Synthesis 2019; 51(02): 407-413
DOI: 10.1055/s-0037-1610844
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© Georg Thieme Verlag Stuttgart · New York

The Preparation of Tetramethyl 1,1′,3,3′-Ruthenocenetetra­carboxylate and Tetramethyl 1,1′,3,3′-Osmocenetetracarboxylate, and a Simplified Synthesis for Tetramethyl 1,1′,3,3′-Ferrocene­tetracarboxylate

Julia Hein
,
Jan Klett  *
Institut für Anorganische Chemie und Analytische Chemie, Johannes Gutenberg-Universität Mainz, Duesbergweg 10–14, 55128 Mainz, Germany   Email: klettj@uni-mainz.de
› Author Affiliations
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Publication History

Received: 06 September 2018

Accepted after revision: 18 October 2018

Publication Date:
12 December 2018 (online)


Dedicated to Jean-Pierre Praly on his 70th birthday

Abstract

Substituted metallocenes with more than two substituents have to be synthesized using doubly substituted cyclopentadiene rings in a reaction with a metal compound or by the introduction of additional functional groups to an already di-substituted metallocene. The direct formation of tetra-substituted metallocenes often suffers due to insufficient reactivity of the reagents or the resulting product mixtures, which are hard to separate. In this work, a protocol, which was successful in a tetra-substitution of ferrocene by a tetra-metalation followed by a reaction with carbon dioxide, is used to perform the tetra-substitution of ruthenocene and osmocene. In addition, a simplified protocol for the tetra-functionalization of ferrocene using commercially available components on a medium scale is described.

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