CHEMICAL AND PHOTOCHEMICAL APPROACHES TO AMINO(ARYL)SILYLENES

Generation by two different methods of silylenes stabilized by o-amino (aryl) groups is reported. The halodemetallation of difluoro- or dichl oro-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 spec ies. The silylenes, however, have been trapped with 2,3-dimethylbutadi ene. An unexpected intramolecular rearrangement to silaacenaphthene ha s been observed in the case of a six-membered ring amino(aryl) coordin ated silylene. Photolysis of amino)methyl]-2-[tris(trimethylsilyl)sily l]benzene produced, among other products, Me(3)SiSiMe(3) and the sila- ylide, which has been trapped with Et(3)SiH and dimethylbutadiene. Our mechanistic interpretation is supported by spectral observation of th e photochemically generated reaction intermediates in a 3-methylpentan e glass at low temperature.