Catching the First Oligomerization Event in the Catalytic Formation of Polyaminoboranes: H3B•NMeHBH2•NMeH2 Bound to Iridium

We report the first insertion step at a metal center for the catalytic dehydropolymerization of H3B center dot NMeH2 to form the simplest oligomeric species, H3B center dot NMeHBH2 center dot NMeH2, by the addition of 1 equiv of H3B center dot NMeH2 to [Ir(PCy3)(2)(H)(2)(eta(2)-H3B center dot NMeH2)] [BAr4F] to give [Ir(PCy3)(2)(H)(2)(eta(2)-H3B center dot NMeHBH2 center dot NMeH2)] [BAr4F]. This reaction is also catalytic for the formation of the free linear diborazane, but this is best obtained by an alternative stoichiometric synthesis.