Khaled Boujlel

Revealing molecular self-assembly and geometry of non-covalent halogen bonding by solid-state NMR spectroscopy

We report a new spectroscopic fingerprint of intermolecular contacts in halogen bond-driven self-assembling aggregates and a precise determination of intermolecular NI distances in microcrystalline samples.

Electrochemically active phenylenediamine probes for transition metal cation detection

A novel family of tetraalkyl-p-phenylenediamine (TAPD)-based ligands has been efficiently prepared by reductive amination of heterocyclic aldehydes. The redox properties of these electrochemical active ligands change dramatically upon complexation of the transition metal cations Zn2+, Ni2+ and Cd2+ leading to large oxidation potential shifts of up to 950 mV depending on the nature of the ligand. Complexes with a metal to ligand ratio of 1 ∶ 2 were formed and 113Cd NMR revealed an octahedral coordination sphere of the metal. All pyridyl derivatives show a distinct chemoselectivity (Zn2+ > Cd2+ > Ni2+). The thiophenyl containing derivatives display a particularly high selectivity for zinc cations (Zn2+ ≫ Ni2+, Cd2+).

Electrogenerated base-promoted synthesis of N-benzylic rhodanine and carbamodithioate derivatives

Electrogenerated magnesium-associated cyanomethyl anions/bases obtained from the electrochemical reduction of acetonitrile and the oxidation of a sacrificial magnesium rod were successfully used to promote the addition of carbon disulfide to primary benzylic amines. Alkylation with ethyl 3-bromopropionate acid ester or with ethyl 2-bromoacetate acid ester yields the corresponding ring-opened carbamodithioate compounds or cyclic rhodanine derivatives, respectively. The effect of the amount of electrogenerated base on the yield of reaction was also evaluated.

Electrogenerated Base-Promoted Synthesis of Dithiocarbamate Acid Esters and 3-(N-Substituted-amino)-2-cyanodithiocrotonates from Primary or Secondary Amines and Carbon Disulfide

Electrogenerated cyanomethyl anion promotes the reaction between primary or secondary amines, carbon disulfide, and alkyl or benzyl halide. Secondary amines are converted to alkyl or benzyl dithiocarbamates, whereas primary amines give N-substituted alkyl or benzyl 3-amino-2-cyanodithiocrotonates. The mechanisms are discussed.

Electrogenerated base promoted synthesis of N-substituted-4-hydroxy- 4-methylthiazolidine-2-thione derivatives

Electrochemically-generated basic species from the reduction of acetonitrile assisted the condensation of carbon disulfide, primary arylmethylamines and chloroacetone to yield the corresponding N-substituted-4-hydroxy-4-methylthiazolidine-2-thione derivatives. In some cases, dehydration reaction led to the N-substituted-4-methylthiazole-2(3H)-thione analogues. The effect of the electrogenerated base amount on the reaction yield was also studied.

Synthèse de [ [1] , [5] , [6] , [7] , [8] , [9] , [10] , [11] , [12] , [13] , [14] , [15] , [16] , 17]quinazolo-1,2,4,3triazaphosphole-4-oxide

Abstract N-(2-cyanophenyl)-imidates 1 react with hydrazine to give 3-amino-4-iminoquinazolines 2 . The condensation of 2 with hexamethylphosphorotriamide or methylphosphonic bis(dimethylamide) constitute an original route for the synthesis of [ [1] , [5] , [6] , [7] , [8] , [9] , [10] , [11] , [12] , [13] , [14] , [15] , [16] , 17]quinazolo-1,2,4,3-triazaphosphole-4-oxides 3 in good yields. The structure of these compounds is unambiguously confirmed by IR, 1 H, 13 C and 31 P NMR spectroscopy, by MS and elementary analysis for some products.

NOUVELLE SYNTHÈSE DE [1,2-A]BENZIMIDAZOLO-1,3,5,2-TRIAZAPHOSPHORINES ET DE [1,2-A]BENZIMIDAZOLO-1,3,5,2- TRIAZAPHOSPHORINE-2-THIONES

The condensation of N1-benzimidazolyl amidines 1 with tris(dimethy- lamino)phosphine leads to the corresponding [1,2a]Benzimidazolo-1,3,5,2-triazaphosphorines 3 . The N2-phosphoroamidine intermediates 2′ are isolated and yielded the corresponding cyclic compounds 4 upon heating. The oxidation by sulfur of the compounds 3 gives the thiooxide derivatives 4 . The structure of these compounds is unambiguously confirmed by IR, 1H, 31P, and 13C NMR spectroscopy and by MS for some products.

A new route of synthesis of 3a, 6a-dihydro-oxazolo[5,4-d]oxazole derivatives

Abstract The electrochemical reduction of N-acylated imidates of a typical structure (Sch. 1) has been investigated by cyclic voltammetry and controlled potential electrolysis at mercury electrode in aprotic solvent. Electrodimerization occurs at the first wave and leads to the formation of 3a,6a-dihydro-oxazolo[5,4-d]oxazole 2 in good yields. Scheme 1.

REDUCTION OF N -2-SUBSTITUTED BENZIMIDAZOYL IMIDATES

ABSTRACT> Cathodic reduction of several iminoesters ( 1 ) and ( 2 ) has been investigated by cyclic voltammetry and controlled potential electrolysis at mercury electrode in aprotic DMF, leading to the formation of two reduction steps. The appropriate choice of the nature of R2 groups allowed the reductive cyclisation when R2 is an ethoxy (or alkoxy) group.

Electrochemical behaviour of hydrazonates in protic and aprotic medium

ABSTRACT Cathodic reduction of several hydrazonates of a typical structure (Scheme 1) has been investigated by cyclic voltammetry and controlled potential electrolysis at mercury electrode in aprotic solvent. Quantitative results for preparative electrolysis run in the presence of a protic donor show the occurrence of reductive cleavage of the median N–N bond leading to the formation of imines and iminoethers in good yields.