- Connecting a carbonyl and a π-conjugated group through a: P-phenylene linker by (5+1) benzene ring formation
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A benzene ring was formed to connect a carbonyl group of various methyl ketones with a π-conjugated group through a p-phenylene linker. Methyl ketones and streptocyanines were used as the C1 and C5 sources, respectively, in the (5+1) annulation, which could form donor-π-acceptor molecules.
- Morofuji, Tatsuya,Kinoshita, Hanae,Kano, Naokazu
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supporting information
p. 8575 - 8578
(2019/07/25)
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- Charge-Assisted Halogen Bonding in Bromo- and Iodophenylpyridinium Chlorides
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Ten N-halophenylpyridinium salts (halogen = Br or I) with chloride (and in one case iodide) counterions have been prepared and structurally characterized in order to examine the degree of solid state halogen bonding exhibited in these systems. N-Halophenylpyridinium salts are easily synthesized from existing pyridines, and the cationic pyridinium group is expected to increase the halogen bond donor ability of attached halophenyl moieties. Halide anions functioning as halogen bond acceptors facilitate formation of charge-assisted halogen bonds. All five substrates featuring iodophenyl or diiodophenyl substituents displayed the expected halogen bonding interactions. In several cases halide ion acceptors were also engaged in complementary hydrogen bonding interactions with C-H groups of pyridinium rings and O-H groups of water solvates. Halogen bond donors containing a diiodophenyl group formed either an extended network or discrete supramolecular macrocyclic constructs through ArI...Cl-...IAr bridging interactions. Significantly fewer and weaker halogen bonding interactions were observed in crystals of N-bromophenylpyridinium salts. The attenuation of halogen bonding in these substrates is attributed to the inability of the activated bromoarene halogen bond donors to compete with hydrogen bond donors (C-H/O-H residues) for the halide anion. (Chemical Equation Presented).
- Kassl, Christopher J.,Swenson, Dale C.,Pigge, F. Christopher
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p. 4571 - 4580
(2015/09/15)
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- Synthesis of n-substituted carbonylamino-1,2,3,6-tetrahydropyridines as potential anti-inflammatory agents
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Several N-substituted carbonyl/sulfonylamino-1,2,3,6-tetrahydropyridines (5a-i and 9a, b) were synthesized via sodium borohydride reduction of the corresponding N-substitutedimino-pyridinium ylides (4a-i and 8a, b) in absolute ethanol. Taylor &FrancisGroup, LLC.
- Ghaffari, Mohammad A.,Ardley, Tiffany W.,Gangapuram, Madhavi,Redda, Kinfe K.
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experimental part
p. 2615 - 2623
(2011/08/07)
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- Complex polycyclic lactams from pericyclic cascade reactions of Zincke aldehydes
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(Chemical Equation Presented) In the course of a simple mechanistic study on the rearrangement of Zincke aldehydes to Z-α,β,γ,δ- unsaturated amides, a thermally induced pericyclic cascade rearrangement that converts Zincke aldehydes derived from allylic and homoallylic amines into polycyclic lactams was discovered. The key reaction involves an E-Z alkene isomerization, a 6? electrocyclic ring closure, a[1,5]-sigmatropic shift of hydrogen, a 6? electrocyclic ring-opening , and a Diels-Alder cycloaddition, and proceeds with excellent stereoselectivity. The unusual observation that furans and an indole serve as dienophiles in this cascade reaction permitted the synthesis of complex, functional group-rich tri- and tetracyclic lactams. In all cases, the rigid polycyclic products are available in only two steps from pyridinium salts and the allylic or homoallylic secondary amines.
- Steinhardt, Sarah E.,Vanderwal, Christopher D.
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supporting information; scheme or table
p. 7546 - 7547
(2009/10/17)
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- Stereocontrolled synthesis of Z-dienes via an unexpected pericyclic cascade rearrangement of 5-amino-2,4-pentadienals
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Donor-acceptor dienes known as Zincke aldehydes, which derive readily from the ring-opening reactions of pyridinium salts with secondary amines, undergo a fascinating thermal rearrangement reaction to afford Z-α,β,γ,δ-unsaturated amides with excellent stereoselectivity. Efficient, stereocontrolled access to Z-trisubstituted alkenes with two different substitution patterns is possible in three steps beginning with the appropriately substituted pyridine derivative. Preliminary studies have shown that both the amide and the monosubstituted alkene termini can be selectively functionalized. Ease of access, generality of scope, and facile product manipulation render this process attractive for the synthesis of complex polyenes. Copyright
- Steinhardt, Sarah E.,Silverston, Joel S.,Vanderwal, Christopher D.
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p. 7560 - 7561
(2008/12/22)
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- N-Arylated pyridinium salts having reactive groups
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The pyridinium salts having reactive amine and/or pyridyl groups were obtained by the reaction using Zincke salts. Optical properties and anion exchange behavior of the obtained pyridinium salts were investigated.
- Yamaguchi, Isao,Higashi, Hideo,Shigesue, Sachiko,Shingai, Saki,Sato, Moriyuki
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p. 7778 - 7781
(2008/03/11)
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- The Solid-Phase Zincke Reaction: Preparation of ω-Hydroxy Pyridinium Salts in the Search for CFTR Activation
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A study of structural modifications of MPB-07 was undertaken as part of a synthetic program aimed at discovering small molecules with CFTR activation potential. Solid-phase synthesis techniques were used to prepare derivatives of MPB-07 employing the Zincke reaction for the construction of aromatic, quaternary ammonium salts such as those found in 2 or 3. In this transformation, primary amines react with highly electrophilic N-2,4-dinitrophenylpyridinium (DNP) salt 4 to afford pyridinium salt 8 with release of 2,4-dinitroaniline 6. Thus, the reaction of 1-(2,4-dinitrophenyl)pyridinium salts with various polymer-bound amino ethers, followed by cleavage from the resin, delivers the desired salts in good yield and high purity.
- Eda, Masahiro,Kurth, Mark J.,Nantz, Michael H.
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p. 5131 - 5135
(2007/10/03)
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- Rat liver microsomal enzyme catalyzed oxidation of 1-cyclopropyl-4-phenyl-1,2,3,6-tetrahydropyridine
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NADPH supplemented rat liver microsomal enzyme preparations catalyze the conversion of 1-cyclopropyl-4-phenyl-1,2,3,6-tetrahydropyridine to the p-hydroxyphenyl (low yield), descyclopropyl (high yield) and 2,3-dihydropyridinium and, subsequently, pyridinium (intermediary yield) metabolites. When the methine proton of the cyclopropyl group was replaced with a deuteron, a normal deuterium isotope effect (1.4) was observed on the formation of the decyclopropylated metabolite and an inverse isotope effect (0.6) on the dihydropyridinium metabolite. A larger deuterium isotope effect (3.6) was observed on the ring α-carbon oxidation pathway with the 2,2,6,6-d4 analogue as substrate. These results and the observation that the ratios of the rates of these two α-carbon oxidation pathways are independent of initial substrate concentrations suggest that both pathways are catalyzed by the same active site of one form of P450. These transformations are discussed in terms of metabolic pathways that have been proposed for the cytochrome P450 catalyzed α-carbon oxidation of amines. Copyright (C) 1998 Elsevier Science Ltd.
- Zhao, Zhiyang,Mabic, Stephane,Kuttab, Simon,Franot, Christelle,Castagnoli, Kay,Castagnoli Jr., Neal
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p. 2531 - 2539
(2007/10/03)
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- Synthesis of Some N-(Phenylsulfonylamino)-1,2,3,6-tetrahydropyridines as Potential Anti-inflammatory Agents
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Several N-(phenylsulfonylamino)-1,2,3,6-tetrahydropyridines were synthesized by substituting a sulfonyl group for the carbonyl group of N-(phenylcarbonylamino)-1,2,3,6-tetrahydropyridines 1 in order to investigate the effect of the substitution on the analgesic and anti-inflammatory activities. Nucleophilic attack of pyridine derivatives 2 on 1-chloro-2,4-dinitrobenzene 3 furnished the pyridinium chlorides 4. Compound 4 and benzenesulfonyl hydrazide 5 were reacted to give the 2,4-dinitroanilino derivatives 6. Hydrolysis of 6 furnished the ylides 7. Sodium borohydride reduction of ylides afforded the tetrahydropyridines 8. Compound 8c was found to be the most active anti-inflammatory agent and was as potent as indomethacin, the reference compound. Compound 8f had the most significant hyperglycemic activity.
- Choi, JongOh,Wilson, Tiffany L.,Ly, Ana M.,Okoro, Cosmas O.,Onubogu, Udobi C.,Redda, Kinfe K.
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p. 281 - 295
(2007/10/03)
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