- Carboxylic Acid Reductase Can Catalyze Ester Synthesis in Aqueous Environments
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Most of the well-known enzymes catalyzing esterification require the minimization of water or activated substrates for activity. This work reports a new reaction catalyzed by carboxylic acid reductase (CAR), an enzyme known to transform a broad spectrum of carboxylic acids into aldehydes, with the use of ATP, Mg2+, and NADPH as co-substrates. When NADPH was replaced by a nucleophilic alcohol, CAR from Mycobacterium marinum can catalyze esterification under aqueous conditions at room temperature. Addition of imidazole, especially at pH 10.0, significantly enhanced ester production. In comparison to other esterification enzymes such as acyltransferase and lipase, CAR gave higher esterification yields in direct esterification under aqueous conditions. The scalability of CAR catalyzed esterification was demonstrated for the synthesis of cinoxate, an active ingredient in sunscreen. The CAR esterification offers a new method for green esterification under high water content conditions.
- Pongpamorn, Pornkanok,Kiattisewee, Cholpisit,Kittipanukul, Narongyot,Jaroensuk, Juthamas,Trisrivirat, Duangthip,Maenpuen, Somchart,Chaiyen, Pimchai
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- Electron-rich Triarylbismuthines as Selective Condensation Reagent under Neutral Conditions. Condensation of Aliphatic Carboxylic Acids with Amines and Alcohols
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On heating with amines or alcohols in the presence of tris(2-methoxyphenyl)- or tris(2,6-dimethoxyphenyl)bismuthine, carboxylic acids bearing α-hydrogen are readily converted into the corresponding amides or esters in good yields while those without α-hydrogen remain intact.
- Ogawa, Takuji,Hikasa, Tetsuya,Ikegami, Tohru,Ono, Noboru,Suzuki, Hitomi
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- N-heterocyclic carbene catalysed oxidative coupling of aldehydes with alcohols/thiols and one-pot oxidation/esterification of allylic alcohols
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A versatile carbene-catalysed oxidation protocol involving N-heterocyclic carbene catalysts and 2,2,6,6-tetramethylpiperidine N-oxyl (TEMPO) is described for the synthesis of esters, cinnamic acids, and thioesters. A wide range of esters, thioesters, and cinnamic acids were obtained by metal-free coupling of aldehydes with aliphatic, allylic and aromatic alcohols, benzyl mercaptan, and water. In addition to the oxidative coupling of aldehydes with nucleophiles, dehydrogenation of saturated aldehydes and oxidation of allylic alcohols were found under our oxidative coupling conditions. Unlike other TEMPO-mediated oxidative esterification reactions, this reaction does not proceed through a TEMPO ester intermediate to form esters and thioesters. N-Heterocyclic carbene complexes catalyse various oxidative coupling reactions in the presence of TEMPO. A variety of α,β-unsaturated and saturated esters, and aromatic esters and thioesters were synthesised. Copyright
- Ji, Miran,Wang, Xi,Lim, Yu Na,Kang, Ye-Won,Jang, Hye-Young
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- Hydro-dediazoniation of diazonium salts using trichlorosilane: New cleavage conditions for the T1 traceless linker
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An efficient, selective cleavage of triazenes and in situ hydro- dediazoniation of the intermediately formed diazonium salts with trichlorosilane (HSiCl3) in liquid as well on solid phase is reported. Starting from anilines, attachment to solid support and subsequent cleavage gives rise to the corresponding unsubstituted arenes. This cleavage reagent is compatible with various functionalities (esters, amides, nitro groups, halides, aliphatic double and triple bonds). (C) 2000 Elsevier Science Ltd.
- Lormann, Matthias,Dahmen, Stefan,Br?se, Stefan
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- Fully recyclable Br?nsted acid catalyst systems
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Homogeneous and heterogeneous sulfonic acid catalysts are some of the most common catalysts used in organic chemistry. This work explores an alternative scheme using a fully recyclable polymeric solvent (a poly-α-olefin (PAO)) and soluble PAO-anchored polyisobutylene (PIB)-bound sulfonic acid catalysts. This PAO solvent is nonvolatile and helps to exclude water by its nonpolar nature which in turn drives reactions without the need for distillation of water, avoiding the need for excess reagents. This highly nonpolar solvent system uses polyisobutylene (PIB) bound sulfonic acid catalysts that are phase-anchored in solvents like PAO. The effectivenes of these catalysts was demonstrated by their use in esterifications, acetalizations, and multicomponent condensations. These catalysts and the PAO solvent phase show excellent recyclability in schemes where products are efficiently separated. For example, this non-volatile polymeric solvent and the PIB-bound catalyst can be recycled quantitatively when volatile products are separated and purified by distillation. In other cases, product purification can be effected by product self-separation or by extraction.
- Watson, Christopher B.,Kuechle, Adrianna,Bergbreiter, David E.
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- A convenient one-step method for the deprotection and esterification of triphenylmethyl ethers
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We have discovered a simple one-pot procedure to convert trityl ethers into esters, using the corresponding acid chloride as the only reagent. (C) 2000 Elsevier Science Ltd.
- Bergmeier, Stephen C.,Arason, Kristján M.
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- Improved ester interchange catalysts
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(equation presented) Mixed alkoxide/aryloxide clusters are long-lived and milder than previously reported ester interchange catalysts. They completely transform difficult substrates in a single synthetic operation with lower catalyst and reagent ester loadings. In addition to superior activities, these mixed clusters are kinetically less basic toward enolizable esters.
- Kissling, Rebecca M.,Gagne, Michel R.
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- Application of Sulfonic Acid Functionalised Hybrid Silicas Obtained by Oxidative Cleavage of Tetrasulfide Bridges as Catalysts in Esterification Reactions
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Hybrid materials with tetrasulfide bridges were synthesised by co-condensation between bis[3-(triethoxysilyl)propyl]tetrasulfide and either tetraethyl orthosilicate or 1,4-bis(triethoxysilyl)benzene under acidic conditions in the presence of Brij-76 as a structure-directing agent. They were post-modified by treatment with H2O2 for 3h or 24h. A progressive loss of the mesostructure in the resulting materials was observed upon increasing the S content in the synthesis mixtures. Thus, only those samples with the lowest tetrasulfide content could be considered as periodic mesoporous organosilicas. This effect was even more pronounced upon oxidation. The oxidised materials exhibited a considerable acidity, particularly those with the two precursors in approximately equal amounts. All sulfonic acid functionalised materials were used as catalysts in the esterification of acetic acid with ethanol, and they exhibited a comparable or very similar activity to that of Amberlyst-15. Several mesoporous and microporous hybrid materials were selected and compared to this commercial resin in the transformation of more hydrophobic substrates. Some of these hybrid materials were especially attractive for the transformation of benzyl alcohol and various secondary alcohols.
- Lopez, Maria Isabel,Esquivel, Dolores,Jimenez-Sanchidrian, Cesar,Romero-Salguero, Francisco Jose
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- Redox-active alkylsulfones as precursors for alkyl radicals under photoredox catalysis
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A method for generating alkyl radicals using visible-light photoredox catalysis is described. This procedure was found to present an efficient means to access a diverse collection of 1°, 2°, and 3° alkyl radicals through the single-electron transfer of sulfones under mild reaction conditions. These alkyl radicals generated via the reductive desulfonylation of readily synthesized and stable alkylsulfones were engaged to forge C-C bonds. A detailed study was also carried out to shed light on the mechanism.
- Patel, Sandeep,Paul, Biprajit,Paul, Hrishikesh,Shankhdhar, Rajat,Chatterjee, Indranil
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p. 4857 - 4860
(2022/04/19)
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- Membrane transport inspired hydrolysis of non-activated esters at near physiological pH
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A positively charged micelle loaded with substrates was transported selectively to the reaction site (cathode) to promote the proximity and localization of the reactants (ester and hydroxide). The guided vehicular delivery coupled with electrolysis allows the hydrolysis of non-activated esters at near physiological pH with significant yields along with recyclability.
- Mandal, Raki,Mahanty, Kingshuk,Mandal, Subhendu,De Sarkar, Suman,Tarafdar, Pradip K.
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p. 11088 - 11091
(2021/10/30)
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- N-Heterocyclic Carbene/Carboxylic Acid Co-Catalysis Enables Oxidative Esterification of Demanding Aldehydes/Enals, at Low Catalyst Loading
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We report the discovery that simple carboxylic acids, such as benzoic acid, boost the activity of N-heterocyclic carbene (NHC) catalysts in the oxidative esterification of aldehydes. A simple and efficient protocol for the transformation of a wide range of sterically hindered α- and β-substituted aliphatic aldehydes/enals, catalyzed by a novel and readily accessible N-Mes-/N-2,4,6-trichlorophenyl 1,2,4-triazolium salt, and benzoic acid as co-catalyst, was developed. A whole series of α/β-substituted aliphatic aldehydes/enals hitherto not amenable to NHC-catalyzed esterification could be reacted at typical catalyst loadings of 0.02–1.0 mol %. For benzaldehyde, even 0.005 mol % of NHC catalyst proved sufficient: the lowest value ever achieved in NHC catalysis. Preliminary studies point to carboxylic acid-induced acceleration of acyl transfer from azolium enolate intermediates as the mechanistic basis of the observed effect.
- Berkessel, Albrecht,Biswas, Animesh,Harnying, Wacharee,Sudkaow, Panyapon
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supporting information
p. 19631 - 19636
(2021/08/09)
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- Catalytic Transfer Hydrodebenzylation with Low Palladium Loading
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A highly-efficient catalytic system for hydrodebenzylation reaction is described. The cleavage of O-benzyl and N-benzyl protecting groups was performed using an uncommonly low palladium loading (0.02–0.3 mol%; TON up to 5000) in a relatively short reaction time. The approach was used for a variety of substrates including pharmaceutically important precursors, and gram-scale deprotection reaction was shown. Transfer conditions together with easy-to-make Pd/C catalyst are the key features of this debenzylation scheme. (Figure presented.).
- Yakukhnov, Sergey A.,Ananikov, Valentine P.
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supporting information
p. 4781 - 4789
(2019/09/16)
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- ESTERIFICATION PROCESS
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The present disclosure relates to a process of esterification in presence of a catalyst. The catalyst of the present disclosure is an aryloxy based phosphoric acid having general formula [{ArO}2P(O)OH] and is represented by the structure: wherein, Ar represents aryl compounds. The process of esterification is carried out by the reaction of a carboxylic acid and an alcohol in a fluid medium in the presence of the aryloxy based phosphoric acid catalyst resulting in the corresponding ester. The process of the present disclosure is simple and results in a product having a comparatively higher purity.
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Paragraph 0032-0034
(2018/04/20)
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- Aerobic oxidative esterification and thioesterification of aldehydes using dibromoisocyanuric acid under mild conditions: No metal catalysts required
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A practical direct method for the direct preparation of esters and thioesters from aldehydes is described. Esters and thioesters were synthesized by oxidative esterification and thioesterification via in situ generated acyl bromide intermediates, which were used to react with various alcohols and thiols. The esterification and thioesterification were readily performed in the presence of dibromoisocyanuric acid in dichloromethane, without any metal catalysts and under mild conditions. By using this reaction protocol, various esters and thioesters were prepared in high yields. This effective method offers a promising approach for the facile esterification and thioesterification of aldehydes.
- Kwon, Young-Do,La, Minh Thanh,Kim, Hee-Kwon
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p. 10833 - 10841
(2018/07/05)
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- Phosphine-pyridonate ligands containing octahedral ruthenium complexes: Access to esters and formic acid
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The preparation of three well-defined ruthenium complexes arising from phosphine-pyridon-e/-ate ligands is described. Solvent dependent Lewis acidic species formation was observed with these complexes. Selective formation of acetals or esters from primary alcohols was observed in the presence of these catalysts. Preliminary evaluation of these complexes in the base free hydrogenation of carbon dioxide is also reported.
- Sahoo,Jiang,Bruneau,Sharma,Suresh,Roisnel,Dorcet,Achard
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p. 3492 - 3498
(2017/08/23)
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- Oxidative Alkane C?H Alkoxycarbonylation
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Directly utilizing a chemical feedstock to construct valuable compounds is an attractive prospect in organic synthesis. In particular, the combination of C(sp3)?H activation and oxidative carbonylation involving alkanes and CO gas is a promising and efficient method to synthesize carbonyl derivatives. However, due to the high C?H bond dissociation energy and low polarity of unactivated alkanes, the carbonylation of unactivated C(sp3)?H bonds still remains a great challenge. In this work, we introduce a palladium-catalyzed radical oxidative alkoxycarbonylation of alkanes to prepare numerous alkyl carboxylates. Various alkanes and alcohols were compatible, generating the desired products in up to 94 % yield. Remarkably, ethane, a constituent of natural gas, could be employed as a substrate under the standard reaction conditions. Preliminary mechanistic studies revealed a probable palladium-catalyzed radical process.
- Lu, Lijun,Shi, Renyi,Liu, Luyao,Yan, Jingwen,Lu, Fangling,Lei, Aiwen
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supporting information
p. 14484 - 14488
(2016/10/03)
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- Palladium-catalyzed benzylation of carboxylic acids with toluene via benzylic C-H activation
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Direct benzylation of carboxylic acids with toluene has been developed via palladium-catalyzed C-H acyloxylation under 1 atm of oxygen. This reaction demonstrates good functional group tolerance and high yields, providing a facile, atom-economic, and efficient method for the synthesis of benzyl esters.
- Liu, Hongqiang,Shi, Guangfa,Pan, Shulei,Jiang, Yuyu,Zhang, Yanghui
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supporting information
p. 4098 - 4101
(2013/09/12)
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- Use of diethoxymethane as a solvent for phase-transfer esterification of carboxylic acids
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The esterification of carboxylic acids with selected primary alkyl halides in diethoxymethane (DEM) utilizing solid-liquid phase-transfer catalysis has been studied. The use of DEM as the solvent simplifies the process in that a single solvent can be used for both reaction and workup.
- Coleman, M. Todd
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scheme or table
p. 1911 - 1913
(2012/06/04)
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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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- Process for the preparation of carboxylic benzyl esters
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Carboxylic benzyl esters can be prepared by reacting benzyl chloride with carboxylic acids in the presence of one or more quaternary ammonium carboxylates as catalyst.
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- Fluorous biphasic esterification directed towards ultimate atom efficiency
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Aperfectly selective esterification that discriminates between primary and sterically hindered or aromatic carboxylic acids occurs in the presence of the fluoroalkyldistannoxane [{Cl(C6F13CH2 CH2)2SnOSn(CH2CH2 -C6F13)2Cl}2] (1). The reaction gives 100% yield with a strict 1:1 ratio of the carboxylic acid and alcohol reactants, and the catalyst can be recycled without any loss of activity.
- Xiang, Jiannan,Orita, Akihiro,Otera, Junzo
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p. 4117 - 4119
(2007/10/03)
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- New efficient nickel-catalyzed cross-coupling reaction between two Csp3 centers
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The presence of a remote unsaturation (double bond, carbonyl group, cyano group) in an alkyl halide facilitates its cross-coupling reaction with various diorganozincs in the presence of Ni(acac)2 (7.5-10 mol % in THF/NMP mixtures). These results were used to develop a new general cross-coupling reaction between functionalized diorganozincs and alkyl iodides using m- or p-trifluoromethylstyrene as a reaction promotor and Ni(acac)2 as a catalyst (7.5-10 mol %; -35 °C, 5-10 h) leading to a broad range of polyfunctional cross-coupling products.
- Giovannini,Strudemann,Devasagayaraj,Dussin,Knochel
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p. 3544 - 3553
(2007/10/03)
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- An efficient nickel-catalyzed cross-coupling between sp3 carbon centers
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Since the pioneering work of Wurtz, cross-couplings between sp3 carbon centers have had the reputation of being difficult. In the presence of a catalytic amount of m-trifluoromethylstyrene, an efficient cross-coupling reaction takes place between polyfunctional primary alkyl iodides and diorganozinc compounds [Eq. (a)] to give a general catalytic cross-coupling between sp3 carbon centers. Piv = pivaloyl; Pent = pentyl; acac = acetalacetonate; NMP = N-methylpyrrolidone.
- Giovannini, Riccardo,Stüdemann, Thomas,Dussin, Gaelle,Knochel, Paul
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p. 2387 - 2390
(2007/10/03)
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- Selective Activation of Primary Carboxylic Acids by Electron-rich Triarylbismuthanes. Application to Amide and Ester Synthesis under Neutral Conditions
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On being heated in benzene in the presence of tris(methoxyphenyl)bismuthanes 1b-1e, primary carboxylic acids are selectively activated to couple with amines and alcohols to produce the corresponding amides and esters in satisfactory yields, while secondary, tertiary and aromatic carboxylic acids remain unaffected. 2-Benzylmalonic acid is similarly converted into its corresponding diamides and diesters, but 2,2-dibenzylmalonic acid suffers extensive decarboxylation and, in the presence of aromatic olefins, it undergoes a novel -type cycloaddition reaction to form 4-substituted 2,2-dibenzyl-4-butanolides in low to fair yields.
- Ogawa, Takuji,Hikasa, Tetsuya,Ikegami, Tohru,Ono, Noboru,Suzuki, Hitomi
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p. 3473 - 3478
(2007/10/02)
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- Ruthenium-Catalyzed Oxidative Transformation of Alcohols and Aldehydes to Esters and Lactones
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Primary alcohols undergo oxidative condensation upon treatment with RuH2(PPh3)4 catalyst to give esters and molecular hydrogen.Similarly, 1,4- and 1,5-diols can be converted into the corresponding γ- and δ-lactones, respectively.The lactonization is greatly enhanced by accepting hydrogen with an appropriate hydrogen acceptor such as acetone.Primary alcohols are oxidized chemoselectively in the presence of secondary alcohols to give the corresponding lactones.These reactions are operationally simple and highly efficient for synthesis of esters and lactones from alcohols.The principle of the oxidative condensation of alcohols can be extended to ester formation from aldehydes and alcohols.The ruthenium-catalyzed reaction of aldehydes with water gives esters, while the same reaction in the presence of a hydrogen acceptor gives carboxylic acids.The key step of these reactions is the oxidative addition of ruthenium into the OH bonds of alcohols and subsequent β-elimination of (RuH) species to give the corresponding carbonyl compounds.
- Murahashi, Shun-Ichi,Naota, Takeshi,Ito, Keiichiro,Maeda, Yoshihiro,Taki, Hiroshi
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p. 4319 - 4327
(2007/10/02)
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- NOVEL DISTANNOXANE-CATALYZED TRANSESTERIFICATION AND A NEW ENTRY TO α,β-UNSATURATED CARBOXYLIC ACIDS
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Novel distannoxane-catalyzed transesterification reaction has been developed which affords various types of esters under very mild conditions.The reaction was applied to the stereo- and regioselective synthesis of trisubstituted α,β-unsaturated carboxylic acids.
- Otera, Junzo,Yano, Toru,Kawabata, Atsuya,Nozaki, Hitosi
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p. 2383 - 2386
(2007/10/02)
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- S,S-Bis Dithiocarbonate. A New Reactive Coupling Agent for the Direct Esterification of Carboxylic Acids
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S,S-Bis dithiocarbonate, prepared from 4,6-dimethyl-2-pyrimidinethiol hydrochloride and phosgene in the presence of triethylamine in dichloromethane/toluene, is a new reactive coupling agent for the direct esterification of carboxylic acids with alcohols.
- Kim, Sunggak,Kim, Sung Soo
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p. 1017 - 1019
(2007/10/02)
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- A Simple and Mild Esterification Method for Carboxylic Acids Using Mixed Carboxylic-Carbonic Anhydrides
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A simple and mild esterification method using mixed carboxylic-carbonic anhydrides has been developed.Simple aliphatic carboxylic esters are prepared in high yields by the reaction of acids with equimolar amounts of chloroformates (2,2,2-trichloroethyl chloroformate is an exception) and triethylamine in the presence of a catalytic amount of 4-(dimethylamino)pyridine.Although aromatic acids give a mixture of the ester, the acid anhydride, and the carbonate under normal conditions utilized in this study, it is found that increasing the amount of 4-(dimethylamino)pyridine drastically decreases the formation of the acid anhydride and the carbonate, affording a satisfactory yield of the ester.This method reaches a limit with sterically hindered acids and the formation of the acid anhydride and the carbonate is favored.
- Kim, Sunggak,Lee, Jae In,Kim, Youn Chul
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p. 560 - 565
(2007/10/02)
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- DI-2-PYRIDYL CARBONATE: A NEW EFFICIENT COUPLING AGENT FOR THE DIRECT ESTERIFICATION OF CARBOXYLIC ACIDS
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Reaction of carboxylic acids with equimolar amounts of di-2-pyridyl carbonate and alcohols or thiols in the presence of 4-dimethylaminopyridine as a catalyst in methylene chloride at room temperature affords the corresponding esters in high yields under mild conditions.
- Kim, Sunggak,Lee, Jae In,Ko, Young Kwan
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p. 4943 - 4946
(2007/10/02)
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- A NEW CONVENIENT METHOD FOR THE ESTERIFICATION OF CARBOXYLIC ACIDS
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Reaction of carboxylic acids with equimolar amounts of alkyl chloroformate and triethylamine in the presence of a catalytic amount of 4-dimethylaminopyridine affords the corresponding esters in high yields without the formation of the symmetrical anhydride in most carboxylic acids.
- Kim, Sunggak,Kim, Youn Chul,Lee, Jae In
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p. 3365 - 3368
(2007/10/02)
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