Chemical and photochemical approaches to amino(aryl) silylenes

Article abstract of DOI:10.1016/0022-328X(94)88029-8

Generation by two different methods of silylenes stabilized by o-amino(aryl) groups is reported.The halodemetallation of difluoro- or dichloro-silanes with Li metal or lithium-naphthalene gave the same product, a stabilized sila-ylide (hypercoordinated silylene).Intramolecular Lewis base stabilization is not sufficient to isolate a monomeric species.The silylenes, however, have been trapped with 2,3-dimethylbutadiene.An unexpected intramolecular rearrangement to silaacenaphthene has been observed in the case of a six-membered ring amino(aryl) coordinated silylene.Photolysis of o-1-<(N,N-dimethylamino)methyl>-2-benzene produced, among other products, Me3SiSiMe3 and the sila-ylide, which has been trapped with Et3SiH and dimethylbutadiene.Our mechanistic interpretation is supported by spectral observation of the photochemically generated reaction intermediates in a 3-methylpentane glass at low temperature. Key words: Silylene; Sila-ylide; Amino-aryl; Alkali metals; Stabilization; Photochemistry