An aim of organic synthesis is to find straightforward synthetic routes towards natural products or functional materials. Therefore, the development of reactions that start from simple molecules but result in complex products is desirable. To this end, domino reactions, which combine several reaction steps into one process and can efficiently afford complex products without any purification of intermediates, are of increasing interest.

Lutz F. Tietze and co-workers, Georg-August-Universität, Göttingen, Germany, synthesized of condensed polycyclic compounds 3 by a fourfold two-component domino process using a diyne as one of the starting materials. This process includes a Sonogashira reaction, two carbopalladations, and a C–H activation starting from substrates of type 1 and 2. A broad range of substrates could be transformed in good yields to provide polycyclic compounds that show strong fluorescence activity.

The researchers suggest that the products of this domino reaction could serve as chemical sensors or fluorescent imaging dyes. 

• A Fast Way to Fluorescence: A Fourfold Domino Reaction to Condensed Polycyclic Compounds
  Lutz F. Tietze, Christoph Eichhorst, Tim Hungerland, Markus Steinert
  Chem. Eur. J. 2014.
  DOI: 10.1002/chem.201402961