Double Ring Expansion from an Aromatic [18]Porphyrin( to an Antiaromatic [20]Porphyrin(

Masataka Umetani, Takayuki Tanaka, Taeyeon Kim, Dongho Kim, Atsuhiro Osuka

Research output: Contribution to journalArticlepeer-review

26 Citations (Scopus)


Double ring expansion from a 5,15-diarylporphyrin to a 5,16-diaryl-10,11,21,22-tetradehydro[20]porphyrin( occurred through a reaction sequence consisting of oxidation with PbO2to 5,15-dioxoporphodimethene, a Corey–Fuchs reaction with tetrabromomethane in the presence of triphenylphosphine, and Fritsch–Buttenberg–Wiechell rearrangement triggered by tert-butyllithium. The obtained tetradehydro[20]porphyrin( and its mono- and dihydrogenated congeners exhibited 20 π antiaromatic character, whereas overhydrogenated congeners bearing a saturated bridge were nonaromatic owing to disrupted π conjugation.

Original languageEnglish
Pages (from-to)8095-8099
Number of pages5
JournalAngewandte Chemie - International Edition
Issue number28
Publication statusPublished - 2016 Jul 4

Bibliographical note

Publisher Copyright:
© 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

All Science Journal Classification (ASJC) codes

  • Catalysis
  • Chemistry(all)


Dive into the research topics of 'Double Ring Expansion from an Aromatic [18]Porphyrin( to an Antiaromatic [20]Porphyrin('. Together they form a unique fingerprint.

Cite this