Breaking Bonds at Tin(II): Reductive or Oxidative Addition?

Here, the addition of H─H, Be─Be, B─B, and B─H bonds to SnII is studied by experimental and theoretical means. We report the first examples of B─B and Be─Be bond additions to a main group metal centre, along with the first example of borazine B─H bond addition to any element of the Periodic Table. Quantum chemical calculations suggest that the classification of these reactions as prototypical “oxidative” addition processes may be misleading and that a more nuanced description is warranted.