Abstract: The oxidant properties of the series of 2,2,5,5-tetraalkyl imidazoline and imidazolidine nitroxides were investigated. An increase in the number of bulky alkyl substituents leads to a decrease in the rate of reduction with ascorbate, which makes the electrochemical reduction potential more negative and shifts the equilibrium in the mixture of nitroxide and reference hydroxylamine (3-carboxy-1-hydroxy-2,2,5,5-tetramethylpyrrolidine-1-oxy1-1-N-15) toward the starting compounds. The effect of structural factors on these reactions was analyzed by means of multiple regression using the Fujita steric constant E-s and the inductive Hammett constant sigma(1). Satisfactory statistical outputs were obtained in all of the biparameter correlations, denoting that the oxidant properties of the nitroxides are determined by steric and electronic effects of the substituents. The data imply that bulky substituents can stabilize nitroxide and/or destabilize hydroxylamine.

Cite: Kirilyuk I.A. , Bobko A.A. , Semenov S.V. , Komarov D.A. , Irtegova I.G. , Grigor'ev I.A. , Bagryanskaya E.
Effect of Sterical Shielding on the Redox Properties of Imidazoline and Imidazolidine Nitroxides
Journal of Organic Chemistry. 2015. V.80. N18. P.9118-9125. DOI: 10.1021/acs.joc.5b01494 WOS Scopus РИНЦ

Dates:

Published online:	Aug 31, 2015
Published print:	Sep 18, 2015

Identifiers:

Web of science	WOS:000361866700019
Scopus	2-s2.0-84941918769
Elibrary	24949748
OpenAlex	W1137914700

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