Synthesis of pyrrolo[3',2':4,5][1,3]diazepino[2,1,7- cd ]pyrrolizine derivatives from dicyanovinylene-bis( meso -aryl)dipyrrin.

Pyrrolo[3',2':4,5][1,3]diazepino[2,1,7- cd ]pyrrolizine derivatives 2 and 3 were synthesized from dicyanovinylene-bis( meso -aryl)dipyrrin in the presence of either BF 3 ·OEt 2 or InBr 3 , where 2 was readily oxidized in aerobic conditions to be 3. It was understood that the fully elongated π-conjugation of 3 is achieved via the conformation of 2. Crystal structures of 2 and 3 were elucidated by X-ray diffraction analysis. Furthermore, two redox states, 3 ox and 3 red were observed in the chemical redox processes.