Conformational Preference of 2′-Fluoro-Substituted Acetophenone Derivatives Revealed by Through-Space <sup>1</sup>H–<sup>19</sup>F and <sup>13</sup>C–<sup>19</sup>F Spin–Spin Couplings
作者:Chinatsu Otake、Takuya Namba、Hidetsugu Tabata、Kosho Makino、Kiriko Hirano、Tetsuta Oshitari、Hideaki Natsugari、Takenori Kusumi、Hideyo Takahashi
DOI:10.1021/acs.joc.1c00051
日期:2021.3.19
analyzing their NMR spectra focused on the TS-couplings. The magnitudes of the coupling constants 5J (Hα, F) and 4J (Cα, F) correlate linearly with the value of the dielectric constant of the solvents. Furthermore, s-trans conformations of the two derivatives were confirmed by X-ray crystallographic analysis. These conformational preferences were consistent with the DFT calculations. The s-cis conformer
2'-氟-取代的苯乙酮衍生物的构象性质阐明基于H α -F和C α -F贯通空间自旋-自旋耦合(TS-联轴器),以比较小的距离约束的两个原子之间发生他们的范德华半径之和。该研究揭示,在解决方案2'-氟取代的乙酰苯衍生物形成专门š -反式,通过分析它们的NMR谱集中在TS-接头构象异构体。耦合常数5 J(Hα,F)和4 J(Cα,F)与溶剂的介电常数的值线性相关。此外,小号-反式的两种衍生物的构象用X射线晶体分析证实。这些构象偏好与DFT计算一致。该小号-顺式构象异构体,其中氟原子和氧原子位于一个顺式-periplanar模式,可能会受到两个极性原子之间的强斥力和变得不稳定。该小号-反式的2'-氟取代的苯乙酮衍生物的偏好可在药物设计中使用。