- Ionization of 2-Brexyl Brosylate: An Exo-Like Rate without Symmetrical Bridging
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2-Brexyl brosylate and exo-norbornyl brosylate show similar ionization rates but differ markedly with respect to internal return, secondary isotope effect, and optical activity
- Nickon, Alex,Swartz, D.,Sainsbury, Donald M.,Toth, Bruce R.
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Read Online
- Consecutive addition esterification and hydrolysis of cyclic olefins catalyzed by multi-SO3H functionalized multi heteropolyanion-based ionic hybrids undersolvent-free conditions
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An efficient protocol for the synthesis of cycloalkyl carboxylates and alcohols from cyclic olefins is described. The cyclic olefins were converted to corresponding target molecules under solvent-free conditions catalyzed by two novel multi-SO3H functionalized multi heteropolyanion-based ionic hybrids through one-pot consecutive addition esterification and hydrolysis reactions. This approach has several advantages, including high yield, simple workup and simple purification.
- Zheng, Guocai,Li, Xinzhong
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p. 933 - 941
(2019/03/17)
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- Preparation method of (methyl)acrylate with bridged ring structure
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The invention relates to a preparation method of (methyl)acrylate with a bridged ring structure. The (methyl)acrylate is synthesized through three-step reaction comprising the following steps: firstly, carrying out direct addition on saturated fatty acid and bridged ring olefin or a derivative thereof; rectifying and purifying, thus removing a byproduct generated by self-polymerization of the bridged ring olefin; then carrying out hydrolysis to obtain corresponding bridged ring alcohol or a derivative thereof; finally, carrying out ester exchange reaction between the (methyl)acrylate and the bridged ring alcohol or the derivative thereof to obtain the (methyl)acrylate with the bridged ring structure. The preparation method provided by the invention is simple, and the steps are easy to operate; a target product is obtained through the three-step reaction and the yield is high; the disadvantages of a rectification process of a direct esterification technology that the requirements are high and the yield is low are overcome; the content of a residual cycloolefin monomer in the product is low; when the preparation method is applied to resin synthesis, the disadvantages that resin becomes yellow and the viscosity is increased can be remarkably relieved.
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Paragraph 0019; 0021; 0022; 0027-0029
(2020/06/16)
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- Addition of alcohols and acids to olefins in presence of zeolite catalyst H-beta
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By studying the reactions of styrene and norbornene with different alcohols and carbonic acids in the presence of heterogenic catalyst, it was found that the selected zeolite H-Beta is an active and selective catalyst for these reactions. Ethers and esters of norbornene have exo-configuration. It has been established that reaction of norbornene with diols, catalyzing by zeolite Beta, leads to the formation of esters, which have not been found before.
- Raskildina, Gulnara Z.,Kazakova, Anna N.,Mikhailova, Natalia N.,Grigor'Eva, Nelly G.,Kutepov, Boris I.,Zlotsky, Simon S.
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p. 811 - 815
(2015/06/30)
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- Hydroacetoxylation of olefins with acetic acid genetated in situ from vinyl acetate in the presence of ruthenium complexes
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Ruthenium complexes catalyze the decomposition of vinyl acetate releasing the acetic acid and its subsequent addition to linear and cyclic olefins.
- Khusnutdinov,Shchadneva,Khisamova,Dzhemilev
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experimental part
p. 155 - 160
(2011/05/03)
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- Stereoselective exo-addition to norbornenes of acetic acid generated from vinyl acetate in the presence of rhodium complexes
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Rhodium complexes catalyzed decomposition of vinyl acetate with liberation of acetic acid and subsequent stereoselective exo-addition of the latter to norbornene and its derivatives under mild conditions.
- Khusnutdinov,Shchadneva,Mukhametshina
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experimental part
p. 54 - 58
(2010/06/19)
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- Dual behavior of alcohols in iodine-catalyzed esterification under solvent-free reaction conditions
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The dual behavior phenomenon of alcohols in iodine-catalyzed esterification under solvent-free reaction conditions (SFRCs) is described; the governing factor is the stability of the carbonium ion generated from the alcohol; high concentration reaction conditions (HCRCs) or dilute solutions are much less suitable. In the case of benzylic alcohols, loss of optical activity was noted, whereas alkyl alcohols furnished a product with retention of stereochemistry.
- Jereb, Marjan,Vra?i?, Dejan,Zupan, Marko
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scheme or table
p. 2347 - 2352
(2009/09/06)
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- Iron-catalysed green synthesis of carboxylic esters by the intermolecular addition of carboxylic acids to alkenes
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Iron triflate, in situ-formed from FeCl3 and triflic acid, or FeCl3 and silver triflate efficiently catalyse the intermolecular addition of carboxylic acids to various alkenes to yield carboxylic esters; the reaction is applicable to the synthesis of unstable esters, such as acrylates. The Royal Society of Chemistry.
- Choi, Jun-Chul,Kohno, Kazufumi,Masuda, Daisuke,Yasuda, Hiroyuki,Sakakura, Toshiyasu
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p. 777 - 779
(2008/09/16)
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- Cationic iron-catalyzed addition of carboxylic acids to olefins
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Cationic iron salts were found to be good catalysts for intraand intermolecular addition of carboxylic acids to olefins, which afforded the corresponding esters in good yields. Copyright
- Komeyama, Kimihiro,Mieno, Yasuhiro,Yukawa, Syotaro,Morimoto, Takayuki,Takaki, Ken
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p. 752 - 753
(2008/02/09)
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- Synthesis of esters from cage-like unsaturated hydrocarbons, carboxylic acid anhydrides, and water
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A convenient method for the preparation of esters was developed on the basis of reaction of cage-like polycyclic olefins with carboxylic acid anhydrides and water. Mixed anhydrides were found to give rise to the corresponding low-molecular acid esters. Among the obtained esters, acetates possess a pleasant odor, and they can be used as components of synthetic fragrant substances.
- Mamedov,Nabieva,Rasulova
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p. 974 - 977
(2007/10/03)
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- Copper(II)-catalysed addition of O-H bonds to norbornene
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Cu(OTf)2 is an inexpensive, air- and moisture-stable catalyst for the O-H addition of aliphatic and aromatic acids and alcohols to norbornene. The Royal Society of Chemistry 2005.
- Taylor, Jason G.,Whittall, Neil,Hii, King Kuok
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p. 5103 - 5105
(2007/10/03)
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- METHOD FOR PRODUCING DEUTERATED NORBORNEOL AND/OR DEUTERATED DINORBORNYL ETHER, AND METHOD FOR PRODUCING UNSATURATED CARBOXYLIC ESTER OF DEUTERATED NORBORNYL
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PROBLEM TO BE SOLVED: To provide a method for producing a deuterated norborneol and a deuterated dinorbornyl ether; and to provide a method for producing an unsaturated carboxylic ester of a deuterated norbornyl synthesized by using the deuterated norborneol and/or the deuterated dinorbornyl ether or the like produced by the method as a raw material. SOLUTION: The method for producing a compound represented by general formulas (I) (wherein, a part or the whole of the hydrogen atoms in a norbornene skeleton is a deuterium atom; and two or more kinds of compounds represented by general formula (I) and mutually having different structures can be included therein) and/or (II) (wherein, a part or the whole of the hydrogen atoms in a norbornene skeleton is a deuterium atom; and two or more kinds of compounds represented by general formula (II) and mutually having different structures can be included therein) involves deuterating 2-norbornene in deuterium oxide in the presence of an acid having pKa ≤1.
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Page/Page column 11-12
(2008/06/13)
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- Aluminium dodecatungstophosphate (AlPW12O40) as a highly efficient catalyst for the selective acetylation of -OH, -SH and -NH2 functional groups in the absence of solvent at room temperature
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AlPW12O40 was found to be an effective catalyst for the selective acetylation of alcohols, thiols, and amines in the absence of solvent at room temperature.
- Firouzabadi, Habib,Iranpoor, Nasser,Nowrouzi, Farhad,Amani, Kamal
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p. 764 - 765
(2007/10/03)
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- Desilylation-acetylation of trimethylsilyl ethers with acetic anhydride catalysed by montmorillonite K-10
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Two mild and simple one-step desilylation-acetylations of a variety of alkyl- and aryl-trimethylsilyl ethers, Me3SiOR(Ar), with acetic anhydride in the presence of montmorillonite K-10 clay are described.
- Movassagh,Lakouraj,Fasihi
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p. 348 - 349
(2007/10/03)
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- Synthesis of esters by addition of carboxylic acids to cage cycloolefins
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The thermal addition of monocarboxylic acids to cage bi-, tri-, tetra-, and pentacyclic hydrocarbons was carried out, and a highly efficient wasteless method of preparing esters of the corresponding alcohols was developed. The reaction has no need for Lewis acids as special catalysts since the initial acids themselves function as both catalyst and reagent. Orientation of the formyloxy and acyloxy groups in cycloolefin hydrocarbons was found, and the degree of regio- and stereoselectivity of the reaction was determined. A number of new esters of polycyclic alcohols were prepared. Some of them are of interest for perfumes.
- Mamedov
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p. 165 - 168
(2007/10/03)
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- Determination of geosmin and methylisoborneol in catfish tissue (Ictalurus punctatus) by microwave-assisted distillation-solid phase adsorbent trapping
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Methylisoborneol (MIB) and geosmin (GEO) are algal off-flavor compounds, which when present in catfish tissue create undesirable taste and odors in the prepared products. These undesirable taste and odor problems are not limited to catfish aquaculture. A procedure was developed for the determination of off-flavor compounds in channel catfish tissue that involves microwave radiation distillation with solid phase trapping. This is a modification of a microwave distillation-cold trapping procedure but without the need of a cryogen or a liquid-liquid extraction step. A channel catfish fillet sample is placed in a container located within a microwave oven. This container, which is directly connected to a thermostated condenser containing a solid phase adsorbent, is continually purged with argon gas. The trapped distillate components are eluted with ethyl acetate and then injected into a gas chromatograph-ion trap mass spectrometer for analysis. This technique offers a rapid and sensitive means of off-flavor analysis in fish tissue and improved recovery for MIB from 73 ± 3% (50 ppb) to 85 ± 5% (10 ppm) compared to 62 ± 6% for microwave-cold trap collection. The method detection limits are 1.7 and 1.1 ppb for MIB and GEO, respectively.
- Conte, Eric D.,Shen, Chun-Yi,Perschbacher, Peter W.,Miller, Dwight W.
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p. 829 - 835
(2007/10/03)
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- PREPARATION OF BICYCLIC ESTERS OF MONOCARBOXYLIC ACIDS
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A method has been developed for the preparation of bicyclic esters by the cycloalkylation of C1-C3 monocarboxylic acids by norbornene hydrocarbons in the presence of p-toluenesulfonic acid as catalyst.The reaction proceeds stereoselectively with the preferential formation of an exo-isomer.
- Mamedov, M. K.,Suleimanova, E. T.
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p. 944 - 947
(2007/10/02)
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- The Protonated Cyclopropane Route to Bicyclic Cations
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The protolytic cleavage of tricyclo2,6>hexane (3), tricyclo2,7>heptane (10), methyltricyclo2,7>heptanes (26), tricyclo2,8>octane (53), and tricyclo2,7>octane (58) in acetic acid and in aqueous dioxane has been investigated.Protonation occurred at a specific site (3, 36b,d, 58) or competitively at two sites (10, 26c, 53), depending on the stability of the incipient carbocations.Product distributions and label redistributions, where applicable, were in good to excellent agreement with previous solvolytic studies.We conclude that the protonated cyclopropane and ? routes are equivalent in generating bridged carbocations.Edge-protonated cyclopropanes play a minor role, if any, in product formation.Stereoselectivity appears to be an intrinsic property of the cationic intermediates, largely independent of the specific orientation of their counterions.
- Kirmse, Wolfgang,Streu, Joachim
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p. 515 - 521
(2007/10/02)
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- Manganese(III)-Mediated γ-Lactone Annulation
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The annulation of a γ-lactone ring onto an alkene by manganese(III) acetate oxidation of acetic acid was investigated.The regioselectivity of addition to unsymmetrically substituted alkenes is reported along with the stereoselectivity of addition to various acyclic and cyclic alkenes.Alkenes with ionization potentials above 8.2 eV were found to react in good yield.The role of acetic anhydride in these reactions was studied, and it was shown to be oxidized faster than acetic acid and also led to different products.The fate of oxidized acetic acid or anhydridein the absence of suitable acceptor molecule has also been quantitatively identified.The relationship of enolizability, or C-H acidity, of the carboxylic acid being oxidized was established quantitatively.
- Fristad, William E.,Peterson, John R.
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- OXYGENATION OF AROMATIC AND ALIPHATIC HYDROCARBONS BY A NEW REAGENT SYSTEM, Fe(CH3CN)6(2+)-H2O2-Ac2O: AN EFFECTIVE MODEL REAGENT FOR MONO-OXYGENASE
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Reactions of aromatic and aliphatic hydrocarbons with a new system, Fe(CH3CN)6(2+) - H2O2 - Ac2O in CH3CN, gave oxygenation products with fairly high reaction efficiency ( Tables I and II )compared to known to reagent systems used as enzyme models for mono-oxygenases.Investigations of the mechanism of these reactions indicated the involvement of either complex C.FeIV(OH)(OAc)(2+), or complex D, FeIV(OAc)(2+), dependig on the organic substrate.Keywords-oxygenation; aromatic hydrocarbon; aliphatic hydrocarbon; hexakisacetonitrile iron(II) perchlorate; hydrogen peroxide; enzyme model; mono-oxygenase
- Kotani, Eiichi,Kobayashi. Shigeki,Ishii, Yoko,Tobinaga, Seisho
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p. 4671 - 4679
(2007/10/02)
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- REACTION OF ORGANOBORANES WITH LEAD(IV) ACETATE AZIDE. A SYNTHESIS OF AZIDOALKANES FROM ALKENES VIA HYDROBORATION.
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Trialkylboranes prepared from alkenes via hydroboration react with lead(IV) acetate azide in dichloromethane at minus 25 degree C to form the corresponding azidoalkanes in a one-pot manner. One of two of the alkyl groups of trialkylboranes are utilized in the reaction. For example, 1-azidohexane is afforded from 1-hexene in 50% yield based on the alkene employed.
- Masuda,Hoshi,Arase
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p. 1026 - 1030
(2007/10/02)
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- The Novel Synthesis of Alkyl Cyanides by the Reaction of Sodium Trialkylcyanoborate with Sodium Cyanide and Lead(IV) Acetate
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Sodium trialkylcyanoborates gave good yields of the corresponding alkyl cyanides in the reaction with sodium cyanide and lead(IV) acetate.
- Masuda, Yuzuru,Hoshi, Masayuki,Yamada, Tetsuo,Arase, Akira
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p. 398 - 399
(2007/10/02)
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- ALKENE OXIDATION BY AN IRON(II)/PERSULFATE/ACETIC ACID SYSTEM
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Mono- and disubstituted alkenes were converted to trans-vicinal diacetates by heating with an iron(II)/persulfate/acetic acid system.The synthetic utility and limitations were identified.A mechanism for the transformation is proposed wich involves an initial addition of sulfate radical anion to the alkene followed by solvolysis, addition, hydrolysis, and acetylation.
- Fristad, William E.,Peterson, John R.
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p. 1469 - 1476
(2007/10/02)
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- 2-Norbornanediazonium Ions Revisited
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The reactions of 2-norbornanediazonium ions have been reinvestigated with the aid of optically active and deuterium-labeled precursors.Enantiomeric purities were determined by direct VPC methods, and deuterium distributions by 2H NMR spectroscopy.The product pattern is strongly affected by the polarity of the solvent. exo-Diazonium ions 13 in water yield racemic exo alcohol (s,kΔ) of the norbornadiazonium ions.Optically active exo products are typical of nonpolar solvents and originate most probably from assymetric ion pairs.Model studies with optically active bicyclooct-3-en-2-amine (36) provide conclusive evidence that ion-pair colapse may lead to optically active products even in the case of delocalized achiral carbocations.
- Kirmse, Wolfgang,Siegfried, Rainer
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p. 950 - 956
(2007/10/02)
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- Reactions with Umpolung via Radicals: CC-Bond Formation between Ketones and Alkenes
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The hydrazones 1 - 11 from ketones react in a general synthetic procedure with alkenes 33a - m to yield products 34 - 44 (table 2 and 3).Important intermediates of these reactions with umpolung are 1-acetoxyalkyl radicals 49 that are formed from organomercuric salts 14 - 24 by reduction with NaBH4.This new CC-bond formation reaction can be carried out in a one-pot synthesis without isolation of the metalorganic compounds (table 4). - In side reactions the reduction products 50 are formed, if bulky starting compounds or less reactive alkenes are used (table 5 and 6).
- Giese, Bernd,Erfort, Ulrich
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p. 1240 - 1251
(2007/10/02)
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- IRON(II) CATALYZED ODIDATION OF ALKENES TO VICINAL DIACETATES
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Mono- and disubstituted alkenes are converted to trans-vicinal diacetates by heating with an acetic acid solution of ammonium persulfate and a ferrous sulfate catalyst.
- Fristad, William E.,Peterson, John R.
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p. 4547 - 4550
(2007/10/02)
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- Norpinyl-Norbornyl Rearrangements: Bicycloheptane, 4-Methyl- and 6-Methylbicycloheptane Derivatives
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Norpinyl-norbornyl rearrangements have been induced by solvolysis of the 2-norpinyl nitrobenzoates 15b, c and by decomposition of norpinane-, 4-methylnorpinane-, and 6-methylnorpinane-2-diazonium ions (19, 49, 64, 65).No fragmentation to monocyclic cations was observed.The yield of norpinyl products was minimal in water (s processes).With 64 and 65, migration of the bridge trans to the leaving group predominated strongly.The rearrangements afforded exo-2- and endo-2-norbornyl products in comparable quantities.The exo/endo rates depended on the nucleophilicity of the solvent but were little effected by methyl substitution at the migrating carbon.We propose the 7-bridged norbornyl cation (21) as the endo-selective intermediate which rearranges to the exo-selective 6-bridged (or rapidly equilibrating) norbornyl cation (22, 23) in competition with solvent capture.Ion-pair collapse (cf. 15b) accentuates the endo-selectivity.However, ion pairing cannot be the only source of endo-2-norbornyl products, as shown by the deamination reactions in water.
- Kirmse, Wolfgang,Siegfried, Rainer,Wroblowsky, Heinz-Juergen
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p. 1880 - 1896
(2007/10/02)
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- Solvomercuration-Demercuration. 10. Oxymercuration-Demercuration of Olefins with the Mercuric Salts Acetate, Trifluoroacetate, Nitrate, and Methanesulfonate
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The oxymercuration-demercuration of a series of representative olefins has been examined with four mercuric salts: acetate, trifluoroacetate, nitrate, and methanesulfonate.Mono- and 1,2-disubstituted olefins undergo hydration with all four mercuric salts in 90-100percent yields with a regioselectivity for the Markovnikov alcohol (from monoolefins) of >99.5percent.Only styrene was found to be an exception.In marked contrast, only mercuric acetate is effective for the Markovnikov hydration of 1,1-di-, tri- ,and tetrasubstituted olefins.The other three mercuric salts provide loweryields of the tertiary alcohols, yields which decrease rapidly with time. 1-Phenylcyclopentene undergoes only allylic oxidation with the mercuric salts trifluoroacetate, nitrate, and methanesulfonate.Mercuric acetate does give the normal hydration product but only in trace amounts.In this case, allylic oxidation is the major reaction pathway with this salt as well.
- Brown, Herbert C.,Geoghegan, Philip J.,Kurek, Joseph T.
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p. 3810 - 3812
(2007/10/02)
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- Reaction of Saturated Organic Compounds with Acetyl and Trifluoroacetyl Nitrate
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The reaction of selected hydrocarbons with trifluoroacetyl nitrate in trifluoroacetic acid results in hydride ion abstraction and formation of alkyl trifluoroacetate.The reaction of reactive alkyl halides and alkyl methyl ethers with protonated acetyl nitrate in acetic acid affords the corresponding alkyl acetates in good yield.The oxidizing reagent in both reactions is ammonium nitrate which is converted in situ to the nitronium acetate by reaction with an anhydride.
- Bach, Robert D.,Taaffee, Thomas H.,Holubka, Joseph W.
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p. 3439 - 3442
(2007/10/02)
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