Synthesis Of Ferrocene Derivatives Research Articles

Recent advances in the synthesis of ferrocene derivatives via 3d transition metal-catalyzed C-H functionalization.

In recent years, transition-metal-catalyzed C-H functionalization has gradually developed into a powerful tool for the synthesis of ferrocenes in an atom- and step-economic fashion. However, despite significant achievements, the vast majority of these C-H functionalizations required precious 4d or 5d transition metal catalysts. The use of inexpensive and sustainable 3d metals in the C-H functionalization of ferrocenes remains challenging, especially the development of asymmetric versions. Herein, we summarize the remarkable recent progress in the synthesis of ferrocenes by 3d transition metal-catalyzed C-H activation until December 2021.

Synthesis of Ferrocene Derivatives Allowing Linear Free Energy Studies of Redox Potentials

AbstractA series of ferrocene derivatives, which have diverse redox potentials modulated by functional groups, have been synthesized as potential ‘multi‐potential’ probes. A Hammett constant analysis revealed a linear free energy correlation between the redox potentials and the electron density of the ferrocene derivatives as determined by the choice of functional group used to modify the ferrocene core.

An Efficient Synthesis of Mono‐Substituted Benzyl Ferrocene Derivatives

The direct alkylation of ferrocene (FC) can be achieved via a Friedel–Craft reaction using an alkyl halide and AlCl3 ; however, this invariably leads to mixtures of mono‐ and poly‐alkylated complexes. Here, we describe the synthesis of mono‐substituted benzyl FC derivatives by a Friedel–Craft reaction utilizing environmentally benign substrates such as benzyl and allyl alcohol and a catalytic amount of Lewis acid in the absence of organic solvents. The use of molten FC, which plays the role of a solvent, proved a robust way to produce excellent yields of the mono‐substituted FC derivatives. Furthermore, this novel synthetic method is very simple and offers great potential for the industrial‐scale synthesis of FC derivatives.

Synthesis of ferrocene derivatives with planar chirality via palladium-catalyzed enantioselective C-H bond activation.

The first catalytic and enantioselective C-H direct acylation of ferrocene derivatives has been developed. A series of 2-acyl-1-dimethylaminomethylferrocenes with planar chirality were provided under highly efficient and concise one-pot conditions with up to 85% yield and 98% ee. The products obtained could be easily converted to various chiral ligands via diverse transformations.

Fries Rearrangement in Synthesis of Ferrocene Derivatives

ortho-Ferrocenoylphenol (salicyloylferrocene) has been synthesized and treated with acetyl, propionyl, benzoyl and 2-furoyl chloride to obtain the corresponding (ortho-acyloxybenzoyl)ferrocenes, which were subjected to conditions for the Fries rearrangement. By treatment with AlCl3 at room temperature in CH2Cl2 they afforded the corresponding heteroanular derivatives, 1-acyl-1′-(ortho-hydroxybenzoyl)ferrocenes in good to high yield. Under the same reaction conditions, but in the presence of ferrocene, all keto esters gave the corresponding monoacylferrocenes through an intermolecular Fries rearrangement.

Synthesis of ferrocene derivatives with π-extended conjugation

Synthesis of ( E)-1-ferrocenyl-2-( p-iodophenyl)ethene was carried out by means of the Wittig reaction between the p-iodobenzyl triphenylphosphonium ylid and the ferrocene carboxaldehyde, satisfactory as a mixture of E/Z isomers. Isomerization Z → E was induced by iodine—NBS in quantitative yield. The X-ray molecular structure of this ( E)-isomer indicates that the molecules are linked by charge transfer complexation between the iodine atom and the cyclopentadiene ring. The conjugation of the molecule of l-ferrocenyl-2-( p-iodophenyl)ethene was expanded to the ( Z,Z)- and ( E, E)-1,4-di[1-ferrocenyl-2( p-iodophenyl)ethenyl]biphenyl and to the ( Z,Z)- and ( E,E)-1,4-di(l-ferrocenyl-2-( p-phenylethenyl)-1,3-butadiyne, both as centrosymmetric structures.

Phase Transfer Catalyzed Synthesis of Ferrocene Derivatives

Phase Transfer Catalyzed Synthesis of Ferrocene Derivatives

Ferrocene derivatives. Part XX. Functionally substituted fulvenes and cyclopentadienes as potential precursors

The synthesis of ferrocene derivatives from a series of functionally substituted fulvenes and cyclopentadienes has been investigated. The course of these transformations has been shown to be dependent upon the electronic structure and stability of the derived cyclopentadienide anions. α-Methoxyfulvene has been prepared and converted into a hexacarbonyldi-iron complex.

Synthesis of ferrocene derivatives from ferrocenecarbonitriles

1. Ferrocenecarbonitrile was converted into ferrocenecarboxylic acid, its amide, and its ethyl ester in good yields. The nitrile was reduced to ferrocenemethylamine and to ferrocenecarboxaldehyde. 2. 1,1′-Ferrocenedicarbonitrile was hydrolyzed to the ferrocenedicarboxylic acid. 3. Ferrocenecarbonitriles are less reactive than nitriles of the benzene series.