微波辐射下无催化剂一锅法合成N-甲基十氢吖啶-1,8-二酮化合物

为了研究从简单易得的原料在无催化剂的条件下一锅法合成N-甲基十氢吖啶-1,8-二酮化合物，我们以各类醛（脂肪醛、芳香醛、二醛）、达咪酮或1,3-环己二酮和甲胺为原料，以乙二醇或水为溶剂，经微波辐射，一步反应得到了一系列N-甲基十氢吖啶-1,8-二酮化合物。反应时间从传统热反应的4-5小时缩短至2-10分钟，产率较高（56-95%），并且不需要使用催化剂。该反应后处理方便，只需要简单洗涤，环境友好，为合成此类化合物提供了一种简便、有效的合成方法。该方法不仅适用于一元脂肪醛、芳香醛，还适用于芳香二醛，因此可以合成含有一个或两个十氢吖啶结构单元的杂环化合物。     

A green protocol for catalyst-free synthesis of 1-oxo-hexahydroxanthenes in aqueous medium

An efficient and eco-friendly synthesis of 1-oxo-hexahydroxanthenes has been expediently accomplished by a reaction of salicylaldehyde with cyclohexane-1,3-dione or dimedone in water as universal solvent at reflux condition without a catalyst. Excellent yields of the products, operational simplicity, simple work-up and catalyst-free synthesis are attractive features of this green protocol.     

Sc(OTf)3 catalysed multicomponent synthesis of chromeno[2,3-d]pyrimidinetriones under solvent-free condition

An efficient, simple, and environmentally friendly synthesis of a series of chromeno[2,3-d]pyrimidine-trione derivatives has been accomplished via the three-component reaction of a barbituric acid, dimedone/cyclohexane-1,3-dione, and aromatic aldehydes using Sc(OTf)₃ as a recyclable catalyst under solvent-free condition. This method exploits the use of Sc(OTf)₃ as a Lewis acid catalyst in organic synthesis and offers many rewards such as excellent product yield and easy work-up procedure. Harmless reaction conditions, as well as the absence of side-products, are another green aspects of this protocol.     

无溶剂条件下氨基磺酸锂催化合成氧杂蒽化合物

在无溶剂条件下, 芳香醛与 5,5-二甲基-1,3-环己二酮或1,3-环己二酮经氨基磺酸锂催化缩合反应合成了氧杂蒽. 结果表明, 当催化剂用量为3%(摩尔分数)时, 在120 ℃反应 40~70 min, 产率高达 90% 以上. 此外, 探讨了该反应的氨基磺酸锂催化机理. 该合成方法具有操作简单, 反应时间短、 产率高及对环境友好等优点, 是现有氧杂蒽化合物合成方法的一个重要补充.     

An efficient synthesis of 2,2′-arylmethylene bis-(3-hydroxy-5,5-dimethyl-2-cyclohexene-1-one) and 1,8-dioxooctahydroxanthenes using ZnO and ZnO-acetyl chloride

<正>2,2'-Arylmethylene bis(3-hydroxy-5,5-dimethyl-2-cyclohexene-1-one) 4l-s produced from reaction between dimedone with various aldehydes in acetonitrile using ZnO as a catalyst;whereas in the presence of ZnO-acetyl chloride catalysts the reaction is limited to give only 1,8-dioxo-octahydroxanthenes 3a-k in very good yields.     

Synthesis of Spiro Dihydrofurans and 1,8-Dioxo-xanthenes via DABCO Catalyzed Tandem Reaction of Aldehyde with Cyclohexane-1,3-dione and Dimedone

The 1,4-diazabicyclo[2.2.2]octane(DABCO) catalyzed reaction of cyclohexane-1,3-dione or dimedone with various aldehydes in acetonitrile resulted in the polysubstituted tetraketones, spiro dihydrofurans or 1,8-dioxo-xanthenes derivatives as main products respectively according to the structure of reactants and reaction conditions.     

Molybdate sulfonic acid: preparation, characterization, and application as an effective and reusable catalyst for octahydroxanthene-1,8-dione synthesis

Molybdate sulfonic acid (MSA) as a highly efficient catalyst was synthesized and employed for the synthesis of octahydroxanthene-1,8-dione derivatives. MSA efficiently catalyzed condensation of a wide range of aryl aldehydes and cyclohexane-1,3-diones to obtain octahydroxanthene-1,8-diones. It was characterized by X-ray fluorescence (XRF), X-ray diffraction (XRD), and FT-IR spectroscopy. This catalyst can be recovered and reused several times in other reactions maintaining its high activity. This novel and green method is very cheap and has many advantages such as excellent yields, the use of recoverable and eco-friendly catalysts, and a simple work-up procedure.     

An expedient and straightforward solvent-free synthesis of 1,8-dioxo-octahydroxanthenes using eco-friendly aluminized polyborate catalyst

The present work deals with a catalytic application of aluminized polyborate as a mild solid acid catalyst for multicomponent synthesis of 1,8-dioxo-octahydroxanthenes under solvent-free condition at 100°C-110°C. It involves selective domino Knoevenagel-Michael reaction of 1 mole of aromatic aldehyde with 2 moles dimedone. The aluminized polyborate is simply synthesized by using boric acid and aluminum trichloride and characterized by FT-IR, XRD, SEM and EDAX techniques. The mild Lewis acidity, crystalline solid nature, stability and recyclability are significant features of the catalyst. The solvent-free condition, clean reaction profile, inexpensive and non-toxic catalyst, operational simplicity, good to excellent product yields, reduced reaction time and applicability to wide range of substrate are crucial features of this protocol.     

A Facile Synthesis of Xanthene‐1,8(2H)‐dione Derivatives by Using Tetrapropylammonium Bromide as Catalyst

Several new derivatives of 9‐aroyl‐3,4,5,6,7,9‐hexahydro‐1H‐xanthene‐1,8(2H)‐dione have been synthesized in yields varying from high to excellent by the condensation reaction of arylglyoxals with 1,3‐diketones (cyclohexane‐1,3‐dione or dimedone) and TPAB as an inexpensive, recoverable, and non‐toxic catalyst in the presence of ethanol/water under reflux conditions.     

Hydrotrope induced synthesis of 1,8-dioxo-octahydroxanthenes in aqueous medium

Abstract

Hydrotrope induced synthesis of 1,8-dioxo-octahydroxanthenes from aromatic aldehydes and dimedone/1,3-cyclohexadione in aqueous medium is reported. The remarkable features of the new procedure are high conversions, shorter reaction times, cleaner reaction profiles, and simple experimental and work-up procedures.     

Neat synthesis of octahydroxanthene-1,8-diones,catalyzed by silicotungstic acid as an efficient reusable inorganic catalyst

In this article, the first use of silicotungstic acid (H₄SiW₁₂O₄₀) as a catalyst for the synthesis of octahydroxanthene-1,8-diones by the reaction of 5,5-dimethylcyclohexane-1,3-dione (dimedone) with various aldehydes under thermal solvent-free conditions is described. The obtained results showed that the catalyst has a high catalytic activity, and the desired products were obtained in high yields. Moreover, the catalyst was found to be reusable, and a considerable catalytic activity still could be achieved after the fifth run. Easy work-up and avoidance of using harmful organic solvents are the other advantages of this simple procedure.     

One‐pot synthesis of novel N‐cyclopropyldecahydroacridine‐1,8‐dione derivatives under microwave irradiation

A series of new N‐cyclopropyldecahydroacridine‐1,8‐dione derivatives were synthesized by one‐pot reaction of aromatic aldehyde, dimedone (or 1,3‐cyclohexanedione) and cyclopropanamine in solution of glycol and water under microwave irradiation with excellent yields (78‐94%) and short reaction time (5‐10 min).     

L-proline/urea catalyzed,novel, and eco-friendly synthesis of coumarin substituted-3-indoloxanthenes

A green and eco-friendly synthesis of coumarin substituted-3-indoloxanthenes 4(a-l) has been developed using urea/L-proline as simple catalyst. Two efficient methods have been described for the synthesis of these 3-indoloxanthene derivatives. In the first method, Knoevenagel condensation, then Pinner cyclisation followed by 1,4 addition between 4-hydroxy-1-methyl-2-oxo-1,2-dihydrocoumarin-3-carbaldehyde 1(a-b) , with cyclohexane-1,3-dione (2) and indole 3(a-f) using of L-proline as catalyst was described. In the second method, urea/thiourea catalyzes the same reaction at 100°C for 10 minutes to afford the title compounds 4(a-l) . These two protocols involve eco-friendly and inexpensive catalysts, give excellent yields of the clean products without the need of column chromatography for their isolation or purification.     

Microwave assisted synthesis of novel Hantzsch 1,4-dihydropyridines, acridine-1,8-diones and polyhydroquinolines bearing the tetrazolo[1,5-a]quinoline moiety and their antimicrobial activity assess

Microwave assisted efficient Hantzsch reaction via four-component coupling reactions of tetrazolo[1,5-α]quinoline-4-carbal-dehyde, dimedone/cyclohexane-1,3-dione,ethyl/methyl acetoacetate and ammonium acetate was described as the preparation of tetrazolo[1,5-α]quinoline based 1,4-dihydropyridines,acridine-1,8-diones and polyhydroquinolines.The process presented here is simple,rapid,environmentally welcoming and high yielding.All the derivatives were subjected to an in vitro antimicrobial screening against a representative panel of bacteria and fungi and results worth further investigations.     

3-Aryl- and 2,3-Diaryl-4-oxo-4,5,6,7-tetrahydroindazoles. 1. Reactions of Phenyl- and Tosylhydrazones of Dimedone and Cyclohexane-1,3-dione with Substituted Benzaldehydes

Sixteen 3-aryl-4-oxo-2-phenyl-4,5,6,7-tetrahydroindazoles were obtained from the reaction of the phenylhydrazones of dimedone and cyclohexane-1,3-dione with 3-bromo-, 4-bromo-, 4-chloro-, 4-fluoro-, 2-hydroxy-, 4-hydroxy-, 4-methoxy-, 2-nitro-, 3-nitro-, 4-nitro-, and 4-dimethylamino-benzaldehydes. The interaction of the tosylhydrazones of dimedone and cyclohexane-1,3-dione with the substituted benzaldehydes gave thirteen 3-aryl-4-oxo-4,5,6,7-tetrahydroindazoles. __________ Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 11, pp. 1662–1668, November 2005.     

新型功能离子液体水相催化芳醛与5,5-二甲基-1,3-环己二酮的反应

以N,N,N′,N′-四甲基乙二胺、1,3-丙磺酸内酯为原料,经酸化合成了功能化离子液体N,N,N′,N′-四甲基N,N′-二磺丙基二硫酸氢盐(TSIL)。 TSIL离子液体兼具Bronsted 酸性官能团和季铵盐相转移催化剂的结构,能够实现水相中芳醛与5,5-二甲基-1,3-环己二酮反应,得到氢化氧杂蒽衍生物。 结果表明,合成的TSIL具有较高的催化活性,在水相中于100 ℃下回流2～3 h即可完成反应,产率可达80%～93%。 反应生成的取代氢化氧杂蒽与离子液体的水溶液不相溶,通过简单的过滤可实现产物与催化体系的分离,简化了分离过程,方法操作简便、环境友好、催化剂可回收并重复使用。     

l-proline as an efficient asymmetric induction catalyst in the synthesis of chromeno[2,3-d]pyrimidine-triones,xanthenes in water

The multi-component reactions involving aromatic aldehydes, dimethylcyclohexane-1, 3-dione/cyclohexane-1, 3-dione and barbituric acids were carried out in presence of the organo catalyst l-proline in aqueous medium at ambient temperature. The reactions afforded chromeno[2,3-d]pyrimidinones in excellent yields and with high enantioselectivities. The above reactions exhibited the efficient asymmetric induction property of the organo catalyst l-proline as reported earlier. In the absence of barbituric acid the method proved equally efficient when aromatic aldehydes readily condensed with 2 mol of cyclohexane-1, 3-dione in presence of l-proline to give Xanthenes derivatives in good yields. The protocol reported here is benign to the environment as water is used as the solvent and purification does not involve any chromatographic procedures. Selected compounds were further studied using DFT calculations in order to establish a clear picture about the geometric parameters and the electronic absorption spectra of the compounds.     

1,8‐Diazabicyclo[5.4.0]undec‐7‐ene: A Highly Efficient Catalyst for One‐Pot Synthesis of Substituted Tetrahydro‐4H‐chromenes,Tetrahydro[b]pyrans,Pyrano[d]pyrimidines,and 4H‐Pyrans in Aqueous Medium

We have reported 1,8‐diazabicyclo[5.4.0]undec‐7‐ene catalyzed one‐pot synthesis of tetrahydro‐4H‐chromenes, tetrahydro[b]pyrans, pyrano[d]pyrimidines and 4H‐pyrans from aldehydes, active methylene compounds malononitrile/ethyl cyanocacetate and activated C–H acids such as dimedone, 1,3‐cyclohexanedione, 1,3‐cyclopentanedione, 1,3‐dimethylbarbituric acid, and ethyl acetoacetate in water under reflux. The attractive features of this process are mild reaction conditions, reusability of the reaction media, short reaction times, easy isolation of products, and excellent yields. Copyright © 2013 HeteroCorporation     

Efficient synthesis of xanthenedione derivatives using cesium salt of phosphotungstic acid as a heterogeneous and reusable catalyst in water

Cs_2.5H_0.5PW₁₂O₄₀ has been reported to be an efficient catalyst for the synthesis of 1,8-dioxo-octahydroxanthene from aldehydes and 1,3-cyclohexanedione/dimedone in water. This approach is environmentally benign with clean synthetic procedure, short reaction time, easy workup procedure, excellent yield, and regeneration of catalyst, which made this protocol efficient and safe.     

Synthesis of novel fluorescent benzo[a]pyrano[2,3-c]phenazine and benzo[a]chromeno[2,3-c]phenazine derivatives via facile four-component domino protocol

An efficient and practical route to novel fluorescent benzo[a]pyrano[2,3-c]phenazine framework has been developed by one-pot, four-component reaction of 2-hydroxynaphthalene-1,4-dione, 1,2-phenylenediamines, aromatic aldehydes, and Meldrum’s acid in glacial acetic acid at 70 °C. Photophysical studies of these compounds have been reported. Reactions involving cyclohexane-1,3-dione/5-methylcyclohexane-1,3-dione/dimedone in the place of Meldrum’s acid yielded corresponding benzo[a]chromeno[2,3-c]phenazine derivatives. Crystal structure of 3k established the regioisomer formed. Mild reaction conditions, good yields, short reaction time, and easy separation are some of the salient features of the present protocol.