71504-60-4Relevant academic research and scientific papers
NMR and kinetic studies on phosphine-induced coupling of (η3-methallyl) (acetylacetonato) palladium and -platinum: Uniquely facile C-C bond formation with an (η3-allyl) platinum complex
Kurosawa, Hideo,Ishii, Koichiro,Kawasaki, Yoshikane,Murai, Shinji
, p. 1756 - 1760 (2008/10/08)
Low-temperature 1H NMR measurements on a mixture of M(η3-CH2CMeCH2) (acac) (1, M = Pt; 2 M = Pd) and 2 equiv of PPh3 or 1 equiv of (Z)-Ph2PCH=CHPPh2 in dichloromethane gave unambiguous evidence for the formation of the ion pair [M(η3-CH2CMeCH2)(PR3) 2]+[CH(COMe)2]-. On warming these solutions to room temperature, the formation of moderate to good yields of the C-C coupling product CH2-CMeCH2CH(COMe)2 and zerovalent metal-phosphine complexes occurred. The kinetics of this process were examined by means of UV-visible spectroscopy to give evidence for almost exclusive participation of [M(η3-CH2CMeCH2)(PR3) 2]+[CH(COMe)2]- (M = Pt, PR3 = PPh3; M = Pd, PR3 = 1/2Ph2PCH2CH2PPh2) in the rate-determining step. The collapse of these ion pairs to the product was estimated to be faster in benzene than that in dichloromethane, the latter in turn having been found to be faster than that in acetonitrile/THF. The platinum analogue 1 reacted more slowly than the palladium analogue 2, but the rate difference was not so remarkable as was the case in the reductive elimination of dialkylmetal complexes of these two metals. The origin of this unique metal effect found in the reaction of 1 and 2 is discussed in terms of the nature of the η3-allyl-metal bonding.
