Conformationally restricted and three-dimensionally extended carbazole-incorporating expanded porphyrinoids

Abstract

Condensation of 3,6-(1-phenyl-1-(2-pyrroyl)methyl)carbazole with pentafluoroaldehyde and subsequent oxidation with DDQ gave a carbazole-incorporating octaphyrin(1.1.1.0.1.1.1.0) analogue, 7, which was shown to exist as two locked conformers 7a and 7b. Both conformers were isolated and handled individually. Heating of 7a and/or 7b in DMSO-d₆ at 130 °C afforded a stationary mixture of 7a/7b = 1/10. On the other hand, similar octaphyrin analogues bearing a 1,8-dibromocarbazole unit 7-2Br and 7-4Br were isolated. These octaphyrin analogues were further decorated by Suzuki–Miyaura coupling with α,α′-diboryltripyrrane to furnish 9 and 10, respectively, as a rare example of a three-dimensionally (3D) extended expanded porphyrinoids. It was shown that the porphyrin-like tetrapyrrolic cavity of 9 and 10 served as an effective ligand to the Cu^II metal.