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3,3-Disubstituted oxindoles with a stereogenic quaternary carbon center exist widely in various natural products and biologically active compounds. Various strategies have been developed for the synthesis of these enantiomerically enriched frameworks, among them the organo- or metal-catalyzed asymmetric addition of reagents to isatins is the most simple and straightforward method. This review highlights...
In this study, first a stainless steel microreactor composed of an array of microchannels was fabricated using CO 2 laser as a simple, rapid, and inexpensive technique. Then, TiO 2 catalyst bed was synthesized using the sol–gel method by pumping titanium n-butoxide/ethanol and water into the microchannels. A silver nitrate solution was pumped into the TiO 2 catalyst bed microchannels...
In this study, the photocatalytic efficiency of anatase‐type TiO2 nanoparticles synthesized using the sol–gel low‐temperature method, were enhanced by a combined process of copper reduction and surface hydroxyl groups enhancement. UV–light‐assisted photo and NaBH4‐assisted chemical reduction methods were used for deposition of copper onto TiO2. The surface hydroxyl groups of TiO2 were enhanced with...
SiO2-Pr-SO3H has been used as an efficient catalyst for an improved and rapid synthesis of 1,2,4,5-tetrasubstituted imidazoles, by four-component, one-pot reaction of 1,2-diketones, aryl aldehydes, ammonium acetate and substituted aromatic amines in excellent yields under solvent-free conditions.
In this work, pure TiO 2 and samarium, cerium mono-doped and co-doped TiO 2 catalysts were synthesized by an ultrasonic-assisted sol–gel method and their sonocatalytic efficiency studied toward removal of Methyl Orange as a model organic pollutant from the textile industry. The relationship of structure and sonocatalytic performance of catalysts was established by using various techniques,...
SBA-Pr-SO3H with pore sizes of 6nm was determined to be a green and effective solid acid catalyst in the reaction of isatins with indoles under mild reaction conditions for the production of a novel class of symmetrical 3,3-di(indolyl)indolin-2-ones with excellent yields. The antimicrobial activities of the synthesized compounds were tested. Antimicrobial tests demonstrated that the MIC value of compound...
A series of benzofuran-based chalconoids 6a–v were designed and synthesized as new potential AChE inhibitors. The in vitro assay of synthesized compounds 6a–v showed that most compounds had significant anti-AChE activity at micromolar or sub-micromolar levels. Among the tested compounds, 3-pyridinium derivative 6m bearing N-(2-bromobenzyl) moiety and 7-methoxy substituent on the benzofuran ring exhibited...
A simple and clean one-pot method for the preparation of 7-amino-2,4-dioxo-5-aryl-1,2,3,4-tetrahydropyrido[2,3-d]pyrimidine-6-carbonitrile derivatives using 6-amino uracil, various aromatic aldehydes and malononitrile in the presence of sulfonic acid functionalized SBA-15 (SBA-Pr-SO3H) is described. Some of synthesized pyrido[2,3-d]pyrimidines showed antimicrobial activities against some fungi and...
A Cr/SBA-16 catalyst was prepared using Cr(NO3)3 as a precursor and mesoporous silica SBA-16 as a support via a simple impregnation method. The catalyst was characterized using wide-angle X-ray diffraction (XRD), low-angle XRD, N2 adsorption-desorption, transmission electron microscopy, and ultraviolet-visible spectroscopy. The catalyst activity was investigated in the direct hydroxylation of benzene...
Pseudomonas cepacia lipase (lipase PS) is an efficient enzyme which catalyzes the enantioselective asymmetric esterification and/or hydrolysis reactions in high yields and enantio excess of products. In this review, the role of lipase PS in the asymmetric esterification and hydrolysis of various heterocyclic compounds or their precursors is investigated.
An organic–inorganic hybrid optical sensor (LQS) was prepared with post grafting of 8-hydroxy-5-quinoline sulfonic acid onto the surface of LUS-1. Its structure was characterized by powder X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), fourier transform infrared spectroscopy (FT-IR), N2 adsorption/desorption, and thermogravimetry analysis (TGA)...
Pure and samarium doped ZnO nanoparticles were synthesized by a sonochemical method and characterized by TEM, SEM, EDX, XRD, Pl, and DRS techniques. The average crystallite size of pure and Sm-doped ZnO nanoparticles was about 20nm. The sonocatalytic activity of pure and Sm-doped ZnO nanoparticles was considered toward degradation of phenazopyridine as a model organic contaminant. The Sm-doped ZnO...
An organic–inorganic hybrid optical sensor (PQ-SBA-15) was designed and prepared through functionalisation of the SBA-15 surface with 3-piperazinepropyltriethoxysilane followed by covalently attaching 8-hydroxyquinoline. Characterisation techniques, including FT-IR, thermal gravimetric, N2 adsorption-desorption and X-ray powder diffraction analyses, showed that the organic moieties were successfully...
Efficient acidic functionalization of mesoporous silica LUS-1 (Laval University Silica) and its application as a recyclable heterogeneous catalyst for DHP (3,4-dihydro-2H-pyran) protection of alcohols and the subsequent removal of the corresponding protecting group have been reported. This green method offers a number of advantages such as short reaction time, good yields of protection and deprotection,...
Charge separation plays a key role in the conversion of solar energy into chemical energy for use in the redox reaction and as well as in the photocatalytic activity. In this study, SrTiO3 particles with different morphologies including irregular, tetrahexahedron, and cube were synthesized by an in situ solvothermal method. The photocatalytic activity of the synthesized nanoparticles was investigated...
A simple, efficient, and environmentally benign protocol for the synthesis of polyhydroquinoline derivatives was developed using a bio-compatible, heterogeneous, and recoverable mesoporous ionic liquid supported nanoporous silica as a nano-catalyst. The polyhydroquinoline derivatives were obtained by the four-component reaction of aldehyde, Meldrum’s acid, dimedone, and ammonium acetate in excellent...
An efficient acidic functionalization of mesoporous silica LUS-1 (Laval University silica) was carried out by grafting and oxidation of (3-mercaptopropyl)trimethoxysilane. The functionalized LUS-1 was characterized by different methods such as TGA, XRD, BET and SEM methods and its catalytic activity for one-pot synthesis of xanthene derivatives via the three-component condensation reaction of aromatic...
A simple cyanide chemosensor tetranitrile compound 1 was designed and synthesized via an efficient method in the presence of nanoporous SBA-Pr-NH2 as the catalyst. The chemosensor exhibited high selectivity and sensitivity for detecting CN¯ among different anions through a visual color change from light yellow to purple. The results confirmed that the chemosensor 1 causes the color of the solution...
An iminocrown ether was synthesized and its fluorescence properties were studied in the presence of a variety of cations and anions in 99 % aqueous medium. The results revealed the interesting ability of the iminocrown ether in discriminately detection of Cr(III) and Cr(VI) ions in addition to detection of Hg2+ ion. Among various environmentally relevant metal ions, Cr3+ and Hg2+ enhanced and quenched...
A novel 8-hydroxyquinoline-based fluorescent and colorimetric chemosensor was designed, synthesized and fully characterized. The sensor showed high selectivity and sensitivity toward Al3+ over other tested cations in EtOH/H2O (1:99, v/v) medium. The increase in fluorescence intensity was linearly proportional to the concentration of Al3+ with a detection limit of 7.38 × 10−6 M. Moreover, the sensor...