Investigations of the Reaction of HB(pin) with Tris(amido) Y(III) Complexes

Transmetallation, or transfer of a group between metals or metalloids, is arguably the most understudied elementary organometallic step, especially with early transition metal complexes. In this work, the reactivity of the organoborane, HB(pin), with yttrium complexes bearing a tris(amido) redox-active ligand was investigated. B–O bond cleavage was observed instead of the expected B–H bond cleavage that would result from transmetallation. Additionally, the tris(amido) ligand was transferred from yttrium to boron. New boron complexes (2) and (3) were synthesized and characterized and an intermediate Y–B complex (4) featuring the B–O bond cleavage is also reported. This work demonstrates the incompatibility of HB(pin) as a transmetallating reagent for yttrium complexes bearing a tris(amido) ligand.