Skeletal　editing　of　N-heterocycles　has　recently　received　considerable　attention,　and　the　introduction　of　boron　atom　into　heterocycles　often　results　in　positive　property　changes.　However,　direct　enlargement　of　N-heterocycles　through　boron　atom　insertion　is　rarely　reported　in　the　literature.　Here,　we　report　a　N-heterocyclic　editing　reaction　through　the　combination　boron　atom　insertion　and　C−H　borylation,　accessing　the　fused-BN-heterocycles.　The　synthetic　potential　of　this　chemistry　was　demonstrated　by　substrate　scope　and　late-stage　diversification　of　products.　©　2024　Wiley-VCH　GmbH.