Efficient unimolecular deprotonation of aniline radical cations

Gary W. Dombrowski, Joseph P. Dinnocenzo, Paul A. Zielinski, Samir Farid, Zofia M. Wosinska, Ian Gould

Research output: Contribution to journalArticle

32 Citations (Scopus)

Abstract

Deprotonation of the radical cations of aromatic amines, such as anilines, generally occurs much more slowly than other fragmentation reactions. Here we report a stereoelectronic effect involving twisting of the anilino group out of the plane of the benzene ring that results in a significantly increased rate of reactivity toward deprotonation. Quantitative studies of the rate constants for deprotonation as a function of aniline radical cation pKa (Brønsted plots) demonstrate that the effect is not simply due to a change in the reaction thermodynamics. By combining this stereoelectronic effect with covalent attachment of carboxylate as a base, aniline radical cations that undergo unimolecular deprotonation with rate constants as high as 10 8 s-1, even in unfavorable protic media, are described.

Original languageEnglish (US)
Pages (from-to)3791-3800
Number of pages10
JournalJournal of Organic Chemistry
Volume70
Issue number10
DOIs
StatePublished - May 13 2005

Fingerprint

Deprotonation
Cations
Rate constants
Aniline Compounds
Benzene
Amines
Thermodynamics
aniline

ASJC Scopus subject areas

  • Organic Chemistry

Cite this

Dombrowski, G. W., Dinnocenzo, J. P., Zielinski, P. A., Farid, S., Wosinska, Z. M., & Gould, I. (2005). Efficient unimolecular deprotonation of aniline radical cations. Journal of Organic Chemistry, 70(10), 3791-3800. https://doi.org/10.1021/jo047813g

Efficient unimolecular deprotonation of aniline radical cations. / Dombrowski, Gary W.; Dinnocenzo, Joseph P.; Zielinski, Paul A.; Farid, Samir; Wosinska, Zofia M.; Gould, Ian.

In: Journal of Organic Chemistry, Vol. 70, No. 10, 13.05.2005, p. 3791-3800.

Research output: Contribution to journalArticle

Dombrowski, GW, Dinnocenzo, JP, Zielinski, PA, Farid, S, Wosinska, ZM & Gould, I 2005, 'Efficient unimolecular deprotonation of aniline radical cations', Journal of Organic Chemistry, vol. 70, no. 10, pp. 3791-3800. https://doi.org/10.1021/jo047813g
Dombrowski GW, Dinnocenzo JP, Zielinski PA, Farid S, Wosinska ZM, Gould I. Efficient unimolecular deprotonation of aniline radical cations. Journal of Organic Chemistry. 2005 May 13;70(10):3791-3800. https://doi.org/10.1021/jo047813g
Dombrowski, Gary W. ; Dinnocenzo, Joseph P. ; Zielinski, Paul A. ; Farid, Samir ; Wosinska, Zofia M. ; Gould, Ian. / Efficient unimolecular deprotonation of aniline radical cations. In: Journal of Organic Chemistry. 2005 ; Vol. 70, No. 10. pp. 3791-3800.
@article{19b93b3ce4fe42a4ab449b9957cd511a,
title = "Efficient unimolecular deprotonation of aniline radical cations",
abstract = "Deprotonation of the radical cations of aromatic amines, such as anilines, generally occurs much more slowly than other fragmentation reactions. Here we report a stereoelectronic effect involving twisting of the anilino group out of the plane of the benzene ring that results in a significantly increased rate of reactivity toward deprotonation. Quantitative studies of the rate constants for deprotonation as a function of aniline radical cation pKa (Br{\o}nsted plots) demonstrate that the effect is not simply due to a change in the reaction thermodynamics. By combining this stereoelectronic effect with covalent attachment of carboxylate as a base, aniline radical cations that undergo unimolecular deprotonation with rate constants as high as 10 8 s-1, even in unfavorable protic media, are described.",
author = "Dombrowski, {Gary W.} and Dinnocenzo, {Joseph P.} and Zielinski, {Paul A.} and Samir Farid and Wosinska, {Zofia M.} and Ian Gould",
year = "2005",
month = "5",
day = "13",
doi = "10.1021/jo047813g",
language = "English (US)",
volume = "70",
pages = "3791--3800",
journal = "Journal of Organic Chemistry",
issn = "0022-3263",
publisher = "American Chemical Society",
number = "10",

}

TY - JOUR

T1 - Efficient unimolecular deprotonation of aniline radical cations

AU - Dombrowski, Gary W.

AU - Dinnocenzo, Joseph P.

AU - Zielinski, Paul A.

AU - Farid, Samir

AU - Wosinska, Zofia M.

AU - Gould, Ian

PY - 2005/5/13

Y1 - 2005/5/13

N2 - Deprotonation of the radical cations of aromatic amines, such as anilines, generally occurs much more slowly than other fragmentation reactions. Here we report a stereoelectronic effect involving twisting of the anilino group out of the plane of the benzene ring that results in a significantly increased rate of reactivity toward deprotonation. Quantitative studies of the rate constants for deprotonation as a function of aniline radical cation pKa (Brønsted plots) demonstrate that the effect is not simply due to a change in the reaction thermodynamics. By combining this stereoelectronic effect with covalent attachment of carboxylate as a base, aniline radical cations that undergo unimolecular deprotonation with rate constants as high as 10 8 s-1, even in unfavorable protic media, are described.

AB - Deprotonation of the radical cations of aromatic amines, such as anilines, generally occurs much more slowly than other fragmentation reactions. Here we report a stereoelectronic effect involving twisting of the anilino group out of the plane of the benzene ring that results in a significantly increased rate of reactivity toward deprotonation. Quantitative studies of the rate constants for deprotonation as a function of aniline radical cation pKa (Brønsted plots) demonstrate that the effect is not simply due to a change in the reaction thermodynamics. By combining this stereoelectronic effect with covalent attachment of carboxylate as a base, aniline radical cations that undergo unimolecular deprotonation with rate constants as high as 10 8 s-1, even in unfavorable protic media, are described.

UR - http://www.scopus.com/inward/record.url?scp=18744403055&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=18744403055&partnerID=8YFLogxK

U2 - 10.1021/jo047813g

DO - 10.1021/jo047813g

M3 - Article

VL - 70

SP - 3791

EP - 3800

JO - Journal of Organic Chemistry

JF - Journal of Organic Chemistry

SN - 0022-3263

IS - 10

ER -