A range of aza-ullazines, which represent a new heterocyclic core structure, were synthesized through a scalable four-step reaction, including a Sonogashira reaction and metal-free cyclization promoted by p-toluenesulfonic acid. The optical and electrochemical properties of selected derivatives were investigated, they were found to have similar absorption and emission spectra but a higher oxidation potential than the parent ullazine core.
Keywords: cyclization; fluorescence; heterocycles; palladium; pyridine.
© 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.