99341-38-5Relevant academic research and scientific papers
Nucleophilic attack on carbon monoxide in carbonyl phosphine complexes of rhodium(I) and ruthenium(II): A novel route to complexes of rhodium(-I)
Johnston, Gregory G.,Hommeltoft, Sven I.,Baird, Michael C.
, p. 1904 - 1909 (2008/10/08)
Reaction of [Rh(CO)2(triphos)]PF6 (triphos = MeC(CH2PPh2)3) with sodium borohydride in CD2Cl2 results in the formation of the hydride RhH(CO)(triphos) and the formyl complex Rh(HCO)(CO)(triphos). In contrast, treatment of [Rh(CO)2(triphos)]PF6 with excess methyllithium in THF results in the formation of the rhodium(-I) complex Li[Rh(CO)(triphos)]. The mechanism of this unusual reaction appears to involve (i) nucleophilic attack of MeLi on a carbonyl carbon of [Rh(CO)2(triphos)]PF6 to yield the acetyl complex Rh(MeCO)(CO)(triphos), (ii) attack by a second mole of MeLi on the acetyl group to produce the complex Li[Rh(Me2CO)(triphos)], and (iii) elimination of acetone to form product. In the presence of excess MeLi, the acetone reacts further to form tert-butoxide, which is also detected in the reaction mixture. The rhodium(-I) complex Li[Rh(CO)(triphos)] reacts with proton sources to yield the hydride RhH(CO)(triphos), with alkyl and acyl halides to form the alkyl complexes RhR(CO)(triphos) (R = Me, Et, Ph, MeCO), with trimethyltin chloride to form Rh(SnMe3)(CO)(triphos), and with CO to form Li[Rh(CO)2(η2-triphos)], with a pendant phosphine. The complex [Ru(CO)3(triphos)][AlCl4]2 can be synthesized by treating [RuCl-(CO)2(triphos)]Cl with AlCl3 under an atmosphere of CO. The dicationic complex [Ru(CO)3(triphos)]2+ is very susceptible to nucleophilic attack at CO and reacts with ethanol, water, and NaBH3CN to form the alkoxycarbonyl complex [Ru(CO2Et)(CO)2(triphos)]+, the hydride complex [RuH(CO)2(triphos)]+ (presumably via [Ru(CO2H)(CO)2(triphos)]+), and the formyl complex [Ru(HCO)(CO)2(triphos)]+, respectively.
