Novel synthesis of liquid crystalline compounds of 5-substituted 2-(4-alkylphenyl)pyridines

Chia, Win‐Long; Shen, Shih Wei; Lin, Hong‐Cheu

doi:10.1016/s0040-4039(00)02196-1

Cited by 16 publications

(8 citation statements)

References 11 publications

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“…The addition reactions of methyl- and phenylmagnesium bromide to the pyridinium salts derived from N -methylbenzamide and substituted pyridines 10a − d (3 equiv) proceeded well to give predominantly, and in some cases exclusively, 2,3-disubstituted 1,2-dihydropyridines 11 (Table ). Although the addition reactions of methylmagnesium bromide provided ratios of products comparable to those observed with N -acylpyridinium salts,17d the addition of phenylmagnesium bromide proceeded in much higher regioselectivity . The minor 2,5-isomer ( 12 ) occurred from nucleophilic addition at C-6, and we did not observe any product arising from attack at C-4.…”

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confidence: 78%

“…Obviously, the addition can occur either at the C-2, C-4, or C-6 position to give potentially three regioisomeric dihydropyridines . On the basis of both the strong directing effect of the imidate nitrogen and stereoelectronic effects, we anticipated that high regiocontrol would be obtained and an expedient route to 2,3-disubstituted piperidines could be developed …”

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confidence: 99%

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Nucleophilic Addition to 3-Substituted Pyridinium Salts: Expedient Syntheses of (−)-L-733,061 and (−)-CP-99,994

et al. 2004

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[reaction: see text] The addition of nucleophiles to 3-substituted pyridinium salts prepared from N-methylbenzamide and various pyridines has been investigated. Good to excellent regioselectivities favoring the 2,3-disubstituted 1,2-dihydropyridines were observed. The resulting 1,2-dihydropyridines led to the corresponding 2,3-disubstituted pyridines upon treatment with Mn(OAc)3/NaIO4. This methodology was also successfully applied to the enantioselective syntheses of (-)-L-733,061 and (-)-CP-99,994, two members of a new class of highly potent, nonpeptide, Substance P antagonists.

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confidence: 78%

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confidence: 99%

Nucleophilic Addition to 3-Substituted Pyridinium Salts: Expedient Syntheses of (−)-L-733,061 and (−)-CP-99,994

et al. 2004

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“…We previously reported a novel method for synthesizing pyridine-containing LC compounds [ 20 , 21 , 22 , 23 , 24 , 25 ]. Here, we report a convenient, short two-step synthesis method of a homologous series of 2-(4-alkoxybiphen-4′-yl)-5-methylpyridines ( n O-PPPyMe; n = 3–8; propyloxy to octoxy).…”

Section: Introductionmentioning

confidence: 99%

Effect of Pyridine on the Mesophase of Teraryl Liquid Crystals: A New Series of Nematic Liquid Crystals Named 2-(4-Alkoxybiphen-4′-yl)-5-methylpyridines

Chia

Huang

2016

IJMS

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A new series of teraryl 2-(4-alkoxybiphen-4′-yl)-5-methylpyridines (nO-PPPyMe, n = 3–8) nematic liquid crystal compounds, bearing a biphenylene core and a picoline terminus, were synthesized using a short two-step reaction, and overall yields between 34% and 38% were obtained. Spectral analysis results were in accordance with the expected structures. The thermotropic behavior of the teraryl liquid crystal compounds was investigated through polarized optical microscopy and differential scanning calorimetry. All compounds exhibited a solely enantiotropic nematic phase at the medium–high temperature range of 162.4–234.2 °C. Furthermore, the results for the nO-PPPyMe series were analyzed relative to three other compound series, mO-PPPyCN (m = 2–8), iO-PPQMe (i = 3–8) and xO-PPyPMe (x = 1–10). Consequently, the effect of pyridine on the mesophase of teraryl liquid crystals was demonstrated.

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“…We previously reported a novel method for the synthesis of pyridine-containing liquid crystalline compounds [18–21]. Here, we report a convenient, short 2-step method for the synthesis of a homologous series of 2-(4′-alkoxybiphen-4-yl)-5-cyanopyridines ( nO- PPPyCN), in which n varies from 2 to 8 (ethoxy to octoxy).…”

Section: Introductionmentioning

confidence: 99%

Synthesis and Thermotropic Studies of a New Series of Teraryl Liquid Crystals 2-(4'-Alkoxybiphen-4-yl)-5-Cyanopyridines

Chia

Lin²

2013

IJMS

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Abstract:A new series of teraryl 2-(4'-alkoxybiphen-4-yl)-5-cyanopyridines (nO-PPPyCN, n = 2-8) compounds, bearing a cyanopyridine terminus, were synthesized using a short 2-step reaction with overall yields between 33% and 69%. Spectral analyses were in accord with the expected structures. Thermotropic behavior of the teraryl compounds was investigated using polarised optical microscopy and differential scanning calorimetry. All compounds exhibited both enantiotropic nematic and smectic A phases, with an additional enantiotropic smectic C phase when n = 7 and 8. Polymesomorphism appears to be a common behavior in this series of linear liquid crystal compounds.

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Novel synthesis of liquid crystalline compounds of 5-substituted 2-(4-alkylphenyl)pyridines

Cited by 16 publications

References 11 publications

Nucleophilic Addition to 3-Substituted Pyridinium Salts: Expedient Syntheses of (−)-L-733,061 and (−)-CP-99,994

Nucleophilic Addition to 3-Substituted Pyridinium Salts: Expedient Syntheses of (−)-L-733,061 and (−)-CP-99,994

Effect of Pyridine on the Mesophase of Teraryl Liquid Crystals: A New Series of Nematic Liquid Crystals Named 2-(4-Alkoxybiphen-4′-yl)-5-methylpyridines

Synthesis and Thermotropic Studies of a New Series of Teraryl Liquid Crystals 2-(4'-Alkoxybiphen-4-yl)-5-Cyanopyridines

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