Synthesis of non- or antiaromatic conjugated macrocycles

Azulene-containing ring-expanded porphyrin with a 24pi-system

A ring-expanded porphyrin, diazuliamethyrin, was successfully synthesized via a “3+3” condensation method. This porphyrin showed a 24pi non- or antiaromatic character. We analyzed the optical and electronic structures using magnetic circular dichroism spectroscopy and time-dependent density functional theory calculations.

Profs. Okujima and Uno, in collaboration with Prof. Kobayashi at Shinshu University, reported their success in the synthesis of diazuliamethyrin, a core-modified hexaphyrin(, and descibed its molecular structure, electronic structure and optical properties.
Amethyrin is a stable and antiaromatic ring-expanded porphyrin comprised of 6 pyrroles and 2 meso-bridged carbons. We successfully synthesized diazuliamethyrin via a “3+3” porphyrin synthesis. We confirmed it to have a 24pi non- or antiaromatic character by NMR, absorption, and MCD spectra analyses, and by TD-DFT calculations. Our findings were published on December 21, 2021 in Organic Letters.

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Bibliographic Information

Journal: Organic Letters
Title: Synthesis of Non- or Antiaromatic Dicarbaamethyrin: [24]Diazulihexaphyrin(
Authors: Tetsuo Okujima, Hayato Inaba, Shigeki Mori, Masayoshi Takase, Hidemitsu Uno, Yoshiaki Chino, Yusuke Okada, Nagao Kobayashi
DOI: 10.1021/acs.orglett.1c03882


  • Synthesis of diazuliamethyrin

    Synthesis of diazuliamethyrin

    credit : Tetsuo Okujima, Ehime University
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Contact Person

Name : Tetsuo Okujima, Hidemitsu Uno
Phone : +81-89-927-9615
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Affiliation : Graduate School of Science and Engineering