The Studies on Quinolizinium Salts. I. Syntheses of Quinolizinium and 1-, 2-, 3-, and 4-Methylquinolizinium Bromides

Miyadera, Tetsuo; Iwai, Issei

doi:10.1248/cpb.12.1338

Cited by 16 publications

(8 citation statements)

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“…However, this straightforward and efficient methodology could not be applied to the other two isomeric bromoquinolizinium cations . For 5 and 7 a new approach to the previously reported precursor ketones 14a and 17 was attempted, but our method, which is based on the reaction of pyridinium carboxylates with propenenitrile (Scheme 2), gave similar yields to that previously reported for the pyridinium salt 14a and failed to produce the bicyclic ketone 17 . However, this approach also led to an improvement in the preparation of 6 from 12b when compared with the classical method 18a (28% vs 17%).…”

Section: Resultsmentioning

confidence: 73%

Palladium-Mediated Functionalization of Heteroaromatic Cations: Comparative Study on Quinolizinium Cations

et al. 2006

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An efficient palladium-catalyzed cross-coupling reaction on heteroaromatic cations is described. A comparative study of the Stille and Suzuki reactions shows that only the Stille reaction is able to produce an efficient C-C bond formation between any of the four isomeric bromoquinolizinium bromides and a variety of stannanes. In the presence of the catalysts Pd(PPh3)4 or Pd2(dba)3P(o-Tol)3, vinyl, ethynyl, aryl, and heteroaryl groups are successfully incorporated into the quinolizinium system in satisfactory yields under mild reaction conditions. This procedure represents a marked improvement on the functionalization of this class of heteroaromatic cation.

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Section: Resultsmentioning

confidence: 73%

Palladium-Mediated Functionalization of Heteroaromatic Cations: Comparative Study on Quinolizinium Cations

et al. 2006

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“…MOP3 was obtained by the Sonogashira reaction as previously reported . The Heck reaction on 2-vinyl quinolizinium hexafluorophosphate allowed for the preparation of compounds MOP2 and DMA2 with acceptable yields. − Finally, quadrupolar V-shape chromophores represented by disubstituted quinolizinium derivatives V-MOP2 and V-DMA2 were both obtained from 2,8-dimethylquinolizinium bromide by a double Knoevenagel condensation under the same conditions used for the synthesis of the dipolar compounds and following the procedure reported earlier. ,, A more detailed description of materials, instrumentation, and synthetic procedure as well the NMR spectra of the new compounds ( MOP1 , MOP2 , DMA1 and DMA2 ) can be found in the Supporting Information (S1–S5).…”

Section: Methodsmentioning

confidence: 99%

Nonlinear Emission of Quinolizinium-Based Dyes with Application in Fluorescence Lifetime Imaging

et al. 2014

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Charged molecules based on the quinolizinum cation have potential applications as labels in fluorescence imaging in biological media under nonlinear excitation. A systematic study of the linear and nonlinear photophysics of derivatives of the quinolizinum cation substituted by either dimethylaniline or methoxyphenyl electron donors is performed. The effects of donor strength, conjugation length, and symmetry in the two-photon emission efficiency are analyzed in detail. The best performing nonlinear fluorophore, with two-photon absorption cross sections of 1140 GM and an emission quantum yield of 0.22, is characterized by a symmetric D-π-A(+)-π-D architecture based on the methoxyphenyl substituent. Application of this molecule as a fluorescent marker in optical microscopy of living cells revealed that, under favorable conditions, the fluorophore can be localized in the cytoplasmatic compartment of the cell, staining vesicular shape organelles. At higher dye concentrations and longer staining times, the fluorophore can also penetrate into the nucleus. The nonlinearly excited fluorescence lifetime imaging shows that the fluorophore lifetime is sensitive to its location in the different cell compartments. Using fluorescence lifetime microscopy, a multicolor map of the cell is drafted with a single dye.

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“…All of the syntheses for quinolizinium salts based on classical cyclization strategies and conditions, including the first synthesis of quinolizinium itself, were first reviewed by Thyagarajan . Jones published a review that covered the chemistry of quinolizinium and its benzo derivatives, and a more recent review focused on the chemistry of these cationic heterocycles, with an updated version published by Ihmels .…”

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confidence: 99%

Recent Advances in the Synthesis of Azonia Aromatic Heterocycles

et al. 2016

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Azonia aromatic heterocycles are an important subclass of aza-heterocyles as they are the structural motif of relevant cationic alkaloids, and they have a wide range of potential applications such as bioactive compounds and organic materials. In this Synopsis, recent and novel approaches to their synthesis are surveyed, with particular emphasis on ring-closing metathesis reactions and annulation reactions based on C-H activation.

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The Studies on Quinolizinium Salts. I. Syntheses of Quinolizinium and 1-, 2-, 3-, and 4-Methylquinolizinium Bromides

Cited by 16 publications

References 0 publications

Palladium-Mediated Functionalization of Heteroaromatic Cations: Comparative Study on Quinolizinium Cations

Palladium-Mediated Functionalization of Heteroaromatic Cations: Comparative Study on Quinolizinium Cations

Nonlinear Emission of Quinolizinium-Based Dyes with Application in Fluorescence Lifetime Imaging

Recent Advances in the Synthesis of Azonia Aromatic Heterocycles

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