- Selective esterification of nonconjugated carboxylic acids in the presence of conjugated or aromatic carboxylic acids under mild conditions
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Nonconjugated carboxylic acids are selectively esterified in good yields in the presence of conjugated or aromatic carboxylic acids by stirring over Amberlyst-15 in alcohol at room temperature.
- Anand, Ramesh C.,Vimal,Milhotra, Archana
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- Preparation method of 3-substituted dimethyl glutarate and dimethyl glutaconate
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The invention relates to the field of fine chemical engineering, and particularly relates to a preparation method of 3-substituted dimethyl pentodiate and pentene diester. According to the preparationmethod of 3-substituted dimethyl pentodiate and pentene diester, malonic ester and halomethane are used as raw materials, substitution reaction is performed under an alkaline action, then decarboxylation and esterification reaction are performed so as to prepare 3-substituted dimethyl pentodiate or pentene diester, a structural formula of 3-substituted dimethyl pentodiate is as shown in a compound (V), and a structural formula of pentene diester is as shown in a compound (IX). The preparation method of 3-substituted dimethyl pentodiate and pentene diester is mild in reaction conditions, is easy to operate and is safe. The formula is shown in the description.
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Paragraph 0032; 0035
(2018/09/08)
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- Rhodium-catalysed alkoxylation/acetalization of diazo compounds: One-step synthesis of highly functionalised quaternary carbon centres
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An intermolecular tandem reaction for the rapid build-up of densely functionalised α-alkoxy-β-oxo-esters has been developed. This novel process applies the easy to handle trimethyl orthoformate as a C1-building block in the rhodium(ii)-catalysed alkoxylation/acetalization of donor-acceptor substituted diazo compounds. The concomitant C-O/C-C bond formation reaction gives products with unique quaternary carbon centers, substituted by groups of different oxidation level (ester, protected aldehyde and alkoxide).
- Pospech, Jola,Lennox, Alastair J. J.,Beller, Matthias
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supporting information
p. 14505 - 14508
(2015/09/28)
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- PROCESS FOR THE PREPARATION OF DIALKYL GLUTACONATES
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The invention relates to a process for preparing a dialkyl glutaconate of formula RO(CO)CH2CH=CH(CO)OR, wherein R is C1-6 alkyl, by heating a dialkyl 3-alkoxyglutarate of formula RO(CO)CH2C(OR)CH2(CO)OR, wherein R is as defined above, in the presence of an acid.
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Page/Page column 10
(2010/11/05)
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- Influence of functional substitution of allyl halides on their ni(co)4 promoted carbonylative cycloaddition with acetylenes
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The effect of functional substitution of allyl halides on the outcome of the title reaction has been studied. Electron withdrawing and olefinic groups had different effects depending on their location. When they were placed at the central position of the allyl moiety carbonylative cycloaddition was found to be the main reaction, in acetone, to yield exclusively cyclohexenone (or aromatic) derivatives. In contrast, the same groups at the terminal site and in exteded conjugation with the allylic funtion were shown to favour competing side reactions such as allyl self-coupling. However, only cyclopentenones were obtained from either centrally or terminally substituted silylallyl halides. Substitution at both ends of the allyl moiety led to the formation of 4,5-disubstituted cyclopentenones. Important mechanistic information could be achieved from determination of the relative stereochemistry in these compounds.
- Camps, Francisco,Moreto, Josep M.,Pages, Lluis
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p. 3147 - 3162
(2007/10/02)
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In the presence of a palladium(0) complex and potassium t-butoxide, the acetylenic compounds 2 bearing in δ a nucleophilic functionality are smoothly transformed with excellent yields, either into 2,2-difunctionalized methylene cyclopentanes or into monofunctionalized 2-methylcyclopentenes. Each of these compounds can be specifically obtained depending on the choice of the experimental conditions. A set of diverse reactions involving mainly potassium hydride as the base showed clearly that HPdOtBu is not the active catalytic species which is mainly a σ-ethynylpalladium hydride formed by the metal insertion in the acetylenic carbon hydrogen bond.
- Monteiro, Nuno,Gore, Jacques,Balme, Genevieve
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p. 10103 - 10114
(2007/10/02)
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- Reactions of 2-alkoxyfurans with nonacarbonyldiiron or dodecacarbonyltriruthenium giving binuclear vinylcarbene complexes and a 2-pyrone complex. A novel precursor for α,β-unsaturated alkylidene ligands and an unusual carbonylation of the furans
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2-Methoxyfuran reacted with nonacarbonyldiiron in diethyl ether at 35°C for 4 h to give a binuclear α,β-unsaturated alkylidene complex, hexacarbonyl(μ-3-η1-anti-(methoxycarbonyl)-η 3:η1-allyl)diiron(i;'e-i'e)(5a) and a 2-pyrone derivative, tricarbonyl(3-6-η-6-methoxy-2-pyrone)iron (6a). 2-Methoxyfuran also reacted with dodecacarbonyltriruthenium in benzene under an atmosphere of carbon monoxide at 150°C for 4 h to give a corresponding binuclear α,β-unsaturated alkylidene complex, hexacarbonyl(μ-3-η1-anti-(methoxycarbonyl)-η 3:η1-allyl)dimthenium(Ru-Ru) (10), 6-methoxy-2-pyrone (11), and dimethyl glutaconate (12). Both reactions could be explained by assuming mononuclear η3-vinylcarbene complexes as reaction intermediates.
- Mitsudo, Take-Aki,Ogino, Yasukazu,Komiya, Yukiatsu,Watanabe, Hiroyoshi,Watanabe, Yoshihisa
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p. 1202 - 1207
(2008/10/08)
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