The Rh(<scp>iii</scp>)-catalysed C–H/N–H annulation of 2-thienyl- and 2-phenyl-quinazolin-4(3H)-ones with diphenylacetylene

A series of 4,5-diphenyl-7H-thieno[2′,3′:3,4]pyrido[2,1-b]quinazolin-7-ones was synthesized via the Rh(III)-catalyzed annulation of 2-thienylquinazolin-4(3H)-ones with diphenylacetylene. 2-Phenylquinazolin-4(3H)-one amide alcoholysis and double C–H functionalization proceeded under the same reaction conditions with the formation of 2,3,7,8-tetraphenyl-1H-benzo[d,e][1,8]-naphthyridine derivatives. All compounds possess fluorescence properties in MeCN and toluene solutions as well as in the solid state. The aggregation induced emission (AIE) properties and the ability to detect Fe3+ cations were evaluated.