Treatment of lithium silenolates, (Me3Si)(2)=C(OLi)R-1 (1; R-1 = t-Bu, Ad,
Mes), with phenyl-substituted acetylenes, PhC=CR2 (R-2 = Ph, Me), produced
lithium ethenylsilenolates, Ph-(Me3Si)C=CR2(Me3Si)Si=C(OLi)R-1,R- cleanly.
The ethenylsilenolates thus produced reacted readily with H2O and Mel to gi
ve Si-substitution products in good yield. In contrast, they underwent O-si
lylation with Et3SiCl to give 2-siladiene derivatives which were characteri
zed by their NMR spectra.