I₂-Mediated One-Pot Three-Component Tandem Cyclization: Synthesis of 1<i>H</i>-Pyrrolo[3,4-<i>c</i>]quinoline-1,3(2<i>H</i>)-diones and Their Photophysical Property Studies

An I₂-mediated one-pot three-component tandem cyclization for the synthesis of 1<i>H</i>-pyrrolo[3,4-<i>c</i>]quinoline-1,3(2<i>H</i>)-diones (PQLs) has been reported. Starting from aromatic amines and maleimides, when aromatic aldehydes or di-<i>tert</i>-butyl peroxide (DTBP) were present, different substitution types of PQLs were obtained. It was noted that DTBP could be used as the C4 unit for constructing the heterocyclic skeleton under the current conditions. Favorable photophysical properties of PQLs have made them candidate compounds for a new generation of innovative fluorescent probes.