4 research outputs found
Ruthenaphosphaalkenyls: Synthesis, Structures, and Their Conversion to η<sup>2</sup>‑Phosphaalkene Complexes
The
ruthenaÂphosphaÂalkenyls [RuÂ{Pî—»CHÂ(SiMe<sub>2</sub>R)}ÂClÂ(CO)Â(PPh<sub>3</sub>)<sub>2</sub>] (R = Me, Ph,
Tol) have been prepared in good yield by the facile hydroruthenation
of the respective phosphaÂalkynes, RMe<sub>2</sub>SiCî—ĽP,
with [RuHClÂ(CO)Â(PPh<sub>3</sub>)<sub>3</sub>]; all three compounds
have been structurally characterized in the solid state. Complemented
by DFT studies of these, and the precedent [RuÂ{Pî—»CHÂ(<sup><i>t</i></sup>Bu)}ÂClÂ(CO)Â(PPh<sub>3</sub>)<sub>2</sub>], the
phosphaÂalkenyl moieties have been established unequivocally
to behave as one-electron donors to the coordinately unsaturated,
15-electron “RuClÂ(CO)Â(PPh<sub>3</sub>)<sub>2</sub>”
fragment, corroborating an earlier demonstration of nucleophilic character
at phosphorus within the <i>tert-</i>butyl system. Notwithstanding,
the ruthenaÂphosphaÂalkenyls are shown to react with the
nucelophiles Lipz′ (pz′ = pz, pz*, pz<sup>H,CF<sub>3</sub></sup>, pz<sup>Me,CF<sub>3</sub></sup>) to afford the η<sup>1</sup>,η<sup>2</sup>-chelated pyrazolylÂphosphaÂalkene
complexes [RuÂ{η<sup>1</sup>-<i>N</i>:η<sup>2</sup><i>-P,C-</i>PÂ(pz′)î—»CHÂ(R)}Â(CO)Â(PPh<sub>3</sub>)<sub>2</sub>], which feature a three-membered metallacyclic
(Ru–C–P) core. The nature of these novel compounds is
discussed, alongside preliminary insight into the process by which
they are formed
Ruthenaphosphaalkenyls: Synthesis, Structures, and Their Conversion to η<sup>2</sup>‑Phosphaalkene Complexes
The
ruthenaÂphosphaÂalkenyls [RuÂ{Pî—»CHÂ(SiMe<sub>2</sub>R)}ÂClÂ(CO)Â(PPh<sub>3</sub>)<sub>2</sub>] (R = Me, Ph,
Tol) have been prepared in good yield by the facile hydroruthenation
of the respective phosphaÂalkynes, RMe<sub>2</sub>SiCî—ĽP,
with [RuHClÂ(CO)Â(PPh<sub>3</sub>)<sub>3</sub>]; all three compounds
have been structurally characterized in the solid state. Complemented
by DFT studies of these, and the precedent [RuÂ{Pî—»CHÂ(<sup><i>t</i></sup>Bu)}ÂClÂ(CO)Â(PPh<sub>3</sub>)<sub>2</sub>], the
phosphaÂalkenyl moieties have been established unequivocally
to behave as one-electron donors to the coordinately unsaturated,
15-electron “RuClÂ(CO)Â(PPh<sub>3</sub>)<sub>2</sub>”
fragment, corroborating an earlier demonstration of nucleophilic character
at phosphorus within the <i>tert-</i>butyl system. Notwithstanding,
the ruthenaÂphosphaÂalkenyls are shown to react with the
nucelophiles Lipz′ (pz′ = pz, pz*, pz<sup>H,CF<sub>3</sub></sup>, pz<sup>Me,CF<sub>3</sub></sup>) to afford the η<sup>1</sup>,η<sup>2</sup>-chelated pyrazolylÂphosphaÂalkene
complexes [RuÂ{η<sup>1</sup>-<i>N</i>:η<sup>2</sup><i>-P,C-</i>PÂ(pz′)î—»CHÂ(R)}Â(CO)Â(PPh<sub>3</sub>)<sub>2</sub>], which feature a three-membered metallacyclic
(Ru–C–P) core. The nature of these novel compounds is
discussed, alongside preliminary insight into the process by which
they are formed
Ambiphilic Reactivity of a Ruthenaphosphaalkenyl: Synthesis of <i>P</i>‑Pyrazolylphosphaalkene Complexes of Ruthenium(0)
The novel ruthenaphosphaalkenyl complex
[RuÂ{Pî—»CHÂ(SiMe<sub>3</sub>)}ÂClÂ(CO)Â(PPh<sub>3</sub>)<sub>2</sub>], prepared from [RuHClÂ(CO)Â(PPh<sub>3</sub>)<sub>3</sub>] and Me<sub>3</sub>SiCî—ĽP, exhibits ambiphilic
behavior, reacting at phosphorus with both nucleophiles and electrophiles.
Its reaction with LiÂ(pz′) or KÂ[HBÂ(pz′)<sub>3</sub>]
(pz′ = pz, pz*) affords [RuÂ{η<sup>1</sup>-<i>N</i>:η<sup>2</sup><i>-P</i>,<i>C-</i>PÂ(pz′)î—»CHÂ(SiMe<sub>3</sub>)}Â(CO)Â(PPh<sub>3</sub>)<sub>2</sub>], a rare example of a
ruthenium(0) η<sup>2</sup>-phosphaalkene complex and the first
example of a <i>P</i>-pyrazolylphosphaalkene. Conversely,
reaction with the electrophilic PhHgCl leads to metalation at phosphorus,
affording [RuÂ{η<sup>1</sup>-PÂ(HgPh)î—»CHÂ(SiMe<sub>3</sub>)}ÂCl<sub>2</sub>(CO)Â(PPh<sub>3</sub>)<sub>2</sub>]
Ambiphilic Reactivity of a Ruthenaphosphaalkenyl: Synthesis of <i>P</i>‑Pyrazolylphosphaalkene Complexes of Ruthenium(0)
The novel ruthenaphosphaalkenyl complex
[RuÂ{Pî—»CHÂ(SiMe<sub>3</sub>)}ÂClÂ(CO)Â(PPh<sub>3</sub>)<sub>2</sub>], prepared from [RuHClÂ(CO)Â(PPh<sub>3</sub>)<sub>3</sub>] and Me<sub>3</sub>SiCî—ĽP, exhibits ambiphilic
behavior, reacting at phosphorus with both nucleophiles and electrophiles.
Its reaction with LiÂ(pz′) or KÂ[HBÂ(pz′)<sub>3</sub>]
(pz′ = pz, pz*) affords [RuÂ{η<sup>1</sup>-<i>N</i>:η<sup>2</sup><i>-P</i>,<i>C-</i>PÂ(pz′)î—»CHÂ(SiMe<sub>3</sub>)}Â(CO)Â(PPh<sub>3</sub>)<sub>2</sub>], a rare example of a
ruthenium(0) η<sup>2</sup>-phosphaalkene complex and the first
example of a <i>P</i>-pyrazolylphosphaalkene. Conversely,
reaction with the electrophilic PhHgCl leads to metalation at phosphorus,
affording [RuÂ{η<sup>1</sup>-PÂ(HgPh)î—»CHÂ(SiMe<sub>3</sub>)}ÂCl<sub>2</sub>(CO)Â(PPh<sub>3</sub>)<sub>2</sub>]