Participation of ethyl 3-formylindole-2-carboxylate with the Ugi four-component condensation reaction

Multicomponent condensation of ethyl 3-formylindole 2-carboxylate, amines, isocyanide and (S)-N-boc-alanine or (S)-N-boc-serine is described. This Ugi four-component condensation (Ugi-4CC) reaction yielded a series of novel dipeptides containing an indolyl moiety. These compounds exhibit potential biological activity.     

Compressible and incompressible constituents in anisotropic poroelasticity: The problem of unconfined compression of a disk

The governing equations for the theory of anisotropic poroelastic materials with incompressible constituents undergoing small deformations are developed from the theory of anisotropic poroelastic materials without the constituent incompressibility constraint. The development of the constituent specific incompressibility constraint is accomplished by restricting the elastic constants rather than by introducing Lagrange multipliers, the conventional method. The advantage of the approach is insight into the nature of the elastic response that characterizes incompressible poroelasticity. An application of the theory to the unconfined compression of a circular porous disk is presented to illustrate the effects of compressibility vs. incompressibility and transverse isotropy vs. isotropy.     

The Quantum Entanglement in the Back Ground of Gauss-Bonnet Gravity for a Generically Entangled State

In this work the Hawking-Unruh effect on the quantum entanglement of bosonic field in background of a spherically symmetric black hole of Gauss-Bonnet gravity is investigated beyond the single mode approximation. The entanglement decreases due to Hawking-Unruh effect. However, it has been shown that the dimensions of space time, Gauss-Bonnet term and the parameter β of initial entangled state would be influenced on this degradation. In our investigation, we consider the accelerated observer either near or far from the event horizon and inspect entanglement degradation for them. The mutual information of this bosonic system is also calculated in beyond the single mode approximation and we show that the mutual information will have different behavior when the Hawking temperature increases.     

无溶剂条件下离子液体催化香豆素衍生物的绿色合成(英文)

Brnsted acidic ionic liquids, namely 2-pyrrolidonium hydrogen sulfate, N-methyl-2-pyrrolidonium hydrogen sulfate, N-methyl-2-pyrrolidonium dihydrogen phosphate, (4-sulfobutyl)tris(4-sulfophenyl)phosphonium hydrogen sulfate, and triphenyl(propyl-3-sulfonyl)phosphonium toluenesulfonate, catalyzed efficient Pechmann condensation of phloroglucinol with β-keto ethyl/ methyl esters. 5,7-Dihydroxy-4-methylcoumarin and 5,7-dihydroxy-4-phenylcoumarin were prepared in good to excellent yields under mild, ambient, and solvent-free conditions. Pyrano[2,3-h] coumarins were then prepared by one-pot three-component reactions of 5,7-dihydroxy-4-subsituted coumarin, malononitrile, and aldehydes in the presence of catalytic amounts of Br nsted basic ionic liquids, namely 2-hydroxyethylammonium formate, 3-hydroxypropanaminium acetate, 1-butyl-3-methylimidazolium hydroxide, pyrrolidinium formate, and pyrrolidinium acetate, under thermal solvent-free conditions. The catalysts are environmentally benign and can be easily prepared, stored, and recovered without significant loss of activity.     

Silver nanoparticle loaded on activated carbon and activated carbon modified with 2-(4-isopropylbenzylideneamino)thiophenol (IPBATP) as new sorbents for trace metal ions enrichment

The efficiencies and performances of silver nanoparticle loaded activated carbon modified with 2-(4-isopropylbenzylideneamino)thiophenol (IPBATP-Ag-NP-AC) and activated carbon modified with IPBATP (IPBATP-AC), as new sorbents, were evaluated for separation and preconcentration of Cu²⁺, Zn²⁺, Co²⁺, Cd²⁺ and Pb²⁺ ions from real environmental samples. The retained metals content was reversibly eluted using 5?mL of CH₃COOH (6.0?mol?L^?1) and/or 10?mL of 4.0?mol?L^?1 HNO₃ for IPBATP-Ag-NP-AC and IPBATP-AC, respectively. The experimental parameters influence the recoveries of metal ions including pH, amounts of ligand and supports, condition of eluents, sample and eluent flow rates of has been investigated. The preconcentration factors were found to be 100 for Zn²⁺, Cd²⁺, Co²⁺, Cu²⁺ and 50 for Pb²⁺ ions using IPBATP-Ag-NP-AC, and 50 for Zn²⁺, Cd²⁺, Co²⁺, Cu²⁺ and 25 for Pb²⁺ ions using IPBATP-AC. The detection limit of both SPE-based sorbents was between 1.6–2.5?ng?mL^?1 for IPBATP-AC and 1.3–2.5?ng?mL^?1 for IPBATP-Ag-NP-AC. The proposed methods have been successfully applied for the extraction and determination of the understudy metal ions content in some real samples with extraction efficiencies higher than 90% and relative standard deviations (RSD) lower than 2.4%.     

The Reaction of N-Isocyaniminotriphenylphosphorane With Biacetyl in the Presence of (E)-Cinnamic Acids: Synthesis of Fully Substituted 1,3,4-Oxadiazole Derivatives via Intramolecular AZA-Wittig Reactions of in Situ Generated Iminophosphoranes

Abstract

Reaction of N-isocyaniminotriphenylphosphorane with biacetyl in the presence of (E)-cinnamic acids proceeds smoothly at room temperature and under neutral conditions to afford sterically congested 1,3,4-oxadiazole derivatives in high yields. The reaction proceeds smoothly and straightforward under mild conditions and no side reactions are observed.     

AN EFFICIENT PRO CEDURE FOR THE PREPARATION OF MONO,AND DI-BIS-INDOLYL METHANES CATALYZED BY MOLIBDATOPHOSPHORIC ACID

H ₃ PMo ₁₂ O ₄₀ · xH ₂ O was found to be an effective catalyst for the preparation of bis-indolyl derivatives from indole and aromatic, aliphatic, heterocyclic aldehydes or ketones in ethanol at room temperature.     

Computational study on the reaction mechanism of atmospheric oxidation of ethanol with ozone

The reaction of C₂H₅OH and O₃ on the singlet potential energy surface is carried out using the MP2 and CCSD(T)//MP2 theoretical approaches in connection with the 6-311++G(d,p) basis set. Three pre-reactive complexes C1, C2, and C3 are formed between ethanol and ozone at atmospheric pressure and 298.15 K temperature. With variety of the complexes, seven types of product are obtained which four types of them have enough thermodynamic stability. In thermodynamic approach, the most favor product begins with the formation of pre-reactive C2 complex and produces the CH₃CH(OH)₂ + O₂ as final adduct in a process that is computed to be exothermic by ?53.759 kcal/mol and spontaneous reaction by ?51.833 kcal/mol in Gibbs free energy. In kinetic viewpoint, the formation of CH₃COH + cis-H₂O₃ as a final adducts is the most favor path.