- Synthesis and characterization of stable ZnO nanoparticles using imidazolium-based ionic liquids and their applications in esterification reaction
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ZnO nanoparticles have been synthesized from zinc acetate using 1-octyl-3-methylimidazolium hexafluorophosphate as capping agent under microwave irradiation condition in a very short period of time and characterized using UV-visible spectroscopy, powder X-ray diffraction, scanning electron microscopy, transmission electron microscopy and NH3-TPD analysis. The ZnO NPs have been used as a solid reusable acid catalyst for esterification of carboxylic acids with alcohols.
- Kavya,Vijaya Kumar,Ramesh Kumar
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p. 1112 - 1120
(2018/09/21)
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- Synthesis of Esters by Functionalisation of CO2
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The invention relates to a method for (I) producing a carboxylic ester of formula (I). Said method comprises the steps of: a) bringing an organosilane/borane of formula Si or B into contact with CO2, in the presence of a catalyst and an electrophilic compound of formula (III), the groups R1, R2, R3, R4, R5, Y, and M′ being as defined in claim 1; and optionally b) recovering the compound of formula (I) produced.
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Paragraph 0136
(2017/09/06)
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- Facile and efficient gold-catalyzed aerobic oxidative esterification of activated alcohols
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A facile and efficient methodology is presented for the direct oxidative esterification of alcohols with alcohols catalyzed by NaAuCl4. Just in the presence of a low catalytic amount of base additive, the newly developed catalytic system proceeds with high selectivity and broad substrate scope under mild conditions with dioxygen or air as the environmentally benign terminal oxidant. Various alcohols including benzylic and allylic alcohols were smoothly reacted with methanol and even with long-chain aliphatic alcohols, affording the desired products in good to excellent yields (up to 95% yield). The present system showed high catalytic activity with a TOF up to 219 h-1. Kinetic studies of the reaction process provide fundamental insights into the catalytic pathway, and a possible reaction pathway was proposed based on the results of the control experiments. XPS, TEM, and UV-vis were carried out to characterize the chemical state of the Au catalyst in the present catalytic system. The results indicate that the Au nanoparticles were generated in situ and supported on K2CO3, forming a simple, recyclable and selective catalyst system for the direct oxidative esterification of alcohols. the Partner Organisations 2014.
- Wang, Lianyue,Li, Jun,Dai, Wen,Lv, Ying,Zhang, Yi,Gao, Shuang
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p. 2164 - 2173
(2014/04/17)
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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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- 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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- Manganese phthalocyanine immobilized on silica gel: Efficient and recyclable catalyst for single-step oxidative esterification of aldehydes with alcohols
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The functionalization of silica gel was carried out using 3-aminopropyltriethoxysilane as a reactive surface modifier followed by covalent grafting of novel tetrakis-(2-methoxy-4-formylphenoxy)phthalocyaninato manganese(III) acetate complex. The resulting inorganic-organic hybrid material was found to be a highly selective and recyclable catalyst for the single-step synthesis of esters. The catalyst was characterized by elemental analysis (CHN), diffuse reflectance UV-visible, 13C CPMAS and 29Si CPMAS NMR spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM), BET surface area analysis, energy dispersive X-ray fluorescence (ED-XRF), Fourier-transform infrared (FT-IR) and atomic absorption spectroscopy (AAS) techniques, which demonstrates the covalent grafting of the complex onto functionalized silica gel. The catalytic performance of the novel inorganic-organic hybrid catalyst was evaluated in the direct oxidative esterification of aldehydes with alcohols, at ambient temperature, using hydrogen peroxide as an environment friendly oxidant. The hybrid catalyst presented up to 100% of substrate conversion with high turn-over numbers (TONs), up to 100% of selectivity toward the ester product, and can be recovered and reused for multiple cycles without appreciable loss in its catalytic activity.
- Sharma,Gulati, Shikha
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p. 291 - 303
(2012/10/30)
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- The first general and selective palladium(II)-catalyzed alkoxycarbonylation of arylboronates: Interplay among benzoquinone-ligated palladium(0) complex, organoboron, and alcohol solvent
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Methoxycarbonylation of aryl- and alken-ylboron compounds was performed using the palladium (II) acetate/triphenylphosphine [PdACHTUNGTRENNUNG(OAc) 2/PPh3] catalyst with p-benzoquinone as a stoichiometric oxidant in methanol at ambient temperature to obtain the corresponding methyl esters in good yields. A wide variety of functional groups including various carbonyl functionalities, nitrile, nitro, sulfone, and unprotected pyrrole rings were tolerated in the methoxycarbonlation, while the use of higher alcohols except for tert-butanol afforded various pchlorobenzoates in moderate to high yields. The catalytic alkoxycarbonylation proceeded without any acid or base additive, and an oxidative transmetalation step is proposed to explain the exceptional efficacy of this protocol. DFT and MP2 calculations support the proposed mechanism.
- Yamamoto, Yoshihiko
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supporting information; experimental part
p. 478 - 492
(2010/07/03)
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- The methoxycarbonylation of aryl chlorides catalysed by palladium complexes of bis(di-tert-butylphosphinomethyl)benzene
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A catalyst system based on palladium-1,2-bis-(di-tert-butylphosphinomethyl) benzene (BDTBPMB) shows good activity for the methoxycarbonylation of strongly activated aryl chlorides, like 4-chloromethylbenzoate or 4-chlorocyanobenzene. Surprisingly, the use of less activated aryl chlorides, like 4-chloroacetophenone, leads to the formation of dimethyl terephthalate amongst other products arising from organic reactions of methoxide ion and/or CO. Less nucleophilic alcohols such as 2,2,2-trifluoroethanol promote the formation of carbonylation products even from 4-chloroacetophenone and chlorobenzene. Labelling studies involving CD3OH, CD3OD or 13CO give information on the origin of many of the products. The Royal Society of Chemistry 2005.
- Jimenez-Rodriguez, Cristina,Eastham, Graham R.,Cole-Hamilton, David J.
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p. 1826 - 1830
(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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- The chemistry of acylals. Part I. The reactivity of acylals towards Grignard and organolithium reagents
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Aldehyde acylals have been prepared and reacted with Grignard and alkyllithium reagents. Acylals from formaldehyde furnished complex reaction mixtures when reacted with both reagents. Acylals of other aldehydes gave reaction mixtures that consisted mainly of an ester, generated by replacing one of the carboxy groups with the organic part of the organometallic reagent, and regenerated aldehyde. The esters were formed in the highest yields. Yields above 90% were experienced when the acylals were reacted with Grignard reagents under Barbier conditions.
- Sydnes, Leiv K.,Sandberg, Marcel
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p. 12679 - 12690
(2007/10/03)
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- Catalytic action of azolium salts. VIII. Oxidative aroylation with arenecarbaldehydes catalyzed by 1,3-dimethylbenzimidazolium iodide
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Refluxing of a mixture of benzaldehyde (1a), 1,3- dimethylbenzimidazolium iodide (7), p-nitroaniline (9b) as an oxidizing agent, and 1,8-diazabicyclo[5,4,0]-7-undecene (DBU) in MeOH afforded methyl benzoate (2a) in good yield. Other methyl arenecarboxylates 2 were similarly obtained from arenecarbaldehydes 1. We showed that this aroylation proceeds via the 2-aroyl-1,3-dimethylbenzimidazolium salt (8). The 1,2,4-triazolium salt (18) and the naphtho[1,2-d]imidazolium salt (19) were also effective catalysts for this oxidative aroylation. However, the aroylation did not proceed with the imidazolium salt (20). In the presence of flavins (25a - c), arenecarbaldehydes 1 reacted in MeOH under aerobic conditions catalyzed by the benzimidozolium salt 7 to give the corresponding methyl arenecarboxylates 2. 1-Methyl-3-[3-(10-phenylisoalloxazin-3-yl)propyl]benzimidazolium bromide (27) is an effective complex catalyst for this oxidative aroylation.
- Miyashita, Akira,Suzuki, Yumiko,Nagasaki, Izuru,Ishiguro, Chie,Iwamoto, Ken-Ichi,Higashino, Takeo
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p. 1254 - 1258
(2007/10/03)
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- Kinetic and Thermodynamic Parameters for the Alcoholysis of 2,2,2-Trichloro-1-arylethanones
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The reactions of 2,2,2-trichloro-1-phenylethanone (1a) and 2,2,2-trichloro-1-(p-chlorophenyl)-ethanone (1b) with MeOH, EtOH, n-PrOH, and n-BuOH in the presence of ethylamine resulted in the formation of the corresponding esters ArCOOR.When the process is carried out in the absence of ethylamine the reaction does not proceed beyond formation of the hemiacetal intermediate.The former reaction occurs through an addition-elimination process and the order of reactivity of the alcohols is MeOH>EtOH>n-PrOH>n-BuOH.If (1a or b) is treated with ethylamine in dioxane the corresponding amide ArCONHEt is the only reaction product.
- Uieara, Marina,Zucco, Cesar,Zanette, Dino,Rezende, Marcos C.,Nome, Faruk
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p. 175 - 180
(2007/10/02)
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