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Brightening Up Circularly Polarized Luminescence of [6]Helicenes by Fusion with BN-Heterocycles

Min Wang1, Meng-Yuan Zhang2, Cui-Hua Zhao1

  • 1School of Chemistry and Chemical Engineering, Shandong University, Jinan 250100, P. R. China.

Organic Letters
|February 20, 2025
PubMed

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Halogenation is another class of electrophilic addition reactions where a halogen molecule gets added across a π bond. In alkynes, the presence of two π bonds allows for the addition of two equivalents of halogens (bromine or chlorine). The addition of the first halogen molecule forms a trans-dihaloalkene as the major product and the cis isomer as the minor product. Subsequent addition of the second equivalent yields the tetrahalide.
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Cycloheptatriene is a neutral monocyclic unsaturated hydrocarbon that consists of an odd number of carbon atoms and an intervening sp3 carbon in the ring. The three double bonds in the ring correspond to 6 π electrons, which is a Huckel number, and therefore satisfies the criteria of 4n + 2 π electrons. However, the intervening sp3 carbon disrupts the continuous overlap of p orbitals. As a result, cycloheptatriene is not aromatic.
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