Biography:

In the past Hossein Eshghi has collaborated on articles with Hashem Sharghi and Ali Reza Berenji. One of their most recent publications is Efficient synthesis of macrocyclic diamides. Which was published in journal Tetrahedron.

More information about Hossein Eshghi research including statistics on their citations can be found on their Copernicus Academic profile page.

Hossein Eshghi's Articles: (8)

Efficient synthesis of macrocyclic diamides

AbstractSome new macrocyclic dibenzotrioxadiamides, tribenzotrioxadiamides and tetrabenzohexaoxatetraamide (1–9) have been prepared. Compounds (2–9) were obtained in the macrocyclization step by reacting the dicarboxylic acid dichloride (13) with appropriate diamine in CH2Cl2. The cyclization does not require high dilution techniques or template effect and provides the expected dilactams in high yields, ranging from 80% to 95%. However, the reaction of diamine (14a) with dicarboxylic acid dichloride (13) in high dilution conditions yielded the mixture of dilactam (2) and tetralactam (1) in moderate yields.

Selective monotetrahydropyranylation of symmetrical diols using P2O5/SiO2 under solvent-free conditions and their depyranylation

AbstractSelective protection of one of the hydroxyl group in 1, n-symmetrical diols is achieved by P2O5/SiO2-catalyzed reaction of the diol with dihydropyran under solvent-free conditions at room temperature. This selective protection is simple and it occurred under economically cheap conditions in high yield. The deprotected diol is simply obtained by refluxing of this compound in methanol using the same catalyst without any byproduct formation or additional purifications.

Fe(HSO4)3: An efficient, heterogeneous and reusable catalyst for the synthesis of 14-aryl- or alkyl-14H-dibenzo[a,j]xanthenes

AbstractFe(HSO4)3 has been used as an efficient and recyclable catalyst for the one-pot synthesis of 14-aryl- or alkyl-14H-dibenzo[a,j]xanthene derivatives by the reaction of 2-naphtol and aldehydes. Different types of aromatic and aliphatic aldehydes are used in the reaction and in all cases the products were obtained in good to excellent yields.

Ferric hydrogensulfate catalyzed aerobic oxidative coupling of 2-naphthols in water or under solvent free conditions

AbstractThe symmetric oxidative coupling reactions of 2-naphthol derivatives with both ferric hydrogensulfate in water and silica ferric hydrogensulfate in solvent free conditions were carried out. The advantages of this green procedure are: inexpensive catalyst or co-catalyst, reusability of catalyst, organic solvent-free procedures and simple workup.

Efficient synthesis of novel 9H-xanthen-9-yl derivatives of bidentate heterocyclic nucleophiles by Fe(HSO4)3 as a catalyst

AbstractWe have demonstrated the direct substitution of 9H-xanthen-9-ol with different nucleophilic reagents such as thiazoles, triazoles, tetrazoles, hydrazines and hydrazinecarboxamides in good to high yields. This reaction catalyzed by ferric hydrogensulfate as a heterogeneous acid catalyst in ethanol through SN1 type reaction of pyrylium with a nucleophilic reagent afforded the heterocycle- and aromatic-N-substituted xanthene derivatives as simple marked molecules in short reaction times.

Structure and vibrational analysis of methyl 3-amino-2-butenoate

AbstractThe molecular structure and vibrational spectra of methyl 3-(amino)-2-butenoate (MAB) and its deuterated analogous, D3MAB, were investigated using density functional theory (DFT) calculations. The geometrical parameters and harmonic vibrational wavenumbers of MAB and D3MAB were obtained at the B3LYP/6-311++G(d,p) level. The calculated vibrational wavenumbers were compared with the corresponding experimental results. The assignment of the IR and Raman spectra of MAB and D3MAB was facilitated by calculating the anharmonic wavenumbers at the B3LYP/6-311G(d,p) level as well as recording and calculating the MAB spectra in CCl4 solution. The assigned normal modes were compared with a similar molecule, 4-amino-3-penten-2-one (APO). The theoretical results were in good agreement with the experimental data. All theoretical and experimental results indicate that substitution of a methyl group with a methoxy group considerably weakens the intramolecular hydrogen bond and reduces the π-electron delocalization in the chelated ring system. The IR spectra also indicate that in the solid state, MAB is not only engaged in an intramolecular hydrogen bond, but also forms an intermolecular hydrogen bond. However, the intermolecular hydrogen bond will be removed in dilute CCl4 solution.

ArticleNano-sized NiLa2O4 spinel–NaBH4-mediated reduction of imines to secondary amines

AbstractNano-sized NiLa2O4 spinel was produced by thermal decomposition of Ni–La compounds via a sol-gel method. The well-crystallized spinel structure was formed after calcination at 750 °C. The physicochemical properties of the spinel were investigated using differential thermal analysis, X-ray diffraction, transmission electron microscopy, scanning electron microscopy, and particle size distribution analysis. The results show that the nanoparticles have regular shapes with well-defined crystal faces and consist of uniform quasi-spherical crystallites of average size 40 nm. The refined unit cell parameters are a = 3.861205 Å and c = 12.6793 Å. This new nano-sized NiLa2O4 spinel is an efficient heterogeneous catalyst for the selective conversion of imines to the corresponding secondary amines in the presence of NaBH4 as a reducing agent, in good to excellent yields. All the reactions were completely chemoselective at room temperature and had relatively short reaction times. Secondary amines with different aryl groups, including those bearing electron-withdrawing or electron-donating groups, were obtained under the optimum reaction conditions. The catalyst was readily recovered and was recycled four times with no significant loss of catalytic activity.

Original articleEfficient transport of lead(II) cations in natural water using a liquid membrane system with dicyclohexano-18-crown-6 as carrier

AbstractSelective transport of lead(II) cation across a bulk liquid membrane(BLM) containing dicyclohexano-18-crown-6 (DC18C6) as carriers has been studied. Various factors that affect the transport efficiency of this heavy metal cation have been optimized in order to obtain maximum transport. It has been observed that in the presence of EDTA as stripping agent and triton X-100 as sufficient surfactant in the receiving phase and at the optimum pH of 5, lead can transport with recovery 101 ± 2%. The carrier can selectively and efficiently transport Pb(II) cation from aqueous solutions containing other interfering cations. A possible application of this carrier system and transport process to the preconcentration and recovery of Pb(II) cation from real samples has also been examined.

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