Influence of Extended Conjugation on Photophysical/Electronic Properties and Photoelimination of BN-Heterocycles

A 1,1-hydroboration reaction was used successfully to create brominated BN-heterocyclic compounds, which are amenable to Stille coupling reactions for the construction of new BN-heterocyclic compounds, including a new polymeric BN-heterocycle that has an extended π-conjugated backbone. The conjugated backbone of the new BN-heterocycles was found to have a great influence on the photophysical and electronic properties of this class of compounds. In addition, the photoelimination reactivity of the new BN-heterocycles was also found to be greatly dependent on the extent of the conjugated backbone. Several new 1,2,4-triazole-fused boranaphthalenes have been obtained successfully via photoelimination.