Multiple sonogashira reactions of polychlorinated molecules. Synthesis and photophysical properties of the first pentaalkynylpyridines

Org Lett. 2011 Apr 1;13(7):1618-21. doi: 10.1021/ol2000183. Epub 2011 Feb 28.

Abstract

Hitherto unknown pentaalkynylpyridines have been prepared in high yields by Sonogashira cross-coupling reactions of pentachloropyridine. Their photophysical properties were studied and compared to those of penta- and hexaalkynylbenzenes which were efficiently prepared by the first Sonogashira reactions of pentachlorobenzene and hexachlorobenzene. The pentaalkynylpyridines show promising fluorescence properties because of their high quantum yields.