A novel and facile synthesis of N-cyclohexyl-benzofurans by one-pot three-component reaction

Abstract  

A simple and efficient synthesis of N-cyclohexyl-benzofuran derivatives was achieved via a one-pot three-component reaction of cyclohexylisocyanide, an aromatic aldehydes, and phenols in DMF for 10 h with good yields.     

Three-component reaction between triphenylphosphine, dialkyl acetylenedicarboxylates and urea or N-methylurea

The stabilized phosphoranes, obtained from the three-component reaction between dialkyl acetylenedicarboxylates and urea or N-methylurea in the presence of triphenylphosphine, undergo a smooth reaction in boiling toluene to produce iminophosphoranes in good yields. Under the same reaction conditions, the phosphorane obtained from N-methylurea and dimethyl acetylenedicarboxylate yields methyl 1-methyl-2,6-dioxo-1,2,3,6-tetrahydro-pyrimidine-4-carboxylate.     

A diversity-oriented synthesis of pyrazolo[4,3-<Emphasis Type="Italic">f</Emphasis>]quinoline derivatives with potential bioactivities via microwave-assisted multi-component reactions

Six new series of pyrazolo[4,3-f]quinoline derivatives with potential bioactivities were synthesized by the three-component reactions of aromatic aldehydes, 5-aminoindazole, and various cyclic 1,3-dicarbonyl compounds under microwave irradiation. This protocol has the valuable features of structural diversity of products, broader substrate scope, operational simplicity, high yields, and short reaction time. Moreover, the structure of compound 88a was confirmed by an X-ray crystallographic analysis and attested to the chemoselectivity of reaction where 1-methyl barbituric acid participated.     

A new synthetic approach to functionalize pyrimido[4,5-<Emphasis Type="Italic">b</Emphasis>]quinoline-2,4(1<Emphasis Type="Italic">H</Emphasis>,3<Emphasis Type="Italic">H</Emphasis>)-diones via a three-component one-pot reaction

Functionalized pyrimido[4,5-b]quinoline-2,4 (1H,3H)-diones were synthesized by a three-component one-pot reaction involving barbituric acid, aldehydes, and anilines. The use of commercially available anilines allowed the facile syntheses of pyrimido[4,5-b]quinolinediones substituted in all the positions on the benzene ring with electron donor or electron withdrawing groups. This straightforward method circumvents the preparation of unstable substituted 2-aminobenzaldehydes that limits the scope of previously described syntheses. Furthermore, access to the 5-substituted derivatives is now also possible starting from aliphatic or aromatic aldehydes. Our strategy and methodology offer significant and practical improvements over other methodologies.     

Three-component aza-Diels–Alder reactions using Yb(OTf)3 catalyst under conventional/ultrasonic techniques

The Yb(OTf)₃ catalyzed formal aza-Diels–Alder (or Povarov) reaction of cyclopentadiene and 1,3-cyclohexadiene with in situ-generated N-arylimines under conventional/ultrasonic techniques is herein described. This kind of three-component Povarov reaction results in quinoline and phenanthridine derivatives, which are important biological compounds.     

Ultrasound mediated,iodine catalyzed green synthesis of novel 2-amino-3-cyano-4H-pyran derivatives

An efficient synthesis of a novel series of twelve substituted 2-amino-3-cyano-4H-pyran derivatives was achieved by a one-pot three-component cyclocondensation reaction of heteroaryl aldehydes, malononitrile and active methylene compounds catalyzed by iodine in aqueous medium under ultrasound irradiation. In comparison with conventional methods, our protocol is convenient and offers several advantages, such as shorter reaction time, higher yields, milder conditions and environmental friendliness. We have herein successfully demonstrated the synergistic outcome of multi-component reaction (MCR) and sonication to offer a facile route for the design of these derivatives.     

A facile and efficient ultrasound-assisted synthesis of novel dispiroheterocycles through 1,3-dipolar cycloaddition reactions

A facile and efficient one-pot three-component procedure for synthesis of novel dispirooxindolecyclo[pyrrolo[1,2-c]thiazole-6,5′-thiazolidine] derivatives without any catalysts under ultrasonic condition has been developed. Combining with the advantages of sonochemistry, such as mild reaction conditions, good yield and short reaction times, we have made a progress on construction of novel disiproheterocyclic compounds via the 1,3-dipolar cycloaddition of azomethine ylides. Several experiments were especially carried out for investigating the acceleration mechanism of ultrasound on the cycloaddition.     

Ugi–Smiles couplings: new entries to N-aryl carboxamide derivatives

The scope of the Ugi reaction has been extended by the use of phenols as carboxylic acid surrogates to afford N-aryl carboxamides. A Smiles rearrangement occurs as the last step of the mechanism instead of the classical final Mumm process. Various parameters concerning the nature of these inputs have been studied: the use of heteroaromatic derivatives, the substitution of the hydroxyl moiety by a thio entity (to afford functionalized thioamides), as well as the influence of the nature and position of substituents on the phenol. A three-component version (Passerini–Smiles) of this coupling has been developed as well. Following these couplings, various post-condensation transformations have been performed to reach more complex heteroaromatic fused systems. The easy functionalizations of phenols offer many opportunities for cyclization strategies: the reduction of the nitro group allows the formation of o-phenylenediamine derivatives, which, in turn, can be transformed into quinoxalines, benzotriazoles, and benzimidazoles. Various organometallic reactions of the Ugi–Smiles adducts have been successfully carried out, either from iodophenols (Heck couplings to give indoles, Ullmann reaction to form quinoxalines), or from allyl pyrimidines (azepine formation by RCM strategy) as starting phenol inputs. Finally, a new palladium-mediated oxidative cyclization led to the formation of tricyclic systems.     

A novel method for the synthesis of substituted 3,4-dihydrocoumarin derivatives via isocyanide-based three-component reaction

A new one-pot procedure for the efficient synthesis of novel 3,4-dihydrocoumarin derivatives using commercially available substituted 2-hydroxybenzaldehydes, Meldrum's acid, and isocyanides by a three-component condensation reaction in dichloromethane at room temperature without using any catalysts and activation was developed.     

Regioselective multi-component synthesis of 1H-pyrazolo[3,4-d]pyrimidine-6(7H)-thiones

A variety of pyrazolo[3,4-d]pyrimidine-6(7H)-thione derivatives were easily synthesized with a novel, simple, efficient, and regioselective method via three-component condensation reaction of 5-methyl-1H-pyrazol-3-amine, arylisothiocyanates, and aldehydes in the presence of catalytic amount of p-toluenesulfonic acid (p-TSA) in 1-butyl-3-methylimidazolium bromide ionic liquid with excellent yields and short reaction times.     

A convenient one-pot synthesis of 3-amino-2, 5-dihydropyridazine and pyrimidine derivatives in the presence of high surface area MgO as a highly effective heterogeneous base catalyst

A new and efficient method for the preparation of 3-amino-2,5-dihydropyridazines from three-component reactions of (phenyl-hydrazono)-propan-2-one, aldehydes, and malononitrile or ethyl cyanoacetate in the presence of magnesium oxide (MgO) as a highly effective heterogeneous base catalyst is presented. Also, the three-component reactions of aldehydes, amidine systems, and malononitrile or ethyl cyanoacetate for the formation of 4-amino-5-pyrimidine carbonitrile and pyrimidinone derivatives, respectively, are investigated. The salient features of these methods include high conversions, short reaction times, cleaner reaction profiles, and the use of inexpensive and readily available catalyst.     

A novel and efficient one-pot four-component tandem approach for the synthesis of pyran derivatives

A series of new pyran derivatives are efficiently synthesized in a one-pot four-component tandem reaction via Suzuki coupling followed by a three-component reaction from readily available 4-bromobenzaldehyde, activated methylene compounds, and carbonyl compounds. Single crystal X-ray structure of the synthesized product is presented. The versatility and efficiency of the proposed methodology has been demonstrated in the synthesis of novel heterocyclic molecules.     

A facile three- and four-component procedure toward the synthesis of functionalized pyrano- and benzo[f]quinoxaline derivatives

A two-step procedure has been used to synthesize quinoxaline derivatives in the presence of a catalytic amount of triethylamine. Products can be separated from the reaction media by simple filtration. When EtOH was used as a solvent, the reaction proceeded via a three-component pathway, but in the presence of MeOH (as a solvent or in a 1-equivalent) the reaction proceeded via a four-component pathway.     

三分量磁场延拓的递推算法

提出一种三分量磁场延拓的递推算法,主要目的是解决三分量磁场的向下延拓问题.应用微分学基本原理,将具有相同水平坐标,不同垂向坐标的点上的三分量磁场,通过磁场的垂向偏导数的积分联系起来.根据磁场向量散度和旋度的性质,将磁场的垂向偏导数与水平方向的偏导数联系起来.这样,在已知一个平面上的磁场时,可以通过递推的办法逐层求取该平面以下任意平面上的三分量磁场.应用实例证明方法的快速性和准确性.     

A green synthetic approach toward the synthesis of structurally diverse spirooxindole derivative libraries under catalyst-free conditions

A catalyst-free green methodology for the synthesis of pharmacologically important spirooxindole derivatives has been developed by a three-component domino reaction between isatin, various amino compounds, and 1,3-dicarbonyl or 3-phenylisoxazolone compounds in ethyl l-lactate medium at room temperature. This new efficient synthetic method facilitated the formation of a wide range of biologically significant spirooxindole derivatives (including 17 new spirooxindoles) under very mild conditions. The cytotoxic activity of one of the isoxazole-fused spirooxindoles was evaluated in MDA-MB 468 breast cancer cell line. It was found that cell survivability decreases with increasing concentration of the selected compound in MDA-MB 468 breast cancer cells.     

Three-component reactions of isocyanides, dialkyl acetylenedicarboxylates, and trans-cinnamoyl chlorides for the synthesis of highly functionalized 2-vinyl furans

Abstract  

In this study, we present a convenient and efficient method for the synthesis of novel, highly substituted 2-vinyl furans using a three-component reaction. The zwitterions generated from the reaction of isocyanides and dialkyl acetylenedicarboxylates are reacted with trans-cinnamoyl chlorides to produce the desired products in good yields.     

An efficient three-component synthesis of highly functionalized tetrahydroacenaphtho[1,2-b]indolone derivatives catalyzed by L-proline

An efficient and diastereoselective synthetic procedure for highly functionalized tetrahydroacenaphtho[1,2- \(b\) ]indolone derivatives was successfully developed by the three-component reaction of acenaphthequinone, enaminones, and barbituric acid in the presence of a catalytic amount of L-proline. This method has the advantages of convenient operation, excellent yields, mild reaction conditions, and environmental friendliness.     

Cavitational chemistry: a mild and efficient multi-component synthesis of amidoalkyl-2-naphthols using reusable silica chloride as catalyst under sonic conditions

An efficient and direct procedure for the synthesis of amidoalkyl-2-naphthol derivatives has been described. The process employs a three-component cyclocondensation reaction in one-pot using β-naphthol, aromatic aldehyde and acetamide or benzamide in the presence of silica chloride accelerated by ultrasound giving the product in excellent yield in very short duration.     

A green one-pot three-component cascade reaction: the synthesis of 2-amino-5,8-dihydro-3H-pyrido[2,3-D]pyrimidin-4-ones in aqueous medium

A one-pot three-component cascade reaction for the green synthesis of a new class of 2-amino-5,8-dihydro-3H-pyrido[2,3-d]pyrimidin-4-ones was developed from the condensation of aromatic aldehydes with 2,6-diaminopyrimidin-4(3H)-one and acetophenone derivatives or various cyclic ketones in the presence of a catalytic amount of sodium carbonate in a mixture of water and ethanol at 60  \({^{\circ }}\hbox {C}\). This reaction led to the construction of two carbon–carbon bonds and one carbon–nitrogen bond in a single synthetic step.     

A new one-pot three-component synthesis of 2,4-diamino-5<Emphasis Type="Italic">H</Emphasis>-chromeno[2,3-<Emphasis Type="Italic">b</Emphasis>]pyridine-3-carbonitrile derivatives

In this study, a three-component one-pot synthesis of new 2,4-diamino-5H-chromeno[2,3-b]pyridine-3-carbonitriles derived from 2-amino-1,1,3-tricyanopropene, salicylic aldehydes and secondary cyclic amines is reported. The reaction is conducted in ethanol at ambient temperature in good-to-excellent yields.