- Reductive Knoevenagel Condensation with the Zn-AcOH System
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An efficient gram-scale one-pot approach to 2-substituted malonates and related structures is developed, starting from commercially available aldehydes and active methylene compounds. The technique combines Knoevenagel condensation with the reduction of the C=C bond in the resulting activated alkenes with the Zn-AcOH system. The relative ease with which the C=C bond reduction occurs can be traced to the accepting abilities of the substituents in the intermediate arylidene malonates.
- Ivanov, Konstantin L.,Melnikov, Mikhail Ya.,Budynina, Ekaterina M.
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p. 1285 - 1291
(2020/11/13)
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- Synthesis of (±)-Pregabalin by Utilizing a Three-Step Sequential-Flow System with Heterogeneous Catalysts
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(±)-Pregabalin, a γ-amino acid derivative, has been synthesized by utilizing flow methods. A three-step sequential-flow reaction starting from commercial isovaleraldehyde and methyl malonate proceeded smoothly with heterogeneous catalysts to afford the precursor of pregabalin in yields of 75–100 %, and a space-time yield of 52.2 g/L d was reached. In addition, a heterogeneous catalyst for the Knoevenagel reactions of aldehydes with malonates, which is the first step of the synthesis, has been developed. Pregabalin was finally obtained by acid-catalyzed hydrolysis of the precursor followed by neutralization.
- Ishitani, Haruro,Kanai, Kan,Saito, Yuki,Tsubogo, Tetsu,Kobayashi, Shū
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supporting information
p. 6491 - 6494
(2017/10/18)
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- PROCESS FOR PRODUCING OPTICALLY ACTIVE 4-NITRO-BUTANOIC ACID ESTER AND PREGABALIN
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PROBLEM TO BE SOLVED: To provide a process for producing optically active pregabalin with low number of reaction steps and low cost, as well as to provide a process for producing optically active 4-nitro-butanoic acid ester for use in said process. SOLUTION: Provided is a process for producing optically active 5-methyl-3-nitromethyl-2-alkoxycarbonyl-hexanoic acid alkyl ester by reacting dialkyl malonate and 4-methyl-1-nitro-1-pentene in the presence of a chiral catalyst containing a pyridine bisoxazoline derivative and calcium oxide; and a process for producing pregabalin using the present production process. SELECTED DRAWING: None COPYRIGHT: (C)2017,JPOandINPIT
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Paragraph 0040
(2017/12/27)
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- β- and δ-amino acids (2,3- and 3,4-trans-CHA) as catalysts in Knoevenagel condensation and asymmetric aldol reactions
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The efficacy of the β- and δ-amino acids (5S,6S)-6-amino-5-hydroxycyclohexa-1,3-dienecarboxylic acid (2,3-trans-CHA) and (3R,4R)-4-amino-3-hydroxycyclohexa-1,5-dienecarboxylic acid (3,4-trans-CHA) as catalysts in Knoevenagel condensation and aldol additio
- Al-Momani, Lo'Ay Ahmed,Lorbach, Volker,Detry, Jean,Geilenkirchen, Petra,Müller, Michael
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supporting information
p. 172 - 183
(2018/05/09)
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- Hydroxy-L-prolines as asymmetric catalysts for aldol, Michael addition and Mannich reactions
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The hydroxyprolines (Hyps) 2-6 are tested as organocatalysts for aldol, Michael additions, and Mannich reactions. The results are compared with the well-known analogous L-proline (1).The effect of the additional hydroxyl group and chiral center was invest
- Al-Momani, Lo'ay A.
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experimental part
p. 101 - 111
(2012/05/20)
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- PROCESSES FOR MAKING PREGABALIN AND INTERMEDIATES THEREFOR
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Processes for making a diester compound of formula (B) and for converting it to pregabalin, especially via a compound of formula (2), can provide several advantages. The compound (B) can be converted to the compound (2) via reductive hydrogenation.
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Page/Page column 8
(2009/12/27)
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- Biosynthetic production of (5S,6S)-6-amino-5-hydroxycyclohexa-1,3-diene-1-carboxylic acid (2,3-CHA)
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The invention relates to a process for the biosynthetic production and recovery of [5S,6S]-6-amino-5-hydroxycyclohexa-1,3-diene-1-carboxylic acid) catalyzed, at increased enzyme activity, at least by an enzyme belonging to the class of aminodeoxyisochoris
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- Carboxylic acid derivatives that inhibit the binding of integrins to their receptors
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A method for the inhibition of the binding of α4β1 integrin to its receptors, for example VCAM-1 (vascular cell adhesion molecule-1) and fibronectin; compounds that inhibit this binding; pharmaceutically active compositions comprising such compounds; and to the use of such compounds either a above, or in formulations for the control or prevention of diseases states in which α4β1 is involved.
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- A straightforward method for the synthesis of alkylidene and arylidene malonates through proline-catalyzed Knoevenagel condensation
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A straightforward method for the synthesis of alkylidene/arylidene malonates and arylidene cyanoacetates, utilizing proline as an alternative to traditional catalysts is presented. A large number of unsaturated esters was obtained from the Knoevenagel reaction under very mild conditions and utilizing cheap reagents.
- Cardillo, Giuliana,Fabbroni, Serena,Gentilucci, Luca,Gianotti, Massimo,Tolomeklli, Alessandra
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p. 1587 - 1594
(2007/10/03)
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- Synthesis of substituted cyclopropylphosphonates by Michael Induced Ring Closure (MIRC) reactions
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A variety of cyclopropylphosphonates were prepared in moderate to good yields by Michael Induced Ring Closure of trialkyl phosphites with the corresponding β-bromoalkylidene cyanoacetates and malonates.
- Stevens, Christian V.,Van Heecke, Gino,Barbero, Carmen,Patora, Krystyna,De Kimpe, Norbert,Verhé, Roland
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p. 1089 - 1092
(2007/10/03)
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- Synthesis of polysubstituted 1,3-cyclohexadicnes from β-branched α,β-alkenals and monoesters of ylidenemalonic acids
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3-Methyl- and 3-phenyl-2-butenal react with monoesters of alkylidene-, alkenylidene-, and arylmethylenemalonic acids in the presence of piperidine as the catalyst to give esters of 4,6-disubstituted 1,3-cyclohexadienecarboxylic acids in 23-96 % yields. Under the same conditions cyclohexylideneacetic aldehyde reacts with the monoesters of prenylidene- and benzylidenemalonic acid to afford mixtures of 1,8a-trans- and 1,8a-cis-isomers of 1-substituted alkyl 1,5,6,7,8,8a-hexahydronaphthalene-2-carboxylates, the ratios and configurations of which were determined by means of 1H NMR spectroscopy. In some cases the formation of cyclic dienes is impeded by the competing process of decarboxylation of acidic ylidenemalonates. The derivatives of 4,6-diphenyl-1,3-cyclohexadienecarboxylic acid were shown to be convenient precursors for the preparation of meta-terphenyls.
- Nigmatov,Kornilova,Serebryakov
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p. 144 - 152
(2007/10/03)
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- Reactions of diazocompounds with carbonyl compounds mediated by diorganyl telluride and catalytic amount of CuI compounds: Conversion of aldehydes to a
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A one-pot reaction of diorganyl telluride, diazo-compounds including dimethyl diazomalonate and ethyl diazoacetate, carbonyl compound and catalytic amount of Cu(I)I afforded the olefination products in high yields. The reaction is proposed to be through diorganyltelluronium bis (methoxycarbonyl)methylide and (ethoxycarbonyl)methylide respectively.
- Zhou, Zhang-Lin,Huang, Yao-Zeng,Shi, Li-Lan
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p. 6821 - 6830
(2007/10/02)
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- A novel olefination of carbonyl compounds with dibromo-malonate promoted by dibutyl telluride
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α,β-Unsaturated malonic esters are conveniently synthesized from the reaction of dibromomalonate with carbonyl compounds promoted by dibutyl telluride in excellent yields. A possible mechanism involving twice halophilic attacks of dibutyl telluride is proposed. This methodology provides a facile route to α,β-unsaturated malonic esters and represents an alternative to the Knoevenagel reaction.
- Zhou,Shi,Huang
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p. 1027 - 1037
(2007/10/02)
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