화학공학소재연구정보센터
Journal of Physical Chemistry A, Vol.119, No.17, 3905-3912, 2015
Electron-Withdrawing beta-Substituent, Ring-Strain, and Ortho Effects on Reactivity, Selectivity, and Stability of o-Alkoxybenzyl Carbocations
o-Alkoxybenzyl carbocations 1 and 2 were generated by laser flash photolysis of the corresponding o-alkoxybenzyl alcohols 3 and 4 to, understand how the electron-Withdrawing beta-Substituent, the ring-strain, and the ortho effects affect the reactivity (electrophilicity), selectivity, and stability of 1 and 2, and to fit the electrophilicity of 1 and 2 into the current carbocation,electrophilicity scale (E). Our finding is that both the electron-withdrawing beta-substituent and the ring-strain effects make 1 less stable than 2 by 3.0 kcal/mol. These effects plus the ortho effect of 2 make 1 more reactive than 2, but the selectivity of 1 and 2 toward amine nucleophiles is almost the same within experimental errors. The electrophilicity of 1 and 2 has been fit into the current carbocation electrophilicity scale (E) quite well.