Ito Hideto, Itami Kenichiro
JST-ERATO, Itami Molecular Nanocarbon Project, Nagoya University, Chikusa, Nagoya 464-8602, Japan.
Chem Commun (Camb). 2019 Aug 8;55(65):9606-9609. doi: 10.1039/c9cc03510a.
Chiral organic π-conjugated molecules have been intensively investigated in the fields of chiral electronic materials and devices. Herein we report a new motif for an axially chiral 1,1'-biazulene and its π-extended derivative, in which biphenyl was annulated by the electron-rich five-membered-ring of the azulene moiety. These two compounds were unexpectedly synthesized from 2-terphenyl azulene by stepwise intermolecular and intramolecular oxidative C-H/C-H couplings. X-ray diffraction analysis revealed that the crystals of both compounds contain a pair of enantiomers. Furthermore, the axially chiral 1,1'-biazulene derivatives were successfully separated into enantiomers that exhibited clear mirror-image circular dichroism spectra up to the near-infrared region.
手性有机π共轭分子在手性电子材料和器件领域已得到深入研究。在此，我们报道了一种新型的轴向手性1,1'-联薁及其π扩展衍生物的结构单元，其中联苯被薁部分的富电子五元环稠合。这两种化合物意外地通过逐步的分子间和分子内氧化C-H/C-H偶联反应由2-三联苯薁合成。X射线衍射分析表明这两种化合物的晶体都包含一对对映体。此外，轴向手性1,1'-联薁衍生物成功地被分离为对映体，它们在近红外区域都表现出清晰的镜像圆二色光谱。
