Thermal and Photochemical Isomerization of Tetraaryl Tetrakis(trifluoromethyl)[4]radialenes
作者:Hidemitsu Uno、Ken-ichi Kasahara、Nobumasa Nibu、Shin-ichi Nagaoka、Noboru Ono
DOI:10.1021/jo990699v
日期:2000.3.1
The isomerization of tetraaryl tetrakis(trifluoromethyl)[4]radialenes was studied. When type II (all-Z) isomers of 5,6,7,8-tetraaryl-5,6,7,8-tetrakis(trifluoromethyl)[4]radialenes were heated in tetralin at 170-200 degrees C, isomerization occurred to give mixtures of four [4]radialenes in a ratio of ca. I:II:III:IV = 1:10:5:1. However, when the isomeric mixtures were heated in the solid state at the
研究了四芳基四(三氟甲基)[4] ale碳烯的异构化。当在170-200摄氏度的四氢化萘中加热5,6,7,8-四芳基-5,6,7,8-四(三氟甲基)[4] Radalenes的II型(全Z型)异构体时,给出比例为约4的四种[4] radialenes的混合物。I:II:III:IV = 1:10:5:1。但是,当异构体混合物在相同温度下以固态加热时,发生选择性异构化,从而以良好的选择性(> 91%)得到II型异构体。在光照射下,II型异构体首先异构化为四种[4]芳烃异构体的混合物(I:II:III:IV = 2:2:48:48),然后通过6pi重排为环丁[b]萘-电环反应,然后进行1,3-氢迁移。