• heterocycles
• organic synthesis
• cross-couplings
• CPL
• chiroptical properties

Heteroaromatic-based π-conjugated systems represent promising scaffolds for developing novel chiral chromophores, which are attractive starting materials for the preparation of several optoelectronic devices such as Circularly Polarized Organic Light-Emitting Diodes (CP-OLEDs) and CP-laser. The presence of chiral elements in the starting material may result in the formation of chiral supramolecular architectures and ultimately affect the electronic properties of the compound in the solid state.
A potential approach for introducing chirality in π-conjugated molecules consists in decorating the chromophore with enantiopure moieties derived from the chiral pool.

Based on this strategy, in this work we synthesized several imidazole- and pyrazine-based chromophores, decorated with (S)-β-citronellol as the chiral aliphatic moiety. The synthetic strategies involved palladium-catalyzed cross-coupling reactions as the most suitable approach for the preparation of imidazole and pyrazine π-conjugated scaffolds. (S)-β-citronellol was introduced in the last step of the synthesis, thus reducing the waste of this enantiopure substrate. Once the target chromophores were synthesized, an extensive spectroscopic characterization was conducted both in solution and in thin films.