CREATION AND CHARACTERIZATION OF CARBENES HAVING UNUSUAL STRUCTURE

虽然已有文献报道二苯亚甲基环丙烷在溶液中经辐照可生成其异构体2，2-二苯基-1-亚甲基环丙烷，但对其机理知之甚少。本研究为2，2-二苯基环亚丁基的中间性提供了实验支持。详细的产物分析表明，除了2，2-二苯基-1-亚甲基环丙烷之外，还形成了2，2-二苯基环丁烯。在氧气中进行类似的光化学反应，也得到了2，2-二苯基环丁酮。我们对这种特殊的卡宾很感兴趣，并试图从前体中生成苯并环丁烯叉，以研究其反应性。苯并环丁烯酮的N-（2-苯基氮杂）亚胺的光解导致苯并环丁烯叉的二聚体和三聚体。在烯烃或甲醇存在下的类似光解导致形成环丙烷或甲氧基苯并环丁烯。虽然N-（2-苯基氮杂吡啶基）亚胺的稳态光解产物暗示为苯并环丁烯亚基，但即使在我们的激光闪光光解条件下，也很难得到苯并环丁烯亚基。然而，它表明，吡啶似乎捕获bensocyclobutelidene得到叶立德。

Although it has been reported that irradiation of diphenylmethylenecyclopropane in solution results in its isomer, 2,2-diphenyl-1-methylenecyclopropane, little has been known on the mechanism. The present study provides experimental support for the intermediacy of 2,2-diphenylcyclobutylidene. The detailed product analysis showed that 2,2-diphenylcyclobutene is formed in addition to 2,2-diphenyl-1-methylenecyclopropane. Similar photoreaction under oxygen afforded 2,2-diphenylcyclobutanoneas well.In contrast to parent phenylcarbene, benzocyclobutenylidene has never been observed directly. We are interested in this particular carbene and have attempted to generate benzocyclobutenylidene from precursors in order to investigate its reactivity.Photolysis of N-(2-phenylazyridyl)imine of benzocyclobutenone results in dimers and trimers of benzocyclobutenylidene. Similar photolysis in the presence of alkenes or methanol leads to formation of cyclopropanes or methoxybenzocyclobutene. It is most likely that benzocyclobutenylidene is involved in the photoreactions.Although the steady-state photolyses of the N-(2-phenylazyridyl)imine afford products suggestive of benzocyclobutenylidene, it is elusive even under our laser flash photolytic conditions. However, it is shown that pyridine seems to trap bensocyclobutelideneto give a ylide.