Department of Chemistry, Federal University of Lavras, Lavras, Minas Gerais, Brazil.
Magn Reson Chem. 2012 Aug;50(8):551-6. doi: 10.1002/mrc.3837. Epub 2012 Jun 26.
Flavonoids are useful compounds in medicinal chemistry and exhibit conformational isomerism, which is ruled by intramolecular interactions. One of the main intramolecular forces governing the stability of conformations is the hydrogen bond. Hydrogen bond involving fluorine covalently bonded to carbon has been found to be rare, but it appears in 2'-fluoroflavonol, although the F···HO hydrogen bond cannot be considered the main effect governing the conformational stability of this compound. Because (19)F is magnetically active and suitable for NMR studies, the (1h)J(F,H(O)) coupling constant can be used as a probe for such an interaction in 2'-fluoroflavonol. In fact, the (1h)J(F,H(O)) coupling was computationally analyzed in this work, and the F···HO hydrogen bond was found to be its main transmission mechanism, which modulates this coupling in 2'-fluoroflavonol, rather than overlap of proximate electronic clouds, such as in 2-fluorophenol.
类黄酮是医学化学中有用的化合物，表现出构象异构，这由分子内相互作用决定。控制构象稳定性的主要分子内力之一是氢键。已经发现与碳共价键合的氟的氢键很少见，但它出现在 2'-氟黄酮醇中，尽管 F···HO 氢键不能被认为是控制该化合物构象稳定性的主要因素。由于 19F 具有磁性且适合 NMR 研究，因此 (1h)J(F,H(O)) 偶合常数可用作 2'-氟黄酮醇中这种相互作用的探针。事实上，在这项工作中对 (1h)J(F,H(O)) 偶合进行了计算分析，发现 F···HO 氢键是其主要的传递机制，它调节 2'-氟黄酮醇中的这种偶合，而不是像 2-氟苯酚那样临近电子云的重叠。
