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Updated: Aug 18, 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
A dispensable methoxy group? Phenyl fencholate as a chiral modifier of n-butyllithium
B Goldfuss1, M Steigelmann, T Löschmann
1Institut für Organische Chemie, Universität zu Köln, Greinstrasse 4, 50939 Köln, Germany. goldfuss@uni-koeln.de
Abstract:
Phenyl fenchol forms a 3:1 aggregate with n-butyllithium (3-BuLi), showing unique lithium-HC agostic interactions both in toluene solution (1H,7Li-HOESY) and in the solid state (X-ray analysis). Although methoxy-lithium coordination is characteristic for many mixed aggregates of anisyl fencholates with n-butyllithium, endo-methyl coordination to lithium ions compensates for the missing methoxy groups in 3-BuLi. This gives rise to a different orientation of the fenchane moiety, encapsulating and chirally modifying the butylide unit.
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