MECHANISM OF ISOCYANIDE INSERTION INTO THE METHYL-IRON BOND OF [FE(CO)2L2(CNR)CH3]BPH4

The equilibrium between alkyl [Fe(CO)2L2(CNR)CH3]BPh4 (1) and eta(2)-iminoacyl [Fe(CO)2L2(eta(2)-C(CH3) = NR)]BPh4 (2) complexes (L = P(CH3)3, R = C(CH3)3), catalyzed by anions, was studied using selected monolabeled (CO)-C-13 derivatives. Scrambling of (CO)-C-13 between monolabeled alkyl and eta(2)-iminoacyl complexes demonstrates that the anion catalysis only affects the methyl migration, and the coordination of nitrogen to iron is not concerted with it.