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Updated: Jun 28, 2025

Accessing Valuable Ligand Supports for Transition Metals: A Modified, Intermediate Scale Preparation of 1,2,3,4,5-Pentamethylcyclopentadiene
Published on: March 20, 2017
Temperature-Dependent Divergent Cyclopentadiene Synthesis through Cobalt-Catalyzed C-C Activation of Cyclopropenes
Tianlong Zeng1, Ying Li1, Ruobin Wang1
1College of Chemistry and Molecular Sciences, Wuhan University, Wuhan, Hubei 430072, China.
Abstract:
We report a temperature-dependent divergent approach to synthesize multisubstituted cyclopentadienes through cobalt-catalyzed carbon-carbon (C-C) bond activation of cyclopropenes and ring expansion with internal alkynes. By employing different heating procedures, two cyclopentadiene substitution isomers were efficiently and selectively constructed. This reaction does not require preactivation of the metal catalyst or additional reducing reagents. Preliminary mechanistic investigations suggest that the key steps are oxidative addition of the cyclopropene to cobalt catalyst, followed by alkyne insertion and 1,5-ester shift.
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