Studies on Amination of Porphyrins – In Search for Effective and Renewable Nucleophilic Aminating Reagent

Studies on amination of electrophilic porphyrins are described. Several reagents such as hydroxylamine, 4-amino-4H-1,2,4-triazole, and seven various sulfenamides were tested in the reactions with nitro-substituted porphyrins. Products of direct amination were observed (formed according to VNS mechanism) which were usually accompanied with other substitution of hydrogen products (formed according to ONSH mechanism), for example compounds substituted with t-BuO group when tert-butoxide was used as a base in the reaction. The best results were achieved with 2,4,6-trichlorophenylsulfenamide, however, the yields varied from low to moderate.