Conversion of Transition-Metal Complexes with Stannyl and Phosphenium Ligands into Those with Stannylene and Phosphine Ligands by Alkyl Migration from Sn to P

Treatment of Cp(CO)(SnMe₃)Fe{PN(Me)CH₂CH₂NMe(OR)} (R = Me, Et) with Me₃SiOSO₂CF₃ (TMSOTf) yields [Cp(CO)(SnMe₂)Fe{PN(Me)CH₂CH₂NMe(Me)}]OTf (2), showing that P−OR bond cleavage and Me migration from Sn to P take place. The X-ray analysis of 2 reveals that this is a stannylene complex of iron stabilized by both an OTf^- anion and an N atom in the phosphorus ligand. In solution, 2 is in equilibrium with an OTf-dissociated species.