TY - JOUR
T1 - Eliminations from (E)-O-arylbenzaldehyde oximes promoted by hydroxide in 60% aq. Dimethyl sulphoxide. Mechanism and transition-state characteristics of nitrile-forming eliminations
AU - Cho, Bong Rae
AU - Lee, Jong Chan
AU - Cho, Nam Soon
AU - Kim, Kee Dong
PY - 1989
Y1 - 1989
N2 - Reactions of the (E)-O-arylbenzaldehyde oximes (1; Ar = 2,4-dinitrophenyl), (2; Ar =p-nitrophenyl), and (3; Ar = phenyl) with OH− in 60% aq. DMSO have been investigated. The eliminations are quantitative, producing only benzonitriles and aryloxides. The observation of second-order kinetics, k2OD-/k2OH-= 1.15-1.84, and βlg =-0.59 is consistent with an E2 mechanism. The Hammett ρ and k2OD-/k2OH- values increased with poorer leaving groups. For a given substrate the k2OD-/k2OH- value remained (within experimental error) roughly constant, in spite of changes in the β-aryl substituents. These changes in transition state parameters can be interpreted in terms of the differing nitrite-forming transition states involved.
AB - Reactions of the (E)-O-arylbenzaldehyde oximes (1; Ar = 2,4-dinitrophenyl), (2; Ar =p-nitrophenyl), and (3; Ar = phenyl) with OH− in 60% aq. DMSO have been investigated. The eliminations are quantitative, producing only benzonitriles and aryloxides. The observation of second-order kinetics, k2OD-/k2OH-= 1.15-1.84, and βlg =-0.59 is consistent with an E2 mechanism. The Hammett ρ and k2OD-/k2OH- values increased with poorer leaving groups. For a given substrate the k2OD-/k2OH- value remained (within experimental error) roughly constant, in spite of changes in the β-aryl substituents. These changes in transition state parameters can be interpreted in terms of the differing nitrite-forming transition states involved.
UR - http://www.scopus.com/inward/record.url?scp=0345163958&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0345163958&partnerID=8YFLogxK
U2 - 10.1039/P29890000489
DO - 10.1039/P29890000489
M3 - Article
AN - SCOPUS:0345163958
SN - 0300-9580
SP - 489
EP - 492
JO - Journal of the Chemical Society, Perkin Transactions 2
JF - Journal of the Chemical Society, Perkin Transactions 2
IS - 5
ER -