Direct C-H electrophilic borylation with (C 6 F 5 ) 2 B-NTf 2 to generate B-N dibenzo[ a , h ]pyrenes.

The borylation of aryl substituted pyridines is an effective way of preparing B-N doped conjugated organic frameworks. Trihaloborane Lewis acids are often employed for this protocol, and may require further functionalization to replace the remaining halides on boron. We report a new, fully characterized, electrophilic borylating agent, (C 6 F 5 ) 2 B(κ 2 -NTf 2 ), that smoothly incorporates a -B(C 6 F 5 ) 2 unit into the model substrate 2-phenylpyridine. To demonstrate its utility in preparing more complex B-N doped structures, we use it to prepare seven examples of the 6a,13a-diaza-7,14-dibora-dibenzo[ a , h ]pyrene framework, with substituents of varying donor properties. The structural, redox, and photophysical properties of this new family of B-N doped polycyclic hydrocarbon compounds were probed experimentally and computationally.