Fe3O4 Nanoparticles as an Efficient and Magnetically Recoverable Catalyst for Friedel–Crafts Acylation Reaction in Solvent-Free Conditions

Application of Fe₃O₄ nanoparticles (NPs) as a robust, very efficient, and magnetically recoverable catalyst was investigated in Friedel–Crafts acylation (FCA) of ferrocene and aromatic compounds. This reaction was performed with acid chlorides in solvent-free conditions at room temperature. The catalyst was easily separated by an external magnetic field from the reaction mixture. The separated catalyst was recycled for several consecutive runs without appreciable loss of its catalytic activity.

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B2O3/Al2O3 as an Efficient and Recyclable Catalyst for the Synthesis of β-Amino Alcohols under Solvent-Free Conditions

A convenient and efficient procedure for the solvent-free synthesis of β-amino alcohols has been achieved via B₂O₃/Al₂O₃-promoted highly regioselective ring opening of epoxides with aromatic amines in good to excellent yields at room temperature. Additionally, the catalyst can be recycled without affecting the catalytic property.     

Sodium Dihydrogen Phosphate as an Efficient Catalyst for One-Pot,Three-Component Synthesis of α-Aminophosphonates Under Solvent-Free Conditions at Room Temperature

A simple, efficient, and general method has been developed for the one-pot, three-component synthesis of α-aminophosphonates from a condensation reaction of trimethyl phosphite, aldehydes, and amines in the presence of sodium dihydrogen phosphate under solvent-free conditions. Thus, α-aminophosphonates were synthesized relatively quickly in good yields at room temperature.     

Al(H_2PO_4)_3 as an Efficient and Reusable Catalyst for One-pot Three-component Synthesis of α-Amino Phosphonates under Solvent-free Conditions

Synthesis of α‐amino phosphonates is described under solvent‐free conditions at 100°C from reaction between aldehydes and amines in the presence of trialkyl phosphites using Al(H₂PO₄)₃ as an efficient and reusable heterogeneous catalyst. The advantages of this procedure are short reaction time, flexibility and having high to excellent yields.     

RuCl3·xH2O: A Novel and Efficient Catalyst for the Facile Synthesis of 1,5-Benzodiazepines Under Solvent-Free Conditions

1,5-Benzodizepines are synthesized in excellent yields via condensation of o-phenylenediamine with ketones having a hydrogen at the α-position. The reaction is performed in solvent-free conditions and 5 mol% of RuCl₃·xH₂O is enough to direct the reaction to completion.     

γ-Al2O3-Supported 12-Tungstosilicic Acid as an Efficient Heterogeneous Catalyst for the Synthesis of α-Aminonitrile

The multicomponent Strecker reaction using trimethylsilyle cyanide was performed in very short reaction times, and α-aminonitriles were prepared in excellent yields in the presence of a catalytic amount of alumina-supported tungstosilicic acid.     

Synthesis of α,β-Unsaturated Ketones using Potassium fluoridealumina Catalyst by Microwave Irradiation

Microwaveirradiationhasf0undalotofapplicati0nsinrecentyears'".Thereactiontimecanbeshortenedgreatlyundermicrowaveirradiation,soitisanewandconvenientsyntheticmethod.Inprevi0uspapers"',wereportedtheethoxylationsofnitro-chlorobenzeneandreactionsofcarboxylicacidwithhalidesunderndcrowaveirradiation.a,6-Unsaturatedketonesareusefulcompounds,whosesynthesiswerenoteasybyconventionalways"9.Ontheotherhand,KF-Al2O3isanewkindofbasecatalyststhatcancatalyzemanyreactionsunderndldconditions,t0givehighcatalytic…     

ZrOCl2·8H2O: An Efficient Catalyst for One-Pot Synthesis of α-Amino Phosphonates Under Solvent-Free Conditions

A highly efficient protocol has been developed for the three-component reaction of an amine, an aldehyde, and diethyl phopshite catalyzed by ZrOCl₂·8H₂O, an environmentally friendly catalyst, at ambient temperature. The catalyst exhibited remarkable activity and tolerated a wide variety of functional groups, providing the desired amino phosphonates in excellent yields under solvent-free conditions. Alternatively, the reaction rate can be significantly enhanced by carrying out the reaction in a monomode microwave reactor as a promoter.     

(NH4)3PW12O40 as an Efficient and Reusable Catalyst for the Synthesis and Deprotection of 1,1‐Diacetates

An efficient method for the synthesis of 1,1‐diacetates (acylals) from different aldehydes in the presence of (NH₄)₃PW₁₂O₄₀ and acetic anhydride under solvent‐free conditions at ambient temperature is achieved. Selective conversion of aldehydes was observed in the presence of ketones. The deprotection of acylals has also been achieved using (NH₄)₃PW₁₂O₄₀ in methanol. The catalyst was found to possess good activity and considerable level of reusability.     

Mild and Efficient Procedure for Michael Addition of N-Heterocycles to α,β-Unsaturated Compounds Using Anhydrous K3PO4 as Catalyst

Imidazole, 1,2,4-triazole, indole, and benzotriazole undergo conjugate additions with α, β-unsaturated carbonyl compounds in the presence of anhydrous potassium phosphate at ambient temperature to afford the corresponding Michael adducts in excellent yields.     

Mg(ClO4)2, an Efficient Catalyst for Synthesis of β-Amino Alcohols by Ring Opening of Epoxides with Amines under Solvent-Free Conditions

Abstract

Commercially available magnesium perchlorate is reported as an extremely efficient catalyst for the ring-opening reaction of epoxide with various primary and secondary amines, especially diphenyl amine, under solvent-free conditions at room temperature.     

Diels-Alder Reactions of N-Functionalized Acryloyl α-Pyrrolidone Derivatives Using FeCl3·6H2O as an Efficient Catalyst under Solvent-free Conditions

Diels-Alder reactions of N-functionalized acryloyl α-pyrrolidone derivatives were investigated, which were catalyzed by FeCl3·6H2O as an efficient catalyst under solvent-free conditions at room temperature. The corresponding cycloadducts with functionalized-pyrrolidone were prepared in high yield with high stereoselectivity by a green chemistry procedure. N-Functionalized acryloyl pyrrolidone derivatives, a kind of pyrrolidone-functionalized chelating α,β-unsaturated ketone usable as a dienophile in Diels-Alder reaction, were synthesized by N-acylation procedure in ionic liquid as a novel synthetic method.     

Heteropoly Acids as Heterogeneous and Reusable Catalyst for α-Thiocyanation of Ketones

Simple, efficient, and mild method for α-thiocyanation of ketones in presence of heteropolyacid has been developed. This methodology offered α-oxothiocyanates in good to excellent yields at room temperature in a highly selective manner. The catalyst could be efficiently recovered from the reaction and reused.     

Amberlyst 15®: An Efficient Green Catalyst for the Synthesis of Heterocyclic Compounds

Russian Journal of Organic Chemistry - Amberlyst 15 (A-15) is one of the most common heterogeneous catalysts in organic synthesis. Since its development in 1962, A-15 has proved to be a highly...     

Brønsted Acidic Ionic Liquid as an Efficient and Reusable Catalyst for One-Pot,Three-Component Synthesis of Pyrimidinone Derivatives via Biginelli-Type Reaction Under Solvent-Free Conditions

A mild and efficient method has been developed for the preparation of pyrimidinone derivatives from the reaction of aromatic aldehydes with cyclopentanone and urea or thiourea in the presence of N-(4-sulfonic acid) butyl triethyl ammonium hydrogen sulfate ([TEBSA][HSO₄]) as the Brønsted acidic ionic liquid and effective catalyst under thermal and solvent-free conditions. Good yields, short reaction times, straightforward workup, reusability of the catalyst, and green conditions are the most obvious advantages of this procedure.

Cu(ClO4)2 · 6H2O as an Efficient Catalyst for the Synthesis of 3,4-Dihydropyrimidin-2(1H)-ones Under Solvent-Free Conditions

Cu(ClO₄) · 6H₂O efficiently catalyzes the three-component Biginelli reaction of aldehyde, β-dicarbonyl compounds, and urea or thiourea under solvent-free conditions to afford the corresponding 3,4-dihydropyrimidin-2(1H)-ones in excellent yields.      

InCl3 as an Efficient Catalyst for Cyclotrimerization of Aldehydes: Synthesis of 1,3,5‐Trioxane Under Solvent‐Free Conditions

1,3,5‐Trioxanes derived from aldehydes were synthesized using indium trichloride as a catalyst. Cyclotrimerization of the aldehydes gave excellent yields under neat conditions within a short span of time.     

Iodine Supported on 3-Aminopropyl Silica Gel as Efficient Catalyst for Acetylation of Alcohols under Solvent-free Conditions

3-Aminopropyl silica gel (I2/APSG) was found to catalyze the acetylation of alcohols and phenols efficiently with acetic anhydride. The reaction is mild and selective with high yields. A wide variety of alcohols and phenols are selectively converted into the corresponding acetates using I2/APSG under solvent-free conditions at room temperature.     

SbCl3 as a Highly Efficient Catalyst for the Acetylation of Alcohols,Phenols, and Amines under Solvent‐Free Conditions

Antimony trichloride has been found to be an efficient and expedient catalyst for the acylation of alcohols, phenols, amines, and sugars with acetic anhydride in high yields and in a short reaction time under solvent‐free conditions at room temperature. Also, racemization of chiral alcohols and epimerization of sugars were not observed in any of the substrates.     

FeCl3·6H2O/C: An Efficient and Recyclable Catalyst for the Synthesis of 2,3-Unsaturated O- and S-Glycosides

A novel method for synthesizing 2,3-unsaturated glycosides has been developed using a handy and eco-friendly immobilized catalyst, FeCl₃·6H₂O/C. A series of 2,3-unsaturated O- and S-glycosides were obtained for bioassay from corresponding 3,4,6-tri-O-acetyl-D-glucal and D-galactal in good to excellent yields (56%–99%) and high anomeric selectivity (α/β = 7:1 to >19:1). Furthermore, the catalyst was efficient on gram-scale reactions and recyclable for at least three times.