Coumarin-pyridine push-pull fluorophores: Synthesis and photophysical studies

Fatykhov, Ramil F.; Sharapov, Ainur D.; Starnovskaya, Еkaterina S.; Shtaitz, Yaroslav K.; Savchuk, Maria I.; Kopchuk, Dmitry S.; Nikonov, Igor L.; Zyryanov, Grigory V.; Khalymbadzha, Igor A.; Чупахин, О. Н.

doi:10.1016/j.saa.2021.120499

Cited by 20 publications

(16 citation statements)

References 45 publications

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“…Replacement of the phenyl moieties in compound 7 with 3,4,5-trimethoxyphenyl residues resulted in an almost complete disappearance of the luminescence of compound 12, with a bathochromic shift in the absorption and emission maxima. These facts correlate with our previously founded pattern of the photophysical properties of 4-phenylcoumarins having a pyridyl substituent at position 8 [28]. Namely, we observed an almost complete absence of the luminescent properties for the compounds with the 4-phenylcoumarin scaffold.…”

Section: Influence Of Chemical Functionalization On the Photophysical...supporting

confidence: 91%

Fluorescent Pyranoindole Congeners: Synthesis and Photophysical Properties of Pyrano[3,2-f], [2,3-g], [2,3-f], and [2,3-e]Indoles

et al. 2022

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This paper reports the synthesis of four types of annulated pyranoindole congeners: pyrano[3,2-f]indole, pyrano[2,3-g]indole, pyrano[2,3-f]indole, and pyrano[2,3-e]indole and photophysical studies in this series. The synthesis of pyrano[3,2-f], [2,3-g], and [2,3-e]indoles involve a tandem of Bischler–Möhlau reaction of 3-aminophenol with benzoin to form 6-hydroxy- or 4-hydroxyindole followed by Pechmann condensation of these hydroxyindoles with β-ketoesters. Pyrano[2,3-f]indoles were synthesized through the Nenitzescu reaction of p-benzoquinone and ethyl aminocrotonates and subsequent Pechmann condensation of the obtained 5-hydroxyindole derivatives. Among the pyranoindoles studied, the most promising were pyrano[3,2-f] and [2,3-g]indoles. These compounds were characterized by moderate to high quantum yields (30–89%) and a large (9000–15,000 cm−1) Stokes shift. More detailed photophysical studies were carried out for a series of the most promising derivatives of pyrano[3,2-f] and [2,3-g]indoles to demonstrate their positive solvatochromism, and the data collected was analyzed using Lippert-Mataga equation. Quantum chemical calculations were performed to deepen the knowledge of the absorption and emission properties of pyrano[3,2-f] and [2,3-g]indoles as well as to explain their unusual geometries and electronic structures.

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Section: Influence Of Chemical Functionalization On the Photophysical...supporting

confidence: 91%

Fluorescent Pyranoindole Congeners: Synthesis and Photophysical Properties of Pyrano[3,2-f], [2,3-g], [2,3-f], and [2,3-e]Indoles

et al. 2022

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“…We started our research with the reaction of dimethoxycoumarin 1 with 3,6-diphenyl-1,2,4-triazine 2a, which was carried out in the presence of three-fold excess of methanesulfonic acid (MsOH) in DCM at room temperature, yielding dihydrotriazine 3a in high yield (Scheme 2), in accordance with the previously described procedure [2o]. Aromatization of the adduct 3a with 1.5 equivalent of DDQ (Table 1, entry 1) [20] provided a complex mixture of products. We hypothesized that, in contrast to our previous work [20,28], DDQ not only oxidizes 1,4-dihydrotriazine core to give expected product of the nucleophilic substitution of hydrogen 4a, but also aromatizes tetrahydrobenzene moiety yielding 5a and 6a, which is confirmed by the literature data [29,30].…”

Section: Resultsmentioning

confidence: 99%

“…The advantages of this approach are the avoidance of TM catalysts and the so-called "chlorine technologies", mild reaction conditions, which, in turn, leads to a decrease in the number of steps and an increase in the overall yield of the desired product. SN H reactions often proceed as the addition of a nucleophile to an electrophilic azine with the formation of a σ Н -adduct, which can subsequently be oxidized in the presence of an external oxidizing agent (air oxygen [19], 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) [20][21][22][23], K3[Fe(CN)6] [24-26], MnO2 [22,27]) to a product of nucleophilic substitution of hydrogen.…”

Section: Introductionmentioning

confidence: 99%

“…Earlier, we proposed a convenient synthetic approach to push-pull 8-pyridinylcoumarin chromophores (Scheme 1, d) by using a sequence of reactions of nucleophilic substitution of hydrogen and Boger pyridine synthesis in the series of 3,6-diaryl-substituted 1,2,4-triazines and 5,7-dimethoxycoumarins [20,28]. Thus, at the first step, coumarin was added to the triazine core with the formation of a 1,4-dihydrotriazine derivative, which then easily underwent aromatization under the action of the external oxidant such as DDQ with the formation of SN H product in high yield, which then transformed to pyridine derivative with 2,5-norbornadiene.…”

Section: Introductionmentioning

confidence: 99%

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Expedient synthesis of 1,2,4-triazinyl substituted benzo[c]coumarins via double oxidation strategy

et al. 2023

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Herein, we report a convenient one-pot synthesis of 1,2,4-triazinyl derivatives of benzocoumarins. The proposed approach consists in the nucleophilic addition of tetrahydrobenzo annulated dimethoxycoumarin to 1,2,4-triazines followed by double oxidation of both dihydrotriazine and tetrahydrobenzo groups with 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ). The nucleophilic addition of the dimethoxycoumarin to 1,2,4-triazines was carried out in the presence of three-fold excess of methanesulfonic acid in DCM at room temperature and take place between positions 4 and 5 of coumarin and 1,2,4-triazine, respectively. The double oxidation step was achieved with 3.6 equivalent of DDQ. Selective oxidation of dihydrotriazine moiety, without affecting the tetrahydrobenzo fragment, was achieved using 1.2 equivalent of tetrachlorobenzoquinone (TCQ). The differences in the oxidation with TCQ and DDQ appear to be related to the higher oxidative potential of DDQ in contrast to TCQ. The advantages of the method are the elimination of the use of transition metals, the availability of starting materials, and the simplicity of the procedure. The proposed approach provides a two-step one-pot protocol for the synthesis of triazinyl benzocoumarins, precursors for the preparation of push-pull pyridinyl chromophore.

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“…The reaction proceeds as [2+4] cycloaddition followed by nitrogen and cyclopentadiene extrusion (Boger reaction). We used previously described conditions suitable for this transformation [ 24 , 25 ]. The structure of compounds 10 is consistent with their NMR spectral data.…”

Section: Resultsmentioning

confidence: 99%

Xanthone-1,2,4-triazine and Acridone-1,2,4-triazine Conjugates: Synthesis and Anticancer Activity

et al. 2023

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A total of 21 novel xanthone and acridone derivatives were synthesized using the reactions of 1,2,4-triazine derivatives with 1-hydroxy-3-methoxy-10-methylacridone, 1,3-dimethoxy-, and 1,3-dihydroxanthone, followed by optional dihydrotiazine ring aromatization. The synthesized compounds were evaluated for their anticancer activity against colorectal cancer HCT116, glioblastoma A-172, breast cancer Hs578T, and human embryonic kidney HEK-293 tumor cell lines. Five compounds (7a, 7e, 9e, 14a, and 14b) displayed good in vitro antiproliferative activities against these cancer cell lines. Compounds 7a and 7e demonstrated low toxicity for normal human embryonic kidney (HEK-293) cells, which determines the possibility of further development of these compounds as anticancer agents. Annexin V assay demonstrated that compound 7e activates apoptotic mechanisms and inhibits proliferation in glioblastoma cells.

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Coumarin-pyridine push-pull fluorophores: Synthesis and photophysical studies

Cited by 20 publications

References 45 publications

Fluorescent Pyranoindole Congeners: Synthesis and Photophysical Properties of Pyrano[3,2-f], [2,3-g], [2,3-f], and [2,3-e]Indoles

Fluorescent Pyranoindole Congeners: Synthesis and Photophysical Properties of Pyrano[3,2-f], [2,3-g], [2,3-f], and [2,3-e]Indoles

Expedient synthesis of 1,2,4-triazinyl substituted benzo[c]coumarins via double oxidation strategy

Xanthone-1,2,4-triazine and Acridone-1,2,4-triazine Conjugates: Synthesis and Anticancer Activity

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