An efficient,rapid and facile procedure for conversion of aldoximes to nitriles using triphenylphosphine and N-halo sulfonamides

N,N,N＇,N＇-Tetrabromobenzene-1,3-disulfonamide （TBBDA）/triphenylphosphine and N,N,N＇,N＇-tetra- chlorobenzene-1,3-disulfonamide （TCBDA）/triphenylphosphine have been introduced as highly efficient systems for the versatile conversion of aldoxime derivatives into nitriles. The process reported here is operationally simple and reactions have been mildly performed in dichloromethane at room temperature.     

Poly(N-bromobenzene-1,3-disulfonamide) and N,N,N′,N′-tetrabromobenzene-1,3-disulfonamide as novel catalytic reagents for silylation of alcohols, phenols, and thiols using hexamethyldisilazane

Poly(N-bromobenzene-1,3-disulfonamide) [PBBS] and N,N,N′,N′-tetrabromobenzene-1,3-disulfonamide [TBBDA] are effective catalysts for the silylation of alcohols, phenols, and thiols in the presence of hexamethyldisilazane with, or without solvent, and also under microwave irradiation.     

One-pot synthesis of aliphatic and aromatic 2H-indazolo[2,1-b]phthalazine-triones catalyzed by N-halosulfonamides under solvent-free conditions

N, N, N′, N′-Tetrabromobenzene-1,3-disulfonamide and poly(N-bromo-N-ethylbenzene-1,3-disulfonamide) were used as efficient catalysts for the one-pot synthesis of aliphatic and aromatic 2H-indazolo[2,1-b]phthalazine-triones in excellent yields from aldehydes, phthalhydrazide, and dimedone at 80-100 °C under solvent-free conditions.     

Poly(N,N′-dibromo-N-ethyl-benzene-1,3-disulfonamide), N,N,N′,N′-tetrabromobenzene-1,3-disulfonamide and novel poly(N,N′-dibromo-N-phenylbenzene-1,3-disulfonamide) as powerful reagents for benzylic bromination

N,N,N′,N′-Tetrabromobenzene-1,3-disulfonamide [TBBDA], poly(N,N′-dibromo-N-ethyl-benzene-1,3-disulfonamide) [PBBS], and novel poly(N,N′-dibromo-N-phenylbenzene-1,3-disulfonamide) [PBPS] can be used for bromination of benzylic positions in solvent.     

Highly efficient one-pot synthesis of tetrahydropyridines

The combination of aromatic aldehydes, and 1,3-dicarbonyl compounds in the presence of a catalytic amount of poly(N,N′-dibromo-N-ethyl-benzene-1,3-disulfonamide) [PBBS] and N,N,N′,N′-tetrabromobenzene-1,3-disulfonamide [TBBDA] leads to the formation of highly substituted tetrahydropyridines. In this way, a series of pharmacologically interesting substituted piperidine derivatives were obtained in moderate to high yields at room temperature.     

Poly(N-bromo-N-ethylbenzene-1,3-disulfonamide) and N,N,N′,N′-tetrabromobenzene-1,3-disulfonamide as efficient reagents for synthesis of quinolines

Poly(N-bromo-N-ethylbenzene-1,3-disulfonamide) [PBBS] and N,N,N′,N′-tetrabromobenzene-1,3-disulfonamide [TBBDA] were used as efficient reagents for the synthesis of quinolines in excellent yields from 2-aminoaryl ketones and carbonyl compounds under aqueous and solvent-free conditions.     

One-pot synthesis of 2-amino-3-cyanopyridine derivatives under solvent-free conditions

A series of 2-amino-3-cyanopyridines were obtained from aryl aldehydes, substituted acetophenones, malononitrile and ammonium acetate in good to excellent yields by proceeding through a simple, mild and efficient procedure utilizing N,N,N′,N′-tetrabromobenzene-1,3-disulfonamide [TBBDA] and poly(N-bromo-N-ethylbenzene-1,3-disulfonamide) [PBBS] as catalysts.     

Poly(N,N′-dibromo-N-ethyl-benzene-1,3-disulfonamide) and N,N,N′,N′- tetrabromobenzene-1,3-disulfonamide as effective catalysts for conversion of aldehydes to 1,1-diacetates and acetals

Poly(N,N′-dibromo-N-ethyl-benzene-1,3-disulfonamide) [PBBS] and N,N,N′,N′-tetrabromobenzene-1,3-disulfonamide [TBBDA] are effective catalysts for easy preparation of 1,1-diacetates from aldehydes and acetic anhydride, and for easy preparation of acetals using diols under microwave irradiation in the presence of SiO₂.     

Poly(N,N′-dichloro-N-ethyl-benzene-1,3-disulfonamide, N,N,N′,N′-tetrachlorobenzene-1,3-disulfonamide, poly(N,N′-dibromo-N-ethyl-benzene-1,3-disulfonamide, and N,N,N′,N′-tetrabromobenzene-1,3-disulfonamide catalyzed formylation of amines and alcohols using ethyl formate under microwave irradiation

A simple, rapid, and efficient procedure for formylation of primary and secondary amines and alcohols using ethyl formate catalyzed with poly(N,N′-dichloro-N-ethyl-benzene-1,3-disulfonamide (PCBS), N,N,N′,N′-tetrachlorobenzene-1,3-disulfonamide (TCBDA), poly(N,N′-dibromo-N-ethyl-benzene-1,3-disulfonamide (PBBS) and also N,N,N′,N′-tetrabromobenzene-1,3-disulfonamide (TBBDA) was adopted. The reactions were performed under microwave irradiation with high yields.     

Poly(N,N′-dibromo-N-ethyl-benzene-1,3-disulfonamide), N,N,N′,N′-tetrabromobenzene-1,3-disulfonamide as new reagents for conjugate addition of indole, pyrrole with α,β-unsaturated ketones

Poly(N,N??-dibromo-N-ethyl-benzene-1,3-disulfonamide) [PBBS] and N,N,N??,N??-tetrabromobenzene-1,3-disulfonamide[TBBDA] were used as efficient reagents for conjugate addition of indole and pyrrole with ??,??-unsaturated ketones and also, double-conjugate 1,4-addition of indoles to dibenzylidenacetones.     

One-pot synthesis of pyrimidines under solvent-free conditions

N,N,N’,N’-Tetrabromobenzene-1,3-disulfonamide was used as an efficient catalyst for the one-pot synthesis of pyrimidine derivatives in excellent yields from triethoxymethane, ammonium acetate, and various ketone derivatives at 100–110 °C under solvent-free conditions.     

Solid-state synthesis of novel 3-substituted indoles

Poly(N-bromo-N-ethyl-benzene-1,3-disulfonamide) [PBBS] and N,N,N’,N’-tetrabromobenzene-1,3-disulfonamide [TBBDA] were used as efficient catalysts for the one-pot synthesis of 3-substituted indoles in good to high yields from indole, aldehydes, and arylamines under solid-state conditions at room temperature.     

Poly(N-bromo-N-ethyl-benzene-1,3-disulfonamide), N,N,N′,N′-tetrabromobenzene-1,3-disulfonamide as new efficient reagents for conversion of alcohols to THP ethers and aldehydes to oxazoline compounds

This paper is concerned with an easy preparation of THP ethers from primary, secondary and tertiary alcohols and oxazoline compounds from various aldehydes using poly(N-bromo-N-ethyl-benzene-1,3-disulfonamide), N,N,N′,N′-tetrabromobenzene-1,3-disulfonamide [TBBDA] as new and efficient reagents under ambient conditions without over-oxidation.     

Kinetic determination of 1,3-propanediamine-N,N′-diacetic-N,N′-di-3-propionic acid and in a mixture with ethylenediaminetetra-acetic acid

A kinetic method is proposed for the determination of propanediamine-N,N′-diacetic-N,N′-di-3-propionic acid, based on its inhibitory effect on the acetonitrile-catalysed oxidation of Pyrocatechol Violet by hydrogen peroxide. The concentrations of 1,3-propanediamine-N,N′-diacetic-N,N′-di-3-propionic acid determined ranged from 5.0 × 10^?7 to 4.0 × 10^?6 M with a relative standard deviation of up to 3.3%. The same indicator reaction can be applied to the determination of 1,3-propanediamine-N,N′-diacetic-N,N′-di-3-propionic acid and ethylenediaminetetra-acetic acid in mixtures. Mixtures of these acids in molar ratios from 1 ∶ 4.5 to 10 ∶ 1 have been analysed. Concentrations of 1,3-propanediamine-N,N′-diacetic-N,N′-di-3-propionic acid from 2.0 × 10^?7 to 1.0 × 10^?6 M and ethylenediaminetetra-acetic acid from 1.0 × 10^?7 to 9.0 × 10^?7 M were determined with relative standard deviations of up to 4.3 and 5.7%, respectively. The effect of foreign ions on the accuracy of these determinations was also investigated.     

Arylation of adamantanamines: III. Palladium-catalyzed arylation of adamantane-1,3-diyldimethanamine and 2,2′-(adamantane-1,3-diyl)diethanamine

Palladium-catalyzed arylation of adamantane-1,3-diyldimethanamine and 2,2′-(adamantane-1,3-diyl) diethanamine with isomeric bromochloro- and dibromobenzenes was studied. The yields of N,N′-diarylation products depend on the initial diamine and dihalobenzene structure. Side reactions were revealed, which reduced the yield of the target products. The arylation of 2,2′-(adamantane-1,3-diyl)diethanamine gives the corresponding N,N′-diaryl derivatives with better yield. The possibility for synthesizing unsymmetrical N,N′-diaryl derivatives of 2,2′-(adamantane-1,3-diyl)diethanamine was demonstrated.     

Thermal degradation of aramids—Part II: Pyrolysis/gas chromatography/mass spectrometry of some model compounds of poly(1,3-phenylene isophthalamide) and poly(1,4-phenylene terephthalamide)

The thermal degradation reactions of seven aromatic amides which are structurally related to the commercial aramids Kevlar (poly(1,4-phenylene terephthalamide)) and Nomex (poly(1,3-phenylene isophthalamide) have been investigated in the temperature range 450 to 700°C by pyrolysis/gas chromatography/mass spectrometry. Benzanilide, N,N′-dibenzoyl-1,4-phenylenediamine, N,N′-dibenzoyl-1,3-phenylenediamine, N,N′-diphenylterephthalamide, N,N′-diphenylisophthalamide, N-(4-aminophenyl)-benzamide and N-(3-aminophenyl)benzamide all gave very low yields of carbon oxides and water. The structures of the higher molecular weight products were related to those of the parent compounds and their yields are presented quantitatively. The principal mechanism for thermal cleavage of the amide bonds in the N,N′-dibenzoylphenylenediamines is mainly heterolytic, while for the other compounds thermal cleavage of the amide bonds is homolytic. The relationship between the pyrolysis products of the model compounds and those of the corresponding aramids is discussed.     

Synthesis and thermal study of polyamides and polyaspartimides

Copolymers were synthesized by polyaddition reactions of aromatic diamine (4,4′-sulphonyl dianiline) and aliphatic diamines (1,2-diaminoethane and 1,3-diaminopropane) with N,N′-arylenebismaleimides (N,N′-m-phenylene-N,N′-p-phenylene-, and N,N′-benzidine-). They were characterized by elemental analysis, i.r. spectra and viscosity. The thermal behaviour of copolymers was studied using Thermogravimetric Analysis (TGA). All the copolymers are stable up to 270°. Polyamides are less stable than polyaspartimides.     

The effect of ligand basicity on the thermal stability of heterodinuclear NiII–ZnII complexes

Four complexes of the nuclear structure Ni^II–Zn^II were prepared with bis-N,N′-(salicylidene)-1,3-propanediamine (LH₂), bis-N,N′-(salicylidene)-2,2′-dimethyl-1,3-propanediamine (LDMH₂) and the reduced derivatives of these Schiff bases, bis-N,N′-(2-hydroxybenzyl)-1,3-propanediamine (L^HH₂), bis-N,N′-(2-hydroxybenzyl)-2,2′-dimethyl-1,3-propanediamine (LDM^HH₂). The complexes were characterized using IR spectroscopy, elemental analysis and thermogravimetric methods. The stoichiometry of the complex molecules were found to be NiL·ZnCl₂·(DMF)₂, NiLDM·ZnCl₂·(DMF)₂, NiL^H·ZnCl₂·(DMF)₂ and NiLDM^H·ZnCl₂·(DMF)₂. The molecular models of the complexes prepared with the reduced Schiff bases were determined according to the X-ray diffraction method. It is seen that in these complexes Ni(II) is in octahedral and Zn(II) is in tetrahedral coordination sphere. Ni(II) ion is coordinated between two nitrogen and two oxygen donors of the ligand and oxygen donors of the two DMF molecules. Zn(II) ion on the other hand is coordinated between two oxygen of the organic ligand forming two μ bonds. It also coordinates two Cl ions. The thermogravimetric analysis showed that the complex NiLDM^H·ZnCl₂·(DMF)₂ containing methyl groups is more stable than the other complex NiL^H·ZnCl₂·(DMF)₂ containing reduced Schiff base. The coordinative DMF molecules in NiLDM^H·ZnCl₂·(DMF)₂ were thermally cleaved. However, the cleavage of DMF molecules NiL^H·ZnCl₂·(DMF)₂ resulted in the thermal degradation of the complex. In order to explain the TG data of the ligands were titrated in non-aqueous medium and their basicity strengths were determined. It was found that the basicity of the ligands containing two methyl groups were stronger. It is understood that the two methyl groups increase the negative charge density on nitrogen causing an increase in complex stability.     

Polymeric adducts of rhodium(II) tetraacetate with aliphatic diamines: natural abundance 13C and 15N CPMAS NMR investigations

Complexation properties of dimeric rhodium(II) tetracarboxylates have been utilised in chemistry, spectroscopy and organic synthesis. Particularly, the combination of these rhodium salts with multifunctional ligands results in the formation of coordination polymers, and these are of interest because of their gas‐occlusion properties. In the present work, the polymeric adducts of rhodium(II) tetraacetate with flexible ligands exhibiting conformational variety, ethane‐1,2‐diamine, propane‐1,3‐diamine and their N,N′‐dimethyl‐ and N,N,N′,N′‐tetramethyl derivatives, have been investigated by means of elemental analysis, ¹³C CPMAS NMR, ¹⁵N CPMAS NMR and density functional theory modelling. Elemental analysis and NMR spectra indicated the axial coordination mode and regular structures of (1 : 1)_n oligomeric chains in the case of adducts of ethane‐1,2‐diamine, N,N′‐dimethylethane‐1,2‐diamine N,N,N′,N′‐tetramethylethane‐1,2‐diamine and N,N,N′,N′‐tetramethylpropane‐1,3‐diamine. Propane‐1,3‐diamine and N,N′‐dimethylpropane‐1,3‐diamine tended to form heterogeneous materials, composed of oligomeric (1 : 1)_n chains and the additive of dirhodium units containing equatorially bonded ligands. Experimental findings have been supported by density functional theory modelling of some hypothetical structures and gauge‐invariant atomic orbital calculations of NMR chemical shifts. Copyright © 2013 John Wiley & Sons, Ltd.     

Thermochemistry of Cu(II) and Ni(II) complexes with N,N-di-n-butyl-N′-thenoylthiourea and N,N-di-iso-butyl-N′-thenoylthiourea

Two substituted N-acylthioureas and the respective Ni(II) and Cu(II) complexes were synthesized, namely: N,N-di-n-butyl-N′-thenoylthiourea (Hnbtu); N,N-di-iso-butyl-N′-thenoylthiourea (Hibtu); bis[N,N-di-n-butyl-N′-thenoylthioureato]nickel(II), [Ni(nbtu)₂]; bis[N,N-di-n-butyl-N′-thenoylthioureato]copper(II), [Cu(nbtu)₂]; bis[N,N-di-iso-butyl-N′-thenoylthioureato]nickel(II), [Ni(ibtu)₂]; bis[N,N-di-iso-butyl-N′-thenoylthioureato]copper(II), [Cu(ibtu)₂]. The standard (p^° = 0.1 MPa) molar enthalpies of formation and sublimation of the two N-acylthioureas were measured, at T = 298.15 K, by rotating-bomb combustion calorimetry and Calvet microcalorimetry, respectively. The standard (p^° = 0.1 MPa) molar enthalpies of formation of the Ni(II) and Cu(II) complexes were determined, at T = 298.15 K, by high precision solution–reaction calorimetry. From the results obtained, the enthalpies of hypothetical metal–ligand and metal–metal exchange reactions, in the gaseous phase, were derived, thus allowing a discussion of the gaseous phase energetic difference between the complexation of Ni(II) and Cu(II) to 1,3-ligand systems with (S,O) ligator atoms.