- Dinuclear manganese alkoxide complexes as catalysts for C-N bond cleavage of simple tertiary: N, N -dialkylamides to give esters
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Amide bonds are stable due to the resonance between the nitrogen lone pair and the carbonyl moiety, and therefore the chemical transformation of amides, especially tertiary amides, involving C-N bond fission is considered one of the most difficult organic reactions, unavoidably requiring harsh reaction conditions and strong acids or bases. We report the catalytic C-N bond cleavage of simple tertiary N,N-dialkylamides to give corresponding esters using a catalyst system (2 mol% based on Mn atoms) of a tetranuclear manganese alkoxide, [Mn(acac)(OEt)(EtOH)]4 (1c), combined with four equivalents of 4,7-bis(dimethylamino)-1,10-phenanthroline (L1: Me2N-Phen). Regarding the reaction mechanism, we isolated a dinuclear manganese complex, [Mn(acac)(OEt)(Phen)]2 (6c), which was revealed as the catalytically active species for the esterification of tertiary amides.
- Nagae, Haruki,Hirai, Takahiro,Kato, Daiki,Soma, Shusei,Akebi, Shin-Ya,Mashima, Kazushi
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- Manganese(II)-Catalyzed Esterification of N-β-Hydroxyethylamides
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A catalyst system of manganese with 2,2-bipyridine for amide alcoholysis of N-β-hydroxyethylamides is described. This protocol enabled selective cleavage of the amide bond through a mechanism involving sequential N,O-acyl rearrangement and transesterification.
- Nishii, Yuji,Akiyama, Shoko,Kita, Yusuke,Mashima, Kazushi
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- Esterification of Tertiary Amides: Remarkable Additive Effects of Potassium Alkoxides for Generating Hetero Manganese–Potassium Dinuclear Active Species
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A catalyst system of mononuclear manganese precursor 3 combined with potassium alkoxide served as a superior catalyst compared with our previously reported manganese homodinuclear catalyst 2 a for esterification of not only tertiary aryl amides, but also tertiary aliphatic amides. On the basis of stoichiometric reactions of 3 and potassium alkoxide salt, kinetic studies, and density functional theory (DFT) calculations, we clarified a plausible reaction mechanism in which in situ generated manganese–potassium heterodinuclear species cooperatively activates the carbonyl moiety of the amide and the OH moiety of the alcohols. We also revealed details of the reaction mechanism of our previous manganese homodinuclear system 2 a, and we found that the activation free energy (ΔG≠) for the manganese–potassium heterodinuclear complex catalyzed esterification of amides is lower than that for the manganese homodinuclear system, which was consistent with the experimental results. We further applied our catalyst system to deprotect the acetyl moiety of primary and secondary amines.
- Akiyama, Shoko,Himo, Fahmi,Hirai, Takahiro,Katayama, Shoichiro,Kato, Daiki,Mai, Binh Khanh,Mashima, Kazushi,Nagae, Haruki
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supporting information
(2020/07/25)
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- A Straightforward Conversion of Activated Amides and Haloalkanes into Esters under Transition-Metal-Free Cs 2 CO 3 /DMAP Conditions
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The esterification of activated amides, N -acylsaccharins, under transition-metal-free conditions with good functional group tolerance has been developed, resulting in C-N cleavage leading to efficient synthesis of a variety of esters in moderate to good yields. This work demonstrates that esterification may proceed by using simple N -acylsaccharins, haloalkanes, and Cs 2 CO 3 as oxygen source.
- Chen, Liuqing,Gu, Ying,Jian, Junsheng,Liu, Yueping,Miao, Liqiong,Wang, Zijia,Zeng, Zhuo
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p. 4078 - 4084
(2019/10/28)
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- Cross-Dehydrogenating Coupling of Aldehydes with Amines/R-OTBS Ethers by Visible-Light Photoredox Catalysis: Synthesis of Amides, Esters, and Ureas
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A straightforward synthesis of amides, ureas, and esters is reported by visible-light cross-dehydrogenating coupling (CDC) of aldehydes (or amine carbaldehydes) and amines/R-OTBS ethers by photoredox catalysis. The reaction is found to be general and high yielding. A plausible mechanistic pathway has been proposed for these transformations and is supported by appropriate controlled experiments.
- Pandey, Ganesh,Koley, Suvajit,Talukdar, Ranadeep,Sahani, Pramod Kumar
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supporting information
p. 5861 - 5865
(2018/09/21)
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- Development of N-Doped Carbon-Supported Cobalt/Copper Bimetallic Nanoparticle Catalysts for Aerobic Oxidative Esterifications Based on Polymer Incarceration Methods
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Heterogeneous nitrogen-doped carbon-incarcerated cobalt/copper bimetallic nanoparticle (NP) catalysts, prepared from nitrogen-containing polymers, were developed, and an efficient catalytic process for aerobic oxidative esterification was achieved in the presence of a low loading (1 mol %) of catalyst that could be reused and easily reactivated. This protocol enabled diverse conditions for the bimetallic NP formation step to be screened, and significant rate acceleration by inclusion of a copper dopant was discovered. The catalytic activity of the bimetallic Co/Cu catalysts is much higher than that for cobalt catalysts reported to date and is even comparable with noble-metal NP catalysts.
- Yasukawa, Tomohiro,Yang, Xi,Kobayashi, Shu
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supporting information
p. 5172 - 5176
(2018/09/12)
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- Selective Oxidative Esterification from Two Different Alcohols via Photoredox Catalysis
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Esters functionalities are important building blocks that are extensively used in the chemical industry and academic laboratories. Direct oxidative esterification from easy-available alcohols to esters would be a much more appealing approach, especially using O2as terminal oxidant. Inputting external energy by photocatalysis for dioxygen activation, a mild and simple method for ester synthesis from two different alcohols has been achieved in this work. This reaction is performed under neutral conditions using O2as the terminal oxidant. A variety of primary alcohols, especially long chain alcohols and secondary alcohols are tolerated in this system.
- Yi, Hong,Hu, Xia,Bian, Changliang,Lei, Aiwen
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- Fe-Catalyzed Aerobic Oxidative C-CN Bond Cleavage of Arylacetonitriles Leading to Various Esters
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Fe-catalyzed aerobic oxidative esterifications of arylacetonitriles with alcohols, tri alkoxsilanes, silicate esters, or borate esters have been developed. The acyl groups which were in situ generated via chemoselective C(CO)-CN bond cleavage were directly used as electrophiles, leading to corresponding aryl esters in good to excellent yields under molecular oxygen when attacked by alcohols or alcohol surrogates. Dioxygen serves as both oxidant and reactant in this protocol. The reaction has a very broad substrate scope. Cheap starting materials as well as environmentally benign and inexpensive iron catalyst and ideal oxidant O2 feature this transformation and make it a practical and sustainable protocol to afford esters.
- Kong, Weiguang,Li, Bingnan,Xu, Xuezhao,Song, Qiuling
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p. 8436 - 8443
(2016/09/28)
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- Synthetic method of an ester compound
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The invention discloses a synthetic method of an ester compound and belongs to the technical field of organic synthesis. The synthetic method includes the steps of: dissolving an aldehyde compound (1) and a halogenated hydrocarbon compound (2) in a solvent, adding an oxidant and a catalyst, and performing a reaction at 60-100 DEG C to obtain the target product ester compound (3). A reaction equation of the synthetic method is represented as follows. The method, compared with the prior art, has the following advantages: 1) the raw materials are easy to obtain and are low in cost; 2) the reaction conditions are mild, operations are simple, and reaction time is short; and 3) a substrate has wide available range and can be used for synthesis of various ester compounds.
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Paragraph 0048; 0049; 0050
(2017/02/02)
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- Palladium-catalyzed carbonylation of aryl halides: An efficient, heterogeneous and phosphine-free catalytic system for aminocarbonylation and alkoxycarbonylation employing Mo(CO)6 as a solid carbon monoxide source
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Immobilized palladium metal-containing magnetic nanoparticles (ImmPd(0)-MNPs) were synthesized and characterized as an immobilized, phosphine-free catalyst for carbonylation reactions, namely the alkoxycarbonylation and aminocarbonylation reactions. Various substituted aryl iodides tolerated the reaction conditions and a wide variety of alcohols and amines were used efficiently. The effects of the solvent, base, and temperature were studied in both the mentioned reactions. The developed catalytic system avoids the use of phosphine ligands and can be reused for up to eight consecutive cycles. The recycled catalyst was characterized by TEM and ICP analysis.
- Hajipour, Abdol-Reza,Tavangar-Rizi, Zeinab,Iranpoor, Nasser
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p. 78468 - 78476
(2016/09/09)
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- A facile, one-pot procedure for the conversion of aromatic aldehydes to esters, as well as thioesters and amides, via acyl hydrazide intermediates
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Herein we present an efficient method for the synthesis of esters from aromatic aldehydes via readily accessible acyl hydrazides. The developed reaction protocol is shown to be tolerant of a range of aromatic aldehydes, bearing various functionalities, as well as being amenable to the synthesis of thioesters and amides.
- Maruani, Antoine,Lee, Maximillian T. W.,Watkins, George,Akhbar, Ahmed R.,Baggs, Henry,Shamsabadi, André,Richards, Daniel A.,Chudasama, Vijay
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p. 3372 - 3376
(2016/01/16)
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- From ketones to esters by a Cu-catalyzed highly selective C(CO)-C(alkyl) bond cleavage: Aerobic oxidation and oxygenation with air
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The Cu-catalyzed aerobic oxidative esterification of simple ketones via C-C bond cleavage has been developed. Varieties of common ketones, even inactive aryl long-chain alkyl ketones, are selectively converted into esters. The reaction tolerates a wide range of alcohols, including primary and secondary alcohols, chiral alcohols with retention of the configuration, electron-deficient phenols, as well as various natural alcohols. The usage of inexpensive copper catalyst, broad substrate scope, and neutral and open air conditions make this protocol very practical. 18O labeling experiments reveal that oxygenation occurs during this transformation. Preliminary mechanism studies indicate that two novel pathways are mainly involved in this process. (Chemical Equation Presented)
- Huang, Xiaoqiang,Li, Xinyao,Zou, Miancheng,Song, Song,Tang, Conghui,Yuan, Yizhi,Jiao, Ning
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supporting information
p. 14858 - 14865
(2014/12/11)
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- Transition metal-free oxidative esterification of benzylic alcohols in aqueous medium
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Oxidative esterification of benzylic alcohols with a catalytic amount of HBr-H2O2 in aqueous medium under mild conditions is reported with a wide range of substrate scope for both benzylic and aliphatic alcohols. The conditions are also suitable for selective mono-esterification of ethylene glycol and glycerol. With catalytic amounts of HBr (20 mol%) and H2O2, the generation of reactive intermediate species BrOH has been ascertained by UV-visible spectra.
- Samanta, Supravat,Pappula, Venkatanarayana,Dinda, Milan,Adimurthy, Subbarayappa
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supporting information
p. 9453 - 9456
(2014/12/11)
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- Solvent-controlled copper-catalyzed oxidation of benzylic alcohols to aldehydes and esters
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A procedure for the copper-catalyzed selective oxidation of primary alcohols to esters and aldehydes was developed. Under solvent-free conditions, self-oxidative esterification and cross-esterification of benzyl alcohols with various aliphatic alcohols proceed smoothly to give the corresponding esters in good yields. If DMF was used as a solvent, the benzyl alcohols were selectively converted into the corresponding aldehydes in excellent yields. Depend on solvent! Under solvent-free conditions, Cu-catalyzed oxidative self-esterification and cross-esterification of benzylic alcohols with various aliphatic alcohols proceed smoothly to give the corresponding esters in good yields. If DMF is used as a solvent, the benzylic alcohols are selectively converted into the corresponding aldehydes in excellent yields. DTBP = di-tert-butyl peroxide. Copyright
- Zhu, Yefeng,Wei, Yunyang
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supporting information
p. 4503 - 4508
(2013/07/26)
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- Enzyme-like catalysis via ternary complex mechanism: Alkoxy-bridged dinuclear cobalt complex mediates chemoselective O-esterification over N-amidation
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Hydroxy group-selective acylation in the presence of more nucleophilic amines was achieved using acetates of first-row late transition metals, such as Mn, Fe, Co, Cu, and Zn. Among them, cobalt(II) acetate was the best catalyst in terms of reactivity and selectivity. The combination of an octanuclear cobalt carboxylate cluster [Co4(OCOR)6O]2 (2a: R = CF3, 2b: R = CH3, 2c: R = tBu) with nitrogen-containing ligands, such as 2,2′-bipyridine, provided an efficient catalytic system for transesterification, in which an alkoxide-bridged dinuclear complex, Co2(OCOtBu)2(bpy) 2(μ2-OCH2-C6H4-4- CH3)2 (10), was successfully isolated as a key intermediate. Kinetic studies and density functional theory calculations revealed Michaelis-Menten behavior of the complex 10 through an ordered ternary complex mechanism similar to dinuclear metallo-enzymes, suggesting the formation of alkoxides followed by coordination of the ester.
- Hayashi, Yukiko,Santoro, Stefano,Azuma, Yuki,Himo, Fahmi,Ohshima, Takashi,Mashima, Kazushi
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supporting information
p. 6192 - 6199
(2013/05/23)
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- Zinc-catalyzed amide cleavage and esterification of β- hydroxyethylamides
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Snipping tool: Zn(OTf)2 is an efficient catalyst for selective cleavage of amides bearing a β-hydroxyethyl group on the nitrogen atom. The mechanism involves an N,O-acyl rearrangement and transesterification. This new catalytic system can be applied to sequence-specific peptide bond scission at the amine side of a serine residue. Tf=trifluoromethanesulfonyl. Copyright
- Kita, Yusuke,Nishii, Yuji,Higuchi, Takafumi,Mashima, Kazushi
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supporting information; experimental part
p. 5723 - 5726
(2012/08/07)
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- A general and efficient catalyst for palladium-catalyzed C-O coupling reactions of aryl halides with primary alcohols
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An efficient procedure for palladium-catalyzed coupling reactions of (hetero)aryl bromides and chlorides with primary aliphatic alcohols has been developed. Key to the success is the synthesis and exploitation of the novel bulky di-1-adamantyl-substituted bipyrazolylphosphine ligand L6. Reaction of aryl halides including activated, nonactivated, and (hetero)aryl bromides as well as aryl chlorides with primary alcohols gave the corresponding alkyl aryl ethers in high yield. Noteworthy, functionalizations of primary alcohols in the presence of secondary and tertiary alcohols proceed with excellent regioselectivity.
- Gowrisankar, Saravanan,Sergeev, Alexey G.,Anbarasan, Pazhamalai,Spannenberg, Anke,Neumann, Helfried,Beller, Matthias
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supporting information; experimental part
p. 11592 - 11598
(2010/10/02)
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- Transesterification of various methyl esters under mild conditions catalyzed by tetranuclear zinc cluster
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(Chemical Equation Presented) A new catalytic transesterification promoted by a tetranuclear zinc cluster was developed. The mild reaction conditions enabled the reactions of various functionalized substrates to proceed in good to high yield. A large-scale reaction under solvent-free conditions proceeded with a low E-factor value (0.66), indicating the high environmental and economical advantage of the present catalysis.
- Iwasaki, Takanori,Maegawa, Yusuke,Hayashi, Yukiko,Ohshima, Takashi,Mashima, Kazushi
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p. 5147 - 5150
(2008/09/21)
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- Alumina sulfuric acid as a novel heterogeneous system for esterification of carboxylic acids in solvent free conditions
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Neat chlorosulfonic acid reacts with alumina to give alumina sulfuric acid (ASA) in which sulfuric acid is immobilised on the surface of alumina via a covalent bond. Carboxylic acids can be readily converted to their corresponding esters with a combination of ASA and alcohols in solvent free conditions.
- Sharghi, Hashem,Sarvari, Mona Hosseini,Eskandari, Razieh
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p. 488 - 491
(2007/10/03)
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- Activity of substituted and unsubstituted bezaldehydes in reaction with butyl hypochlorite
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Substituted benzaldehydes under daylight react with butyl hypochlorite affording the corresponding butyl benzoates. Electron-donating substituents in the benzene ring of the aldehyde accelerate, and the electron-withdrawing one decelerate the reaction. The yields of the substituted butyl benzoates in all cases are lower than that of bytyl benzoate.
- Bikbulatov,Zorin,Zorina,Rakhmankulov
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p. 1633 - 1635
(2007/10/03)
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- Oxidative conversion of aldoximes into carboxylic acid esters
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Aromatic and aliphatic aldoximes or their O-methyl ethers can be efficiently converted into the corresponding carboxylic acid esters by treatment with an alcoholic solution of 30% hydrogen peroxide in the presence of catalytic amounts of 2-nitrobenzeneseleninic acid. Primary alcohols give excellent to good yields, secondary ones - good to moderate, but with tertiary alcohols no esterification is observed.
- Said,Skarzewski,Mlochowski
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p. 1851 - 1862
(2007/10/02)
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- Bimolecular Reactions of Mutagenic N-Acetoxy-N-alkoxybenzamides and N-Methylaniline
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N-Methylaniline reacts bimolecularly with mutagenic N-acetoxy-N-alkoxybenzamides and the resultant N-alkoxy-N-(N-methylanilino)benzamides undergo a novel, concerted rearrangement to alkylbenzoates and 1-methyl-1-phenyldiazene which dimerizes to 1,4-dimethyl-1,4-diphenyl-tetrazene.
- Campbell, John J.,Glover, Stephen A.
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p. 1661 - 1663
(2007/10/02)
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