摘要
The effect of the nitrogen nonbonding electron pair on the 1JC,H values of 1,3-diazaheterocycles was analyzed and compared to 1,5-diazabiciclo[3.2.1]octanes, which have a restricted conformation. The 1JC,H values were measured by observing the 13C satellites in the 1H NMR spectra and then determining the 1H-coupled 13C NMR spectra. The 1JC,H values are 10 Hz larger when the 伪-hydrogen is synperiplanar rather than antiperiplanar to the nonbonding electron pair on the nitrogen, which serves as experimental evidence of the orbital nN鈫捪?sup>鈭?/sup>C,Hap interactions. In addition, the homoanomeric effect from the interactions of the nitrogen lone pair with the antibonding orbital of the equatorial hydrogen, which was in the 尾 position, was discussed (nN鈫捪?sup>鈭?/sup>C(尾),Heq).