Synthesis of open-shell ladder π-systems by catalytic C-H annulation of diarylacetylenes

Takehisa Maekawa, Hiroshi Ueno, Yasutomo Segawa, Michael M. Haley, Kenichiro Itami

Research output: Contribution to journalArticlepeer-review

28 Citations (Scopus)


A new open-shell ladder-shaped π-system has been synthesized. Pentaleno[1,2-b:4,5-b′]difluorene derivatives, 8 fused ring systems bearing 5- and 6-membered rings, were constructed from alkynylfluorenone through a reaction sequence including Pd-catalyzed C-H/C-H annulation. X-ray crystallography and ESR spectroscopy revealed the open-shell character of these ladder-shaped molecules, which derives from their extended π-electron conjugation. Absorption peaks in the near IR region as well as narrow redox potentials observed by cyclic voltammetry indicated small optical and fundamental energy gaps of these fused ring systems.

Original languageEnglish
Pages (from-to)650-654
Number of pages5
JournalChemical Science
Issue number1
Publication statusPublished - 2016 Jan 1


Dive into the research topics of 'Synthesis of open-shell ladder π-systems by catalytic C-H annulation of diarylacetylenes'. Together they form a unique fingerprint.

Cite this