Abstract: Heteroaromatic compounds are among the most important heterocyclic compounds. Olefinated aromatic heterocyclic compounds are important intermediates used not only as building blocks in the synthesis of natural products but also as key structural units of compounds with interesting biological activity. In this study, a series of olefinated aromatic heterocyclic compounds were prepared by palladium-catalyzed olefination via cross dehydrogenative coupling of C—H bonds. The effects of various conditions[5%(molar fraction) Pd(OAc)₂, 60 ℃, 24 h] on the reaction were investigated by HPLC analysis. Their structures were determined by UV spectra, proton magnetic resonance and single crystal X-ray diffraction. The reaction was highly region- and stereoselective, giving trans-olefins predominantly by solvent controlled(AcOH/Ac₂O), and its reaction mechanism was discussed.

Key words: Aromatic heterocyclic compound, Olefination, Cross dehydrogenative coupling, X-Ray single crystal diffraction