Propagation of Polar Substituent Effects in 1-(Substituted phenyl)-6,7-dimethoxy-3,4-dihydro- and -1,2,3,4-tetrahydroisoquinolines As Explained by Resonance Polarization Concept
作者:Kari Neuvonen、Ferenc Fülöp、Helmi Neuvonen、Andreas Koch、Erich Kleinpeter、Kalevi Pihlaja
DOI:10.1021/jo0507946
日期:2005.12.1
Propagation of inductive and resonance effects of phenyl substituents within 1-(substituted phenyl)-6,7-dimethoxy-3,4-dihydro- and -1,2,3,4-tetrahydroisoquinolines were studied with the aid of 13C and 15N NMR chemical shifts and ab initio calculations. The substituent-induced changes in the chemical shift (SCS) were correlated with a dual substituent parameter equation. The contributions of conjugative
借助13 C和15研究了1-(取代的苯基)-6,7-二甲氧基-3,4-二氢-和-1,2,3,4-四氢异喹啉中苯基取代基的感应和共振效应的传播。N NMR化学位移和从头算。取代基诱导的化学位移变化(SCS)与双取代基参数方程式相关。共轭(ρ的贡献- [R )和nonconjugative效应(ρ ˚F进行了分析),并给出了两个系列在整个异喹啉部分上取代基引起的变化的图谱。借助谐振极化概念可以使实验结果合理化。这意味着要考虑不同共振结构的取代基敏感平衡,即电子离域,以及芳环取代基对其相对贡献的影响。对于四氢异喹啉,氮孤对的离域作用(立体电子效应)尤为重要。还对二氢异喹啉衍生物的Mulliken原子电荷进行了相关分析。该结果支持异喹啉部分对取代基敏感的极化的概念,即使通过NMR方法获得的极化模式与计算电荷所预测的极化模式并不完全相同。以前,局部π极化和扩展极化的概念已用于解释芳族侧链衍生物内