The four isomeric bromoquinolizium bromides reacted with aryl- and heteroarylacetylenes under Sonogashira conditions. The reactions proceed with moderate-to-high yields to afford aryl- and heteroarylethynyl quinolizium cations. This is the first reported example of the Sonogashira reaction on heteroaromatic cations, and it allowed easy access to potential pi-donor pi-acceptor systems bearing cationic units.

Fused pyridine derivatives R 0450 Sonogashira Reaction on Quinolizium Cations. -The title reaction of 4 isomeric bromoquinolizium bromides with substituted acetylenes affords triisopropylsilyl-, aryland heteroarylethynyl quinolizium cations in moderate to high yields. The method is new for heteroaromatic cations. -(GARCIA, D.; CUARDO*, A. M.; ALVAREZ-BUILLA, J.; VAQUERO, J.