作者:Gebhard Haberhauer、Christina Tepper、Christoph Wölper、Dieter Bläser
DOI:10.1002/ejoc.201300087
日期:2013.4
Biphenyl derivatives with small substituents in the ortho and ortho′ positions are called tropos. Due to the low rotation barrier around the C–C bond connecting the two phenyl units, the isolation of only one conformer is not possible; thus they are conformationally unstable. Using DFT calculations, we were able to show that using a suitable peptidic bridging unit, biphenyl systems can become conformationally
在邻位和邻'位具有小取代基的联苯衍生物称为对苯。由于连接两个苯基单元的 C-C 键周围的旋转势垒较低,因此不可能仅分离一种构象异构体;因此它们在构象上不稳定。使用 DFT 计算,我们能够证明使用合适的肽桥接单元,联苯系统可以变得构象稳定。这种稳定化应该与邻位和邻位'位置的取代基类型无关。一些提议的联苯衍生物已成功合成并在溶液和固态下进行研究。记录的 VT-NMR、2D-NMR 和 CD 光谱表明所有联苯衍生物都表现出 P 构象。固态联苯衍生物的结构证实了对 P 构象的偏好。