Eliminations from (E)-2,4-Dinitrobenzaldehyde O-Aryloximes Promoted by R3N/R3NH + in 70 mol % MeCN(aq). Effects of Leaving Group and Base-Solvent on the Nitrile-Forming Transition-State

Content Provider	Semantic Scholar
Author	Cho, Bong Rae Pyun, Sang Yong
Copyright Year	2013
Abstract	Elimination reactions of (E)-2,4-(NO2)2C6H2CH=NOC6H3-2-X-4-NO2 (1a-e) promoted by R3N/R3NH + in 70 mol % MeCN(aq) have been studied kinetically. The reactions are second-order and exhibit Bronsted β = 0.800.84 and |βlg| = 0.39-0.42, respectively. For all leaving groups and bases employed in this study, the β and |βlg| values remained almost the same. The results can be described by a negligible pxy interaction coefficient, pxy = ∂β/pKlg = ∂βlg/pKBH ≈ 0, which describes the interaction between the base catalyst and the leaving group. The negligible pxy interaction coefficient is consistent with the (E1cb)irr mechanism. Change of the base-solvent system from R3N/MeCN to R3N/R3NH + -70 mol % MeCN(aq) changed the reaction mechanism from E2 to (E1cb)irr. Noteworthy was the relative insensitivity of the transition state structure to the reaction mechanism change.
Starting Page	1030
Ending Page	1034
Page Count	5
File Format	PDF HTM / HTML
DOI	10.5012/bkcs.2013.34.4.1030
Volume Number	34
Alternate Webpage(s)	http://ocean.kisti.re.kr/downfile/volume/chemical/JCGMCS/2013/v34n4/JCGMCS_2013_v34n4_1030.pdf
Alternate Webpage(s)	https://doi.org/10.5012/bkcs.2013.34.4.1030
Language	English
Access Restriction	Open
Content Type	Text
Resource Type	Article