Collect. Czech. Chem. Commun. 1996, 61, 615-621
https://doi.org/10.1135/cccc19960615

Sterically Crowded Heterocycles. IV. Diastereoisomeric Products by Ferricyanide Oxidation of Quaternary Pyridinium Salts

Richard Kubík and Josef Kuthan

Department of Organic Chemistry, Prague Institute of Chemical Technology, 166 28 Prague 6, Czech Republic

This article is part of serial Sterically crowded heterocycles.

Abstract

While ferricyanide oxidation of achiral 4-(4-dimethylaminophenyl)-2,6-diphenyl-1-(pyridin-2-yl)pyridinium perchlorate (2) gave racemic 3-(4-dimethylaminophenyl)-1-phenyl-3-(2-phenylimidazo[1,2-a]pyridin-3-yl)prop-2-en-1-one (7), the same oxidative procedure applied to racemic 1-[5-(1-methylpyrrolidin-2-yl)pyridin-2-yl]-2,4,6-triphenylpyridinium perchlorate (5) or its dimethylamino derivative 6 let to mixtures of diastereoisomeric 3-[6-(1-methylpyrrolidin-2-yl)-2-phenylimidazo[1,2-a]pyridin-3-yl]-1,3-diphenyl-2-en-1-ones (8) or their dimethylamino derivatives 9, respectively.

Keywords: Ferricyanide oxidation; Sterically crowded heterocycles; Atropisomerism.