Designing a sequential Ugi/Ullmann type reaction for the synthesis of indolo[1,2-a]quinoxalinones catalyzed by CuI/l-proline

An efficient strategy for the one-pot syntheses of indolo[1,2-a]quinoxalinones catalyzed by CuI have been developed. The procedures combine the Ugi four-component reaction of aldehydes, 2-iodoaniline, 2-indole carboxylic acid, and isocyanides followed by the copper-catalyzed intramolecular N-arylation of the Ugi product in one-pot procedure, which afford the desired products in good to very good yields.     

Palladium catalyzed stereoselective synthesis of 3-(anilinoarylmethylene)-2-oxindoles as Hesperadin analogoues

Potentially bioactive 3-(anilinoarylmethylene)-2-oxindoles as Hesperadin analogoues have been synthesized via a two-step procedure: (a) an Ugi-4MCR and (b) reaction of the Ugi adduct with aniline in the presence of a palladium catalyst via domino Heck/Buchwald reaction. In all cases, a single isomer with the Z-configuration was obtained in good to high yields.     

Granulated copper oxide nanocatalyst: a mild and efficient reusable catalyst for the one-pot synthesis of 4-amino-5-pyrimidinecarbonitriles under aqueous conditions

Abstract  

An efficient method for the synthesis of 4-amino-5-pyrimidinecarbonitriles by the three-component reaction of malononitrile, aldehydes, and N-unsubstituted amidines under aqueous conditions using CuO microspheres as catalyst is reported. The catalyst exhibited remarkable reusable activity.     

Preconcentration/Separation of Some Metal Ions Using Sodium Dodecyl Sulfate Coated Alumina Modified with Bis(5‐bromo‐2‐hydroxy‐benzaldehyde)‐2‐methyl‐1,5‐pentane Diimine (BBHBPDI) Prior to Their Flame‐AAS Determination

Preconcentration/separation of Co(II), Fe(III), Pb(II), Cr(III), Cu(II) and Cd(II) ions using bis(5‐bromo‐2‐hydroxy‐benzaldehyde)‐2‐methyl‐1,5‐pentane diimine (BBHBPDI) on SDS coated alumina has been reported. The influences of the analytical parameters including pH, ligand and SDS amount, type and concentration of eluent and sample volume on metal ions recoveries were investigated. At optimum values of all variables the relative standard deviation are between 2.5–2.7 and preconcentration factor was 375, while recoveries for all understudy metal ions are higher than 95%, determination limits are between 1.5–2.7. The method has been successfully applied to determination of Co(II), Fe(III), Pb(II), Cr(III), Cu(II) and Cd(II) ions content in some real samples.     

The effect of carrier gas flow on structural and optical properties of TiO2 nanowires

Optical properties and photoluminescence of TiO₂ nanowires, synthesized by two-step thermal evaporation process, under different Ar gas flow as carrier have been studied. The gas flow was varied from 50 to 150 sccm in order to find the optimum gas flow to growth TiO₂ nanowires. As evidenced by X-ray diffraction patterns, our synthesized nanowires, were found to be crystalline rutile TiO₂. Our results indicated a convenient gas flow for controlling diameter size of nanowires was about 100 sccm. In this case, diameters and lengths were, respectively, within the ranges of 40–100 and 400–1800 nm. The experimental data of the reflectance of TiO₂ nanowires have been obtained through using spectrometer of wavelength 250–800 nm that has been indicated reflectance decreasing with increasing the gas flow, due to the scattering from the surface of the nanowires and also an increase in voids’ roughness. Under excitation 370 nm, the TiO₂ nanowires can emit light peaked at 435 nm. It is believed that peak 435 may be due to free excitons emission.     

A facile synthesis of novel pyrrolizidines under classical and ultrasonic conditions

Novel pyrrolizidines (1) were synthesized from 1,3-dipolar cycloaddition of azomethine ylides and dipolarophiles (4). The reactions were highly diastereoselective and regioselective and were carried out under reflux and ultrasonic condition at room temperature. In general, milder conditions and moderate improvements in rates and reaction times were observed when ultrasonic condition was used. The products were obtained in high yields, and their structures were determined by (1)H and (13)C NMR spectral data and X-ray diffraction.     

A simple and efficient route for the synthesis of di and tri(bis(indolyl) methanes) as new triarylmethanes

Preparation of di and tri(bis(indolyl) methanes) from di and trialdehydes and indoles in the presence of silica sulfuric acid was described. Reactions proceeded in good to excellent yields in acetonitrile as solvent at room temperature.     

Synthesis of new tripodal Hantzsch 1,4-dihydropyridines under solvent-free condition and their conversion to the corresponding tripodal pyridines

A mixture of β-ketoester and tri-aldehydes in the presence of ammonium fluoride was converted to their corresponding tripodal 1,4-dihydropyridines under solvent-free condition with good yields. The obtained tripodal 1,4-dihydropyridines were also aromatized with oxone^®/NaNO₂/wet SiO₂ system under mild and heterogeneous conditions quantitatively.     

Optimization of One-Way Quantum Computation Measurement Patterns

In one-way quantum computation (1WQC), an initial highly entangled state, called a graph state, is used to perform universal quantum computations by a sequence of adaptive single-qubit measurements and post-measurement Pauli-X and Pauli-Z corrections. 1WQC computation can be represented by a measurement pattern (or simply a pattern). The entanglement operations in a pattern can be shown by a graph which together with the identified set of its input and output qubits is called the geometry of the pattern. Since a pattern is based on quantum measurements, which are fundamentally nondeterministic evolutions, there must be conditions over geometries to guarantee determinism. These conditions are formalized by the notions of flow and generalized flow (gflow). Previously, three optimization methods have been proposed to optimize 1WQC patterns which can be performed using the measurement calculus formalism by rewriting rules. However, the serial implementation of these rules is time consuming due to executing many ineffective commutation rules. To overcome this problem, in this paper, a new scheme is proposed to perform the optimization techniques simultaneously on patterns with flow and only gflow based on their geometries. Furthermore, the proposed scheme obtains the maximally delayed gflow order for geometries with flow. It is shown that the time complexity of the proposed approach is improved over the previous ones.