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An unprecedented and efficient methodology for the synthesis of 2,4-dichloro-substituted pyrano[2,3-d]pyrimidines and 2,4-dichloro-substituted furo[2,3-d]-pyrimidines is conducted through the one-pot heterocyclization and four-component condensation of acetophenone derivatives, various aromatic aldehydes/potassium iodide, malononitrile, and carbon tetrachloride. The cerium(IV) ammonium nitrate (CAN) was used as a single electron oxidant and ionic liquid (HTPB) as a green promoter under mild conditions at ambient temperature for synthesizing pyrimidine derivatives in high yields. A possible radical mechanism is proposed for these transformations. CAN is found to play an essential role in each step of the reaction. The major advantages of this methodology are experimentally simplicity, environmentally benign, nontoxic, and inexpensive catalyst, excellent yields, and short reaction times. [ABSTRACT FROM AUTHOR]

The aim of this research is the study of hexyltriphenylphosphonium bromide (HTPB) ionic liquid as a bifunctional promoter (solvent and catalyst) in the presence of cerium(IV) ammonium nitrate as a single electron oxidant for the Michael reaction at room temperature and solvent-free conditions. A novel, one-pot and environmentally benign the process to achieve the chemoselective of 2-(3-oxo-1,3-diarylpropyl)malononitrile derivatives instead of 2-(1,3-diarylallylidene)malononitriles using a three-component reaction involving acetophenone derivatives, various aromatic aldehydes and malononitrile was developed. This protocol is simple and provides biologically interesting products in good yields, short reaction times at ambient conditions without the need for using volatile solvents. The remarkable feature of this method is the chemoselectivity of its which makes this protocol effective and distinctive. [ABSTRACT FROM AUTHOR]

A new and simple method for synthesizing iodohydrins and iodoethers from aromatic alkenes is described. Iodohydrins and iodoether derivatives were prepared in excellent yield using Mercury(II) tetrafluoroborate (Hg(BF4)2.SiO2)/I2 in aqueous THF or alcohols (methanol, iso-propanol and tert-butanol). The reactions take place at room temperature, short reaction times, and high regioselectivity, following Markovnikov fashion. [ABSTRACT FROM AUTHOR]

A new and simple method for synthesizing iodohydrins and iodoethers from aromatic alkenes is described. Iodohydrins and iodoether derivatives were prepared in excellent yield using Mercury(II) tetrafluoroborate (Hg(BF4)2.SiO2)/I2 in aqueous THF or alcohols (methanol, iso-propanol and tert-butanol). The reactions take place at room temperature, short reaction times, and high regioselectivity, following Markovnikov fashion. [ABSTRACT FROM AUTHOR]

Acridine derivatives were synthesized by reaction of dimedone, aromatic amines/ammonium acetate and various aromatic aldehydes in the presence of a new and green graphene oxide incorporated strontium magnetic nanocatalyst (MSrGO NCs) under solvent-free conditions. This methodology offers many advantages including operational simplicity, good to excellent yields (up to 97%), short reaction times, the remarkable magnetic property of the nanocomposite, and easy separation of the nanocatalyst from the reaction mixture by magnetic decantation and reused several times without significant loss of catalytic activity. [ABSTRACT FROM AUTHOR]

Fumaric and maleic acids are utilized as two environmental-friendly and efficient catalysts for a one-pot, pseudo five-component coupling reaction, containing aromatic amines, aromatic aldehydes and methyl acetoacetate/ethyl acetoacetate. In this work, a variety of differently substituted aldehydes and amines were tolerated very well, affording cyclic compounds with two consecutive stereogenic centers in moderate to high yields and with excellent diastereoselectivities. In this research, the catalytic effect of maleic acid is compared with that of fumaric acid. According to the obtained results in the presence of both of them, products were produced with the same streochemistry. These reactions were performed under mild conditions to yield 1,2,5,6-tetrahydropyridine-3-carboxylate derivatives with good to excellent yields (46-91%). When fumaric acid was used instead of maleic acid as catalyst the yields of products were relatively low. This is probably because of the stereochemistry of fumaric acid. The main benefits of this process are the easy work-up, short reaction times, green catalysts and no chromatographic purifications. The work-up of these reactions involves only a filtration and a simple washing step with EtOH, and there is no need for column chromatography. [ABSTRACT FROM AUTHOR]

Herein, we described a one-pot, three-component and environmentally benign method for the synthesis of ß-amino ketones based on the reaction of acetophenones, aromatic aldehydes, and aromatic amines using maleic acid as a green catalyst in ethanol as green solvent. The present methodology offers several advantages including good yields, mild reaction conditions and an inexpensive catalyst with a very easy work up. In addition, this method excludes the use of volatile organic solvents, tedious workup and column chromatographic purification of compounds, making the method greener, convenient and superior. All new compounds were well characterized by IR, 1H and 13C NMR spectroscopy and physical data. [ABSTRACT FROM AUTHOR]

A simple, green, and direct three-component condensation of acetophenone, aromatic aldehydes with 3-oxo-N-phenylbutanamide (acetoacetanilide) to generate some novel (1S,6R)/(1R,6S)-2-oxo-N,4,6-triarylcyclohex-3-enecarboxamide derivatives was carried out over K2CO3 (10 mol%) with high efficiency in water/ethanol as green solvent at room temperature. This protocol proceeded via Claisen-Schmidt condensation and Michael addition. The present methodology offers several advantages, such as short reaction time, high yield, more readily available and inexpensive materials, more environmentally friendly, no need for column chromatography, simple work-up procedure, and the absence of volatile and hazardous organic solvents. [ABSTRACT FROM AUTHOR]

A novel magnetic SrFeGO nanocatalyst (NC) was synthesized through a simple sol–gel technique by introducing strontium and iron oxide nanoparticles onto graphene. The synthesized NC was characterized using FT‐IR and FE‐SEM. Subsequently, the catalytic activity of SrFeGO was tested in a reaction between β‐dicarbonyl compounds and aniline derivatives to gain β‐enamino ketone derivatives under solvent‐free conditions. It was found that SrFeGO NC is a potential catalyst for the synthesis of β‐enamino ketones. The β‐enamino ketone produced by such reactions could be isolated in high purity without the need for chromatographic purifications. The newly prepared magnetic graphene oxide nanocomposite could be recovered and reused for numerous times with no significant decrease in efficiency. Moreover, the protocol has the advantages of excellent yielding (up to 98%) in short a reaction time, benefitting an easy workup procedure and being environmentally friendly. A novel magnetic SrFeGO nanocatalyst (NC) was successfully prepared through a simple sol–gel technique by introducing strontium and iron oxide nanoparticles onto graphene. The as prepared nanocatalyst was well characterized and found to be highly efficient heterogeneous catalyst for the synthesis of β‐enamino ketones under sustainable conditions (solvent‐free at 110 °C in short reaction time). Furthermore, the newly synthesized magnetic graphene oxide nanocomposite could be simply recovered and reused for numerous times without substantial decrease in its catalytic activity. [ABSTRACT FROM AUTHOR]