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Rodolfo Lavilla - One of the best experts on this subject based on the ideXlab platform.
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Dihydropyridine-based multicomponent reactions. Efficient entry into new tetrahydroquinoline systems through Lewis acid-catalyzed formal [4 + 2] cycloadditions.
Organic letters, 2003Co-Authors: Rodolfo Lavilla, M. Carmen Bernabeu, And Inés Carranco, José Luis DíazAbstract:The three-component reaction of Dihydropyridines, aldehydes, and p-methylaniline efficiently forms highly substituted tetrahydroquinolines in a stereoselective manner through a Lewis acid-catalyzed formal [4 + 2] cycloaddition. InCl3 and Sc(OTf)3 are the catalysts of choice for this process. The in situ generation of a reactive 1,4-Dihydropyridine through the regioselective nucleophilic addition of cyanide to pyridinium salts allows a one-pot four-component transformation.
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Oxidative Diphosphonylation of 1,4-Dihydropyridines and Pyridinium Salts
Organic letters, 2000Co-Authors: Rodolfo Lavilla, Alessandro Spada, Joan BoschAbstract:An oxidative double phosphonylation of Dihydropyridines 1 and pyridinium salts 2 is achieved through the use of dialkyl phosphites, DDQ, and triethylamine. Acceptable to good yields of 2, 6-diphosphonylated-1,2-Dihydropyridines 3 are obtained in a one-pot reaction involving tandem nucleophilic addition/oxidation processes. Isomerization of 3 to the more stable 2,4-diphosphonylated-1, 4-Dihydropyridine 4 was observed in some cases.
Arkadij Sobolev - One of the best experts on this subject based on the ideXlab platform.
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Recent Approaches to Chiral 1,4-Dihydropyridines and their Fused Analogues
Catalysts, 2020Co-Authors: Martins Rucins, Aiva Plotniece, Eiva Bernotiene, Wei-bor Tsai, Arkadij SobolevAbstract:The purpose of this review is to highlight recent developments in the synthesis of chiral 1,4-Dihydropyridines and their fused analogues. 1,4-Dihydropyridines are among the most active calcium antagonists that are used for the treatment of hypertension. Enantiomers of unsymmetrical 1,4-Dihydropyridines often show different biological activities and may have even an opposite action profile. Hantzsch synthesis usually produces racemic mixtures of unsymmetrical 1,4-Dihydropyridines. Therefore, the development of stereoselective synthesis of 1,4-Dihydropyridines is one of the priorities of medicinal chemistry. Over the years, numerous methodologies have been developed for the production of enantiopure 1,4-Dihydropyridines, such as stereoselective synthesis using chiral auxiliaries and chiral cyclocondensation partners, chromatographical methods, resolution of diastereomeric 1,4-Dihydropyridine salts, enzyme catalysed kinetic resolution, or asymmetrisation of ester groups of 1,4-Dihydropyridines. These approaches have been studied in detail and are relatively well established. The catalytic asymmetric approach holds the greatest promise in delivering the most practical and widely applicable methods. Substantial progress has been made toward the development of enantioselective organocatalytic methods for the construction of the chiral Dihydropyridines. However, most of them do not provide a convenient way to pharmacologically important 1,4-Dihydropyridine-3,5-dicarboxylates. Organocatalytic enantioselective desymmetrisation of prochiral 1,4-Dihydropyridine-3,5-dicarbaldehydes also has great promise in the synthesis of pharmacologically important 1,4-Dihydropyridine-3,5-dicarboxylates.
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Data for the synthesis and characterisation of 2,6-di(bromomethyl)-3,5-bis(alkoxycarbonyl)-4-aryl-1,4-Dihydropyridines as important intermediates for synthesis of amphiphilic 1,4-Dihydropyridines.
Data in brief, 2020Co-Authors: Martins Rucins, Arkadij Sobolev, Karlis Pajuste, Mara Plotniece, Nadiia V. Pikun, Aiva PlotnieceAbstract:Abstract This data file describes the synthetic protocol for preparation of the original 2,6-di(bromomethyl)-3,5-bis(alkoxycarbonyl)-4-aryl-1,4-Dihydropyridines. In total, 6 unpublished compounds were obtained and characterised. The 2,6-di(bromomethyl)-1,4-Dihydropyridines are mainly used as intermediates for synthesis of various lipid-like compounds based on 1,4-Dihydropyridine cycle. All the structures of 2,6-di(bromomethyl)-1,4-Dihydropyridines were confirmed by Nuclear Magnetic Resonance (NMR, including 1H NMR and 13C NMR) data. The data provided herein are directly related to the previously published research article – “Novel cationic amphiphilic 1,4-Dihydropyridine derivatives for DNA delivery” [1] where three derivatives (2,6-di(bromomethyl)-4-phenyl-1,4-Dihydropyridines 2a-c) from six presented in this data file were used as starting materials in synthesis of amphiphilic 1,4-Dihydropyridines without any purification and characterisation. Synthesis of other three 2,6-di(bromomethyl)-3,5-bis(alkoxycarbonyl)-4-aryl-1,4-Dihydropyridines 2d-f and their characterisation are reported herein at the first time. Information provided in this data file can be used in organic synthesis by other chemists to develop synthetic strategies for the construction of various cationic 1,4-Dihydropyridine derivatives and related heterocycles.
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Direct Aminolysis of Ethoxycarbonylmethyl 1,4-Dihydropyridine-3-carboxylates.
Molecules, 2015Co-Authors: Brigita Vigante, Iveta Luntena, Brigita Cekavicus, Egils Bisenieks, Rufus Smits, Gunars Duburs, Aiva Plotniece, Martins Rucins, Karlis Pajuste, Arkadij SobolevAbstract:The ethoxycarbonylmethyl esters of 1,4-Dihydropyridines were directly converted into carbamoylmethyl esters in the presence of 1,5,7-triazabicyclo[4.4.0]dec-5-ene (TBD) in good to excellent yields under mild conditions. The use of TBD is crucial for the successful aminolysis of ethoxycarbonylmethyl ester of 1,4-Dihydropyridines with secondary amines as without it the reaction does not proceed at all. The aminolysis reaction proceeded regioselectively, as the alkyl ester conjugated with the 1,4-Dihydropyridine cycle was not involved in the reaction. Screening of other N-containing bases, such as triethylamine (TEA), pyridine, 4-(N,N-dimethylamino)pyridine (DMAP), 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU), 1,5-diazabicyclo[4.3.0]non-5-ene (DBN), imidazole, tetramethyl guanidine (TMG) and 7-methyl-1,5,7-triazabicyclo[4.4.0]dec-5-ene (MTBD) as catalysts revealed no activity in the studied reaction.
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Chemoenzymatic synthesis of enantiopure 1,4-Dihydropyridine derivatives
Biocatalysis and Biotransformation, 2004Co-Authors: Arkadij Sobolev, Gunars Duburs, Maurice C. R. Franssen, Ae. De GrootAbstract:1,4-Dihydropyridines possess a broad range of biological activities, such as the ability to control the influx of calcium into cells, as well as neuroprotective, antineurodegenerative, cognition and memory enhancing, anti-inflammatory, antiviral and many other properties. Chirality plays an important role in the biological activity of 1,4-Dihydropyridines. The chemoenzymatic synthesis of 1,4-Dihydropyridine derivatives in enantiopure form as the key intermediates for the synthesis of enantiopure drugs and chiral analogues of symmetrical drugs has become an advantageous alternative to the other synthetic methods. Hydrolytic enzymes, as efficient chemo-, regio- and stereoselective biocatalysts have been successfully applied for the asymmetrisation or kinetic resolution of various 1,4-Dihydropyridine derivatives. Several synthetic strategies to overcome the inactivity of hydrolytic enzymes towards 1,4-Dihydropyridine carboxylic acids have been developed during the last decade, often based on the introduction...
Christian Marazano - One of the best experts on this subject based on the ideXlab platform.
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stereocontrolled alkylation of chiral pyridinium salt toward a short enantioselective access to 2 alkyl and 2 6 dialkyl 1 2 5 6 tetrahydropyridines
European Journal of Organic Chemistry, 2000Co-Authors: Berangere Guilloteaubertin, Delphine Compere, Christian MarazanoAbstract:Treatment of salts 1a-b with Grignard reagents gives, after reduction of the resulting unstable Dihydropyridines 7, the tetrahydropyridines 8a-c, with modest selectivities but in very few steps and under practical conditions. Higher stereo- and regioselectivities are obtained with salt 1c which gives the tetrahydropyridines 15a-e. In addition, the Dihydropyridine intermediates 11b cyclize to give the new oxazolidine derivatives 12a-e, which turn out to be good precursors of the 2,6-trans-disubstituted tetrahydropyridines 21a-e. Selective syntheses of (−)-lupetidin, (+)-solenopsin, and indolizidines (−)-5 and (−)-6 are presented as representative examples of applications.
Joan Bosch - One of the best experts on this subject based on the ideXlab platform.
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Oxidative Diphosphonylation of 1,4-Dihydropyridines and Pyridinium Salts
Organic letters, 2000Co-Authors: Rodolfo Lavilla, Alessandro Spada, Joan BoschAbstract:An oxidative double phosphonylation of Dihydropyridines 1 and pyridinium salts 2 is achieved through the use of dialkyl phosphites, DDQ, and triethylamine. Acceptable to good yields of 2, 6-diphosphonylated-1,2-Dihydropyridines 3 are obtained in a one-pot reaction involving tandem nucleophilic addition/oxidation processes. Isomerization of 3 to the more stable 2,4-diphosphonylated-1, 4-Dihydropyridine 4 was observed in some cases.
Toshimitsu Okamura - One of the best experts on this subject based on the ideXlab platform.
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an approach for measuring in vivo cerebral redox states using the oxidative conversion of Dihydropyridine to pyridinium ion and the metabolic trapping principle
Free Radical Biology and Medicine, 2005Co-Authors: Ayaka Nagamine, Kiyoshi Fukushi, Yasushi Arano, Toshikazu Sekine, Toshimitsu Okamura, Tatsuya Kikuchi, Toshiaki IrieAbstract:This study was undertaken to develop radiopharmaceuticals for measuring in vivo cerebral redox states. Based on the oxidative conversion of Dihydropyridine to pyridinium ion and the metabolic trapping principle, five N-[14C]methyl-3 or 3,5-substituted 1,4-Dihydropyridines with different oxidation rates were designed, synthesized, and evaluated as a prototype of radiotracers for measuring in vivo cerebral redox states. When these tracers were injected into mice, they crossed the blood–brain barrier (BBB) and became trapped in the brain depending on their oxidation rates, while the corresponding oxidized forms hardly crossed the BBB. Furthermore, a significant increase in the radioactivity trapped in the brain was observed following injection of N-[14C]methyl-3-acetyl-1,4-Dihydropyridine to mice pretreated with diethylmaleate that depletes glutathione in the brain. These findings suggested that an approach based on the oxidative conversion of Dihydropyridine to the pyridinium ion and the metabolic trapping principle would be useful for measuring in vivo cerebral redox states.