A Combined Experimental and Theoretical Study on the Conformation of Multiarmed Chiral Aryl Ethers
作者:Tadashi Mori、Stefan Grimme、Yoshihisa Inoue
DOI:10.1021/jo071216n
日期:2007.8.31
Four series of multiarmed chiral aryl ethers carrying two, three, five, or eight side-chains on a variety of aromatic core molecules (2−5) were prepared. The structure and conformation of 2 and 3 (in the solid state) were determined by the X-ray crystallographic analyses. While a pair of alternated (anti) conformers (i.e, up−down and down−up) were found in the crystal of 2, three side-arms in 3 were
四个系列多臂手性芳基醚上的各种芳核的分子带有两个,三个,五个或八个侧链的(2 - 5)中制备。通过X射线晶体学分析确定2和3(固态)的结构和构象。而一对交替(抗)构象异构体(即,上下和下向上)的晶体中发现2,在三个侧臂3在相同方向上对齐,得到ç 3 -对称顺式构象。通过色散校正的密度泛函(DFT-D)计算得出的结果表明,六个反抗构象中的两个和两个2的同构构象异构体中的两个在能量上最重要。通过X射线分析发现,两种计算的抗规整剂结构与固态发现的结构非常吻合。同样,在DFT-DB-LYP / TZVP级别上优化了syn - 3,完全交替4和C 5-对称5的相关构象。该侧臂在结构和构象2 - 5中溶液温度依赖性的进一步研究1H NMR和紫外可见光谱。此外,进行了对比实验和理论CD光谱研究,以阐明溶液中热力学不稳定的次要异构体的作用。在不同温度下观察到的2和3的CD光谱变化完全不同,而亲本手性芳烃1以及4和5则仅显示1