Copper and Magnetic Activated Carbon Nanocomposites: Application as Recoverable Catalyst for C-S Coupling Reaction.

In this study, activated carbon (AC) was prepared from pistachio nut shell precursor as agricultural by-product. The prepared AC was used to synthesize an efficient nanocomposite via loading of the copper metal and magnetic nanoparticles (Cu-MAC@C4H8SO3H NCs) onto its structure. The structure of the nanocatalyst was characterized by different methods such as FT-IR, TEM, EDS, XRD, VSM, and TGA analysis. The catalytic activity of the prepared composite was tested in a special C-S coupling, namely with the reaction of 2-mercapto-3-phenylquinazolin-4(3H)-one with iodobenzene or bromobenzene. The products of the aryl thioquinazoline derivatives were obtained in good yields and in short reaction times and the products were characterized with 1H, 13C NMR and CHNS analysis. On the other hand, with easy and high recovery of Cu-MAC@C4H8SO3H NCs through magnetic separation, a simple and green method to enhance the efficiency of the nanocatalyst has been provided. The nanocatalyst was reused in the next reaction in up to five cycles without obvious activity decrease.

Thermal and Microwave-Assisted Synthesis of New Highly Functionalized Bis-ß-lactams from Available Compounds via Bisketene as an Intermediate.

The synthesis of highly functionalized bis-ß-lactams containing aromatic rings was achieved by thermal and microwave-assisted methods starting from easily available 2-(4-hydroxyphenyl)acetic acid and 2,2'-(propane-2,2-diyl)diphenol precursors. The approach to these valuable heterocyclic scaffolds involved formal [2π + 2π] cycloadditions between Schiff bases and novel bisketenes, which were generated in situ, followed by an electrocyclic reaction of zwitterionic intermediates. Reactions carried out under microwave irradiation were clean and gave high yields with significantly reduced reaction times. Interestingly, in the thermal method, the reaction proceeded in a stereospecific manner, and only the trans-cis or cis-cis isomers were formed. However, under the microwave conditions, the reaction proceeded stereoselectively, and other possible isomers such trans-trans and cis-trans isomers were formed in addition to the product formed under thermal conditions. More interestingly, when the two compounds that did not produce any products under thermal conditions were reacted under microwave conditions, one formed the trans-cis isomer and the other formed the cis-trans and trans-trans isomers as two products .

Green synthesis of Ag@AgCl/Elaeagnus angustifolia seed nanocomposite using Elaeagnus angustifolia leaves: an amazing nanophotocatalyst with highly photocatalytic activity under sunlight irradiation.

In this investigation, Ag@AgCl nanoparticles were synthesized by a green and inexpensive method using Elaeagnus angustifolia leaves, as a reducing and stabilizing agent without using any toxic solvent, external halide source, harsh chemicals, or capping agents. In this protocol, the nanophotocatalyst was synthesized via immobilization of Ag@AgCl NPs on the surface of biowaste Elaeagnus angustifolia seed (EAS) as a green support, which prevents the agglomeration Ag@AgCl NPs and improves the catalytic activity. The biosynthesized nanophotocatalyst were characterized by UV-Vis spectroscopy, Fourier transform-infrared spectroscopy (FT-IR), X-ray diffraction (XRD), field emission scanning electron microscopy (FE SEM), energy dispersive X-ray spectroscopy (EDS), and transform electron microscopy (TEM) and inductively couple plasma mass spectrometry (ICP). In order to investigate the photocatalytic activity of the biosynthesized nanophotocatalyst, it was used in the degradation of methylene blue (MB) under sunlight. The results showed that nanophotocatalyst had an excellent photo activity without any agglomeration. In addition, the nanophotocatalyst can be easily be recycled and reused several times without losing its activity. Graphical abstract.

Correction to: Intelligent-activated carbon prepared from pistachio shells precursor for effective adsorption of heavy metals from industrial waste of copper mine.

The original publication of this paper contains a mistake.

Intelligent-activated carbon prepared from pistachio shells precursor for effective adsorption of heavy metals from industrial waste of copper mine.

A novel and efficient bio-adsorbent based on magnetic activated carbon nanocomposites (MAC NCs)-modified by sulfamic acid (H3NSO3) has been developed from pistachio shell precursor as agricultural by-products and then was applied for heavy metal removal. Design an experimental model (Central Composite Design (CCD)) for adopting surface response could efficiently be used for adsorption process, and it is an economical way of obtaining the optimal adsorption conditions based on the limited number of experiments. The variants of adsorbent dosage, metal ion concentration, and contact time were optimized for Cu(II) metal by CCD. In addition, adsorption capacity and isoelectric point (pHzpc) of adsorbent were studied at different pH values. Kinetic and isotherm of adsorption were investigated via the Langmuir and the pseudo-second-order model. The maximum adsorption capacity using the Langmuir model was 277.77 mg g-1 for Cu(II) ions on H2NSO3-MAC NCs. Then adsorption process was investigated for ions of Fe(II), Zn(II), and Ni(II) under optimized condition. Also, the competitive adsorption of Fe(II), Zn(II), and Ni(II) ions mixed solution onto H2NSO3-MAC NCs was conducted. Adsorption-desorption results exhibited that the H2NSO3-MAC NCs can be used up to seven cycles while they have excellent performance. Finally, to evaluate the efficiency of this bio-adsorbent, the removal of heavy metals from wastewater of the Sarcheshmeh copper mine as a real sample was studied. Graphical abstract.

Adsorption capacity of heavy metal ions using sultone-modified magnetic activated carbon as a bio-adsorbent.

A novel magnetic bio-adsorbent has been prepared by the loading of Fe3O4 NPs and immobilization of 1,4-butane sultone on the surface of activated carbon. The activated carbon was synthesized from pistachio shell as a carbon material of biogenic, bio-resources and its use is cost effective. Structure, morphology and magnetic property of the prepared adsorbent were studied by transmission electron microscopy (TEM), vibrating sample magnetometer (VSM), Fourier transform infrared spectroscopy (FT-IR), and thermal gravimetric analysis (TGA). The capacity of the adsorbent for removing heavy metals ions Pb(II), As(III) and Cd(II) was studied using Langmuir adsorption isotherm under ultrasound-assisted condition. The maximum adsorption capacities of Pb(II), As(III) and Cd(II) were found to be 147.05, 151.51 and 119.04 mg g-1, respectively. In addition to high adsorption capacity, this adsorbent shows advantages such as green synthesis, low cast, recyclability, and easy separation. So this nanocomposite can be a suitable absorbent for removal of heavy metal ions from aqueous solutions. Meanwhile, the use of ultrasound radiation is an effective and rapid uptake technology for separating of heavy metal ions from aqueous solutions.

N-pyrrolylketene: a nonconjugated heteroarylketene.

N-Pyrrolylketene (5) is calculated to be destabilized and nonconjugated, with a preferred geometry with the pyrrolyl ring orthogonal to the ketenyl group. Ketene 5 is generated from N-pyrrolylacetic acid (7) with use of Mukaiyama's reagent, and reacts with imines forming ß-lactams 10, with a product ratio correlation of log(cis/trans) with σ(+). Photolysis of N-diazoacetylpyrrole (14) in MeOH gives methyl N-pyrrolylacetate (15) from 5 and also ester 17, evidently by trapping of 2-(1-pyrrolylketene) (21), formed by a new vinylogous Wolff rearrangement.

An efficient one-pot synthesis of octahydroquinazolinone derivatives using catalytic amount of H2SO4 in water.

In this investigation, a practical green chemistry procedure for synthesis of octahydroquinazolinone according to the Biginelli reaction using 5,5-dimethyl-1,3-cyclohexanedione, urea or thiourea, and appropriate aromatic aldehydes in the presence of two drops of concentrated H(2)SO(4) as a catalyst is described in water. This methodology is of interest due to the use of water as a solvent without use of any organic solvent and toxic metals as catalyst, thus minimizing the cost, the operational hazards, and environmental pollution. Also this modified route provides much higher yields and simple work-up procedure of products.