Hydroboration and Hydrosilylation of a Molybdenum–Nitride Complex Bearing a PNP-Type Pincer Ligand

Hydroboration
and hydrosilylation of a molybdenum–nitride
complex, prepared from the direct cleavage of the bridging dinitrogen
coordinated to the two molybdenum atoms of a dinitrogen-bridged dimolybdenum
complex, with pinacolborane and diphenylsilane give the corresponding
borylimide–hydride and silylimide–hydride complexes,
respectively. DFT calculations support a proposed reaction pathway
of hydroboration toward the molybdenum–nitride complex to afford
the corresponding borylimide–hydride complex. The reaction
of the molybdenum–nitride complex with an excess amount of
catecholborane under atmospheric nitrogen gas affords up to 2 equiv
of ammonia based on the molybdenum atom after hydrolysis of the reaction
mixture. This result indicates that a superstoichiometric reaction
to afford the corresponding borylamine proceeds via hydroboration
of a molybdenum–nitride complex as a key step.