Tormena Cláudio F
Institute of Chemistry, University of Campinas, PO Box 6154, 13083-970 Campinas, Sao Paulo, Brazil.
Prog Nucl Magn Reson Spectrosc. 2016 Aug;96:73-88. doi: 10.1016/j.pnmrs.2016.04.001. Epub 2016 Apr 22.
This review deals with conformational analysis in small organic molecules, and describes the stereoelectronic interactions responsible for conformational stability. Conformational analysis is usually performed using NMR spectroscopy through measurement of coupling constants at room or low temperature in different solvents to determine the populations of conformers in solution. Quantum mechanical calculations are used to address the interactions responsible for conformer stability. The conformational analysis of a large number of small molecules is described, using coupling constant measurements in different solvents and at low temperature, as well as recent applications of through-space and through-hydrogen bond coupling constants JFH as tools for the conformational analysis of fluorinated molecules. Besides NMR parameters, stereoelectronic interactions such as conjugative, hyperconjugative, steric and intramolecular hydrogen bond interactions involved in conformational preferences are discussed.
本综述涉及小分子有机化合物的构象分析，并描述了决定构象稳定性的立体电子相互作用。构象分析通常通过核磁共振光谱法进行，即在不同溶剂中于室温或低温下测量耦合常数，以确定溶液中构象异构体的数量。量子力学计算用于研究决定构象异构体稳定性的相互作用。本文描述了大量小分子的构象分析，包括在不同溶剂和低温下的耦合常数测量，以及最近将空间耦合和氢键耦合常数JFH用作氟化分子构象分析工具的应用。除了核磁共振参数外，还讨论了构象偏好中涉及的共轭、超共轭、空间和分子内氢键等立体电子相互作用。
