Efficient Synthesis of β‐Acetamido Ketones and Esters Using Aluminum Chloride as an Inexpensive and Green Catalyst

Aluminum chloride (AlCl₃) efficiently catalyzes one‐pot multicomponent condensation of enolizable ketones or alkyl acetoacetates with aldehydes, acetonitrile and acetyl chloride to afford β‐acetamido ketone or ester derivatives in high to excellent yields and in relatively short reaction times. Moreover, by this synthetic method, some novel β‐acetamido ketones and esters (i.e. one complex structure) are prepared.     

Design of ionic liquid 3-methyl-1-sulfonic acid imidazolium nitrate as reagent for the nitration of aromatic compounds by in situ generation of NO(2) in acidic media

3-Methyl-1-sulfonic acid imidazolium nitrate ([Msim]NO(3)) as a new Br?nsted acidic ionic liquid and nitrating agent was prepared and used for the efficient nitration of aromatic compounds (even aniline derivatives). The dramatic effect of this reagent by in situ generation of nitrogen dioxide as a radical on aromatic compounds to give nitroarenes has been studied.     

Solvent‐Free Synthesis of Some New PolyAromatic Hydrocarbons by Diels‐Alder Reaction of Tetracyclone

Diels‐Alder reactions of tetracyclone with various dienophiles under solvent free conditions were studied. In the case of cyclic dienophiles that exhibit more steric hindrance, decarbonylation of [4+2] adducts were carried out.     

The application of N,N′-dibromo-N,N′-1,2-ethanediylbis-(p-toluenesulphonamide) as a powerful reagent for the oxidation of primary and secondary alcohols to aldehydes and ketones

Aliphatic and benzylic alcohols are readily oxidized to aldehydes and ketones in good yields under mild conditions by N,N′-dibromo-N,N′-1,2-ethanediylbis(p-toluenesulphonamide) [BNBTS].     

N‐Bromosuccinimide (NBS): A Mild and Efficient Catalyst for Tetrahydropyranylation of Alcohols and Phenols under Solvent‐Free Conditions

Different types of alcohols and phenols are tetrahydropyranylated in the presence of NBS catalyst in good to excellent yields under mild, neutral and solvent‐free conditions.     

Highly Efficient Etherification and Oxidation of Aromatic Alcohols Using Supported and Unsupported Phosphorus Pentoxide as a Heterogeneous Reagent

A highly efficient procedure for etherification and oxidation of aromatic alcohol is described using unsupported and supported P₂O₅ on alumina and/or silica gel. The silica gel and alumina proved to be the most suitable support among the supports examined in our experiments. It was illustrated that the etherification and oxidative performance in reactions depend largely upon variables including reaction temperature, the nature of the P₂O₅ used (supported or unsupported P₂O₅), and whether solvent-free conditions are applied. It was shown that P₂O₅ not only can convert the aromatic alcohols into corresponding ethers and/or aldehyde and ketone but also can convert aromatic ethers into aldehyde or ketone via oxidative cleavage. Finally, quantum mechanical calculations were performed to rationalized these events, and it was indicated that aldehyde and ketone are more favorable products on the basis of the heat of formation (ΔH_f).

Removal of thorium from aqueous solutions by sodium clinoptilolite

Adsorptive behavior of natural clinoptilolite was assessed for removal of thorium from aqueous solutions. Natural zeolite was characterized by X-ray diffraction and X-ray fluorescence. The zeolite sample composed mainly of clinoptilolite. Na-exchanged form of zeolite was prepared and its sorption capacity for removal of thorium from aqueous solutions was examined. The effects of relevant parameters, including initial concentration, contact time, solid to liquid ratio, temperature and initial pH on the removal efficiency were investigated in batch studies. The pH strongly influenced thorium adsorption capacity and maximal capacity was obtained at pH 4.0. Kinetics and isotherm of adsorption were also studied. The pseudo-first-order, pseudo-second-order, Elovich and intra-particle diffusion models were used to describe the kinetic data. The pseudo-second-order kinetic model provided excellent kinetic data fitting (R ² > 0.999) with rate constant of 1.25, 1.37 and 1.44 g mmol⁻¹ min⁻¹ respectively for 25, 40 and 55 °C. The Langmuir and Freundlich models were applied to describe the equilibrium isotherms for thorium uptake and the Langmuir model agrees very well with experimental data. Thermodynamic parameters were determined and are discussed.     

Application of polyionic magnetic nanoparticles as a catalyst for the synthesis of carbonitriles with both indole and triazole moieties via a cooperative geminal-vinylogous anomeric-based oxidation

Molecular Diversity - Three-component reaction of aldehydes with 3-(1H-indol-3-yl)-3-oxopropanenitrile and 1H-1,2,4-triazol-5-amine under the solvent-free condition at 70 °C was...