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Solvent-free

Tìm thấy 19+ kết quả cho từ khóa "Solvent-free"

Economic synthesis of quinaldinium fluorochromate(VI), (QnFC), and solvent-free periodic acid oxidation of alcohols catalyzed by QnFC

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Economic synthesis of quinaldinium fluorochromate(VI), (QnFC), and solvent-free periodic acid oxidation of alcohols catalyzed by QnFC. A highly efficient, simple, chemoselective, and environmentally benign procedure for QnFC (3 mol%) catalyzed oxidation of primary and secondary alcohols to aldehydes and ketones using 1.1 equiv of H 5 IO 6 under solvent-free conditions is described.. Key words: Periodic acid, solvent-free, oxidation of alcohols, quinaldinium fluorochromate(VI).

A microwave-assisted highly stereoselective one-pot Wittig reaction under solvent-free conditions

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A microwave-assisted highly stereoselective one-pot Wittig reaction under solvent-free conditions. Abstract: We report a novel microwave-assisted two-step, one-pot protocol for the synthesis of olefins (alkenes) via Wittig reaction. The reaction was carried out under solvent-free conditions using basic alumina both as a heterogeneous catalyst and a solid support.

Metal- and solvent-free preparation of benzo[4,5]imidazo[1,2-a]pyrimidine derivatives catalysed by deep eutectic solvents

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Metal- and solvent-free preparation of benzo[4,5]imidazo[1,2-a]pyrimidine. derivatives catalysed by deep eutectic solvents. A straightforward method for the preparation of benzo[4,5]imidazo[1,2-a]pyrimidine derivatives catalysed by an acidic deep eutectic solvent from choline chloride (ChCl) and phenol via the Biginelli reaction of 2-aminobenzimidazole, ethyl acetoacetate, and aldehydes has been developed under metal- and solvent-free conditions.

Boric acid as an efficient and green catalyst for the synthesis of 2-amino-4,6-diarylnicotinonitrile under microwave irradiation in solvent-free conditions

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Key words: Boric acid, microwave irradiation, solvent-free, green method, 2-amino-4,6-diarylnicotinonitrile. The removal of toxic solvents in organic synthesis is introduced as the most significant purpose of green chemistry that includes solvent-free reactions. Solvent-free reactions have attracted noticeable attention because they enhance yield, save energy, reduce pollution, prevent solvent wastes, toxicity, and facilitate the methods..

Preparation of G-CuO NPs and G-ZnO NPs with mallow leaves, investigation of their antibacterial behavior and synthesis of bis(indolyl)methane compounds under solventfree microwave assisted dry milling conditions using G-CuO NPs as a catalyst

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An efficient and clean synthesis of bis(indolyl)methanes in a protic solvent at room temperature. doi: 10.1007/bf02910889. doi: 10.1016/jmolcata200603043. Synthesis of Bis(indolyl)methanes using a Catalytic Amount of ZnO under Solvent-Free Conditions. doi: 10.1134/s . doi: 10.22034/ajca2020106912. doi: 10.1016/S . doi: 10.4236/anp201321012 P. 10.1016/S . doi: 10.1016/jarabjc .

Poly(N-vinylimidazole): A biocompatible and biodegradable functional polymer, metal-free, and highly recyclable heterogeneous catalyst for the mechanochemical synthesis of oximes

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The low temperature, solvent-free condition, and the formation of PVIm∙HCl suppress the possible hydrolysis of the obtained oximes, which can be promoted in the presence of free hydrochloric acid and normal environmental humidity in the laboratory.. a Reaction conditions: 4-Nitrobenzaldehyde (5.0 mmol), hydroxylamine hydrochloride (6.0 mmol), room temperature, solvent-free..

4,4’-trimethylenedipiperidine as a nitrogen heterocycle solvent and/or catalyst: Liquid phase tandem Knoevenagel–Michael condensation

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Mechanochemical solvent-free and catalyst-free one-pot synthesis of pyrano[2,3-d]pyrimidine- 2,4(1H,3H)-diones with quantitative yields. doi: 10.3390/molecules14010474. Glycerol as a biodegradable and reusable promoting medium for the catalyst-free one-pot three component synthesis of 4H-pyrans. doi: 10.1039/c2gc35135h. Magnetic nanoparticles catalyzed synthesis of diverse N-heterocycles. doi: 10.1007/s z.

Advances in polymer based Friedlander quinoline synthesis

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Titania nanomaterials: Efficient and recyclable heterogeneous catalysts for the solvent-free synthesis of poly-substituted quinolines via Friedlander hetero-annulation. A mild and highly efficient Friedländer synthesis of quinolines in the presence of heterogeneous solid acid nano-catalyst. Synthesis of quinolines using nano-flake ZnO as a new catalyst under solvent-free conditions.

A Challenging Classic Coupling: Esterification of Camphoric Acid - a Steric-Hindered Polar Carboxylic Acid and Solanesol - a Long-Chain Nonpolar Alcohol

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A vial containing a mixture of camphoric anhydride (20.0 mg, 0.11 mmol), solanesol 95% (76.2 mg, 0.115 mmol), with or without DMAP (13.4 mg, 0.11 mmol), and 1 mL of solvent except for the cases of solvent-free. Synthesis and purification of solanesyl camphorate.

Crystal structure and Hirshfeld surface analysis of 1,2-ethylene-bis (para-methyl pyridinium) dichromate as a new selective and mild agent in oxidation of alcohols

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Crystal structure and Hirshfeld surface analysis of 1,2-ethylene-bis (para-methyl pyridinium) dichromate as a new selective and mild agent in oxidation of alcohols. is used as a new oxidizing agent in conversion of some alcohols to their corresponding carbonyl compounds in CH 3 CN solvent and also under solvent-free conditions. However, a much shorter reaction time is achieved in solvent-free conditions.

Tổng hợp một số dẫn xuất Coumarin bằng phương pháp sử dụng lò vi sóng

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The microwave-assisted solvent-free synthesis of coumarins has many advantages: closed reaction system, solvent free, no use of heat sources, etc. Synthesis of new oxadiazole,. Regioselective synthesis of benzo[c]chromen-6-ones by one-pot cyclocondensation of 1,3-bis(trimethylsilyloxy)- 1,3-butadienes with 4-chloro-2-oxo-2H-chromene- 3-carbaldehyde, Tetrahedron Letters, 51(36):.

Application of guanidine and its salts in multicomponent reactions

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Zomordbakhsh et al. synthesized 2,4,6-triarylpyridine derivatives 116 by the reaction of chalcone derivatives 115 with guanidine 46 and acetophenones 5 in solvent-free conditions (Scheme 44).

Graphite oxide catalyzed synthesis of β-amino alcohols by ring-opening of epoxides

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The comparison of entries 2 and 3–5 clearly indicates that the tested solvents do not improve the reaction yield and solvent-free conditions are better. The obtained results under our experimental conditions showed that the reaction is faster under solvent-free conditions.

Amino-functionalized mesostructured cellular foam silica: A highly efficient and recyclable catalyst in the Knoevenagel condensation reaction

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MCF-NH 2. 1 MCF-NH 2 Solvent-free c 25.0 82. 2 MCF-NH 2 Solvent-free d 22.0 90. 3 MCF-NH 2 C 2 H 5 OH d 36.0 91. 4 MCF-NH 2 H 2 O d 8.7 88. 5 MCF-NH 2 C 2 H 5 OH-H 2 O (3:1) d,e 1.0 94 6 MCF-NH 2 C 2 H 5 OH-H 2 O (2:2) d,e 2.7 92 7 MCF-NH 2 C 2 H 5 OH-H 2 O (1:3) d,e 3.5 93.

Acid-activated clay as heterogeneous and reusable catalyst for the synthesis of bioactive cyclic ketal derivatives

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The Gold(I)/AgBF 4 system has been proven as an efficient catalyst in the transformation of alkynes into cyclic acetals and thioacetals, using toluene as solvent. Scope of alcohols using Clay-H0.5.. In contrast, Clay-H0.5 has both Brönsted and Lewis active sites, affording a synergistic catalyst in acetalization and thioacetalization without an additive under solvent-free conditions.. Clay-H0.5 has particularly interesting Brönsted acid sites where chemical reactions occur.

Synthesis, cytotoxic assessment, and molecular docking studies of 2,6-diaryl-substituted pyridine and 3,4- dihydropyrimidine-2(1H)-one scaffolds

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Finally, 0.015 g of the nanocatalyst and 400 W of microwave irradiation under solvent-free conditions were obtained as the optimum conditions.. After optimization of the reaction conditions, reactions of ethyl acetoacetate with a wide range of substituted aldehydes (1a–1r) and urea were performed in the presence of CoFe 2 O 4 @silica sulfuric acid MNPs under solvent-free conditions with microwave irradiation within 3–5 min (Table 3). The yields of all of the reactions were good to excellent.

Sustainable process for the production of symmetrical dibasic acid ester-based thermal energy storage materials from lipids

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Thus, in the present work, a series of dibasic acid esters were synthesized through ionic liquid catalyzed scalable chemical esterification or transesterification reactions in a solvent-free medium. The starting compounds, dicarboxylic acids or their methyl esters and fatty alcohols or cholesterol, were reacted in the ratio of 1:2 respectively and the synthesized esters were characterized by FT-IR, 1 H NMR, and 13 C NMR..

Graphite oxide as an efficient solid reagent for esterification reactions

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The esterification reaction in the presence of a solid acid, GO, in a solvent-free system proved to be highly efficient on the investigated substrates. The esterification of aliphatic and aromatic acids with aliphatic and aromatic alcohols afforded the corresponding esters in the presence of GO. This method has several advantages as the reaction occurs in solvent-free conditions, and takes place in short reaction times and mild conditions..

Recent synthetic methodologies for pyrimidine and its derivatives

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Aminopyrido[2,3-d]pyrimidines 243 were achieved in three synthetic steps, initiating from the coupling of arylethylidenemalononitriles 239 with different acetophenones 240 in the presence of ammonium acetate or ammonium carbonate under solvent-free conditions to achieve 3-cyano-2-aminopyridines 241.

Electrochemical Capacitors: Ionic Liquid Electrolytes

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Solvent-free IL. Double-layer thickness. Figure 2 Schematic representation of the double layer at the negatively charged carbon electrode–electrolyte interface in (a) conventional electrolyte solution and (b) solvent-free ionic liquid (IL) electrolyte..