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Abstract: A series of new imines and amines have been synthesized by condensation of 1H-3-ferrocenyl-1-phenylpyrazole-4-carboxaldehyde with the corresponding amines, followed by reduction with sodium borohydride. The synthesized compounds have been screened for their in vitro antimicrobial activity against 11 bacteria and three fungal/yeast strains, using disc diffusion and broth microdilution susceptibility assays. They have shown a wide range of activities, from completely inactive to the highly active compounds. [Copyright &y& Elsevier]

Acylation of ferrocene by an acylating agent generated in situ from the corresponding carboxylic acid and phosphorus trichloride, in the presence of the catalyst generated electrochemically from a sacrificial aluminum anode, was investigated. The corresponding monoacylferrocenes were obtained in very high yields when the molar ratio of reactants was ferrocene/carboxylic acid/PCl3=1:1.2:1, and by consumption 4.5 F/mol charge. The conditions for electrochemical diacylation of ferrocene were not found. However, acylation of ferrocene by the acylating agent generated in situ, but in the presence of commercial anhydrous aluminum trichloride as the catalyst, was successful in both monoacylation and diacylation processes. [Copyright &y& Elsevier]

Abstract: The reaction of 1-ferrocenyl-3-thiabutan-1-one with methyl iodide in acetonitrile at room temperature gave dimethyl(2-oxo-2-ferrocenylethyl)sulfonium iodide, which was characterized by spectral data (1H NMR, 13C NMR, IR) and X-ray crystallographic analysis. This salt reacted with a base (sodium hydride) in acetonitrile yielding a stabilized ylide—dimethylsulfonium ferrocenoylmethylide, which was in turn, submitted to reactions with seven conjugated enones. The obtained results showed that this methodology is potentially a new and useful approach to ferrocene-containing cyclopropanes. [Copyright &y& Elsevier]

Abstract: New ferrocene derivatives – 1H-1-phenylpyrazole-4-carboxaldehydes containing o-, m- and p-ferrocenylphenyl group at position 3 – were synthesized and characterized. The electrochemical investigation showed that the position of the ferrocenyl group does not affect the redox potential of these compounds. The X-ray crystal structure of the ortho-derivative is also presented. The screening for the in vitro antimicrobial activity against eleven bacterial and three fungal/yeast strains exhibited complete inactivity of these aldehydes, but n-butyl imines of ortho and meta derivatives showed moderate activity compared to those of the used standards. [Copyright &y& Elsevier]

Abstract: Dimethyl(2-ferrocenoylethyl)sulfonium iodide was synthesized by reacting 1-ferrocenyl-4-thiapentan-1-one with iodomethane and characterized from spectral data and single crystal X-ray structure analysis. This compound was capable of reacting with different N-, S-, and O-nucleophiles giving the corresponding β-functionalized ferrocene-containing ketones. Furthermore, dimethyl sulfide can be displaced from the dimethyl(2-ferrocenoylethyl)sulfonium ion with cyanide or carbanions derived from 1,3-bifunctional compounds and nitropropane, leading to products with a new carbon–carbon bond. [Copyright &y& Elsevier]

Abstract: Syntheses of three new ferrocene containing heterocycles – 2-ferrocenyl-2,3-dihydroquinolin-4(1H)-one and its 6-chloro and 6-bromo derivatives – starting from 2-aminoacetophenones and ferrocenecarboxaldehyde was achieved in two steps. The aldol condensation of these substrates gave the corresponding 2′-aminochalcones in the first stage, whereas a further intramolecular cyclization gives the final products. This cyclization was performed by either a solvent-free microwave irradiation (500W/5min) of a mixture of chalcones and mortmorillonite K-10 or by using an acidic catalyst (the mixture of acetic and orthophosphoric acid). The latter method, which can be performed by simple stirring at room temperature or by irradiation in an ultrasonic bath, gave much better results. The obtained compounds were spectrally and electrochemically (cyclic voltammetry) fully characterized, as well as by single-crystal X-ray analysis. A microdilution assay revealed that the three dihydroquinolinones can be regarded as potential lead compounds in the discovery of new antimicrobial drugs due to their very strong and unselective activity towards pathogenic bacteria and one yeast with MIC values (0.01–10.0μg/mL) lower than that of tetracycline. [Copyright &y& Elsevier]

Abstract: Syntheses of fourteen new 3-(arylamino)-1-ferrocenylpropan-1-ones have been achieved in good to excellent yields by an aza-Michael addition of different arylamines to acryloylferrocene. The reaction was performed by microwave (MW) irradiation (500W/5min) of a mixture of reactants and montmorillonite K-10, without a solvent. The obtained compounds were spectrally and electrochemically (cyclic voltammetry) fully characterized, whereas single-crystal X-ray analysis has been performed for three of them. In a microdilution assay, all of the compounds were shown to have a broad-spectrum effect on Gram-negative and -positive bacteria, although the degree of inhibition varied. A notable activity was observed for all compounds in inhibiting the growth of an important human pathogen Staphylococcus aureus. [Copyright &y& Elsevier]

Abstract: Several known and eight new sulfur containing acylferrocenes of the general formula FcCO(CH2) n SR (where Fc=ferrocenyl, n =1or2 and R=alkyl,4-bromobenzylor2,6-dichlorobenzyl group) were synthesized in order to test their in vitro antimicrobial activity against 11 bacterial and three fungal/yeast strains. It has been shown that only four of the 14 ketones are completely inactive at the tested dose, while the activities of the other ones were noteworthy. All new compounds were well characterized by IR and NMR spectral data, and their electrochemical properties were investigated by cyclic voltammetry. The X-ray crystal structures of two representative ketones are also presented. [Copyright &y& Elsevier]