Reactions of Manganese and Rhenium Vinylidene Complexes with Hydrophosphoryl Compounds

We studied the reactions of manganese and rhenium phenylvinylidenes Cp(CO)2M═C═C(H)Ph (Mn1 M = Mn; Re1 M = Re) with HP(O)R2 (R = C6F5, Ph, and OEt) and HP(S)Ph2, which resulted in the selective formation of η2-E-phosphorylalkene complexes Cp(CO)2M{η2-E-H[R2(O)P]C═C(H)Ph} (Mn2, Re2 R = C6F5; Mn3, Re3 R = Ph; and Mn6, Re6 R = OEt) and Cp(CO)2M{η2-E-H[Ph2(S)P]C═C(H)Ph} (Mn5, Re5). The DFT/B3LYP(6-31G*) analysis showed the model reactions of Mn1 with HP(O)Me2 and HP(O) (OMe)2 to proceed via the initial transition state Cp(CO)2{Ph(H)C═C═}Mn···HO–PR2 (TS1) where the minor PA form HO–PR2 is hydrogen-bonded to the metal, followed by stereoselective (trans- to the phenyl group) addition of the PA phosphorus atom to the Cα-vinylidene atom, which defines both the rate of the process and the anti-Markovnikov structure of the reaction product. The reactions can proceed at a relatively low content of the reactive PA form.