A New Synthetic Approach to N-Arylquinolino[2,3,4-at]porphyrins from β-Arylaminoporphyrins
journal contributionposted on 19.09.2008, 00:00 by Ana M. V. M. Pereira, Cristina M. A. Alonso, Maria G. P. M. S. Neves, Augusto C. Tomé, Artur M. S. Silva, Filipe A. A. Paz, José A. S. Cavaleiro
A new reaction leading to porphyrins bearing fused rings is described. Novel N-arylquinolino[2,3,4-at]porphyrins 2 were obtained by thermal oxidative cyclization of β-arylaminoporphyrins 1. The starting β-arylaminoporphyrins were prepared by two routes: (i) nucleophilic displacement of the nitro group from 2-nitro-5,10,15,20-tetraphenylporphyrin by anilines and (ii) palladium-catalyzed amination of bromobenzene derivatives with (2-amino-5,10,15,20-tetraphenylporphyrinato)nickel(II). The N-arylquinolino[2,3,4-at]porphyrins show interesting UV−vis spectra with strong absorption bands in the red region.