Multiple C-H borylation of phenylhydrazones to boron-nitrogen analogues of benzopentalene

One-pot multiple borylation of phenylhydrazones to a series of novel boron-nitrogen analogues of benzopentalene by the cleavage of C-H bonds with PhBBr2 mediated by NEt3 has been established. The resulting BN benzopentalenes feature unique electronic structures and are luminescent both in solution and the solid state.