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

► Monophosphite complex [Rh(acetylacetonato)(CO)(P(OCH2)3CCH3)] synthesized. ► Oxidative addition of methyl iodide with rhodium(I) gives a RhIII-alkyl product. ► The RhIII-acyl results from the migratory insertion of the methyl group of the RhIII-alkyl to the carbonyl group.