title: Synthesis of peripherally nitrated, aminated, and arylaminated subporphyrins.
abstract: 2-Nitro-5,10,15-tri(4-tert-butylphenyl)subporphyrin 2 was prepared by the nitration of 5,10,15-tri(4-tert- butylphenyl)subporphyrin 1a with five equivalents of Cu(NO3)2·5H2O in a mixed EtOAc/Ac2O solution and was reduced into 2-amino-5,10,15-tri(4-tert-butylphenyl)subporphyrin 3. Bromination of 5,10,15-triphenylsubporphyrin 1b with 1.5 equivalents of N-bromosuccinimide (NBS) gave 2-bromo-5,10,15-triphenylsubporphyrin, which was converted into various 2-arylamino-5,10,15-triphenylsubporphyrins (4a-4d) and 2-benzamido-5,10,15-triphenylsubporphyrin 5 through Pd-catalyzed cross-coupling reactions. These molecules constitute the first examples of mono-β-substituted subporphyrins. These subporphyrins exhibit significantly perturbed optical and electrochemical properties, which reflect a large influence of the peripherally attached substituents on the electronic networks of subporphyrins.
authors.affiliation: Department of Chemistry, Graduate School of Science, Kyoto University, Sakyo-ku, Kyoto 606-8502 (Japan), Fax: (+81) 75-753-3970.
authors.forename: Eiji
authors.initials: E
authors.lastname: Tsurumaki
authors.forename: Atsuhiro
authors.initials: A
authors.lastname: Osuka
keywords: amination; boron; electrochemistry; nitration; subporphyrins