8,8′-Dialkyl-1,1′-biisoquinolines: preparation, absolute configuration and unexpected racemization behaviour †
作者:Hirohito Tsue、Hideyuki Fujinami、Takeshi Itakura、Ryuta Tsuchiya、Kimiko Kobayashi、Hiroki Takahashi、Ken-ichi Hirao
DOI:10.1039/a905161i
日期:——
A series of 8,8â²-dialkyl-1,1â²-biisoquinolines, in which methyl, ethyl and isopropyl groups are introduced for enhancing the transannular steric hindrance, are synthesized. The atropisomeric biisoquinolines are separated into both enantiomers, of which the absolute configurations and the optical stabilities are determined. Contrary to prior expectations, the racemization behaviour is inversely proportional to the steric size of the alkyl groups.
我们合成了一系列 8,8â²-二烷基-1,1â²-双喹啉,其中引入了甲基、乙基和异丙基基团以增强跨annular立体阻碍。异构体生物异喹啉被分离成两种对映体,并确定了它们的绝对构型和光学稳定性。与之前的预期相反,外消旋行为与烷基的立体尺寸成反比。