A novel bioglycerol-based recyclable carbon catalyst for an efficient one-pot synthesis of highly substituted imidazoles

The new bioglycerol-based carbon catalyst acts as an efficient, readily available, and reusable catalyst for the synthesis of 2,4,5-trisubstituted imidazoles/1,2,4,5-tetrasubstituted imidazoles, when aromatic aldehyde, ammonium acetate/amine, and 1,2-diketone are reacted in acetonitrile.     

Nano-sulfated zirconia as an efficient, recyclable and environmentally benign catalyst for one-pot three component synthesis of amidoalkyl naphthols

One pot synthesis of amidoalkyl naphthols by reaction of aromatic aldehydes,2-naphthol and amide/urea using nano-sulfated zirconia as a catalyst is reported.The reaction was carried out under solvent-free conditions.The method gave good yields of amidoalkyl naphthols in short reaction time.The catalyst is recycled for five consecutive times without loss of activity.     

Protic pyridinium ionic liquid: As an efficient,green and environmentally friendly catalyst for the one-pot synthesis of amidoalkyl naphthol derivatives

A green and efficient synthesis of amidoalkyl naphthol derivatives via the three-component reaction between aryl aldehyde, 2-naphthol and amide derivatives using 2-methylpyridinium trifluoromethanesulfonate ([2-MPyH]OTf) as a catalyst (5 mol%) is described. This method provides several advantages over alternative procedures such as low cost, under thermal solvent-free green procedure, simple procedure and direct isolation of the products in high yields.     

Sulfamic acid: an efficient, cost-effective and recyclable solid acid catalyst for the Friedlander quinoline synthesis

o-Aminoaryl ketones undergo smooth condensation with α-methylene ketones in the presence of sulfamic acid (NH₂SO₃H) (SA) under mild reaction conditions to afford the corresponding polysubstituted quinolines in excellent yields. The catalyst can be recovered by simple filtration and can be recycled in subsequent reactions. The method is simple, cost-effective and environmentally benign.     

Carbon-based nanocatalyst: An efficient and recyclable heterogeneous catalyst for one-pot synthesis of gem-bisamides,hexahydroacridine-1,8-diones and 1,8-dioxo-octahydroxanthenes

Journal of the Iranian Chemical Society - In this abstract, we discuss the progress related to sulfonated carbon-based materials in various acid-catalyzed organic transformations which are then...     

A molybdenum(VI) complex as an efficient catalyst for the synthesis of dihydropyridines

An efficient synthesis of various substituted Hantzsch-1,4-dihydropyridines and hexahydroquinolines, using a molybdenum(VI) complex as homogenous catalyst, from aldehydes, β-keto esters or cyclohexadiones and ammonium acetate in molten tetrabutyl ammonium bromide as an ionic liquid is described. This novel method consistently gave excellent yields (70–92%) and short reaction times (7–30 min).     

Alum as an efficient catalyst for the multicomponent synthesis of functionalized piperidines

An effective approach to the synthesis of functionalized piperidines via a one-pot multicomponent reaction of aniline, β-ketoester and aldehyde in the presence of alum as an efficient catalyst has been reported. The present procedure offers advantages such as simple workup, short reaction time and offers rapid access to a variety of functionalized piperidines.     

Palladium(0) nanoparticles: an efficient catalyst for the one-pot synthesis of polyhydroquinolines

A mild, concise, and efficient protocol for the synthesis of polyhydroquinoline via four component reaction of aromatic aldehydes, dimedone, ethyl acetoacetate or ethyl cyanoacetate, and ammonium acetate using Pd-nanoparticles is described. The same phenomenon was observed in the case of arylmethylene bis(3-hydroxy-2-cyclohexene-1-ones), ethyl acetoacetate, ammonium acetate, and Pd-nanoparticles in one-pot. The present method also allows us to synthesize highly functionalized title compounds from simple and readily available inputs.     

Sulfamic acid: an efficient, cost-effective and recyclable solid acid catalyst for the three-component synthesis of α-amino nitriles

α-Amino nitriles are synthesized by the three-component coupling reaction of aldehydes, amines and trimethylsilyl cyanide using sulfamic acid as a heterogeneous solid acid catalyst, under solvent-free conditions in excellent yields. The catalyst was recovered by simple filtration and was recycled in subsequent reactions.     

Montmorillonite K10 clay: an efficient catalyst for the one-pot stereoselective synthesis of beta-acetamido ketones

An efficient one-pot three-component coupling process for the synthesis of beta-acetamido ketones catalyzed by montmorillonite K10 clay is described. The reaction is highly stereoselective and the catalyst can be recycled.     

Meglumine promoted one-pot,four-component synthesis of pyranopyrazole derivatives

Meglumine, a bio-based chemical, was demonstrated to be a highly efficient and reusable catalyst for the synthesis of a series of pyranopyrazole derivatives via a one-pot, four-component reaction of carbonyl compound or isatin, hydrazine hydrate, malononitrile, and β-keto ester in EtOH–H₂O. The catalyst was found to work extremely for aldehydes, ketones or isatins at room temperature to give the corresponding dihydropyrano[2,3-c]pyrazole or spiro[indoline-3,4′-pyrano[2,3-c]pyrazole] derivatives in high yields. The salient features of this new methodology are broad substrate scope, room temperature reaction conditions, short reaction times, high yields, easy work-up process, reusability of catalyst, and the absence of hazardous organic solvents.     

Ferrous methanesulfonate as an efficient and recyclable catalyst for chemoselective synthesis of 1,1-diacetate from aldehydes

Ferrous methanesulfonate catalysing the conversion of aromatic,heteroaromatic,unsaturated,and aliphatic aldehydes to 1,1- diacetates at room temperature under solvent-free condition has been developed.The catalytic activity of seventeen metal methanesulfonates was compared under the same condition,ferrous methanesufonate proved to be the best.It can be easily recovered and reused for several times without distinct deterioration in catalytic activity.During the competitive protection between a ketone and ...     

CoFe2O4@SiO2-NH2-CoII NPs catalyzed Hantzsch reaction as an efficient,reusable catalyst for the facile,green, one-pot synthesis of novel functionalized 1,4-dihydropyridine derivatives

A magnetically heterogeneous CoFe₂O₄@SiO₂-NH₂-Co^II nanoparticle was synthesized by the immobilization of Co (II) complex onto CoFe₂O₄@SiO₂ nanoparticles, and the heterogeneous magnetic nanocatalyst was characterized by XRD, TEM, TGA, EDX, and FT-IR techniques. Then, the green and reusable method was introduced for a multicomponent synthesis of 1,4-dihydropyridine derivatives via Hantszch reaction. The synthesis of 1,4-dihydropyridine derivatives was proceeded by the reaction of aldehyde, ethyl acetoacetate, and ammonium acetate in the presence of this magnetic nanocatalyst in EtOH/Water (1:1). Simple work-up, short reaction times, excellent yields (60–96%) as well as green solvent are some advantages of this novel approach, and the corresponding products were purified with no need for chromatographic separation.     

Fe3O4 nanoparticles: As an efficient,green and magnetically reusable catalyst for the one-pot synthesis of 1,8-dioxo-decahydroacridine derivatives under solvent-free conditions

An efficient and environmentally friendly method for the one-pot synthesis of 1,8-dioxo-decahydroacridines has been developed in the presence of Fe₃O₄ nanoparticles. The multicomponent reactions of aldehydes, dimedone and amines were carried out under solvent-free conditions to obtain some 1,8-dioxo-9-aryl-10-aryl-decahydroacridine derivatives. The present approach provides several advantages including high yields, short reaction times, little catalyst loading and facile catalyst separation.     

One pot synthesis of unsymmetrical dihydropyridines by green,catalyst free and environmentally benign protocol

Abstract

A facile and ecofriendly synthesis of β-enamino esters is reported by reaction of both aliphatic and aromatic amines with β-keto esters by refluxing in ethanol in absence of any catalyst. Addition of α,β-unsaturated aldehydes to the reaction mixture leads to the formation of unsymmetrical dihydropyridine derivatives which generally are metal free hydrogen sources for asymmetric reduction reactions.     

Sulfonic acid functionalized silica as an efficient heterogeneous recyclable catalyst for one‐pot synthesis of 2‐substituted benziimidazoles

An efficient one‐pot synthesis of 2‐substituted benzimidazoles from o‐phenylenediamine and aldehydes in the presence of sulfonic acid functionalized silica at room temperature is reported.     

Cobalt(II) schiff base functionalized mesoporous silica as an efficient and recyclable chemoselective acetalization catalyst

Cobalt(II) Schiff base functionalized mesoporous silica was synthesized from covalent attachment via the introduction of Co(OAc)₂ to salicylaldimine functionalized mesoporous silica. The catalyst proved to be chemoselective one for the acetalization of aldehydes to the corresponding acetals in alcohol. The immobilized catalyst can be easily recovered and reused for at least ten reaction cycles without significant loss of its catalytic activity.