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.