Synthesis of arylacetic acid derivatives from diethyl malonate using in situ formed palladium(1,3-dialkylimidazolidin-2-ylidene) catalysts

The in situ prepared three component system Pd(OAc)₂/1,3-bis(alkyl) imidazolinium halide LHX (1-5)/Cs₂CO₃ catalyses the arylation of diethyl malonate efficiently with accompanying dealkoxycarbonylation. Imidazolinium salts with bulky benzyl and alkoxyethyl groups were found to be the most efficient and afforded α-arylacetates in high yields when employing a wide variety of substrates.     

A first-principles studies on TlX (X=P, As)

We present an ab initio study of the structural, electronic and thermodynamic properties of TlX(X=P,As). The plane-wave pseudopotential approach to the density-functional theory within the LDA and GGA approximations implemented in VASP (Viena Ab-initio Simulation Package) is used. The calculated lattice parameter, elastic constants, and band structures are compared with other available theoretical results, and good agreement is obtained. In addition, we have calculated the transition pressure (P _t ) from zinc-blende (ZB) to (rock-salt) NaCl structures, and have examined some thermodynamic properties.      

The structure of 1-(p-fluorophenylmethyl)-2-(4-methyl-1-piperazinyl)-1H-benzimidazole hydrogen fumarate

The crystal and molecular structure of the title compound has been determined by X-ray analysis. The 1-(p-fluorophenylmethyl)-2-(4-methyl-1-piperazinyl)-1H-benzimidazole ion cocrystallizes with fumaric acid, (C₁₉H₂₂N₄F⁺·C₄H₃O ₄ ^– ), in space group P-1 with cell dimensions a = 9.938(1), b = 10.131(1), c = 12.712(1) Å, = 86.57(1), = 69.41(2), and = 67.22(2)°. The piperazine N4 atom is protonated and contacts the deprotonated O atom of the fumarate anion through a hydrogen bond. The benzimidazole ring is nearly planar and makes a dihedral angle of 111.25(12)° with the fluorophenyl ring. The piperazine ring adopts a chair conformation.     

Utilization of transport efficacy of novel calix[4]arene-embedded polymer inclusion membrane towards trace metals

In this study, 25,27-bis(3-mercaptopropoxyl)-26,28-dihydroxy calix[4]arene was successfully synthesized from the reaction of calix[4]arene-dialkylbromide derivative with thiourea. The structure of 25,27-bis(3-mercaptopropoxyl)-26,28-dihydroxy calix[4]arene was fully characterized using ¹HNMR, ¹³CNMR and elemental analysis techniques. The obtained mercapto-substituted calix[4]arene derivative was employed as an additive material along with cellulose triacetate (CTA) and 2-nitrophenyl octyl ether (o-NPOE) for the preparation of a novel polymer inclusion membrane (C@PIM). The structure and surface morphology of mercapto-substituted calix[4]arene-embedded polymer inclusion membrane was determined using thermogravimetric analysis, scanning electron microscopy and elemental analysis techniques. Donnan dialysis system was also used to assess the transport efficacy of C@PIM towards Pb(II), Zn(II), Cu(II), Ni(II), Cd(II) and Co(II) ions. The results show that new C@PIM exhibited 99% transport efficacy but also selectivity toward Ni(II) and other ions.     

Synthesis, antihistaminic action and theoretical studies of (4-methoxybenzyl)(1,4,5,6-tetrahydropirimidin-2-yl)amine hydroiodide

In this study, (4-methoxybenzyl)(1,4,5,6-tetrahydropyrimidin-2-yl)amine hydroiodide (2) was synthesized by reaction of 2-methylmercapto-1,4,5,6-tetrahydropyrimidine hydroiodide (1) and 4-methoxybenzylamine. The synthesized compound was tested for its in vitro H1-antihistaminic activity on guinea pig trachea. A promising bronchorelaxant effect of 2 was observed in histamine-contracted guinea pig tracheal chain via H1 receptor antagonism. In addition, the molecular geometry and gauge including atomic orbital (GIAO) ¹H chemical shift values of the title compound in the ground state were calculated using the density functional method (DFT/UB3LYP) and Hartree–Fock (HF) approach using 6–311G+(d), 6–311G+(d,p), LANL2DZ, DGDZVP, and DGDZVP2 basis sets and compared with the experimental data. According to the experimental and theoretical results, HF/6–311G+(d) showed a better fit to experimental values in evaluating ¹H-nuclear magnetic resonance (NMR) chemical shift values. Theoretical studies supported our findings, revealing the N₁₂ atom as the most nucleophilic. In addition, other structures of the compound such as the aromatic ring and OCH₃ group increased this property.     

Synthesis and investigation of cytotoxicity of new N- and S,S-substituted-1,4-naphthoquinone (1,4-NQ) derivatives on selected cancer lines

1,4-Naphthoquinones (1,4-NQ) have been reported to possess a variety of pharma-cological properties including antibacterial, antifungal, antiviral, anti-inflammatory, anti-artherosclerotic, and anticancer effects. In this study, new N- and S,S-substituted-1,4-NQ derivatives were synthesized in excellent yields and were completely characterized by spectroscopic analysis IR, NMR (¹H and ¹³C), MS and microanalysis. The cytotoxic activities of 1,4-NQ derivatives were examined against to A-549, DU145, HCT-116 and MDA-MB-231 cancer cells. Among these compounds, 2-[4-(2-furoyl)piperazine-1-yl]-3-chloro-1,4-NQ 5 and 2,3-bis(cyclobuthylsulfanyl)-1,4-NQ 17 were identified as the most potent anticancer agents with cytotoxic activity against three cell lines (breast (MDA-MB-231), prostate (DU145), colorectal (HCT-116).     

Synthesis of sterically constrained tricyclic pyrrolidinyl alcohol ligands for the enantioselective ethylation of aryl aldehydes: assessment of the influence of ring strain and N-alkyl chain length on asymmetric induction

A series of chiral sterically constrained tricyclic pyrrolidinyl alcohol ligands were synthesized from the appropriate amino acids, and a comparative study of the activity and selectivity of the ligands for the enantioselective ethylation of aromatic aldehydes was carried out. The results obtained were compared with those previously reported for related monocyclic analogues; it was found that the bicyclo[2.2.2]octane backbone fused to pyrrolidine and the groups attached to the carbinol centre, as well as the chain length of the β-amino alcohol, had a marked effect on the enantioselectivity. The enantioselective addition of dialkylzincs to aryl aldehydes in the presence of ligands with diethyl substituents on the carbinol carbon afforded (R)-sec-alcohols in up to 99% enantiomeric excess (ee).     

Graybody radiation phenomena in a fractional manner

In this paper, the graybody radiation phenomena has been handled with the help of fractional calculus. Fractional definition of graybody spectrum has been written in terms of Mittag‐Leffler function. The obtained data from fractional calculus approximation for nearly 2.87 × 10⁷ K have been compared with literature values and standard blackbody radiation.