J. Ostermeier et al., AMPHIPHILIC QUALITIES OF ETA(2)-PHOSPHINO CARBENE COMPLEXES OF TUNGSTEN, Journal of organometallic chemistry, 491(1-2), 1995, pp. 283-289
eta(2)-Phosphinocarbene complexes of tungsten containing a trimethyl-p
hosphine ligand show an amphiphilic behavior. With the Lewis acid SMe(
+) an electrophilic attack occurs at the metal-carbon double bond to g
ive 1-tungsta-2-phospha-4-thia-bicyclo[1.1.0]butane complexes. On the
contrary the Lewis base, PMe(3), adds at the carbene carbon atom to yi
eld a cationic trimethylphosphoraneylidene complex. However, treatment
of hosphino)methylcarbene]-tungsten-tetraphenylborate with the less n
ucleophilic triethylamine causes deprotonation at the methyl group pro
viding entadienyl)-eta(2)-diphenylphosphinovinyltungsten.