Excellent correlation between substituent constants and pyridinium N-methyl chemical shifts
作者:Sha Huang、Jesse C.S. Wong、Adam K.C. Leung、Yee Man Chan、Lili Wong、Myrien R. Fernendez、Amanda K. Miller、Weiming Wu
DOI:10.1016/j.tetlet.2009.06.081
日期:2009.9
Substituents on the pyridinium ring of N-methylpyridinium derivatives, especially those on the 2- or 4-position, have a large effect on the 1H and 13C NMR chemical shifts of the N-methyl group. Reasonable correlations between the chemical shift changes and the resonance substituent constants are observed. The dual substituent parameter approach provides an excellent correlation when a combination of
的吡啶鎓环上的取代基Ñ -methylpyridinium衍生物,特别是那些在2-或4-位,对具有大的影响1 H和13个C NMR的化学位移ñ -甲基组。观察到化学位移变化与共振取代基常数之间的合理相关性。当采用极性和共振取代基常数的组合时,双取代基参数方法提供了极好的相关性。