Divergent Oxidative Rearrangements in Solution and in a Zeolite: Distal vs Proximal Bond Cleavage of Methylenecyclopropanes

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• 作者：Hiroshi Ikeda ; Tsuyoshi Nomura ; Kimio Akiyama ; Mitsuhiro Oshima ; Heinz D. Roth ; Shozo Tero-Kubota ; and Tsutomu Miyashi
• 刊名：Journal of the American Chemical Society
• 出版年：2005
• 出版时间：October 19, 2005
• 年：2005
• 卷：127
• 期：41
• 页码：14497 - 14504
• 全文大小：281K
• 年卷期：v.127,no.41(October 19, 2005)
• ISSN：1520-5126

文摘

Irradiation of 9,10-dicyanoanthracene (DCA) or p-chloranil in the presence of E-1-benzylidene-2-phenylcyclopropane (E-5) in CH₂Cl₂ causes E-5 to undergo methylenecyclopropane rearrangement. Anadduct, Z-7, between DCA and 5 firmly supports the involvement of a bifunctional trimethylenemethaneradical cation. In contrast, incorporation of E-5 into HZSM-5 produces trans,trans-1,4-diphenyl-1,3-butadieneradical cation sequestered in the HZSM-5 interior, tt-8⁺@HZSM-5, identified by ESR and diffuse reflectancespectroscopy. In addition, low yields of tt-8, its cis,trans-isomer (ct-8), and 1-phenyl-1,2-dihydronaphthalene(9) were isolated from the supernatant solution. The sharp contrast between the photoinduced electron-transfer reaction with photosensitizers in solution and the spontaneous reaction with redox-active acidiczeolite offers the prospect of further zeolite-induced regiodivergent reactions in a range of additionalsubstrates.