- N-Heterocyclic Carbene Catalyzed Ester Synthesis from Organic Halides through Incorporation of Oxygen Atoms from Air
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Oxygenation reactions with molecular oxygen (O2) as the oxygen source provides a green and straightforward strategy for the construction of O-containing compounds. Demonstrated here is a novel N-heterocyclic carbene (NHC) catalyzed oxidative transformation of simple and readily available organic halides into valuable esters through the incorporation of O-atoms from O2. Mechanistic studies prove that the deoxy Breslow intermediate generated in situ is oxidized to a Breslow intermediate for further transformation by this oxidative protocol. This method broadens the field of NHC catalysis and promotes oxygenation reactions with O2.
- Tan, Hui,Wang, Shen-An,Yan, Zixi,Liu, Jianzhong,Wei, Jialiang,Song, Song,Jiao, Ning
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supporting information
p. 2140 - 2144
(2020/12/01)
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- Vitamin B1-catalyzed aerobic oxidative esterification of aromatic aldehydes with alcohols
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A straightforward aerobic oxidative esterification of aryl aldehydes with alcohols has been developed for the synthesis of substituted esters by employing vitamin B1 as a cost-effective, metal-free, and eco-friendly NHC catalyst. Air is used as a green terminal oxidant. The reaction is a useful addition to the existing NHC-catalytic oxidative esterification.
- Chu, Xue-Qiang,Ge, Danhua,Luo, Xin-Long,Xu, Pei,Yu, Zi-Lun
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supporting information
p. 30937 - 30942
(2021/11/19)
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- DBU-Based Dicationic Ionic Liquids Promoted Esterification Reaction of Carboxylic Acid with Primary Chloroalkane Under Mild Conditions
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Abstract: A series of DBU-based (DBU = 1, 8-diazabicyclo [5.4.0] undec-7-ene) dicationic ionic liquids with different anions were successfully synthesized by the reaction of DBU and 1, 6-dichlorohexane. Therein, the dicationic ionic liquid 1, 1′-(hexane-1, 6-diyl)bis(1, 8-diazabicyclo [5.4.0]undec-7-enium) dichlorine (IL-1) was successfully employed as an efficient catalyst in esterification reaction of carboxylic acids with primary chloroalkanes under mild conditions without any additional basic reagents. Moreover, the optimum catalyst could be efficiently reused for five times without any significant change on the catalytic effect. The improved protocol is not only efficient, but also green and pollution-free.
- Liu, Yang,Mao, Guijie,Zhao, Hongyan,Song, Jinyi,Han, Huatao,Li, Zhuofei,Chu, Wenyi,Sun, Zhizhong
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p. 2764 - 2771
(2017/09/14)
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- Zinc-Catalyzed Esterification of N-β-Hydroxyethylamides: Removal of Directing Groups under Mild Conditions
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Amide transformations involving C–N bond cleavage are recognized as difficult reactions owing to the inert nature of amides resulting from resonance. Accordingly, a strong inductive effect and geometrical distortion reasonably decrease the resonance stabilization to attenuate the C–N linkage. Although the conversion of such activated amides has been studied intensively, reaction systems for “unactivated” amides are underdeveloped. We herein report that a zinc(II) trifluoromethanesulfonate [Zn(OTf)2] catalyst achieves the esterification of a wide range of unactivated tertiary amides with the assistance of intramolecular acyl rearrangement. The reaction was applied to the one-pot removal of various amide-based directing groups under mild reaction conditions to afford the corresponding esters in high yields.
- Nishii, Yuji,Hirai, Takahiro,Fernandez, Sarah,Knochel, Paul,Mashima, Kazushi
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p. 5010 - 5014
(2017/09/21)
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- ZnII and CdII MOFs based on an amidoisophthalic acid ligand: Synthesis, structure and catalytic application in transesterification
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Solvothermal reaction of zinc(ii) and cadmium(ii) salts with 5-propionamidoisophthalic acid (H2L1) and 5-benzamidoisophthalic acid (H2L2) in the presence or absence of an auxiliary ligand gives rise to a series of 1D, 2D and 3D Zn(ii) or Cd(ii) self-assembled metal-organic frameworks as revealed by X-ray diffraction structural analyses: [Zn(μ-L1-μ-1κOO′:2κO′′)(formamide)2]n (1), [{Zn2(μ-L1-1κO:2κO′)2(4,4′-bipyridine)2(H2O)}·2(DMF)·5(H2O)]n (2), [Cd(μ-L1-μ-1κO2O′:2κO′′2O′′′)(DMF)]n (3), [{Zn(μ-L2-1κO:2κO′)(4,4′-bipyridine)(H2O)}·(H2O)]n (4) and [{Cd(μ-L2-μ-1κO2O′:2κO′′2O′′′)(formamide)(4,4′-bipyridine)}·(formamide)]n (5), which are also characterized by elemental analysis, IR spectroscopy and thermogravimetric analysis. The different architectures found in 1-5 result from the coordination modes of the carboxylate groups, which can assume nonbridging monodentate (in 1, 2 and 4), bridging bidentate (also in 1), bridging chelate (in 3 and 5) and chelate bidentate (also in 5) coordination. While 1 and 5 possess one dimensional double chain type structures, 3 has a 1D cyclic type structure and 2 and 4 have 2D or 3D wave-like structures, respectively. Topological analysis has shown that 1 and 5 have a 3-connected uninodal net with a topological type SP1-periodic net, 2 has a 2,4-connected binodal net, 3 has a 4-connected uninodal net structure and 4 has a more complex 2,2,2,4-connected tetranodal net. Frameworks 1-5 act as heterogeneous catalysts for the transesterification reaction of different carboxylate esters, with 4 showing the highest activity. These heterogeneous catalysts can be recycled without losing activity.
- Karmakar, Anirban,Rúbio, Guilherme M. D. M.,Guedes da Silva, M. Fátima C.,Ribeiro, Ana P. C.,Pombeiro, Armando J. L.
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p. 89007 - 89018
(2016/10/03)
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- Ultrasound assisted direct oxidative esterification of aldehydes and alcohols using graphite oxide and Oxone
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A sonochemical procedure for direct oxidative esterification of aldehydes and alcohols using graphite oxide and Oxone in an alcoholic solvent is described. Mild reaction conditions, short reaction times, cost-effectiveness, and facile isolation of the products make the present system as a practical method.
- Mirza-Aghayan, Maryam,Zonoubi, Somayeh,Molaee Tavana, Mahdieh,Boukherroub, Rabah
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p. 359 - 364
(2014/10/16)
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- Base-free oxidation of alcohols to esters at room temperature and atmospheric conditions using nanoscale Co-based catalysts
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The direct oxidation of alcohols to esters with molecular oxygen is an attractive and crucial process for the synthesis of fine chemicals. To date, the heterogeneous catalyst systems that have been identified are based on noble metals or have required the addition of base additives. Here, we show that Co nanoparticles embedded in nitrogen-doped graphite catalyze the aerobic oxidation of alcohols to esters at room temperature under base-free and atmospheric conditions. Our Co@C-N catalytic system features a broad substrate scope for aromatic and aliphatic alcohols as well as diols, giving their corresponding esters in good to excellent yields. This apparently environmentally benign process provides a new strategy with which to achieve selective oxidation of alcohols.
- Zhong, Wei,Liu, Hongli,Bai, Cuihua,Liao, Shijun,Li, Yingwei
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p. 1850 - 1856
(2015/03/14)
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- An efficient one-pot oxidative esterification of aldehydes to carboxylic esters using B(C6F5)3-TBHP
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A simple and efficient protocol for oxidative esterification of diverse aldehydes with alcohols was accomplished with tert-butyl hydroperoxide and 1 mol % of tris(pentafluorophenyl)borane [B(C6F5)3] to generate the corresponding esters in good to excellent yields. The present protocol represents compatibility with wide range of functional groups as well as exceptional tolerance toward acid labile protecting groups such as TBDPS, TBDMS, acetonide, and Boc.
- Guggilapu, Sravanthi Devi,Prajapti, Santosh Kumar,Babu, Bathini Nagendra
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supporting information
p. 889 - 892
(2015/02/05)
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- Inclusion complex containing epoxy resin composition for semiconductor encapsulation
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The invention is an epoxy resin composition for sealing a semiconductor, including (A) an epoxy resin and (B) a clathrate complex. The clathrate complex is one of (b1) an aromatic carboxylic acid compound, and (b2) at least one imidazole compound represented by formula (II): wherein R2 represents a hydrogen atom, C1-C10 alkyl group, phenyl group, benzyl group or cyanoethyl group, and R3 to R5 represent a hydrogen atom, nitro group, halogen atom, C1-C20 alkyl group, phenyl group, benzyl group, hydroxymethyl group or C1-C20 acyl group. The composition has improved storage stability, retains flowability when sealing, and achieves an effective curing rate applicable for sealing delicate semiconductors.
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- Reaction mechanism studies involving the correlation of the rates of solvolysis of benzoyl and p-nitrobenzoyl p-toluenesulfonates
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The solvolyses of benzoyl and p-nitrobenzoyl p-toluenesulfonates (tosylates) are considerably slower than those of the previously studied mixed anhydride of acetic and p-toluenesulfonic acids (acetyl tosylate), which, even with application of rapid-response conductivity, could only be studied at considerably reduced temperatures. For the presently studied compounds, the specific rates over a wide variety of solvents could be conveniently studied at -10 °C. For solvolyses of benzoyl tosylate, application of the extended (two-term) Grunwald-Winstein equation gives sensitivities to changes in solvent nucleophilicity and solvent ionising power consistent with an ionisation (S Nl) pathway. Indeed, a good correlation is obtained against only solvent ionising power. For the solvolyses of the p-nitro-derivative, very different sensitivities are obtained, with an appreciable dependence on solvent nucleophilicity, and a dominant biomolecular pathway for the substitution is proposed for all of these solvolyses, except for those in solvents rich in fluoroalcohol. Studies of solvent deuterium isotope effects in methanolysis, of leaving-group effects relative to a halide and of temperature variation effects are consistent with the proposed mechanistic pathways.
- Kevill, Dennis N.,Ryu, Zoon Ha
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p. 387 - 395
(2014/08/05)
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- Facile esterification of carboxylic acid using amide functionalized benzimidazolium dicationic ionic liquids
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Herein, we report the synthesis of a new series of amide functionalized dicationic benzimidazolium based ionic liquids (DBimILs) and appraised their efficacy towards perceptive esterification of carboxylic acids with alkyl/allyl/aryl halides in presence of triethylamine. The amide groups present in this new series of DBimILs are expected to form hydrogen bonding with the carboxylic acids and this could facilitate the esterification reactions under mild conditions devoid of any added catalyst or organic solvent. The plausible mechanism for the enhanced catalytic activity in presence of this new series of ILs has been proposed. The corresponding alkyl/allyl/aryl esters isolated from this reaction were of high purity after simple extraction, which wipe out the necessity for further purification. This protocol addresses clean methodology and the efficient recyclability as well as reusability of the catalyst.
- Muskawar, Prashant Narayan,Thenmozhi,Gajbhiye, Jayant M.,Bhagat, Pundlik Rambhau
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p. 214 - 220
(2014/07/08)
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- Oxidation of benzaldehydes to benzoate esters using household bleach and sodium iodide in alcohol solvents
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Various substituted benzaldehydes were converted into benzoate esters with household bleach and sodium iodide in an alcohol solvent. The reaction works best with methanol. Only 4-chlorobenzaldehyde, 3-nitrobenzaldehyde, and 4-nitrobenzaldehyde reacted completely with 1-propanol under these conditions. [Supplementary materials are available for this article. Go to the publisher's online edition of Synthetic Communications for the following free supplemental resource(s): Full experimental and spectral details.] Copyright
- Hathaway, Bruce A.,Dekastle, Christopher A. D.,Arnett, Brianna A.
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supporting information
p. 660 - 664
(2014/01/17)
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- Polymer-supported sulfonated magnetic resin: An efficient reagent for esterification of O-alkyl alkylphosphonic-and carboxylic-acids
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A mild and efficient synthetic method has been developed for the esterification of O-alkyl alkylphosphonic-and carboxylic-acids using polymer-supported sulfonated magnetic resins. Polymer-supported resins are recovered using an external magnet and reused several times.
- Purohit, Ajay Kumar,Kumar, Ajeet,Singh, Varoon,Goud D, Raghavender,Jain, Rajiv,Dubey
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supporting information
p. 6844 - 6846
(2015/01/09)
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- A facile and efficient [bmim]N3 catalyzed direct oxidative esterification of arylaldehydes with alcohols
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Task-specific ionic liquid, [bmim]N3 was used as an effective catalyst and reaction medium for the direct oxidative esterification of arylaldehydes with alcohols. The oxidative esterification reaction of a variety of arylaldehydes took place smoothly with some primary and secondary alcohols in [bmim]N3. Satisfactory results were obtained with arylaldehydes containing electron withdrawing groups. Tertiary alcohols did not react under these conditions.
- Valizadeh, Hassan,Ahmadi, Mina
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p. 1077 - 1080
(2013/02/23)
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- Solvent-free esterification of carboxylic acids and alcohols in the presence of silphos [PCl3-n(SiO2)n] as a heterogeneous phosphine reagent
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An efficient solvent-free method for the preparation of esters from various aromatic and aliphatic acids with primary, secondary, and tertiary alcohols using a heterogeneous phosphine reagent, silphos [PCl3-n(SiO 2)n], in good yields is reported.
- Rao, Ambati Narasimha,Ganesan, Kumaran,Shinde, Chandra Kant
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experimental part
p. 2299 - 2308
(2012/06/18)
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- Hydrogen peroxide mediated efficient amidation and esterification of aldehydes: Scope and selectivity
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An efficient method for the amidation and esterification of aldehydes utilizing hydrogen peroxide as an oxidant has been developed. Cyclic amines and primary alcohols selectively reacted with aromatic aldehydes under mild conditions to yield the corresponding amides and esters.
- Tank, Rekha,Pathak, Uma,Vimal, Manorama,Bhattacharyya, Shubhankar,Pandey, Lokesh Kumar
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p. 3350 - 3354
(2012/01/06)
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- Single-step conversion of electron-deficient aldehydes into the corresponding esters in aqueous alcohols in the presence of iodine and sodium nitrite
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The direct conversion of aldehydes into their corresponding esters in the presence of iodine and sodium nitrite in aqueous alcohols is reported. In all these reactions, alcohol serves as reactant and also as reaction medium. Almost quantitative yields were obtained with aldehydes containing electron-withdrawing substituents and heterocyclic aldehydes. Georg Thieme Verlag Stuttgart.
- Kiran,Ikeda, Reiko,Sakai, Norio,Konakahara, Takeo
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experimental part
p. 276 - 282
(2010/03/26)
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- Catalytic oxidative esterification of aldehydes and alcohols using KI-TBHP
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A simple and mild procedure for the facile oxidative esterification of aldehydes and alcohols using potassium iodide (KI) in combinzation with tert-butyl hydroperoxide (TBHP) as an external oxidant is described. Oxidative esterification is induced by iodine generated in situ by the chemical oxidation of KI with TBHP.
- Reddy, K. Rajender,Venkateshwar,Maheswari, C. Uma,Prashanthi
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experimental part
p. 186 - 195
(2010/03/24)
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- Carbon-carbon bond cleavage and esterification of phenylacetonitrile and its derivatives affording the corresponding benzoic esters
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Phenylacetonitrile and its derivatives were treated with alcohols in the presence of potassium iodide and iodine affording the corresponding benzoate esters via degradation, oxidation and esterification under mild conditions. The products were characterised by IR, 1H NMR, MS and elemental analysis.
- Wang, Zhiyuan,Kang, Junhui,Yu, Mingxin
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p. 323 - 324
(2008/02/10)
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- Novel C-C bond cleavage from arylacetonitriles in alcohols to aryl carboxylic esters using potassium iodide and catalytic amount of samarium
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A novel way to cleave the carbon-carbon bond from arylacetonitriles in alcohols to their corresponding aryl carboxylic esters using potassium iodide and a catalytic amount of samarium under mild and neutral conditions is described. Useful yields of the reaction can be obtained with electron-deficient subsistent groups in aromatic rings, and the yields are higher when the subsistent group is an electron-withdrawing group (EWG) rather than an electron-donating group (EDG). Products were characterized by IR, 1H NMR, 13C NMR, and MS. Copyright Taylor & Francis Group, LLC.
- Yu, Mingxin,Wen, Weijiang,Wang, Zhiyuan
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p. 2851 - 2857
(2007/10/03)
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- Fe2(SO4)3·xH2O in synthesis: A convenient and efficient catalyst for the esterification of aromatic carboxylic acids with alcohols
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Fe2(SO4)3·xH2O has been used for the catalyst in the esterification of aromatic carboxylic acids with alcohols. The method offers mild reaction condition, easy work-up, and high yields of the esterification products.
- Zhang, Gui-Sheng
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p. 607 - 611
(2007/10/03)
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- Facile oxidation of benzyl ethers by the 2-nitrobenzene-sulfonylperoxyl intermediate generated from 2-nitrobenzenesulfonyl chloride and superoxide
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Various benzyl ethers react with a 2-nitrobenzenesulfonyl-peroxyl radical intermediate generated from 2-nitrobenzenesulfonyl chloride and potassium superoxide at -25°C in acetonitrile to give the corresponding esters in high yields.
- Kim, Yong Hae,Kim, Yong Il,Kim, Joong Young
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p. 633 - 634
(2007/10/03)
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- Liquid-Phase Hydrogenation of p-Nitrobenzoic Acid Esters on Palladium Catalysts
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Hydrogenation of some p-nitrobenzoic esters on palladium catalysts (conventional heterogeneous Pd/C and Pd/Al2O3 and polymeric AV-17-8-Pd and AN-1-Pd) is studied. The maximum rate of the hydrogenation reaction was observed in methanol at t = 55°C and PH2 = 0.1 MPa. MNDO calculations of some electronic characteristics of p-nitrobenzoic ester molecules were performed. A two-parameter correlation between the hydrogenation rate constant, the charge of the nitro group, and the steric substituent constant was found for the reaction conducted on the AV-17-8-Pd and AN-1-Pd catalysts.
- Morogina,Nasibulin,Klyuev
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p. 251 - 255
(2007/10/03)
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- Smectogenic Salts Formed by Combination of Alkyl p-Aminobenzoates and p-Ethyl- or p-Chlorobenzenesulfonic Acid
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Two series of smectogenic salts were obtained by combining alkyl p-aminobenzoates with p-ethyl- and p-chlorobenzenesulfonic acids, respectively.The shortest ester alkyl chain required to generate a smectic A phase is nonyl when the former sulfonic acid is employed but the chain may be as short as butyl when the latter is employed.The smectic A-isotropic transition temperature in the second series is significantly higher than that in the first series, indicating that the terminal substituent on the anion is as crucial as that in non-ionic mesogens in determining the mesophase stability. - Keywords: Smectic, alkyl p-aminobenzoates, benzenesulfonates
- Matsunaga, Y.,Sakamoto S.,Togashi, A.,Tsujimoto, M.
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p. 161 - 166
(2007/10/02)
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- EFFECTS OF BRANCHING OF THE ALKYL CHAIN ON THE LIQUID CRYSTALLINE PROPERTIES OF N-(p-PHENYLBENZYLIDENE)-p-ALKOXYCARBONYLANILINES.
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The liquid crystal behavior of twenty-three N-(p-phenylbenzylidene)-p-alkoxycarbonylanilines has been examined by optical microscopy and differential scanning calorimetry in order to study the effects of branching of the alkyl groups.
- Matsunaga,Miyajima
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p. 353 - 359
(2007/10/02)
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- Esterification of Aromatic Carboxylic Acids with Alcohols Using 2-Chloro-3,5-dinitropyridine as a Condensing Agent
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The reaction of 2-chloro-3,5-dinitropyridine (CDNP) with carboxylic acids and alcohols was examined, and it was found that CDNP was a useful condensing agent.Various esters were prepared in good yields.
- Takimoto, Seiji,Abe, Naomi,Kodera, Yasushi,Ohta, Hiroshi
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p. 639 - 640
(2007/10/02)
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- ALKYLATING PROPERTIES OF ALKYL PHOSPHITEDIETHYL AZODICARBOXYLATE REAGENT
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Reaction of caoxylic acids, phenols, and some imides with phosphite esters in presence of diethyl azodicarboxylate result in transfer of an alkyl group from phosphite to a protic acid molecule In the case of enolizable C-H acids selective formation of O-alkylated products was observed.The reactions proceed under mild, virtually neutral conditions, affording good yields of alkylated products.
- Grynkiewicz, Grzegorz
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p. 149 - 152
(2007/10/02)
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