Thermolysis of 6-aryl-1,5-diazabicyclo[3.1.0]hexanes in the presence of 2-alkyl-3-phenylcyclopropenones gives fused polycyclic systems of the 4a,7b-diazacyclopenta[cd]inden-7-one series as a result of addition of two cyclopropenone molecules and extrusion of CO molecule. The first step of the process is characterized by 100% regioselectivity, leading to the adduct with vicinal arrangement of the aryl groups, while the regioselectivity of the second step is likely to be determined by spatial interactions between substituents in the cyclopropenone molecule and trimethylene bridge of the diazabicyclohexane. Steric hindrances in the second step could eliminate formation of stable products.
6- 芳基-
1,5-二氮杂双环[3.1.0]己烷在 2-烷基-3-苯基
环丙烯酮存在下发生热解,产生 4a,7b-二氮杂环戊并[cd]
茚-7-酮系列的融合多环体系,这是两个
环丙烯酮分子相加和 CO 分子挤出的结果。该过程第一步的特点是具有 100% 的区域选择性,可产生芳基邻接排列的加合物,而第二步的区域选择性可能取决于
环丙烯酮分子中的取代基和二氮杂双
环己烷的三亚甲基桥之间的空间相互作用。第二步中的立体阻碍可能会导致无法形成稳定的产物。