NMR study of 1,4-dihydropyridine derivatives endowed with long alkyl and functionalized chains

Suárez, Margarita; Molero, Dolores; Salfrán, Esperanza; Rodríguez, Hortensia; Coro, Julieta; Sáez, Estéban; Martínez‐Álvarez, Roberto; Martı́n, Nazario

doi:10.1590/s0103-50532011000100022

Cited by 5 publications

(5 citation statements)

References 10 publications

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“…These findings have been accounted for by the strong push–pull effect of the groups linked to the olefinic double bonds like ones previously observed in other related systems. The carbon signal of C 4 is in agreement with the previous data [ 32 , 33 ] and appears at 28.5 ppm for the aliphatic R and in the interval 34.2–39.8 ppm when R is aromatics.…”

Section: Resultssupporting

confidence: 92%

Intramolecular hydrogen bonds in 1,4-dihydropyridine derivatives

Петрова¹,

Muhamadejev²,

Vı̄gante³

et al. 2018

R. Soc. open sci.

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1,4-Dihydropyridine (1,4-DHP) derivatives have been synthesized and characterized by 1H, 13C, 15N nuclear magnetic resonance (NMR) spectroscopy, secondary proton/deuterium 13C isotope shifts, variable temperature 1H NMR experiments and quantum-chemical calculation. The intramolecular hydrogen bonds NH⋯O=C and CH⋯O=C in these compounds were established by NMR and quantum-chemical studies The downfield shift of the NH proton, accompanied by the upfield shift of the 15N nuclear magnetic resonance signals, the shift to the higher wavenumbers of the NH stretching vibration in the infrared spectra and the increase of the 1J(15N,1H) values may indicate the shortening of the N–H bond length upon intramolecular NH⋯O=C hydrogen bond formation.

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Section: Resultssupporting

confidence: 92%

Intramolecular hydrogen bonds in 1,4-dihydropyridine derivatives

Петрова¹,

Muhamadejev²,

Vı̄gante³

et al. 2018

R. Soc. open sci.

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“…In the downfield region, between 6 and 8.5 ppm, several signals can be assigned to the presence of rings of pyrrole (6.5 and 7 ppm) and 1,4‐dihydropyridine. In particular, the resonance structures of the dihydropyridine allow us to account for the presence of a chemical shift at around 8.4 ppm . The 1 H‐NMR spectrum of the membrane does not show specific changes compared to the spectrum of PK‐PDAP.…”

Section: Resultsmentioning

confidence: 99%

Chemical modification and structural rearrangements of polyketone‐based polymer membrane

Ataollahi

Girardi

Cappelletto

et al. 2017

J of Applied Polymer Sci

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Alternating polyketones constitute a very interesting class of polymers, which can be modified for the preparation of functional polymers. The chemical modification of polyketone using 1,2-diaminopropane was used to prepare a conductive membrane. This paper is focused on the synthesis and structural rearrangements of polyamine for preparing anion-exchange membranes by the solvent casting technique. According to the Paal-Knorr mechanism, 1,4-dicarbonyl of polyketone reacts with 1,2-diaminopropane to form a pyrrole ring along the polyketone backbone. In addition, the so-modified polyamines can undergo structural rearrangements to form N-substituted pyrrole crosslinked with dihydropyridine units. The conversion degree and the N content are quite low. The pathway reactions have been proposed on the basis of 1H-NMR, ultraviolet–visible, and Fourier transform infrared results. Scanning electron microscopy,differential scanning calorimetry, and X-ray diffraction techniques were used to study the morphological, thermal, and structural characteristics of the modified polyketone, as well as the correspondoing membrane. The experimental results indicated that the membrane is a potential candidate for energy conversion technolog

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“…The formation of the former is unlikely, as unsubstituted dihydropyridines are very unstable. [39,40] However, in some publications, [41,42] dihydropyridines were detected upon pyridine reduction with lithium aluminum hydride or zinc hydride. These studies demonstrated that isomeric dihydropyridines can give rise to NMR signals at 22-25, 28-30, 40-50, and 90-100 ppm.…”

Section: Pyridine Complexesmentioning

confidence: 99%

Non-innocent ligands in copper complexes catalyzed oxidation of thiols

Gantman

Tarkhanova

Kolyagin

2016

Journal of Sulfur Chemistry

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Copper(II) chloride complexes with nitrogen-containing ligands (amines, amides, heterocycles) were studied as catalysts of selective oxidation of thiols to disulfides. This process has an important biochemical analogue -the formation of disulfide bridge in proteins [Wang C, Wesener SR, Zhang H, Cheng Y-Q. An FAD-dependent pyridine nucleotide-disulfide oxidoreductase is involved in disulfide bond formation in FK228 anticancer depsipeptide. Chem and Biol. 2009;16:585-593]; which affects their activity [Zhang L, Chou CP, Moo-Young M. Disulfide bond formation and its impact on the biological activity and stability of recombinant therapeutic proteins produced by Escherichia coli expression system. Biotech Adv. 2011;29:923-929]. Also, thiol oxidation is an important process of oil sweetening. The search for effective and stable catalysts for this reaction is still topical [Ganguly SK, Das G, Kumar S, Sain B, Garg MO. Mechanistic kinetics of catalytic oxidation of 1-butanethiol in light oil sweetening. Catal Tod. 2012;198:246-251]. This article describes a mechanistic study of thiol oxidation and non-innocent ligands transformations during this reaction. The studied ligands are capable of oxidizing thiols, the reaction being followed by reoxidation of the reduced forms of the ligands with air oxygen. The oxidative activity of the ligand correlates with catalyst activity for thiol oxidation. ARTICLE HISTORY

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NMR study of 1,4-dihydropyridine derivatives endowed with long alkyl and functionalized chains

Cited by 5 publications

References 10 publications

Intramolecular hydrogen bonds in 1,4-dihydropyridine derivatives

Intramolecular hydrogen bonds in 1,4-dihydropyridine derivatives

Chemical modification and structural rearrangements of polyketone‐based polymer membrane

Non-innocent ligands in copper complexes catalyzed oxidation of thiols

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