Highly efficient ring opening reactions of epoxides with deactivated aromatic amines catalyzed by heteropoly acids in water

Heteropoly acid was found to be an effective and efficient catalyst for the ring opening reaction of epoxides with various aromatic amines to produce the corresponding β-amino alcohols in moderate to excellent yields in water. This method provides a new and efficient protocol in terms of mild reaction conditions, clean reaction profiles, small quantity of catalyst, and simple work-up procedure.     

Sulfonated Porous Carbon (SPC)-Catalyzed Synthesis of Benzothiazole Derivatives in Water

Abstract

A simple and efficient procedure has been developed for the synthesis of benzothiazole derivatives in water by the condensation of 2-aminothiophenol with aldehydes in the presence of Sulfonated porous carbon (SPC). This method provides a simple and efficient protocol in terms of mild reaction conditions, clean reaction profiles, small quantity of catalyst, and simple workup procedure.     

PTSA catalyzed simple and green synthesis of benzothiazole derivatives in water

Abstract  

p-Toluenesulfonic acid (10 mol%) was found to be an effective and efficient catalyst for the synthesis of 2-substituted benzothiazoles from aromatic aldehydes and 2-aminothiophenol in moderate to excellent yields in water. This method provides a simple and efficient protocol in terms of mild reaction conditions, clean reaction profiles, small quantity of catalyst, and simple workup procedure.     

A heterogeneous strong basic Mg/La mixed oxide catalyst for efficient synthesis of polyfunctionalized pyrans

An efficient synthesis of polyfunctionalized 4H-pyrans is carried out in one pot through condensation of an aldehyde, malononitrile, and an active methylenic diketo compound using a heterogeneous strong basic Mg/La mixed oxide catalyst. The protocol offers advantages in terms of higher yields, short reaction times, and mild reaction conditions, with reusability of the catalyst.     

A new green approach for the synthesis of 12-aryl-8,9,10,12-tetrahydrobenzo[a]xanthene-11-one derivatives using task specific acidic ionic liquid[NMP]H_2PO_4

12-Aryl-8,9,10,12-tetrahydrobenzo[a]xanthene-11-one derivatives were synthesized by a convenient and environmentally benign procedure involving multicomponent condensation reactions of substituted aromatic aldehydes with 2,7-dihydroxynaphthalene/2-naphthols/2,6-dihydroxynaphthlene and cyclic 1,3-dicarbonyl compounds in task specific acidic ionic liquid[NMP]H_2PO_4 at 80 ℃.This protocol has proved to be efficient in terms of good yields,operational simplicity,easy workup,recyclability of reaction medium/catalyst,and short reaction time.     

CsF mediated rapid condensation of 1,3-cyclohexadione with aromatic aldehydes:Comparative study of conventional heating vs.ambient temperature

A mild,efficient and high yielding protocol for the synthesis of 2,2'-arylmethelene dicyclohexane-1,3-dione derivatives at room temperature and 9-aryl-l,8-dihydrooctahydroxanthene at conventional heating using cesium fluoride as a catalyst is reported.The major advantages of this reaction are excellent yield,very short reaction time and use of inexpensive catalyst.     

Sulfamic acid as a recyclable and green catalyst for rapid and highly efficient synthesis of 2-arylbenzothiazoles in water at room temperature

2-Arylbenzothiazoles have been synthesized in water in good to excellent yield from direct condensation of various aromatic aldehydes with 2-aminothiophenol promoted by catalytic amount of sulfamic acid at room temperature. This method provides a simple, rapid and efficient protocol in terms of mild reaction conditions, clean reaction profiles, small quantity of catalyst and simple work-up procedure.     

DABCO-catalyzed synthesis of 3-substituted-3-hydroxyindolin-2-ones in aqueous media

An efficient and greener protocol for easy access to 3-susbstituted-3-hydroxy-2-oxindoles by the reaction with various substituted isatins and acetophenones is described. This protocol is widely applicable for a variety of isatins and acetophenones using water as a reaction media and 1,4-diazabicyclo[2.2.2]octane (DABCO) as catalyst with shorter reaction time and good to excellent yield of products.     

Multifunctional Catalysis of Heteropoly Acid: One‐Pot Synthesis of Quinolines from Nitroarene and Various Aldehydes in the Presence of Hydrazine

12‐Molybdophosphoric acid catalyzed transfer hydrogenation of nitroarene by hydrazine in a homogeneous phase. This catalytic system was applicable to one‐pot quinolines synthesis in the presence of various aldehydes in water. This method provides a new and efficient protocol in terms of mild reaction conditions, clean reaction profiles, small quantity of catalyst, and simple work‐up procedure.     

Selective hydroformylation–acetalization of various olefins using simple and efficient Rh-phosphinite complex catalyst

A simple and efficient Rh-phosphinite complex catalyst was studied for the selective hydroformylation of various olefins. The influence of various reaction parameters including the effect of temperature, pressure, catalyst loading, time, and solvents was studied. The protocol was also applied for the synthesis of various acetals via tandem hydroformylation–acetalization of olefins in alcohols as solvents. High activity and selectivity for acetal formation was achieved in the absence of co-catalysts with admirable substrate to catalyst mole ratio (TON 2500). The developed protocol works for a wide range of olefins to synthesize corresponding aldehydes and acetals under optimized reaction conditions.     

Solvent-free multicomponent synthesis of pyranopyrazoles: per-6-amino-β-cyclodextrin as a remarkable catalyst and host

A simple, green and efficient protocol is developed with per-6-amino-β-cyclodextrin (per-6-ABCD) which acts simultaneously as a supramolecular host and as an efficient solid base catalyst for the solvent-free syntheses of various dihydropyrano[2,3-c]pyrazole derivatives involving a four-component reaction. This atom-economical protocol, reported for the first time with ketones also, includes a much milder procedure, does not involve any tedious work-up or purification, avoids hazardous reagents/byproducts and results in near quantitative yields. The catalyst can be reused at least six times without any change in its catalytic activity.     

One‐pot Synthesis of 3,4‐Dihydropyrimidin‐2(1H)‐ones Catalysed by Cupric Acetate under Solvent‐free Conditions

A solvent‐free synthesis of 3,4‐dihydropyrimidin‐2(1H)‐ones from aromatic aldehydes, β‐keto ester/acetyl acetone and urea catalysed by cupric acetate under thermal condition is reported as a simple and an efficient protocol. Compared with classical Biginelli reaction reported in 1893, this new method provides much improved modification in terms of yield and reaction time. The usage of milder catalyst, environmental friendly procedures and excellent yields within a very short time (5–15 min) are the advantages of the method in which the involvement of solvent‐free condition adds an edge to the method. Thus, the efficiency of the protocol enabled the rapid synthesis of 3,4‐dihydropyrimidin‐2(1H)‐one derivatives in a short duration.     

Copper@PMO nanocomposites as a novel reusable heterogeneous catalyst for microwave‐assisted green synthesis of β‐hydroxy‐1,2,3‐triazoles through experimental design protocol

A microwave‐assisted multicomponent reaction was used to prepare a series of β‐hydroxy‐1,2,3‐triazoles in the presence of copper@PMO nanocomposites as a catalyst. Box–Behnken design and response surface methodology were used to optimize the influencing parameters such as catalyst content, reaction time and microwave power, being an economical way of obtaining the optimal reaction conditions based on restricted number of experiments. Aqueous reaction medium, easy recovery of catalyst, efficient recycling and high stability of the catalyst render the protocol sustainable and economic. Copyright © 2015 John Wiley & Sons, Ltd.     

A cesium fluoride promoted efficient and rapid multicomponent synthesis of functionalized 2-amino-3-cyano-4H-pyran and spirooxindole derivatives

A rapid, one-pot and highly efficient protocol for the synthesis of pharmaceutically interesting functionalized 2-amino-3-cyano-4H-pyran and spirooxindole derivatives has been developed using commercially available Cs F as a catalyst in the reaction of malononitrile and aryl aldehydes or isatins with 1,3-cyclohexanediones. The major advantages of this methodology are excellent yield at ambient temperature, very short reaction time(5–10 min), and use of an inexpensive catalyst.     

Synthesis of 5-substituted 1H-tetrazoles catalyzed by ceric ammonium nitrate supported HY-zeolite

In this Letter we wish to report a simple and efficient synthetic protocol for the synthesis of 5-substituted 1H-tetrazole derivatives through the [2+3] cycloaddition of nitriles with sodium azide using ceric ammonium nitrate supported HY-zeolite as a novel catalyst. Excellent yields of the corresponding tetrazoles were obtained through this cost-effective protocol under aerobic conditions with shorter reaction time under mild reaction conditions.     

无溶剂条件下勃姆石纳米粒子锅催化多组分合成3,4-二氢嘧啶-2-(1H)酮简

A simple, green, and efficient synthesis protocol for the synthesis of 3,4-dihydropyrimidin-2-(1H)-ones using boehmite nanoparticles as catalyst was developed. It did not use any toxic metal catalysts or corrosive acidic reagents. The method gave good to excellent yields and has short reaction time, operational simplicity, and a recyclable catalyst.     

无溶剂条件下勃姆石纳米粒子一锅催化多组分合成3,4-二氢嘧啶-2-(1H)酮(英文)

A simple, green, and efficient synthesis protocol for the synthesis of 3,4-dihydropyrimidin-2-(1H)-ones using boehmite nanoparticles as catalyst was developed.It did not use any toxic metal catalysts or corrosive acidic reagents.The method gave good to excellent yields and has short reaction time, operational simplicity, and a recyclable catalyst.     

ZnO nanoparticle-catalyzed efficient one-pot three-component synthesis of 3,4,5-trisubstituted furan-2(5H)-ones

An efficient and high-yielding protocol using nano-ZnO (50–100 nm) as an efficient heterogeneous catalyst for one-pot three-component synthesis of pharmacologically significant furanone derivatives by the condensation of aromatic aldehyde, amine and dimethylacetylenedicarboxylate has been developed. Since the catalyst is heterogeneous, it can be easily separated and recycled several times without much loss of its catalytic activity. Use of aqueous medium, recyclable nanocatalyst, operational simplicity, non-chromatographic purification technique, excellent yield and short reaction time makes this approach an attractive protocol for the synthesis of 3,4,5-trisubstituted furan-2(5H)-ones.     

T3P catalyzed one pot three-component synthesis of 2,3-disubstituted 3H-quinazolin-4-ones

An efficient methodology for the synthesis of 2,3-disubstituted 3H-quinazolin-4-ones is described via one-pot three component reaction from anthranilic acid using T3P as catalyst. Mild reaction conditions, short reaction time, broad functional group tolerance, easy isolation of products and good yields are main advantages of this protocol.     

Cobalt mediated by desulfurization toward the synthesis of isothiocyanates

A highly efficient and simple protocol for the construction of aromatic and aliphatic isothiocyanates from their respective amines in the presence of cheap, readily available, and air-stable cobalt catalyst is described. All reactions were carried out under optimized reaction conditions and gave target products in good to excellent yields within shorter reaction time.