REACTIVITY OF A CATIONIC TRIRUTHENIUM HYDRIDOALKENYLCARBONYL CLUSTER COMPLEX TOWARD NUCLEOPHILIC-REAGENTS - CARBONYL SUBSTITUTION VERSUS ALKENE ELIMINATION-REACTIONS

The reactions of the cationic hydridoalkenyl cluster complex [Ru-3(mu- H)(mu(3)-ampy)(mu-PhC=CHPh)(CO)(8)][BF4] (1) (Hampy=2-amino-6-methylpy ridine) with neutral and anionic nucleophiles have been studied. Compl ex 1 reacts with different amounts of triphenylphosphine to replace CO giving u-H)(mu(3)-ampy)(mu-PhC=CHPh)(PPh(3))(CO)(7)][BF4] (two isomer s), )(mu(3)-ampy)(mu-PhC=CHPh)(PPh(3))(2)(CO)(6)][BF4] and )(mu(3)-amp y)(mu-PhC=CHPh)(PPh(3))(3)(CO)(5)][BF4] (two isomers). Analogous resul ts are obtained using tri-4-tolylphosphine. The reaction of compound 1 with two equivalents of bis(diphenylphosphino)methane (dppm) induces the reductive elimination of cis-stilbene, yielding [Ru-3(mu(3)-ampy)( mu-dppm)(dppm)(CO)(7)][BF4]. Complex 1 undergoes deprotonation upon tr eatment with NaOMe to give [Ru3(mu(3)-ampy)(mu-PhC=CHPh)(CO)(8)]. Howe ver, a similar reaction with NaOH yields cis-stilbene and the neutral hydride [Ru-3(mu-H)(mu(3)-ampy)(CO)(9)].