Scope and mechanism of nitrile dihydroboration mediated by a β-diketiminate manganese hydride catalyst.

The manganese hydride dimer, [(2,6-iPr(2)PhBDI)Mn(mu-H)](2), was found to mediate nitrile dihydroboration, rendering it the first manganese catalyst for this transformation. Stoichiometric experiments revealed that benzonitrile insertion affords [(2,6-iPr(2)PBDI)Mn(mu-NCHC6H5)](2) en route to N,N-diborylamine formation. Density functional theory calculations reveal the precise mechanism and demonstrate that catalysis is promoted by monomeric species.