Boraphosphaalkene Synthesis via Phosphaalkyne Insertion into 9‑Borafluorene

The reaction of 1-adamantylphosphaalkyne with 9-phenyl-9-borafluorene resulted in the insertion of the PC unit into the endocyclic B–C bond, generating a seven-membered 1,3-boraphosphaalkene. The mechanism was investigated computationally, indicating that the reaction proceeds via a bond metathesis pathway.