DIE CHEMIE DER SCHWEREN CARBEN-ANALOGEN R2M, M=Si, Ge, Sn. XI. REAKTIONEN VON THERMISCH ERZEUGTEM DIMETHYLSILYLEN MIT C-C-MEHRFACHBINDUNGEN

Article abstract of DOI:10.1016/0022-328X(86)80390-4

Phenylated alkynes from 1,4-disila-cyclohexadienes (VIII-X) with thermally generated Me2Si (200 deg C).Bulky substituents (CMe3, SiMe3) prevent the addition.The strained cycloalkyne 3,3,6,6-tetramethyl-1-thia-cycloheptyne-4 (XI), however, yields the known silirene XII (2,2,6,6,8,8-hexamethyl-8-sila-4-thia-bicyclo<5.1.0^Δ1.7>octane); its transformation to the 1,4-disila-cyclohexadiene is prevented by steric effects.Thermally stable 1,3-dienes give, depending on their substitution pattern, 1-silacyclopentenes-2 or -3.A mechanism is proposed giving the observed products via an initial 1,2-addition.