Substrate-Tuned Domino Annulation for Selective Synthesis of Polysubstituted Benzo[f]imidazo[2,1-a][2,7]naphthyridines and 3-Azaheterocyclic Substituted 2-Arylquinolines

A domino annulation/oxidation of heterocyclic ketene aminals (HKAs) and 2-aminochalcones has been developed for the selective synthesis of poly-substituted benzo[f]imidazo[2,1-a][2,7]naphthyridines and 3-azaheterocyclic substituted 2-arylquinolines. These reactions proceed well under mild conditions without any additives. Plausible mechanisms for such a polycyclic ring system assembly were also proposed. Moreover, benzo [f]imidazo [2,1-a] [2,7]naphthyridine 3g displayed a fluorescence effect, demonstrating the potential applications in organic optical materials.

Automated summary

A novel domino annulation/oxidation reaction using heterocyclic ketene aminals and 2-aminochalcones has been developed for the selective synthesis of poly-substituted benzo[f]imidazo[2,1-a][2,7]naphthyridines and 3-azaheterocyclic substituted 2-arylquinolines. The reactions proceed smoothly under mild conditions without any additives. The synthesized benzo[f]imidazo[2,1-a][2,7]naphthyridine 3g exhibited a fluorescence effect, indicating potential applications in organic optical materials.