Methyl palladium complexe

From experimental results of acceleration of CO insertion into cationic methyl-palladium complexes [Pd(CH3)(CH3CN)(P-P)]+ in the order of DPPE < DPPF < DPPP DPPB (DPPF = l,2-bis(diphenylphosphino)ethane DPPF = 1,F-bis(diphenylphosphino)ferrocene DPPP = l,3-bis(diphenylphosphino)propane DPPB = l,4-bis(diphenylphosphino)butane) the kinetic barriers to migratory insertion in [Pd(CH3)(CO)(P-P)]+ were found to decrease with increase of the P-Pd-P angle as well as the steric bulk of the diphosphine ligand [50]. 

However, formation of stable iminoacyl complexes does not always prevail in the competition reaction systems involving CO and isocyanide. Cationic methyl-palladium complexes bearing isocyanides react with CO under ambient conditions to give the corresponding acetylpalladium complexes through CO insertion and not the iminoacylpalladium complexes as shown in Scheme 7.14 [61b],... 

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