Synthetic Hosts for Molecular Recognition of Ureas
摘要:
Four hosts (7-10) containing 2,6-bisamidopyridine- and 2,5-bisamidopyrrole-bearing pyridyl or 1,8-naphthyridyl groups have been prepared and their structures studied by a combination of multinuclear NMR spectroscopy and X-ray crystallography. Their behavior in molecular recognition of urea derivatives, including (+)-biotin methyl ester, has been approached by molecular modeling (Monte Carlo conformational search, AMBER force field). The minimum energy values for the complexes are correlated with the experimental binding energies determined by means of H-1 NMR titrations.
1H and 13C NMR investigations of N,N′-bis(2- and 3-pyridinyl)-2,6-pyridine dicarboxamides
作者:Netai C. Singha、D.N. Sathyanarayana
DOI:10.1016/s0022-2860(96)09409-4
日期:1997.1
$^IH NMR$ spectra of N,N'-bis(2-pyridinyl)-2,6- pyridinedicarboxamides (1 to 3) and N,N'-bis(3-pyridinyl)-2,6-pyridinedicar- boxamide (4) have been analysed using the COSY spectra. Accurate IH chemical shifts and coupling constants have been obtained from the simulation of the resolution enhanced spectra. $^13}C NMR$ spectra were analysed with the help of HETCORR and proton coupled $^13}C$ spectra
N,N'-双(2-吡啶基)-2,6-吡啶二甲酰胺(1至3)和N,N'-双(3-吡啶基)-2,6-吡啶二甲酰胺( 4) 已使用 COZY 光谱进行分析。从分辨率增强光谱的模拟中获得了准确的 IH 化学位移和耦合常数。$^13}C NMR$光谱在HETCORR和质子耦合$^13}C$光谱的帮助下进行分析。$^13}C-^H$耦合常数是通过模拟质子耦合$^13}C NMR$谱获得的。从$^1H NMR$谱和NOE增强推断,1~3的两个2-吡啶环与酰胺平面共面,而4的3-吡啶环在酰胺平面外。