The iron complex [FeH(CO) (PNP)]
(PNP = N(CH<sub>2</sub>CH<sub>2</sub>P<i>i</i>Pr<sub>2</sub>)<sub>2</sub>) is a highly
active catalyst for ammonia borane dehydrocoupling at room temperature.
Mainly linear polyaminoborane is obtained upon release of 1 equiv
of H<sub>2</sub>. Mechanistic studies suggest that both hydrogen release
and B–N coupling are metal-catalyzed and proceed via free aminoborane.
Catalyst deactivation results from reaction with free BH<sub>3</sub> that is formed by aminoborane rearrangement. Importantly, borane
trapping with a simple amine allows for the observation of a TON that
is unprecedented for a well-defined base metal catalyst
