Elimination reactions of YC6H4CH(R)N(X)CH3 in which R = Me and Ph and X = Cl and Br promoted by MeONa-MeOH and t-BuOK-t-BuOH have been studied kinetically. The elimination reactions are regiospecific, producing only the corresponding N-benzylidenemethylamines, and are quantitative when X = Cl. Comparison with published data for R = H reveals that with both base-solvent combinations variation of the β-carbon substituent from Me to H to Ph produces an increase in the ρ value, first an increase and then a decrease in kH/kD, and a decrease in kBr,/kCl. When the base-solvent system is changed from MeONa-MeOH to t-BuOK-t-BuOH, the ρ value increases, kH/kD remains nearly constant, and kBr,/kCl decreases for all three R groups. From these results, the changes in transition-state structure wrought by variation of the β-carbon substituent and the base-solvent system are assessed.
|Number of pages||6|
|Journal||Journal of the American Chemical Society|
|Publication status||Published - 1989 Dec 1|
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