Oxidative addition of methyl iodide to [Rh(CH3COCHCOCH3)(CO)(P(OCH2)3CCH3)]

The reaction rate of the oxidative addition and the following CO insertion step of methyl iodide with [Rh(acac)(CO)(P(OCH2)3CCH3)] is determined. The key finding is that while [Rh(acac)(CO)(P(OCH2)3CCH3)] oxidatively adds methyl iodide ca 300 times faster than the Monsanto catalyst, the CO insertion step is much slower. However, the rate-determining step of the oxidative addition reaction of the phosphorus-containing acetylacetonato-rhodium(I) complex, the carbonyl insertion step, is still in the same order or faster than the rate-determining oxidative addition step of iodomethane to [Rh(CO)2I2]−.