Ferrier rearrangement promoted by an electrochemically generated zirconium catalyst.

In situ generated zirconium catalyst from a sacrificial zirconium anode was successfully applied to promote Ferrier rearrangement of 3,4,5-tri-O-acetyl-D-glucal and 6-deoxy-3,4-di-O-acetyl-L-glucal (3,4-di-O-acetyl-L-rhamnal) in the presence of three thiols and eleven thiophenols as nucleophiles. A simple constant current electrolysis (20 mA, 0.4 F mol(-1)) of an acetonitrile solution of lithium perchlorate (0.

Discovery of anxiolytic 2-ferrocenyl-1,3-thiazolidin-4-ones exerting GABAA receptor interaction via the benzodiazepine-binding site.

Herein, we report on the synthesis, spectral, crystallographic and electrochemical properties of a small library of N-substituted 2-ferrocenyl-1,3-thiazolidin-4-ones, designed as novel GABAA benzodiazepine-binding site ligands. The anxiolytic properties of the title compounds were evaluated in several different in vivo models, whereas the involvement of the GABAA receptor complex in the activity of the most potent compound, 2-ferrocenyl-3-(4-methoxyphenylethyl)-1,3-thiazolidin-4-one, was inferred from experiments with known GABAA-targeting agents. Ligand docking experiments revealed that the high, dose-dependent, anxiolytic activity of the new compounds might be due to their favorable interactions with the benzodiazepine-binding site of the GABAA receptor complex.

Synthesis, characterization, and antimicrobial evaluation of a small library of ferrocene-containing acetoacetates and phenyl analogs: the discovery of a potent anticandidal agent.

A library of 16 2-substituted methyl acetoacetates containing ferrocenyl or phenyl units was designed to disclose differences in the antimicrobial activity of ferrocene-containing compounds and their phenyl analogs. Two methyl acetoacetates, whose structures do not contain an aromatic nucleus, were also included in order to probe the inherent activity of the scaffold itself. The acetoacetates were synthesized (low-to-good yields) and fully characterized by spectral (MS, IR, UV-Vis, 1D and 2D NMR) and electrochemical (cyclic voltammetry) techniques.

4-Eth-oxy-3-meth-oxy-benzaldehyde.

In the title compound, C10H12O3, all non-H atoms are approximately coplanar, with an r.m.s.

Sulfur-containing ferrocenyl alcohols and oximes: new promising antistaphylococcal agents.

A small library containing four different series of new ferrocene derivatives, 2-(alkylsulfanyl)-1-ferrocenylethan-1-ols, 3-(alkylsulfanyl)-1-ferrocenylpropan-1-ols, (E)- and (Z)-2-(alkylsulfanyl)-1-ferrocenylethan-1-one oximes, and (E)- and (Z)-3-(alkylsulfanyl)-1-ferrocenylpropan-1-one oximes (36 different compounds in total) was synthesized starting from ferrocene and the corresponding sulfanyl acids. All compounds were spectrally (IR and NMR) and electrochemically characterized. In general, the obtained compounds were found to exhibit very strong antimicrobial activities (broth microdilution assay) against the tested microorganisms (six common human pathogens).

1-Ferrocenyl-3-(2-methyl-anilino)propan-1-one.

In the ferrocene-containing Mannich base, [Fe(C(5)H(5))(C(15)H(16)NO)], the dihedral angle between the mean planes of the benzene ring and the substituted cyclo-penta-dienyl ring is 84.63 (7)°. The conformation of the title compound significantly differs from those found in corresponding m-tolyl-amino and p-tolyl-amino derivatives.

3-(3-Acetyl-anilino)-1-ferrocenylpropan-1-one.

The title ferrocene-containing Mannich base, [Fe(C(5)H(5))(C(16)H(16)NO(2))], crystallizes with two independent mol-ecules (A and B) in the asymmetric unit. Mol-ecules A and B have similar conformations. The dihedral angles between the best planes of the benzene and substituted cyclo-penta-dienyl rings are 88.

1-Ferrocenyl-3-(3-fluoro-anilino)propan-1-one.

The title ferrocene derivative, [Fe(C(5)H(5))(C(14)H(13)FNO)], crystallizes in the same space group with similar unit-cell parameters as the derivatives 3-anilino-1-ferrocenylpropan-1-one [Leka et al. (2012 ▶). Acta Cryst.

1-Ferrocenyl-3-(4-methyl-anilino)propan-1-one.

In the title ferrocene derivative, [Fe(C(5)H(5))(C(15)H(16)NO)], the dihedral angle between the best planes of the benzene and the substituted cyclo-penta-dienyl ring is 83.4 (1)°. The presence of a methyl substituent in the para position of the aniline group does not alter the crystal packing compared to that of 3-anilino-1-ferrocenylpropan-1-one [Leka et al.

3-Anilino-1-ferrocenylpropan-1-one.

In the title ferrocene derivative, [Fe(C(5)H(5))(C(14)H(14)NO)], the dihedral angle between the mean planes of the phenyl ring and the substituted cyclo-penta-dienyl ring is 84.4 (1)°. The mol-ecules are connected into centrosymmetric dimers via N-H⋯O hydrogen bonds.

A new polymorph of 1-ferrocenyl-3-(3-nitroanilino)propan-1-one.

Recrystallization of the title compound, [Fe(C(5)H(5))(C(14)H(13)N(2)O(3))], from a mixture of n-hexane and dichloromethane gave the new polymorph, denoted (I), which crystallizes in the same space group (P1) as the previously reported structure, denoted (II). The Fe-C distances in (I) range from 2.015 (3) to 2.

Chemotaxonomy of Serbian Teucrium species inferred from essential oil chemical composition: the case of Teucrium scordium L. ssp. scordioides.

The volatile constituents of Teucrium scordium L. ssp. scordioides, T.

Electrochemical bromochlorination of peracetylated glycals.

Peracetylated glycals-3,4,5-tri-O-acetyl-D-glucal (1a), 3,4,5-tri-O-acetyl-D-galactal (1b) and 3,4-di-O-acetyl-6-deoxy-L-glucal (1c)-have been bromochlorinated by a suitable halogenating agent, generated electrochemically from a mixture of bromides and chlorides in dichloromethane. The reaction was performed in two ways: (i) by a constant current electrolysis (2Fmol(-1)) of bromides and substrates in a milieu containing an excess of chlorides (Br(θ)/1/Cl(θ)=1:1:6.8) and (ii) by anodic generation of free chlorine from chlorides (2Fmol(-1)) and subsequent addition of bromides and substrates in a ratio Br(θ)/1=1:1.

Complete assignment of the 1H and 13C NMR spectra of antimicrobial 4-arylamino- 3-nitrocoumarin derivatives.

Herein, we describe the synthesis and complete assignment of the (1)H and (13)C NMR chemical shifts of a series of antimicrobial 4-arylamino-3-nitrocoumarin derivatives based on a combination of (1)H and (13)C NMR, (1)H-(1)H-COSY, NOESY, HSQC and HMBC experiments. Conformational effects upon the chemical shifts of the coumarin moiety arising from the anisotropy of the aryl side group are briefly discussed. This study provides the first complete and fully assigned NMR data for this important group of antimicrobial compounds and bridges the gap existing in the literature with regard to NMR structural data for 4-arylamino-3-nitrocoumarins.

Synthesis and antimicrobial activity of new 4-heteroarylamino coumarin derivatives containing nitrogen and sulfur as heteroatoms.

Synthesis, spectral analysis and bioactivity of new coumarin derivatives are described in this paper. Eight new coumarin derivatives were synthesized in moderate to good yields by condensation of 4-chloro-3-nitrocoumarin and the corresponding heteroarylamine. The synthesized compounds were tested for their in vitro antimicrobial activity, in a standard disk diffusion assay, against thirteen strains of bacteria and three fungal strains.

Synthesis, characterization, electrochemical studies and antitumor activity of some new chalcone analogues containing ferrocenyl pyrazole moiety.

A series of new alpha,beta-unsaturated conjugated ketones containing ferrocenyl pyrazole unit were synthesized and fully characterized by IR and NMR spectroscopy. Electrochemical characterization of subject compounds was performed by means of cyclic voltametry. The in vitro cytotoxic activity of all the synthesized compounds was studied against cervix adenocarcinoma HeLa, melanoma Fem-x and myelogenous leukemia K562 cell lines by the MTT method.

Synthesis and antimicrobial activity of some new pyrazole derivatives containing a ferrocene unit.

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.

Electrochemical bromination of cholest-5-enes.

Four 5,6-unsaturated steroids--3beta-chlorocholest-5-ene (1a), cholesterol (1b) and its acetate (1c) and benzoate (1d)-were subjected to constant current electrolysis (50 mA, 2 F mol(-1)) in an electrolytic cell divided by a ceramic membrane, using a platinum foil as the anode and a graphite stick as the cathode. When electrolysis was carried out in a solution of tetraethylammonium bromide in aprotic solvents (dichloromethane, acetonitrile or acetic anhydride), the addition of electrochemically-generated elemental bromine onto the double bond of the cholesterol derivatives gave their corresponding 5alpha,6beta-dibromosteroids--3beta-chloro-5alpha,6beta-dibromocholestane (2a), 5alpha,6beta-dibromocholestan-3beta-ol (2b), 5alpha,6beta-dibromocholestan-3beta-yl acetate (2c) and 5alpha,6beta-dibromocholestan-3beta-yl benzoate (2d)--as the sole products, and in good yields (58-91%). However, the electrolysis of steroids 1a-c in a solution of tetraethylammonium bromide with methanol as the solvent proceeded to give, in addition to dibromides 2a-c, the corresponding diastereomeric pairs of 5-bromo-6-methoxysteroids: 5alpha-bromo-3beta-chloro-6beta-methoxycholestane (3a) and 5beta-bromo-3beta-chloro-6alpha-methoxycholestane (4a), 5alpha-bromo-6beta-methoxycholestan-3beta-ol (3b) and 5beta-bromo-6alpha-methoxycholestan-3beta-ol (4b) and 5alpha-bromo-6beta-methoxycholestan-3beta-yl acetate (3c) and 5alpha-bromo-6beta-methoxycholestan-3beta-yl acetate (4c).

Electrochemical synthesis and X-ray crystal structures of beta-D-2-phenylselenyl-1,3,4,6-tetra-O-acetylglucopyranose and alpha-D-2-phenylselenyl-1,3,4,6-tetra-O-acetylmannopyranose.

Electrochemical acetoxyphenylselenation of 3,4-dihydro-2H-pyran and D-3,4,6-tri-O-acetylglucal was studied. The constant current electrolysis (50mA) of dihydropyran and diphenyl diselenide in an acetic acid solution of tetramethylammonium chloride was performed at room temperature in an undivided cell using a graphite anode and an aluminum cathode and yielded trans-DL-2-acetoxy-3-phenylselenyltetrahydropyran (27%), in agreement with Markovnikov's rule. The analysis of the 1H NMR spectral data showed that the acetoxy and phenylselenyl groups adopt axial positions in the most stable conformation of this compound due to the anomeric effect.