7-Silabicyclo octadiene

Evidence for additional silene-to-silylene isomerizations on simple systems is now available. Thus the pyrolysis of a silabicyclo[2.2.2]octadiene precursor for 1-chlorosil-ene229 produces a mixture of matrix-isolated 1-chlorosilene and chloromethylsilylene. In this instance the thermal rearrangement of the silene to the silylene is probably facilitated by the increased exothermicity of the reaction, since halogenated silylenes are particularly stable (equation 95). 

Photolysis of the silabicyclo[2.2.2]octadiene (51) in cyclohexane with methanol, methanoW, or methoxytrimethylsilane as trapping agents, gave (52 R = H, D, TMS) by novel ring-closures of the... 

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