Synthesis of Conjugated Polycyclic Quinoliniums by Rhodium(III)-Catalyzed Multiple C–H Activation and Annulation of Arylpyridiniums with Alkynes

A simple method for the efficient synthesis of highly substituted pyrido­[1,2-a]­quinolinium- and quinolizino­[3,4,5,6-ija]­quinolinium-based polyheteroaromatic compounds via rhodium­(III)-catalyzed multiple C–H activation annulation reactions has been developed. Moreover, some of the quinolizino­[3,4,5,6-ija]­quinolinium salts exhibit intense fluorescence and have potential application in optoelectronic materials.