Budget Amount *help |
¥3,800,000 (Direct Cost: ¥3,800,000)
Fiscal Year 1999: ¥1,800,000 (Direct Cost: ¥1,800,000)
Fiscal Year 1998: ¥2,000,000 (Direct Cost: ¥2,000,000)
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Research Abstract |
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.
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