141185-70-8Relevant articles and documents
Radical Cations from N-Alkyl Substituted Imines: an EPR Study
Rhodes, Christopher J.,Agirbas, Hikmet
, p. 397 - 402 (2007/10/02)
Following γ-radiolysis of dilute solutions of imines in trichlorofluoromethane at 77 K, EPR spectra of the corresponding radical cations were recorded.For PhCH=NEt amnd PhCH=NCHMe2 the primary 2A' cations were formed, but in each case as a mixt
Reactions of N-Chloro-N-alkylbenzylamines with Amines in Acetonitrile. Origin of Steric Effect in Imine-Forming Elimination
Cho, Bong Rae,Suh, Young Wook
, p. 2855 - 2858 (2007/10/02)
Reaction of N-chloro-N-alkylbenzylamines in which the alkyl group is Me, Et, i-Pr, sec-Bu, and t-Bu with MeNH2 and Et2NH in MeCN have been studied kinetically.The eliminations are quantitative and regiospecific, producing only N-benzylidenealkylamines.The relative rates of elimination for Me/Et/i-Pr/sec-Bu/t-Bu alkyl substituents are 1/0.6/0.4/0.3/0.1 with MeNH2 and 1/0.5/0.3/0.2/0.03 with Et2NH, respectively.Comparison with published data reveals that Charton's value for the imine-forming elimination decreases with the variation of the base-solvent from MeONa-MeOH to MeNH2-MeCN but increases when the base is changed from MeNH2 to Et2NH.For a given base, Hammett ρ and kH/kD values decrease and the ΔH(excit.) and ΔS(excit.) values increase with bulkier alkyl substituents.From these results, the origin of the steric effect in imine-forming elimination is attributed to the repulsive interaction between the alkyl group and the base in the transition state.