Sterically Crowded Heterocycles. X. A New Mechanistic Approach to the Ferricyanide Oxidation of 4,6'-Disubstituted 1-(Pyridin-2'-yl)-2,6-diphenylpyridinium Salts

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Title:Sterically Crowded Heterocycles. X. A New Mechanistic Approach to the Ferricyanide Oxidation of 4,6'-Disubstituted 1-(Pyridin-2'-yl)-2,6-diphenylpyridinium Salts
Creators:
Pohl, Radek
Böhm, Stanislav
Kuthan, Josef
Journal or Publication Title:
Collection of Czechoslovak Chemical Communications, 64, 8, pp. 1274-1294
Uncontrolled Keywords:Aminopyridines, Pyrilium salts, Pyrroles, Imidazo[1,2-<i>a</i>]pyridines, Pyridinium salts, Semiempirical calculations, Ferricyanide oxidation, PM3 calculations

Abstract

The oxidations of the title perchlorates, bearing the sterically diverse 6'-substituents (H, Me, Et, i-Pr, n-Bu, <i>t</i>-Bu and Ph) in two series with the same 4-substituents (Ph and <i>t</i>-Bu) lead to pairs of isomeric 3',5-disubstituted (<i>Z</i>)-1'-phenyl-3'-(2-phenylimidazo[1,2-<i>a</i>]pyridin-3-yl)prop-2'- en-1'-ones and 3,6'-disubstituted [5-phenyl-1-(6'-pyridin-2'-yl)-1<i>H</i>-pyrrol-2-yl](phenyl)methanones except where the both variable substituents are <i>t</i>-Bu and then only pyrrolic product is formed. Considering steric interactions of the substituents in some intermediate and/or transition states a multistep mechanism for the oxidative transformation is proposed and supported by model PM3-PECI calculations of some radical intermediates. <p>

Title:Sterically Crowded Heterocycles. X. A New Mechanistic Approach to the Ferricyanide Oxidation of 4,6'-Disubstituted 1-(Pyridin-2'-yl)-2,6-diphenylpyridinium Salts
Creators:
Pohl, Radek
Böhm, Stanislav
Kuthan, Josef
Uncontrolled Keywords:Aminopyridines, Pyrilium salts, Pyrroles, Imidazo[1,2-<i>a</i>]pyridines, Pyridinium salts, Semiempirical calculations, Ferricyanide oxidation, PM3 calculations
Divisions:Life and Chemical Sciences > Institute of Organic Chemistry and Biochemistry > Collection of Czechoslovak Chemical Communications
Journal or Publication Title:Collection of Czechoslovak Chemical Communications
Volume:64
Number:8
Page Range:pp. 1274-1294
ISSN:0010-0765
E-ISSN:1212-6950
Publisher:Institute of Organic Chemistry and Biochemistry
Related URLs:
URLURL Type
http://dx.doi.org/10.1135/cccc19991274UNSPECIFIED
ID Code:1555
Item Type:Article
Deposited On:06 Feb 2009 17:10
Last Modified:06 Feb 2009 16:10

Citation

Pohl, Radek; Böhm, Stanislav; Kuthan, Josef (1999) Sterically Crowded Heterocycles. X. A New Mechanistic Approach to the Ferricyanide Oxidation of 4,6'-Disubstituted 1-(Pyridin-2'-yl)-2,6-diphenylpyridinium Salts. Collection of Czechoslovak Chemical Communications, 64 (8). pp. 1274-1294. ISSN 0010-0765

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