Catalytic and asymmetric Michael reactions constitute very powerful tools for the construction of new C–C bonds in synthesis, but most reports claiming high selectivity are limited to some specific combinations nucleophile/electrophile compound types, only few successful methods deal with generation all-carbon quaternary stereocenters. A contribution solve this gap is presented here based on chiral bifunctional Brønsted base (BB) catalysis use α′-oxy enones as enabling acceptors ambivalent...

The Pd-catalyzed enantioselective C–P cross-coupling between racemic, configurationally stable heterobiaryl triflates and trialkylsilyldiaryl(dialkyl)phosphines has been used for the synthesis of several families enantiomerically enriched phosphines including QUINAP, PINAP, QUINAZOLINAP analogues, which can be performed with good yields enantioselectivities using JOSIPHOS-type bidentate phosphines. strategy relies on two key assumptions: (I) N atom heterocycle is a better ligand than...

Plastic production is skyrocketing due to convenience needs and thus, the amount of plastic waste increasing. There are several different methods handle waste, within which waste-to-energy processes viable options in certain settings. However, combustion materials a complicated complex process that can take place number ways. When exposed heat, polymers behave differently (e.g. have emission factors) not all types recommended be handled through combustion. Therefore, it vital achieve deeper...

The direct α-arylation of cyclic and acyclic ethers with azoles has been achieved, which features a novel iron-catalyzed cross-dehydrogenative coupling (CDC) process.

The antioxidant potential of commonly used synthetic and natural additives, including butylated hydroxytoluene (BHT), hydroxyanisole (BHA), tert‑butylhydroquinone (TBHQ), additive, curcumin have been studied compared by calculating the bond dissociation enthalpy (BDE), ionization (IP), proton (PDE), affinity (PA), electron transfer (ETE) values for each hydrogen donor site. results indicate that, in additive an OH group has highest (lowest BDE value). molecules can be ranked based on their...

Drug repositioning is a high-priority and feasible strategy in the field of oncology research, where unmet medical needs are continuously unbalanced. Disulfiram potential non-chemotherapeutic, adjuvant anticancer agent. However, clinical translation limited by drug's poor bioavailability. Therefore, molecular encapsulation disulfiram with cyclodextrins evaluated to enhance solubility stability drug. The present work describes for first time complexation randomly methylated-β-cyclodextrin. A...

Palladium-catalyzed regio- and enantioselective addition of azole heterocycles to alkoxyallenes was developed (up 92% yields up 94% ee). DFT calculations suggest a new Pd(0)-driven mechanistic pathway proceeding through protonation the Pd-coordinated allene (4-PdL2), which develops strongly nucleophilic character at central C atom.

Pressure sensors based on nitrogen-doped bamboo-shaped carbon nanotubes (N-BCNT) and black (CB) as nanofillers, polyurethane foam (PU) supporting substrate, silicone rubber (SR) a matrix were prepared. Dip coating was used to coat PU with 0.44 wt% nanofiller, including different mixing ratios of N-BCNT CB (5:5; 6:4; 7:3; 8:2; 9:1). Then, the coated is impregnated in SR fill pores. Due higher aspect ratio N-BCNT, it contributes more improving electrical conductivity composites, while fills...

Abstract Enticed by the present scenario of infectious diseases, four new Co(II), Ni(II), Cu(II), and Cd(II) complexes Schiff base ligand were synthesized from 6,6′-((1E-1′E)(phenazine-2,3-dielbis(azanylidene)-bis-(methanylidene)-bis-(3-(diethylamino)phenol)) ( H 2 L ) to ascertain as effective drug for antituberculosis, anti-inflammatory, antioxidant, cytotoxic antimicrobial activities. The organic its metal(II) characterized numerous physical spectroscopic methods, which showed that have a...

ABSTRACT A novel high‐performance liquid chromatography method for the enantioseparation of mirabegron ( R ‐mirabegron), a selective β‐3 adrenergic receptor agonist, using cyclodextrin (CD)‐based chiral stationary phases (CSPs) was developed. Seven different CSPs containing β‐, γ‐, hydroxypropyl‐β‐, sulfobutyl‐β‐, carboxymethyl‐β‐, permethyl‐β‐, and phenylcarbamate‐β‐cyclodextrin were evaluated under both polar organic reversed‐phase conditions. Only Chiral CD‐Ph column displayed...

Abstract A simple change in the polarity of solvent allows both enantiomers substituted succinimides to be obtained enantioselective conjugate addition reaction aldehydes, mainly α,α‐disubstituted, maleimides catalysed by chiral carbamate‐monoprotected trans ‐cyclohexane‐1,2‐diamines. Using a single enantiomer organocatalyst, resulting Michael adducts are high yields simply changing from aqueous DMF (up 84 % ee ) chloroform 86 ). Theoretical calculations used explain this uncommon reversal...

Abstract Ten borylated bipyridines (BOBIPYs) have been synthesized and selected structural modifications made that allow useful structure–optical property relationships to be gathered. These systems further investigated using DFT calculations spectroscopic measurements, showing blue green fluorescence with quantum yields up 41 %. They full mapping of the structure determine where functionalities can implemented, tune optical properties or incorporate linking groups. The best derivative was...

A tandem gold(I)-catalyzed rearrangement/Nazarov reaction of enynyl acetates which efficiently provides cyclopenta[b]indol-1-ones as useful precursors for the synthesis natural and bioactive compounds is described. The synthetic potential methodology demonstrated by first total bruceolline H.

The formation of polycyclic aromatic hydrocarbons (PAHs) is a strong global concern due to their harmful effects. To help the reduction emissions, crucial understanding and deep exploration growth mechanism required. In present work, benzo(a)pyrene was investigated computationally employing chrysene benz(a)anthracene as starting materials. It assumed type methyl addition/cyclization (MAC) valid in this case. Consequently, reactions implied addition reactions, ring closures, hydrogen...

The combination of the sonochemical activation Ni(NO3)2 and Co(NO3)2 in presence Fe(NO3)3 polyethylene glycol consecutive heat treatment formed metal hydroxides offers a cheap efficient method for preparation nickel ferrite cobalt magnetic nanoparticles, which can be successfully applied selective capture fluorescently derivatized N-glycans from human serum. XRD measurement revealed that, besides phase, oxides also form during treatment. amount simple well controlled by temperature...

The interaction between human serum albumin (HSA) and apremilast (APR), a novel antipsoriatic drug, was characterized by multimodal analytical techniques including high-performance liquid chromatography (HPLC), fluorescence spectroscopy molecular docking for the first time. Using an HSA chiral stationary phase, APR enantiomers were well separated, indicating enantioselective binding protein analytes. influence of chromatographic parameters—type concentration organic modifier, buffer type,...

The chiral separation capability of Chiral-CD-Ph column, containing phenylcarbamate-β-cyclodextrin as the selector in polar organic mode was investigated. A total twenty-five compounds with different structures and acid-base properties were evaluated, twenty them separated using acetonitrile or methanol eluent. effects various chromatographic parameters, such type proportion modifier, flow rate, column temperature analyzed detail relation to performance. U-shape retention curve observed when...

Cu salts have been found to promote the cycloaddition reaction of sydnones and terminal alkynes, providing significant reduction in times. Specifically, use Cu(OTf)2 is provide 1,3-disubstituted pyrazoles, whereas simply switching promoter system Cu(OAc)2 allows corresponding 1,4-isomers be produced. The mechanism Cu-effect each case has investigated by experimental theoretical studies, they suggest that functions Lewis acid activation sydnone, promotes formation reactive Cu(I) acetylides.

Micellisation process for sodium dodecyl sulphate and cholate in 1∶1 molar ratio was investigated a combined approach, including several experimental methods coarse grained molecular dynamics simulation. The critical micelle concentration (cmc) of mixed determined by spectrofluorimetric surface tension measurements the temperature range 0–50°C values obtained agreed with each other within statistical error measurements. In 0–25°C cmc are independent while were increased at higher...

Abstract The gold(I)‐catalyzed tandem rearrangement/Nazarov reaction of propargylic ester derivatives is a useful strategy for the synthesis cyclopenta‐fused N‐heterocyclic structures present in many natural compounds. Readily available lactams are converted into enol phosphates and triflates coupled to propargyl alcohols under Sonogashira conditions. After acetylation, gold‐catalyzed rearrangement enynyl acetates readily occurs when using 3–5 mol‐% gold(I) catalyst. generates divinyl cation...

A metal-free protocol of chlorination C–H bond with NCS is presented. Both experiments and theoretical analysis suggest NHPI functions as a catalyst rather than an initiator.

Pressure-assisted stereospecific capillary electrophoresis method was developed for the determination of enantiomeric purity antiparkinsonian agent (R)-rasagiline. The optimized method, 50 mM glycine-HCl buffer pH 2, supplied with 30 sulfobutylether-β-cyclodextrin, at 35°C, applying 12 kV in reversed polarity, and -8 mbar pressure (vacuum), short-end injection -25 × 2 s, successful baseline separation rasagiline enantiomers (Rs = 3.5 ± 0.1) a short analysis time. validated according to...

A reversed-phase high-performance liquid chromatographic (HPLC) method was developed for the simultaneous determination of potential impurities dexketoprofen, including distomer R-ketoprofen. After screening separation capability four polysaccharide columns (Lux Amylose-1, Lux Amylose-2, Cellulose-1 and Cellulose-2) in polar organic modes, appropriate enantioseparation observed only on Amylose-2 column an acidified acetonitrile/water mixture. detailed investigation mobile phase composition...