Ni(II)-Schiff base/SBA-15: a nanostructure and reusable catalyst for one-pot three-component green synthesis of 3,4-dihydropyrano[3,2-c]chromene derivatives

Research on Chemical Intermediates - An efficient, rapid, and environmentally benign Ni(II)-Schiff base/SBA-15-catalyzed one-pot three-component cyclocondensation process was described via the...     

Hydrophilic alginate based multidentate biopolymers for surface modification of CdS quantum dots

We report that sodium alginate and its graft-copolymers with (2-dimethylaminoethyl) methacrylate may attach to the surface of colloidal CdS-thioglycerol quantum dots (QDs) via a ligand exchange process and result in water-soluble and highly stable QD supramolecules. Optical properties of modified QDs in water showed that the emission intensity of QDs was still high after surface passivation.     

Bi(NO3)3 · 5H2O mediated synthesis of 4,4′-diaminotriarylmethane leuco malachite compounds under solvent-free conditions

In this report, we described the synthesis and characterization of a variety of diaminotriarylmethane derivatives with dimethylamino functional groups. These compounds were synthesized by the tandem regio-selective electrophilic aromatic substitution reaction of N,N-dimethylaniline with aryl aldehydes to form the corresponding diaminotriarylmethane compounds. In our strategy, Bi(NO₃)₃ was used as a catalyst under solvent free conditions to afford the desired products in good to excellent yields.      

Efficient solvent-free synthesis of pyridopyrazine and quinoxaline derivatives using copper-DiAmSar complex anchored on SBA-15 as a reusable catalyst

A catalytic system comprising mesoporous silica functionalized with Cu(II)-DiAmSar was synthe-sized. This was demonstrated as an efficient heterogeneous catalyst for the synthesis of biologically useful pyridopyrazine and quinoxaline heterocycles under solvent-free conditions. X-ray diffraction, transmission electron microscopy, N2 adsorption-desorption, Fourtier transformation infrared spectroscopy, and thermogravimetric analysis were used to characterize the catalyst and investi-gate the texture of SBA-15 during the grafting process.     

UV-prepared salep-based nanoporous hydrogel for controlled release of tetracycline hydrochloride in colon

A highly swelling nanoporous hydrogel (NPH) was synthesized via UV-irradiation graft copolymerization of acrylic acid (AA) onto salep backbone and its application as a carrier matrix for colonic delivery of tetracycline hydrochloride (TH) was investigated. Optimized synthesis of the hydrogel was performed by the classic method. The swelling behavior of optimum hydrogel was measured in different media. The hydrogel formation was confirmed by Fourier transform infrared spectroscopy (FTIR) and thermo-gravimetric analysis (TGA/DTG/DTA). The study of the surface morphology of hydrogels using SEM showed a nanoporous (average pore size: about 350nm) structure for the sample obtained under optimized conditions. The drug delivery results demonstrated that this NPH could successfully deliver a drug to the colon without losing the drug in the stomach, and could be a good candidate as an orally administrated drug delivery system.     

Rapid and Highly Sensitive Detection of Target DNA Related to COVID-19 Virus With a Fluorescent Bio-conjugated Probe via a FRET Mechanism

Journal of Fluorescence - A novel cyanine 3 (Cy3)-based bio-conjugated sensor has been developed to detect target DNA or extracted RNA from COVID -19 samples using the fluorescence resonance energy...     

Copper(II)–diaminosarcophagine‐functionalized SBA‐15: a heterogeneous nanocatalyst for the synthesis of benzimidazole,benzoxazole and benzothiazole derivatives under solvent‐free conditions

Solvent‐free organic reactions were studied over periodic mesoporous silica (SBA‐15) containing a Cu(II) organometallic complex. This heterogeneous catalyst was achieved by coordination of Cu(II) ions with the diaminosarcophagine ligand and then its grafting onto the surface of SBA‐15. This catalyst displayed ordered mesoporous channels, which implies an extremely high dispersion of the Cu(II) complex and the convenient diffusion of reactant molecules into the pore channels. Therefore, this catalyst can offer high activity and also facile separation or recycling when compared with its homogeneous counterparts. Copyright © 2015 John Wiley & Sons, Ltd.     

OH−/Silica-Mediated One-Pot Synthesis of Dithiocarbamates Under Solvent-Free Conditions

Abstract

An efficient, versatile, and environmentally benign method for the synthesis of dithiocarbamates under solvent-free conditions is reported. The Michael addition of electron-deficient alkenes with alkyl or aryl amines and CS₂ in the presence of OH^?/silica in a one-pot three-component reaction protocol gave the corresponding dithiocarbamates in good to excellent yields. This method is suitable for a wide range of amines and a variety of Michael acceptors in solvent-free conditions. The results of the present work show the desired products in excellent yields.     

KF/Al2O3‐Mediated N‐Alkylation of Amines and Nitrogen Heterocycles and S‐Alkylation of Thiols

KF/Al₂O₃ efficiently catalyzes N‐alkylation of heterocyclic, primary, and secondary amines and S‐alkylation of thiols with a variety of alkyl halides. The N‐alkylation and S‐alkylation adducts were produced in good to excellent yields and in short times.