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.