Substituent effects in ring-chain tautomerism of the condensation products of non-racemic 1,2-aminoalcohols with aromatic aldehydes
作者:Márta Juhász、László Lázár、Ferenc Fülöp
DOI:10.1016/j.tetasy.2011.11.011
日期:2011.12
at 300 K as three-component (ringcis-open-ringtrans) tautomeric mixtures. The electronic effects of the 2-aryl substituents on the tautomeric equilibria were described by the Hammett equation. Good correlations were found between the equilibrium constants and the Hammett–Brown parameter (σ+) of the substituent X on the 2-phenyl group.
(S)-2-氨基-2-苯基乙醇或(S)-2-氨基-3-苯基丙醇与取代的苯甲醛在甲醇或水中的缩合生成结晶产物,证明该产物在300 K的CDCl 3中以3 -组分(环顺式-开环反式)互变异构混合物。通过哈米特方程描述了2-芳基取代基对互变异构体平衡的电子效应。在平衡常数与2-苯基上的取代基X的Hammett-Brown参数(σ +)之间发现了良好的相关性。