Elimination reactions of (E)-2,4,6-trinitrobenzaldehyde O-aryloximes promoted by R3N/R3NH+ in 70 mol% MeCN(aq). Effect of β-aryl group the nitrile-forming transition-state

Sang Yong Pyun; Woong Sub Byun; Bong Rae Cho

doi:10.5012/bkcs.2011.32.6.1921

Elimination reactions of (E)-2,4,6-trinitrobenzaldehyde O-aryloximes promoted by R₃N/R₃NH⁺ in 70 mol% MeCN(aq). Effect of β-aryl group the nitrile-forming transition-state

Sang Yong Pyun, Woong Sub Byun, Bong Rae Cho

Research output: Contribution to journal › Article › peer-review

1 Citation (Scopus)

Abstract

Nitrile-forming eliminations from (E)-2,4,6-(NO₂) ₃C₆H₂CH=NOC₆H₄-2-X-4- NO₂ (1) promoted by R₃NH/R₃NH⁺ in 70 mol % MeCN(aq) have been studied kinetically. When X = NO₂, the reactions exhibited secondorder kinetics as well as Brönsted β = 0.63 and |β_lg| = 0.34-0.46, and an E2 mechanism is evident. As the leaving group was made poorer (X = H, Cl, and CF₃), Brönsted β value increased from 0.63 to 0.85-0.89 without much change in the |β_lg| value E2, indicating that structure of the transition state changed to an E1cb-like with extensive C_β-H bond cleavage, significant negative charge development at the β-carbon, and limited C_α-Oar bond cleavage.

Original language	English
Pages (from-to)	1921-1924
Number of pages	4
Journal	Bulletin of the Korean Chemical Society
Volume	32
Issue number	6
DOIs	https://doi.org/10.5012/bkcs.2011.32.6.1921
Publication status	Published - 2011 Jun 20

Keywords

E2 and Elcb-like
Elimination
β-aryl group effect

ASJC Scopus subject areas

General Chemistry

Access to Document

10.5012/bkcs.2011.32.6.1921

Cite this

Elimination reactions of (E)-2,4,6-trinitrobenzaldehyde O-aryloximes promoted by R₃N/R₃NH⁺ in 70 mol% MeCN(aq). Effect of β-aryl group the nitrile-forming transition-state. / Pyun, Sang Yong; Byun, Woong Sub; Cho, Bong Rae.
In: Bulletin of the Korean Chemical Society, Vol. 32, No. 6, 20.06.2011, p. 1921-1924.

Research output: Contribution to journal › Article › peer-review

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abstract = "Nitrile-forming eliminations from (E)-2,4,6-(NO2) 3C6H2CH=NOC6H4-2-X-4- NO2 (1) promoted by R3NH/R3NH+ in 70 mol % MeCN(aq) have been studied kinetically. When X = NO2, the reactions exhibited secondorder kinetics as well as Br{\"o}nsted β = 0.63 and |βlg| = 0.34-0.46, and an E2 mechanism is evident. As the leaving group was made poorer (X = H, Cl, and CF3), Br{\"o}nsted β value increased from 0.63 to 0.85-0.89 without much change in the |βlg| value E2, indicating that structure of the transition state changed to an E1cb-like with extensive Cβ-H bond cleavage, significant negative charge development at the β-carbon, and limited Cα-Oar bond cleavage.",

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AU - Pyun, Sang Yong

AU - Byun, Woong Sub

AU - Cho, Bong Rae

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N2 - Nitrile-forming eliminations from (E)-2,4,6-(NO2) 3C6H2CH=NOC6H4-2-X-4- NO2 (1) promoted by R3NH/R3NH+ in 70 mol % MeCN(aq) have been studied kinetically. When X = NO2, the reactions exhibited secondorder kinetics as well as Brönsted β = 0.63 and |βlg| = 0.34-0.46, and an E2 mechanism is evident. As the leaving group was made poorer (X = H, Cl, and CF3), Brönsted β value increased from 0.63 to 0.85-0.89 without much change in the |βlg| value E2, indicating that structure of the transition state changed to an E1cb-like with extensive Cβ-H bond cleavage, significant negative charge development at the β-carbon, and limited Cα-Oar bond cleavage.

AB - Nitrile-forming eliminations from (E)-2,4,6-(NO2) 3C6H2CH=NOC6H4-2-X-4- NO2 (1) promoted by R3NH/R3NH+ in 70 mol % MeCN(aq) have been studied kinetically. When X = NO2, the reactions exhibited secondorder kinetics as well as Brönsted β = 0.63 and |βlg| = 0.34-0.46, and an E2 mechanism is evident. As the leaving group was made poorer (X = H, Cl, and CF3), Brönsted β value increased from 0.63 to 0.85-0.89 without much change in the |βlg| value E2, indicating that structure of the transition state changed to an E1cb-like with extensive Cβ-H bond cleavage, significant negative charge development at the β-carbon, and limited Cα-Oar bond cleavage.

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