Pyrylium Salts of g-Thiapyrones --- A Simple Step to Phosphono-phosphino Substituted Pyridines and Pyridinium Salts

Heterocycles ◽  
1998 ◽  
Vol 48 (4) ◽  
pp. 711 ◽  
Author(s):  
Richard Neidlein ◽  
Dirk Uwe Hahn
2018 ◽  
Vol 69 (1) ◽  
pp. 64-69
Author(s):  
Liviu Birzan ◽  
Mihaela Cristea ◽  
Constantin C. Draghici ◽  
Alexandru C. Razus

The 1H and 13C NMR spectra of several 2,6-diheteroarylvinyl heterocycles containing 4-azulenyl moiety were recorded and their proton and carbon chemical shifts were compared with those of the compounds without double bond between the heterocycles. The influence of the nature of central and side heterocycles, molecule polarization and anisotropic effects were revealed. The highest chemical shifts were recorded for the pyrylium salts and the lowest at pyridines, but in the case of the pyridinium salts, the protons chemical shifts at the central heterocycle are more shielded due to a peculiar anisotropy of the attached vinyl groups.


Synthesis ◽  
2005 ◽  
Vol 2005 (05) ◽  
pp. 781-786 ◽  
Author(s):  
Andreas Schmidt ◽  
Thorsten Mordhorst

Heterocycles ◽  
1983 ◽  
Vol 20 (2) ◽  
pp. 239 ◽  
Author(s):  
Roger A. Dommisse ◽  
Roger Dommisse ◽  
Eddy Freyne ◽  
Josef Lepoivre ◽  
Frank Alderweireldt

ChemInform ◽  
2007 ◽  
Vol 38 (25) ◽  
Author(s):  
Alexandru C. Razus ◽  
Liviu Birzan ◽  
Claudia Pavel ◽  
Oana Lehadus ◽  
Andreea Corbu ◽  
...  

ChemInform ◽  
2010 ◽  
Vol 28 (34) ◽  
pp. no-no
Author(s):  
M. BOGATIAN ◽  
G. MIHAI ◽  
M. PLAVETI ◽  
F. CHIRALEU ◽  
C. DELEANU ◽  
...  

2014 ◽  
Vol 69 (5) ◽  
pp. 605-614 ◽  
Author(s):  
Nazar Pidlypnyi ◽  
Sandra Kaul ◽  
Sebastian Wolf ◽  
Martin H. H. Drafz ◽  
Andreas Schmidt

3-Methylindole reacts with pyridines in the presence of NBS to give indol-2-yl-pyridinium salts which were converted into their ylides by an anion exchange resin in its hydroxide form. Indol-3- amine was subjected to a nucleophilic ring transformation with pyrylium salts which resulted in the formation of indol-3-yl-pyridinium salts, the 2,4,6-trimethylpyridinium derivative of which proved to be unstable. The 2,4,6-triphenylpyridinium derivate was deprotonated to the corresponding ylide. The isomeric indol-2-yl and indol-3-yl derivatives are cycloimmonium ylides which are members of the compound class of heterocyclic mesomeric betaines (MB). By contrast, the ylide of indol- 2-yl-pyrrolidinium is a cycloammonium ylide. It was prepared by reaction of 3-methylindole with pyrrolidine in the presence of NBS, followed by deprotonation.


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