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-c]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.