The Experts below are selected from a list of 282 Experts worldwide ranked by ideXlab platform
Masaki Matsui - One of the best experts on this subject based on the ideXlab platform.
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Synthesis and Characterization of Fluorescent 4,6‐Disubstituted‐3‐ cyano‐2‐Methylpyridines.
ChemInform, 2010Co-Authors: Masaki Matsui, Katsuyoshi Shibata, Akira Oji, Keiichi Hiramatsu, Hiroshige MuramatsuAbstract:4,6-Disubstituted-3-cyano-2-Methylpyridines, easily prepared by treating α,β-unsaturated carbonyl compounds with β-aminocrotononitrile in the presence of potassium tert-butoxide, have been found to show intense fluorescence in the region of 400–552 nm. 3-Cyano-4,6-bis(4-methoxyphenyl)- and 3-cyano-4,6-di(2-furyl)-2-Methylpyridines show more intense fluorescence than 7-diethylamino-4-methylcoumarin. The 3-cyano group of pyridines increases the fluorescence intensities and improves photostabilities.
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Fluorescent α,β-Unsaturated Carbonyl Compounds and 2-Methylpyridines. Their Application to a Quantitative Analysis of Carnitine
Bulletin of the Chemical Society of Japan, 1996Co-Authors: Ken-ichi Nakaya, Kazumasa Funabiki, Katsuyoshi Shibata, Hiroshige Muramatsu, Masaki MatsuiAbstract:α,β-Unsaturated carbonyl compounds and 2-Methylpyridines containing a 4-(dialkylamino)phenyl substituent can be used as fluorescent labeling reagents for the quantitative analysis of carnitine. 6-(4-Aminophenyl)-3-cyano-4-[4-(diethylamino)phenyl]-2-methylpyridine showed the best properties among the synthesized reagents.
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Synthesis and characterization of fluorescent 4,6-disubstituted-3-cyano-2-Methylpyridines
Journal of The Chemical Society-perkin Transactions 1, 1992Co-Authors: Masaki Matsui, Katsuyoshi Shibata, Akira Oji, Keiichi Hiramatsu, Hiroshige MuramatsuAbstract:4,6-Disubstituted-3-cyano-2-Methylpyridines, easily prepared by treating α,β-unsaturated carbonyl compounds with β-aminocrotononitrile in the presence of potassium tert-butoxide, have been found to show intense fluorescence in the region of 400–552 nm. 3-Cyano-4,6-bis(4-methoxyphenyl)- and 3-cyano-4,6-di(2-furyl)-2-Methylpyridines show more intense fluorescence than 7-diethylamino-4-methylcoumarin. The 3-cyano group of pyridines increases the fluorescence intensities and improves photostabilities.
Hiroshige Muramatsu - One of the best experts on this subject based on the ideXlab platform.
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Synthesis and Characterization of Fluorescent 4,6‐Disubstituted‐3‐ cyano‐2‐Methylpyridines.
ChemInform, 2010Co-Authors: Masaki Matsui, Katsuyoshi Shibata, Akira Oji, Keiichi Hiramatsu, Hiroshige MuramatsuAbstract:4,6-Disubstituted-3-cyano-2-Methylpyridines, easily prepared by treating α,β-unsaturated carbonyl compounds with β-aminocrotononitrile in the presence of potassium tert-butoxide, have been found to show intense fluorescence in the region of 400–552 nm. 3-Cyano-4,6-bis(4-methoxyphenyl)- and 3-cyano-4,6-di(2-furyl)-2-Methylpyridines show more intense fluorescence than 7-diethylamino-4-methylcoumarin. The 3-cyano group of pyridines increases the fluorescence intensities and improves photostabilities.
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Fluorescent α,β-Unsaturated Carbonyl Compounds and 2-Methylpyridines. Their Application to a Quantitative Analysis of Carnitine
Bulletin of the Chemical Society of Japan, 1996Co-Authors: Ken-ichi Nakaya, Kazumasa Funabiki, Katsuyoshi Shibata, Hiroshige Muramatsu, Masaki MatsuiAbstract:α,β-Unsaturated carbonyl compounds and 2-Methylpyridines containing a 4-(dialkylamino)phenyl substituent can be used as fluorescent labeling reagents for the quantitative analysis of carnitine. 6-(4-Aminophenyl)-3-cyano-4-[4-(diethylamino)phenyl]-2-methylpyridine showed the best properties among the synthesized reagents.
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Synthesis and characterization of fluorescent 4,6-disubstituted-3-cyano-2-Methylpyridines
Journal of The Chemical Society-perkin Transactions 1, 1992Co-Authors: Masaki Matsui, Katsuyoshi Shibata, Akira Oji, Keiichi Hiramatsu, Hiroshige MuramatsuAbstract:4,6-Disubstituted-3-cyano-2-Methylpyridines, easily prepared by treating α,β-unsaturated carbonyl compounds with β-aminocrotononitrile in the presence of potassium tert-butoxide, have been found to show intense fluorescence in the region of 400–552 nm. 3-Cyano-4,6-bis(4-methoxyphenyl)- and 3-cyano-4,6-di(2-furyl)-2-Methylpyridines show more intense fluorescence than 7-diethylamino-4-methylcoumarin. The 3-cyano group of pyridines increases the fluorescence intensities and improves photostabilities.
Katsuyoshi Shibata - One of the best experts on this subject based on the ideXlab platform.
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Synthesis and Characterization of Fluorescent 4,6‐Disubstituted‐3‐ cyano‐2‐Methylpyridines.
ChemInform, 2010Co-Authors: Masaki Matsui, Katsuyoshi Shibata, Akira Oji, Keiichi Hiramatsu, Hiroshige MuramatsuAbstract:4,6-Disubstituted-3-cyano-2-Methylpyridines, easily prepared by treating α,β-unsaturated carbonyl compounds with β-aminocrotononitrile in the presence of potassium tert-butoxide, have been found to show intense fluorescence in the region of 400–552 nm. 3-Cyano-4,6-bis(4-methoxyphenyl)- and 3-cyano-4,6-di(2-furyl)-2-Methylpyridines show more intense fluorescence than 7-diethylamino-4-methylcoumarin. The 3-cyano group of pyridines increases the fluorescence intensities and improves photostabilities.
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Fluorescent α,β-Unsaturated Carbonyl Compounds and 2-Methylpyridines. Their Application to a Quantitative Analysis of Carnitine
Bulletin of the Chemical Society of Japan, 1996Co-Authors: Ken-ichi Nakaya, Kazumasa Funabiki, Katsuyoshi Shibata, Hiroshige Muramatsu, Masaki MatsuiAbstract:α,β-Unsaturated carbonyl compounds and 2-Methylpyridines containing a 4-(dialkylamino)phenyl substituent can be used as fluorescent labeling reagents for the quantitative analysis of carnitine. 6-(4-Aminophenyl)-3-cyano-4-[4-(diethylamino)phenyl]-2-methylpyridine showed the best properties among the synthesized reagents.
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Synthesis and characterization of fluorescent 4,6-disubstituted-3-cyano-2-Methylpyridines
Journal of The Chemical Society-perkin Transactions 1, 1992Co-Authors: Masaki Matsui, Katsuyoshi Shibata, Akira Oji, Keiichi Hiramatsu, Hiroshige MuramatsuAbstract:4,6-Disubstituted-3-cyano-2-Methylpyridines, easily prepared by treating α,β-unsaturated carbonyl compounds with β-aminocrotononitrile in the presence of potassium tert-butoxide, have been found to show intense fluorescence in the region of 400–552 nm. 3-Cyano-4,6-bis(4-methoxyphenyl)- and 3-cyano-4,6-di(2-furyl)-2-Methylpyridines show more intense fluorescence than 7-diethylamino-4-methylcoumarin. The 3-cyano group of pyridines increases the fluorescence intensities and improves photostabilities.
Fabrice Cottet - One of the best experts on this subject based on the ideXlab platform.
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Silyl‐Mediated Halogen/Halogen Displacement in Pyridines and Other Heterocycles
European Journal of Organic Chemistry, 2002Co-Authors: Manfred Schlosser, Fabrice CottetAbstract:Heating with bromotrimethylsilane converts 2-chloropyridine into 2-bromopyridine and 2-chloro-6-methylpyridine into 2-bromo-6-methylpyridine. Both 2-chloropyridines and 2-bromopyridines give the corresponding iodo compd. when treated with in situ generated iodotrimethylsilane. Although 3- and 4-chloropyridine are completely inert, 2,4-dichloropyridine undergoes the halogen/halogen exchange simultaneously at the 2- and 4-position. Halogen displacement takes place exclusively at the 2-position with 2,3-dichloropyridine and 2,5-dichloropyridine. In agreement with the intermediacy of N-trimethylsilylpyridinium salts as a prerequisite for the occurrence of halogen exchange, neither 2-fluoropyridine and 2-fluoro-6-methylpyridine nor any 2,6-dihalopyridine reacts. Finally, bromine/chlorine and iodine/chlorine substitution can also be accomplished with 2- or 4-chloroquinoline, 1-chloroisoquinoline, 2-chloropyrimidine, chloropyrazine, and 2,3-dichloroquinoxaline as substrates. [on SciFinder (R)]
Eric C. Hosten - One of the best experts on this subject based on the ideXlab platform.
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Host proficiency of N,N′-bis(9-phenyl-9-thioxanthenyl)ethylenediamine for pyridine and the methylpyridine guests – a competition study
Supramolecular Chemistry, 2017Co-Authors: Benita Barton, Lize De Jager, Eric C. HostenAbstract:AbstractN,N′-Bis(9-phenyl-9-thioxanthenyl)ethylenediamine proved to be an extremely efficient host compound for pyridine and the isomeric Methylpyridines. Furthermore, this host displayed selective behaviour during equimolar guest competitions, consistently favouring 3-methylpyridine in binary, ternary and quaternary experiments. Selectivity orders were 3-methylpyridine >> 4-methylpyridine > 2-methylpyridine, and 3-methylpyridine > pyridine > 4-methylpyridine > 2-methylpyridine, for equimolar ternary and quaternary solutions, respectively. When guest concentrations in binary competitions were varied, 3-methylpyridine remained the favoured guest, even at low 3-methylpyridine concentrations. Single crystal X-ray diffraction showed that all four complexes were isostructural (monoclinic, P21/n) while guests occupy discrete cavities in the crystal. Only 3-methylpyridine experiences (guest methyl)C–H∙∙∙π(host) and (guest methyl)C–H∙∙∙H–Ar(host) interactions, explaining the observed affinity of the host for this...
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Comparative investigation of the inclusion preferences of optically pure versus racemic TADDOL hosts for pyridine and isomeric methylpyridine guests
Tetrahedron, 2017Co-Authors: Benita Barton, Eric C. Hosten, Daniel V. JoosteAbstract:Abstract Here we consider the effect of the optical purity of TADDOL (α,α,α′,α’-tetraphenyl-2,2-dimethyl-1,3-dioxolane-4,5-dimethanol) on its discriminatory behaviour. We synthesized optically pure and racemic TADDOL, which form complexes with pyridine and the Methylpyridines, and recrystallized them from various equimolar mixtures of these guests, and showed that both TADDOLs, surprisingly, discriminate similarly between them. The selectivity of optically active TADDOL was in the order 3-methylpyridine > 4-methylpyridine > pyridine > 2-methylpyridine, while this order was 3-methylpyridine > 4-methylpyridine > 2-methylpyridine > pyridine for the racemate. For many of the experiments, the extent of selectivity displayed by the two hosts was comparable. Single crystal X-ray diffraction experiments showed that preferred guests experienced stronger π-π and, even more so, H-bonding interactions with the host. Thermal analyses confirmed reports that suggested that guests that reside in channels in the host structure form less thermally stable complexes than those where the guests are accommodated in discrete cavities.
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Host proficiency of N,N′-bis(9-phenyl-9-thioxanthenyl)ethylenediamine for pyridine and the methylpyridine guests – a competition study
2017Co-Authors: Benita Barton, Lize De Jager, Eric C. HostenAbstract:N,N′-Bis(9-phenyl-9-thioxanthenyl)ethylenediamine proved to be an extremely efficient host compound for pyridine and the isomeric Methylpyridines. Furthermore, this host displayed selective behaviour during equimolar guest competitions, consistently favouring 3-methylpyridine in binary, ternary and quaternary experiments. Selectivity orders were 3-methylpyridine >> 4-methylpyridine > 2-methylpyridine, and 3-methylpyridine > pyridine > 4-methylpyridine > 2-methylpyridine, for equimolar ternary and quaternary solutions, respectively. When guest concentrations in binary competitions were varied, 3-methylpyridine remained the favoured guest, even at low 3-methylpyridine concentrations. Single crystal X-ray diffraction showed that all four complexes were isostructural (monoclinic, P21/n) while guests occupy discrete cavities in the crystal. Only 3-methylpyridine experiences (guest methyl)C–H∙∙∙π(host) and (guest methyl)C–H∙∙∙H–Ar(host) interactions, explaining the observed affinity of the host for this guest. DSC analyses provided further affirmation for the host preference: endotherm peak temperatures for the guest release processes correlated directly with the selectivity order for the three methylpyridine isomers. Stereoview showing the (guest methyl)C–H∙∙∙π(host) interaction experienced only by the preferred guest, 3-methylpyridine