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)(SnMe<sub>3</sub>)Fe{PN(Me)CH<sub>2</sub>CH<sub>2</sub>NMe(OR)} (R = Me, Et) with Me<sub>3</sub>SiOSO<sub>2</sub>CF<sub>3</sub> (TMSOTf) yields [Cp(CO)(SnMe<sub>2</sub>)Fe{PN(Me)CH<sub>2</sub>CH<sub>2</sub>NMe(Me)}]OTf (<b>2</b>), showing that P−OR bond cleavage and Me migration from Sn to P take place. The X-ray analysis of <b>2</b> reveals that this is a stannylene complex of iron stabilized by both an OTf<sup>-</sup> anion and an N atom in the phosphorus ligand. In solution, <b>2</b> is in equilibrium with an OTf-dissociated species.