-dideuterionorbornan-3-one and the corresponding 5,6-endo-dideuterio isomer has been studied.The nature of the products, the deuterium location in them, and the high retention of steric identity in the carbocations are interpreted in terms of ?-bond participation leading to corner- and edge-protonated cyclopropanes as reaction intermediates.Results with other destabilized carbocations are correlated.
- Edwards, Oliver E.,Dixon, John,Elder, John W.,Kolt, Ralph J.,Lesage, Maurice
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p. 2096 - 2115
(2007/10/02)
-
