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  • Open access
  • 22 Reads
A simple, convenient three component one-pot procedure for the synthesis of benzimidazolo-quinazolinone derivatives in the presence Silica-based sulfonic acid (MCM-41-SO3H): a efficient and practical catalyst

A variety of quinazolinones are readily prepared via one-pot three-component reaction in good to excellent yields. The desired products were obtained from the reaction of dimedone, various aldehydes with 2-aminobenzimidazole under mild reaction conditions using MCM- 41-SO3H as effective catalyst in green and reusable catalyst in refluxing ethanol has been developed. Starting from the corresponding available materials, this friendly and environmentally free-metal procedure has been successfully extended to the synthesis of benzimidazoquinazolinones. The salient advantages of this method are mild reaction conditions, nontoxic and inexpensive catalyst, environmentally benign, high to excellent yields, shorter reaction times, easy operation, and no column chromatographic separation.[1,2]

[1] M. Heravi, F. Derikvand, L. Ranjbar, “Sulfamic acid–catalyzed, threeComponent, one-pot synthesis of [1, 2, 4] triazolo/benzimidazolo quinazolinone derivatives”, synthetic communications, 2010, 677–685.

[2] Gh. H. Mahdavinia, M. M. Ghanbari, H. Sepehrian, F. Kooti, “MCM-41 functionalized sulfonic acid catalyzed one-pot synthesis of 1,8-dioxo-octahydroxanthenes”, 2010, 117-120.

  • Open access
  • 28 Reads
Highlight on the reactivity of PhSeZnX

The first bench stable selenolates, PhSeZnHalides have been synthesized through a completely atom economy oxidative insertion of the elemental zinc on the commercially available PhSeHalides. These reagents showed the characteristic nucleophilic reactivity which will be reviewed in this report. All of the reactions were strongly accelerated when effected in water suspension. Alkyl, aryl, vinyl and acyl substitutions, ring-opening reactions of epoxides and aziridines and Michael type addition will be described including the role of the zinc in the control of the chemoselectivity and stereoselectivity.

  • Open access
  • 21 Reads
Superbasic system CsOH/DMSO as a reagent for a fast one-step synthesis of symmetrical dialkyl trithiocarbonates

Symmetrical dialkyl trithiocarbonates were readily synthesized in excellent yields by one-step reaction
of carbon disulfide and various alkyl halides under mild reaction conditions in the presence of
cesium hydroxide as a super basic system. This method provides a synthesis of symmetrical dialkyl
trithiocarbonates in short reaction times without the use of highly toxic starting materials.

  • Open access
  • 21 Reads
An efficient synthesis of bis(indolyl) methanes and N, N'-alkylidene bisamides by silzic under solvent free conditions

An operationally simple and green method for the synthesis of a wide range of bis(indolyl)methanes, and N,N'-alkylidene bisamides  under mild conditions, with excellent yields using silzic, has been developed. This improved method furnishes in good yields bis(indolyl)methanes derivatives starting from indole and  aldehydes, or ketones, and N,N'-alkylidene bisamides derivatives starting from acetamide and aldehydes. the catalytic system was reused up for three times with The same efficiency

  • Open access
  • 17 Reads
Benzo[a]phenoxazinium chlorides functionalized with chloride atoms and/or ester groups

Fluorescent probes are recognised tools in the various fields, including in studies of biochemical processes, diagnosis of disease, and detection of hazardous compounds, among others. For biological and medicinal applications, fluorescent near-infrared (NIR) probes are more adequate, due to the reduced interference with the self-fluorescence of the biological material, in addition to less harming effects induced by light at wavelengths longer than 600 nm.

With the aim of contributing to the development of NIR probes with applications in biomedicine, our research group is committed to the development of new water-soluble benzo[a]phenoxazine derivatives and the evaluation of their photophysical and biological potential. Herein we report the photophysical behaviour in anhydrous ethanol of four synthesised benzo[a]phenoxazinium chlorides, possessing the (3-chloropropyl)amino and/or (4-ethoxy-4-oxobutyl)amino groups at 5- and 9-positions of the polycyclic system.

 

  • Open access
  • 27 Reads
Catalyzing the Oxidation of Alcohols to Aldehydes with an Efficient Zr-based Metal-Organic Framework

Metal-organic frameworks (MOFs) as zeolite analogues with permanent porosity and absorption capacity are a class of hybrid functional materials that are self-assembled by the coordination of metal cations with organic linkers. MOFs have received considerable attention due to their high surface area, well-defined structure and chemical tenability. These unique properties enable myriad applications in various fields such as catalysis, gas storage, separation, drug delivery, and chemical sensing.

The title material are among the first examples of Zr(IV)-based UiO (University of Oslo) MOFs with coordinative unsaturated active metal centers.

From both synthetic and industrial points of view, Liquid-phase oxidation of alcohols is a very attractive reaction for the preparation of intermediates and fine chemicals. A case in point is the oxidation of primary alcohols to aldehydes which is a fundamentally important reaction in both laboratory and commercial scales.

The oxidation of alcohols has been traditionally achieved with stoichiometric amounts of inorganic oxidants. In this work, Zr-benzenedicarboxylate (UiO-66) is successfully synthesized via a facile solvothermal approach and applied to oxidation reactions as a catalyst.

(UiO-66) is a recyclable and efficient heterogeneous catalyst for oxidation of primary and secondary alcohols to benzaldehydes. Using aqueous hydrogen peroxide as an oxidant in CH3CN, the reaction was investigated. The synthesized sample is characterized by powder X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), Scanning electron microscopy (SEM), BET surface area and Thermogravimetric analysis (TGA).

  • Open access
  • 15 Reads
Copper(I)–Terpyridine, an Efficient Catalyst for the Synthesis of Symmetrical Trithiocarbonates

Symmetrical trithiocarbonates were readily synthesized in excellent yields by reaction of carbon disulfide and various aryl or alkyl halides under mild reaction conditions in the presence of Copper(I) –Terpyridine as an efficient catalyst. This method allows the synthesis of symmetrical trithiocarbonates in short times without the use of highly toxic starting materials.

  • Open access
  • 34 Reads
Explorative application of selenium catalysts in the oxidation of benzyl alcohol.

Oxidation mediated by hydrogen peroxide needs to be accelerate by approrpiate catalyst in order to be completed in a reasonable reaction time. As a part of our investigation in the use of organoselenium cataysts in bio-mimetic oxidative protocol we reported here some preliminary results on the oxidation of benzyl alcohol into the corresponding benzoic acid.

  • Open access
  • 31 Reads
Periodic mesoporous organosilica (PMO-ICS): a highly efficient nanocatalyst for the one-pot multicomponent reactions

Isocyanurate bridging periodic mesoporous organosilica (PMO-ICS) was shown to be a highly active and efficient recyclable catalyst for three-component synthesis of imidazole derivatives from benzoin, different aldehydes and ammonium acetate under mild reaction conditions in short reaction times and good to excellent yields in EtOH. Also, benzimidazole derivatives were efficiently prepared from o-phenylenediamine and different aldehydes in the presence of PMO-ICS. Moreover, the catalyst was also recovered and reused at least four times without significant decrease in its reactivity. The PMO-ICS catalyst was characterizred by Fourier transformer infrared (FTIR) spectroscopy, thermogravimetry analysis (TGA), powder X-ray diffraction (XRD) and nitrogen adsorption–desorption isotherms (NADI) techniques as well as scanning electron microscopy (SEM) and transmission electron microscopy (TEM).

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