Cyclopenta-fused B2N2-pyrene (B2N2CP) and diazaborepin (NBNM) have been accomplished from a same bi-indoles pre-cursor in three steps. Borylative cyclization of bi-indoles precursor with 2.0 equiva-lents BCl3 afforded NBNM as the major product, whereas increasing the BCl3 to 3.0 equivalents deliv-ered B2N2CP as the major product. Both B2N2CP and NBNM are highly emissive in solution. B2N2CP emit in deep blue region, while NBNM emit in the region of blue to green. Moreover, we found that flu-oride anion addition to the solution of B2N2CP and NBNM led to great change of their absorption and emission spectra.

We have developed an efficient synthetic route of parental ullazine in three steps from commercially available synthons with overall yield of 53%. The single crystal X-ray structure of parental ullazine was studied in detail. Parental ullazine core can be functionalized either by late-stage Vilsmeier-Haack formylation/condensation sequence or by C-N cross-coupling with a pre-installed bromine. Pre-liminary results show that the condensation of CHO-substituted ullazine (U-CHO) gave a novel imidazole substituted ullazine. The brominated ullazine (U-Br) can undergo Buchwald-Hartwig cross-coupling smoothly, resulting a carbazole substituted ullazine. In ad-dition, parental ullazine showed redshifted absorption and emission spectra as compared to its isoelectronic isomer pyrene, and no excimer formation in higher concentration.