Electroactive 1,5-benzodiazepines bearing either a tetrathiafulvalene or a ferrocene moiety

International audienceThe synthesis of a series of electroactive 1,5-benzodiazepines bearing either a ferrocene or tetrathiafulvalene core, acting as the electroactive moiety, is reported. The electron donating ability of these redox active 1,5-benzodiazepines is described together with their molecular structures, investigated by X-ray diffraction studies

Synthesis of [3,4-C] dihydropyrano-1, 5-dihydr0benz0diazepines

We report a simple method for the synthesis of [3,4-C] dihydropyrano-1,5-dihydrobenzodiazepines. © 1990, Taylor & Francis Group, LLC. All rights reserved.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

How to drive imine-enamine tautomerism of pyronic derivatives of biological interest - A theoretical and experimental study of substituent and solvent effects

International audienceAn investigation of the tautomerism of five series of aminated pyronic compounds of pharmacological interest was carried out using NMR experiments and standard quantum mechanical B3LYP/6-311+G** calculations. The obtained results indicate that among four possible tautomers, imine and enamine forms are the two predominating ones in the gas phase as well as in solution. Depending on the nature of the substituting group, the enamine or the imine form is the most stable tautomer, the calculations being in agreement with experiment. The calculated equilibrium constants in the gas phase and in solution show that the enamine form is stabilized by polar solvents, in all cases. NBO analysis explains well the predominance of a form over another one when changing a substituting group. We give indications on how to favour the imine form which is preferred for synthesis purposes

Tetrathiafulvalene hydrazone: efficient synthon for the synthesis of novel bidentate redox active ligands

International audienceThe synthesis and the ability of TTF-hydrazone to act as a versatile precursor for the design of electroactive ligands are reported together with the chelating ability of these ligands through their M(CO)4 complexes, (M = Mo, W)

Synthesis of Substituted 1,4-Diazepines and 1,5-Benzodiazepines Using an Efficient Heteropolyacid-Catalyzed Procedure

An efficient and improved procedure for the synthesis of 1,4-diazepine and 1,5-benzodiazepine derivatives via the reaction of ketimine intermediates with aldehydes in the presence of Keggin-type heteropolyacids (HPAs) was developed. High yields and short reaction times were obtained for both electron-releasing and electron-withdrawing substituted 1,4-diazepine and 1,5-benzodiazepines derivatives

Synthesis of new substituted imidazo[1,2-a]pyridinylpropenenitriles through sequential one-pot Suzuki-Miyaura/Knoevenagel reactions in aqueous medium

WOS:000475040300001A series of imidazo[1,2-a]pyridinylpropenenitriles were synthesized via consecutive one-pot Suzuki-Miyaura and Knoevenagel reactions in water/ethanol mixture between imidazo[1,2-a]pyridine-2-carbaldehydes, arylboronic acids and malononitrile, methyl cyanoacetate or ethyl cyanoacetate. This environmental friendly procedure tolerates a wide range of boronic acids and affords a new substituted imidazo[1,2-a]pyridinyl propenenitriles in good yields under microwave irradiation. [GRAPHICS]

Tetrathiafulvalene hydrazone an efficient precursor of various chelating electroactive ligands

International audienceNovel bidentate electroactive ligands containing one or two tetrathiafulvalene (TTF) cores as redox active unit have been synthesized thanks to the condensation of various carbonyl derivatives with TTF hydrazone. The electron donating ability of these redox active ligands determined by cyclic voltammetry is described together with the investigations of their molecular structures by X-ray diffraction studies. The chelating ability of these ligands has been exemplified through the coordination to molybdenum carbonyl fragment or the complexation to difluoroboron moiety

Copper(II) and nickel(II) complexes derived from a carbothioamide-5-pyrazolone ligand: synthesis, characterization, crystal structures, electrochemical, potentiometric and DNA-binding studies

International audienceThe synthesis of a 5-pyrazolone derivative (H2L) bearing a carbothioamide group at N1, N-ethyl-4-(2-hydroxyethyl)-3-methyl-5-oxo-2,5-dihydro-1H-pyrazole-1-carbothioamide, using a Keggin catalyst (H4SiW12O14·nH2O), is described. Complexes of copper(II) and nickel(II) have been prepared with this potential ligand and studied by potentiometry. Processing the pH-metric titrations revealed remarkable chelation ability of the ligand and high stability constants for the complexes. The complexes have been characterized by IR, UV/visible, electrochemistry, magnetic measurements, Electron Paramagnetic Resonance (EPR) and single-crystal X-ray diffraction. The structures are [Cu(HL)2H2O]·2H2O and [Ni(HL)2H2O]·2H2O, where the metal is five coordinate in an almost perfect trigonal bipyramidal geometry (D3h). The pyrazolone derivative (H2L) is a NS bidentate negative ligand, which coordinates to the metal through sulfur and amine nitrogen of the pyrazolone ring. The electronic results and the EPR of the complexes have been carefully studied in this (D3h) crystal field with a special emphasis on the energy levels. DNA-binding experiments have been conducted by UV spectroscopy and electrochemistry. The results reveal an interaction between the complexes and DNA and suggest an intercalative binding mode. UV titrations allowed determination of the binding constants Kb and revealed that the nickel(II) complex binds more strongl

Simple synthesis of imidazo[1,2-A]pyridine derivatives bearing 2-aminonicotinonitrile or 2-aminochromene moiety

WOS:000443914600003A simple and general method for the synthesis of new imidazopyridines bearing an aminopyridinyl, chromenyl, or quinolinyl moiety in the C2 position was developed. The Knoevenagel reaction between imidazo[1,2-a]pyridine-2-carbaldehyde 1 and malononitrile resulted in the formation of starting material 2. Subsequently, intramolecular cyclization between the cyano group of 2 and acetophenones, naphtols, hydroxyquinolines, or phenols, gave 3, 4, 5, and 6 compounds, respectively. This is a simple, reproducible, and environmentally friendly method of synthesizing substituted imidazopyridines using water as a solvent or under solvent-free conditions. [GRAPHICS]