17281-59-3Relevant academic research and scientific papers
Switching the reactivity of cyanomethylpyridinium salts in the 1,3-cycloaddition conditions with alkyl propiolates to cyanoindolizines or cyanoazaindolizinyl-indolizines
Moise, Iuliana-Monica,Ghinet, Alina,Shova, Sergiu,B?cu, Elena
, (2020)
A particular reactivity of 1-cyanomethylpyridinium salts was revealed in the [3 + 2] cycloaddition conditions with alkyl propiolates. Cycloadducts 3 were obtained in reactions carried out at room temperature while refluxing in CH3CN provided unexpected ethyl or methyl 3-(3-cyanoimidazo[1,2-a]pyridin-2-yl)indolizine-1-carboxylates 4. The structure of the new 2:1 azaindolizine-indolizine adducts was secured by X-ray analysis. Methodological efforts have enabled the adjustment of the reactivity towards the formation of 3-cyanoindolizines 3 or cyanoazaindolizine-indolizines 4. A mechanism for the formation of azaindolizine-indolizines was proposed. A portfolio of rare cyanoindolizines and cyanoazaindolizine-indolizines has been successfully obtained.
Synthesis, CYP 450 evaluation, and docking simulation of novel 4-aminopyridine and coumarin derivatives
Ghalehshahi, Hajar G.,Balalaie, Saeed,Sohbati, Hamid R.,Azizian, Homa,Alavijeh, Mohammad S.
, (2019/01/21)
Four series of novel compounds based on 4-aminopyridine, glatiramer acetate, pyrone, and coumarin backbones were sufficiently synthesized and identified by spectroscopic methods. CYP enzyme inhibition assays of five predominate human P450 isozymes indicate that all compounds, except for 4-hydrazide pyridine 1c, seem to be less toxic than 4-aminopyridine. Further investigation of the compounds using molecular docking experiments revealed different, the same, or stronger binding modes for most of the synthesized compounds, with both polar and hydrophobic interactions with the 1WDA and 1J95 receptors compared to benzoyl l-arginine amide and 4-aminopyridine, respectively. These results introduce the synthesized compounds as K+ channel blockers that could be considered for in vivo CNS disease studies.
Synthesis of 3-aminochromenes: The Zincke reaction revisited
Costa, Marta,Rodrigues, Ana I.,Proen?a, Fernanda
, p. 4869 - 4875 (2014/07/07)
3-Aminocoumarines and 2-iminochromen-3-amines were efficiently prepared from the Zincke-ring-opening reaction of the corresponding 2H-chromen-3- pyridinium chlorides using N-methylpiperazine. This methodology unravels the marked potential of pyridinium salts as protective groups for primary amines. These scaffolds can be considered important building blocks for new novobiocin analogues and heterocyclic compounds.
Convenient synthesis of 2-aryl-1-haloindolizines from pyridinium salts and 2-aryl-1,1-dihaloalk-1-enes
Yang, Yiwen,Kuang, Chunxiang,Jin, Hui,Yang, Qing
supporting information; experimental part, p. 3447 - 3452 (2011/12/04)
2-Aryl-1-haloindolizines were synthesized from pyridinium salts and 2-aryl-1,1-dihaloalk-1-enes using a DBU/THF system. 2-Aryl-1,1-dihaloalk-1-enes containing electron-withdrawing or -donating groups were efficiently converted into the corresponding 2-aryl-1-haloindolizines in moderate to excellent yields. Georg Thieme Verlag Stuttgart.
One-pot approach to the synthesis of novel 12H-chromeno[2′,3′:4,5]imidazo[1,2-a]pyridines in aqueous media
Proen?a, M. Fernanda,Costa, Marta
experimental part, p. 4542 - 4550 (2010/07/05)
The chromeno-imidazo[1,2-a]pyridine scaffold was generated in an one pot condensation/cyclization reaction involving a salicylaldehyde and 1-(cyanomethyl)pyridinium chloride, in aqueous sodium carbonate solution. These novel compounds were isolated in 47-71% yield. The reaction pathway was followed by 1H NMR spectroscopy allowing a clear understanding of the side reactions involved in the process. Different mono-substituted pyridinium chlorides were synthesized and reacted with mono-substituted salicylaldehydes and a detailed discussion of the scope of the synthetic method is also presented.
Equilibrium Acidities and Homolytic Bond Dissociation Energies of the Acidic C-H Bonds in N-Substituted Trimethylammonium and Pyridinium Cations
Zhang, Xian-Man,Bordwell, Frederick G.,Puy, Michael Van Der,Fried, Herbert E.
, p. 3060 - 3066 (2007/10/02)
Equilibrium acidities (pKHAs) of the cations in sixteen N-substituted trimethylammonium salts, one N-phenacylquinuclidinium salt, eight N-substituted pyridinium salts, and N-(ethoxycarbonyl)-isoquinolinium bromide, together with the oxidation potentials of their conjugate bases, have been determined in dimethyl sulfoxide (DMSO) solution.The acidifying effects of the α-trimethylammonium groups (α-Me3N+) and the α-pyridinium groups (α-PyN+) on the adjacent acidic C-H bonds in these cations were found to average about 10 and 18 pKHA units, respectively, in DMSO.The homolytic bond dissociation energies of the acidic C-H bonds in these cations, estimated by the combination of the equilibrium acidities with the oxidation potentials of their corresponding conjugate bases (ylides), show that the α-trimethylammonium groups destabilize adjacent radicals by 2-6 kcal/mol, whereas α-pyridinium groups stabilize adjacent radicals by 3-6 kcal/mol.The effects of α-pyridinium groups on the stabilization energies of the radicals derived from these cations were found to be ca. 4-10 kcal/mol smaller than those of the corresponding phenyl groups, whereas their effects on the equilibrium acidities of the cations were 5.4-13.1 pKHA units larger.The pKHA value of tetramethylammonium cation (Me4N+) was estimated by extrapolation to be about 42 in DMSO.
Synthesis of 2-Methylthioindolizine-3-carbonitriles Using Nitro Ketene Dithioacetal
Tominaga, Yoshinori,Shiroshita, Yoshihide,Hosomi, Akira
, p. 1745 - 1749 (2007/10/02)
The reaction of 1-cyanomethylpyridinium chloride or bromide, 1a-i, with 1,1-bis(methylthio)-2-nitroethylene (2) in the presence of triethylamine as a base in ethanol gave the corresponding 2-methylthioindolizine-3-carbonitrile 3 and 2-methyl-thio-1-nitroindolizine-3-carbonitrile 4 in good yields, respectively.Compounds 3a,f were key intermediates for the synthesis of cyclazine derivatives.
