Adducts of Mn and Re vinylidenes with P-OR nucleophiles: Hydrolysis rather than the intramolecular Michaelis-Arbuzov rearrangement

The reactions of vinylidene complexes S(cyrillic)r(cyrillic)(CO)2Mn = C=C(H)Ph (Mn1) and Cp(CO)2Re = C=C(H)Ph (Re1) with P-OR nucleophiles P(OR)R'R" (OR = R' = R" = OMe, OEt, OPri, OPh; OR = OEt, R' = R" = Ph; OR = R' = OEt, R" = Ph) proceed as nucleophilic addition to the Cα vinylidene atom to initially afford zwitter-ionic complexes Z-S(cyrillic)r(cyrillic)(CO)2M--C[+P(OR)R'R"] = C(H)Ph which were identified by spectroscopic methods and, in some cases, their molecular structures were confirmed by X-ray diffraction. These adducts are extremely sensitive to water and hydrolyzed by water traces to afford the corresponding η 2-phosphorylalkene complexes Cp(CO)2M(η2-E-HC[P(O)R'R"] = C(H)Ph). The isotopic label experiments with D2O and H2 18O showed the hydrolysis to proceed with the phosphorus-oxygen bond cleavage and binding of the water hydrogen to the carbon atom bearing the > P=O group. © 2017.