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Updated: Oct 1, 2026

Accessing Valuable Ligand Supports for Transition Metals: A Modified, Intermediate Scale Preparation of 1,2,3,4,5-Pentamethylcyclopentadiene
Published on: March 20, 2017
Cobalt-mediated synthesis of angular [4]phenylene: structural characterization of a metallacyclopentadiene(alkyne)
Peter I Dosa1, Glenn D Whitener, K Peter C Vollhardt
1CLRC Daresbury Laboratory, Warrington, Cheshire, WA4 4AD, UK.
Abstract:
[reaction: see text] The first X-ray crystal structure of a mononuclear metallacyclopentadiene(alkyne) complex has been obtained. This type of metallacycle is believed to be the key intermediate in the cobalt-mediated [2 + 2 + 2]cycloaddition of alkynes. Thermal treatment leads to the generation of angular [4]phenylene, the X-ray structural details of which are described. Under photochemical conditions, the cobaltacycle isomerizes to a highly strained (cyclobutadieno)dibenzocyclooctatrienyne complex.
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