Ambiphilic reactivity of a ruthenaphosphaalkenyl: synthesis of P-pyrazolylphosphaalkene complexes of ruthenium(0)

Abstract

The novel ruthenaphosphaalkenyl complex [Ru{P═CH(SiMe3)}Cl(CO)(PPh3)2], prepared from [RuHCl(CO)(PPh3)3] and Me3SiC≡P, exhibits ambiphilic behavior, reacting at phosphorus with both nucleophiles and electrophiles. Its reaction with Li(pz′) or K[HB(pz′)3] (pz′ = pz, pz*) affords [Ru{η1-N:η2-P,C-P(pz′)═CH(SiMe3)}(CO)(PPh3)2], a rare example of a ruthenium(0) η2-phosphaalkene complex and the first example of a P-pyrazolylphosphaalkene. Conversely, reaction with the electrophilic PhHgCl leads to metalation at phosphorus, affording [Ru{η1-P(HgPh)═CH(SiMe3)}Cl2(CO)(PPh3)2]