A fast way to fluorescence: a fourfold domino reaction to condensed polycyclic compounds.

A fast and efficient palladium-catalyzed fourfold domino Sonogashira/double-carbopalladation/CH-activation reaction that converts simple aromatic systems into complex polycyclic hydrocarbons has been developed. A number of substituted products has thus been prepared in yields up to 89 %. The structural assignment has been confirmed by using single-crystal X-ray crystallography. The products show intriguing fluorescence activity and thus might serve as chemical sensors or fluorescent imaging dyes.