Tenfold Metalation of Ferrocene: Synthesis, Structures, and Metallophilic Interactions in FeC10 (HgX)10.

Susanne Margot Rupf,Robin Sievers,Gabriel Schröder,Moritz Malischewski

doi:10.1002/chem.202100261

Abstract

The permercuration of ferrocene was achieved by reacting ferrocene with 10 equivalents of mercury(II) butyrate Hg(O2CC3H7)2 in a facile one‐pot reaction in multi‐gram scale and high yields. The butyrate groups in FeC10(HgX)10 (X=O2CC3H7) can be exchanged by treatment with trifluoro‐ or trichloroacetic acid (X=O2CCF3, O2CCCl3). Substitution of the trifluoroacetate groups by halides (X=Cl, F) proceeds easily in aqueous THF. The completeness of metalation was confirmed by NMR and vibrational spectroscopy, mass spectrometry, as well as elemental analysis. Additionally, the first crystal structures of permetallated metallocenes are presented: FeC10(HgX)10 (X=Cl, O2CCF3, O2CCCl3).

Highlights

The permercuration of ferrocene was achieved by reacting ferrocene with 10 equivalents of mercury(II) butyrate Hg(O2CC3H7)2 in a facile one-pot reaction in multi-gram scale and high yields
The functionalization of unreactive CÀH bonds is a constant challenge in organometallic chemistry due to their high intrinsic stability.[1]
Even unreactive CÀH bonds such as methane can be brought to reaction using Hg(NTf2)2.[14] interest in organomercury chemistry has declined during the past decades due to the high toxicity of organomercury compounds

Summary

Introduction

The permercuration of ferrocene was achieved by reacting ferrocene with 10 equivalents of mercury(II) butyrate Hg(O2CC3H7)2 in a facile one-pot reaction in multi-gram scale and high yields. The utility of such mercurations can be demonstrated by the reaction of ferrocene with mercury(II) carboxylates. The permercuration of ferrocene seemed to be incomplete.[29] In a review article, it was mentioned that the solubility and the degree of mercuration could be improved by replacing mercury(II) acetate by mercury(II) butyrate, but details were never published.[7] organomercury compounds are highly toxic, they are valuable starting materials for functionalization or transmetalation reactions.[30,31,32] we reinvestigated the permercuration of ferrocene with modern spectroscopic techniques.

Results

Conclusion