T. Lehotkay et al., REACTIONS OF CATIONIC ETA(2)-PHOSPHINOCAR BENE COMPLEXES OF TUNGSTEN WITH ANIONIC NUCLEOPHILES, Journal of organometallic chemistry, 520(1-2), 1996, pp. 59-62
eta(2)-Phosphinocarbene complexes of tungsten show a different behavio
ur towards anionic nucleophiles. The cationic eta(2)-phosphinocarbene
complex [Cp(CO)(2)<(W=C(Tol)PP)over bar>h(2)][BPh(4)] reacts with the
thiophenolate anion PhS(-) via carbonyl substitution, whereas the corr
esponding trimethylphosphine substituted carbene complex [Cp(CO)(PMe(3
))<(W=C(Tol)PP)over bar>h(2)][BF4] adds the cyclopentadienyl anion at
the carbene carbon atom. A third reaction pathway is observed on treat
ing [Cp(CO)(2)<(W=C(Me)PP)over bar>h(2)][BPh(4)] with lithium diethyla
mide, providing a neutral eta(2)-phosphinovinyl complex.