Synthesis of Push-Pull Pyrroles and their Oxidative Anellation Reaction

Significance

The authors present a general synthesis of push-pull pyrroles using a Hinsberg-like cyclization between dielectrophile 1 and compounds of type 2. All the derivatives of compound 4 were fluorescent with Stokes shifts and quantum yields dependent on both the N-aryl and electron-withdrawing substituents. The benzothiazole-containing derivatives showed a strong solvent-dependent fluorescence. Under oxidative conditions 4 was converted into 3H-pyrroles as well as the ring-fused 3H-pyrroloquinoxalines 5.