Elimination Reactions of Aryl Furylacetates Promoted by R2NH in MeCN: Effects of Base Solvent and β-Aryl Group on the Ketene-forming Transition State

Sang Yong Pyun, Kyu Cheol Paik, Man So Han, Byung Tae Kim, Bong-Rae Cho

Research output: Contribution to journalArticle

Abstract

Ketene-forming elimination from C4H3(O)CH2C(O)OC6H3-2-X-4-NO2 (1) promoted by R2NH in MeCN has been studied. The reactions produced elimination products and exhibited second-order kinetics with Brönsted β=0.51, and |βlg|=0.47-0.53, indicating that the reaction proceeds by the E2 mechanism via an E2-central transition state. Comparison of β, |βlg|, ΔH, and ΔS values for R2NH-promoted eliminations from ArCH2C(O)OC6H3-2-X-4-NO2 reveals that the transition-state structures for Ar=furyl and thienyl are similar and more symmetrical than that for Ar=Ph. This outcome has been attributed to the greater double bond stabilizing ability of the former than that of the latter.

Original languageEnglish
JournalBulletin of the Korean Chemical Society
DOIs
Publication statusAccepted/In press - 2017

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Kinetics
ketene

Keywords

  • Base solvent
  • E2 mechanism
  • Elimination
  • Ketene
  • β-Aryl group

ASJC Scopus subject areas

  • Chemistry(all)

Cite this

@article{4e30e2e5d52049b28941f148fd7cca55,
title = "Elimination Reactions of Aryl Furylacetates Promoted by R2NH in MeCN: Effects of Base Solvent and β-Aryl Group on the Ketene-forming Transition State",
abstract = "Ketene-forming elimination from C4H3(O)CH2C(O)OC6H3-2-X-4-NO2 (1) promoted by R2NH in MeCN has been studied. The reactions produced elimination products and exhibited second-order kinetics with Br{\"o}nsted β=0.51, and |βlg|=0.47-0.53, indicating that the reaction proceeds by the E2 mechanism via an E2-central transition state. Comparison of β, |βlg|, ΔH≠, and ΔS≠ values for R2NH-promoted eliminations from ArCH2C(O)OC6H3-2-X-4-NO2 reveals that the transition-state structures for Ar=furyl and thienyl are similar and more symmetrical than that for Ar=Ph. This outcome has been attributed to the greater double bond stabilizing ability of the former than that of the latter.",
keywords = "Base solvent, E2 mechanism, Elimination, Ketene, β-Aryl group",
author = "Pyun, {Sang Yong} and Paik, {Kyu Cheol} and Han, {Man So} and Kim, {Byung Tae} and Bong-Rae Cho",
year = "2017",
doi = "10.1002/bkcs.11285",
language = "English",
journal = "Bulletin of the Korean Chemical Society",
issn = "0253-2964",
publisher = "Wiley-Blackwell",

}

TY - JOUR

T1 - Elimination Reactions of Aryl Furylacetates Promoted by R2NH in MeCN

T2 - Effects of Base Solvent and β-Aryl Group on the Ketene-forming Transition State

AU - Pyun, Sang Yong

AU - Paik, Kyu Cheol

AU - Han, Man So

AU - Kim, Byung Tae

AU - Cho, Bong-Rae

PY - 2017

Y1 - 2017

N2 - Ketene-forming elimination from C4H3(O)CH2C(O)OC6H3-2-X-4-NO2 (1) promoted by R2NH in MeCN has been studied. The reactions produced elimination products and exhibited second-order kinetics with Brönsted β=0.51, and |βlg|=0.47-0.53, indicating that the reaction proceeds by the E2 mechanism via an E2-central transition state. Comparison of β, |βlg|, ΔH≠, and ΔS≠ values for R2NH-promoted eliminations from ArCH2C(O)OC6H3-2-X-4-NO2 reveals that the transition-state structures for Ar=furyl and thienyl are similar and more symmetrical than that for Ar=Ph. This outcome has been attributed to the greater double bond stabilizing ability of the former than that of the latter.

AB - Ketene-forming elimination from C4H3(O)CH2C(O)OC6H3-2-X-4-NO2 (1) promoted by R2NH in MeCN has been studied. The reactions produced elimination products and exhibited second-order kinetics with Brönsted β=0.51, and |βlg|=0.47-0.53, indicating that the reaction proceeds by the E2 mechanism via an E2-central transition state. Comparison of β, |βlg|, ΔH≠, and ΔS≠ values for R2NH-promoted eliminations from ArCH2C(O)OC6H3-2-X-4-NO2 reveals that the transition-state structures for Ar=furyl and thienyl are similar and more symmetrical than that for Ar=Ph. This outcome has been attributed to the greater double bond stabilizing ability of the former than that of the latter.

KW - Base solvent

KW - E2 mechanism

KW - Elimination

KW - Ketene

KW - β-Aryl group

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U2 - 10.1002/bkcs.11285

DO - 10.1002/bkcs.11285

M3 - Article

AN - SCOPUS:85030762873

JO - Bulletin of the Korean Chemical Society

JF - Bulletin of the Korean Chemical Society

SN - 0253-2964

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