Stereoelectronic interaction and their effects on conformational preference for 2-substituted methylenecyclohexane: An experimental and theoretical investigation
Stereoelectronic interaction and their effects on conformational preference for 2-substituted methylenecyclohexane: An experimental and theoretical investigation
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DOI：
10.1021/jp8048636
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发表时间：
2008-09-18
影响因子：
2.9
通讯作者：
Tormena, Claudio F.
中科院分区：
文献类型：
--
作者：
Anizelli, Pedro R.;Vilcachagua, Janaina D.;Tormena, Claudio F.
用（3）JH（2）H（3）自旋-自旋耦合常数确定了2-取代亚甲基环己烷的构象偏好，并通过理论计算和NBO分析得到了立体电子相互作用.所研究的化合物的构象平衡可以由它们的轴向和赤道构象来表示，轴向构象在极性和非极性溶剂中是最稳定的形式。这些构象偏好归因于pi（C-C）->sigma*（C-Xax）之间的超共轭相互作用。和sigma（C-H）->sigma*（C-Xax）轨道，以及在sigma（C-H）-> n（Xeq）之间观察到的排斥空间相互作用。
Conformational preferences for 2-substituted methylenecyclohexanes were determined using (3)JH(2)H(3) spin-spin coupling constants, while stereoelectronic interactions were obtained by means of theoretical calculations and NBO analysis. The conformational equilibrium of compounds studied can be represented by their axial and equatorial conformers, the axial conformers being the most stable form in polar and nonpolar solvents. These conformational preferences were attributed to the hyperconjugative interactions between the pi(C-C)->sigma*(C-Xax). and sigma(C-H)->sigma*(C-Xax) orbitals, and the repulsive steric interaction observed between sigma(C-H)-> n(Xeq).