共查询到20条相似文献,搜索用时 0 毫秒
1.
Three new metal coordination complexes, namely, [Co ( DPE )(H2O)4]( DPE )( BS )2 ( 1 ), [Co ( DPE )2(H2O)4]( ABS )2 ( 2 ), [Co ( DPE )(H2O)4]( MBS )2(CH3OH)2 ( 3 ) [ DPE = (E)-1,2-di (pyridin-4-yl) ethene, BS = phenyl sulfonic acid, ABS = p-aminobenzene sulfonic acid, MBS = p-methylbenzene sulfonic acid] were obtained under hydrothermal conditions. Complexes 1 - 3 were structurally characterized by X-ray single-crystal diffraction, powder X-ray diffraction and IR. Complexes 1 and 3 exhibit a one-dimensional chain structure, and complex 2 does a zero-dimensional one. These three complexes further generate a three-dimensional supramolecular architecture via strong hydrogen bonding interactions and packing interactions. These three metal coordination complexes show high catalytic performance for green synthesis of a variety of 3,4-dihydropyrimidin-2(1H)-ones through the Biginelli reactions, which show several advantages such as excellent yields, short reaction times, eco-friendly synthesis conditions, and simple isolated workup procedure. Interestingly, the order of catalytic activities for these catalysts is the following: 3 > 1 > 2 , which can be ascribed to the acidities and hydrophobic interactions of phenyl sulfonate groups. 相似文献
2.
3.
Sixteen 5-unsubstituted-3,4-dihydropyrimidin-2(1H)-ones have been synthesized by microwave-assisted Biginelli reactions in a short and concise manner employing ZnI2 as a catalyst under solvent-free conditions. All products were identified by IR, NMR, elemental analysis and HRMS. The advantages of this novel protocol include the excellent yield, operational simplicity, short time and the avoidance of the use of organic solvents and expensive catalysts. 相似文献
4.
5.
Gholamhassan Imanzadeh Aazam Aliabadi Mohammadreza Zamanloo 《Green Chemistry Letters and Reviews》2016,9(2):106-113
A regioselective N3-alkylation of 5,5-diphenyl-2-thiohydantoin (2-thiophenytoin) using a very efficient mild base K2CO3 and α,β-unsaturated esters in the presence of organic salt TBAB (tetrabutylammonium bromide) at room temperature has been reported (3b–3h). The selectivity of this reaction is excellent and products have been produced in good yields under solvent-free conditions. The increase of the reaction temperature to 70°C mostly disappeared this selectivity and afforded only the N1,N3-dialkylated derivatives of 2-thiophenytoin in good yields (4b–4g). We were unable to selectively N3-alkylate 2-thiophenytoin with ethyl acrylate at both room temperature and 70°C under the same conditions (4a). Dimethyl and diethyl fumarates cannot work as Michael acceptors and were hydrolyzed to fumaric acid under reaction conditions. 相似文献
6.
<正>4,6-Diarylpyrimidin-2(1H)-one derivatives have been synthesized from three-component one-pot condensation of acetophe-none derivatives,aldehydes and urea in the presence of trimethylsilyl chloride and a catalytic amount of H_3PMo_(12)O_(40)under solvent-free conditions. 相似文献
7.
The Biginelli reaction, known for over 100 years, is an important multicomponent reaction for accessing dihydropyrimidinones (DHPMs). The individual enantiomers of DHPMs exhibit different or even opposite pharmaceutical activities, which require synthetic methods to easily access the optically pure DHPMs. In recent decades, many efforts have focused on developing procedures for the preparation of optically active Biginelli products. In this article, we will summarize the developments in the synthetic methods to access optically active DHPMs with an emphasis on the recent advances in the asymmetric catalytic Biginelli reactions, along with concepts to design the organocatalytic asymmetric variants. 相似文献
8.
Abstract One-pot, three-components synthesis of 2,4,6-triarylpyridines and 5-unsubstituted-3,4-dihydropyrimidin-2(1H)-ones was performed under solvent-free conditions using molecular iodine as the catalyst in moderate to good product yields.
Graphical abstract
相似文献
9.
Vivek Polshettiwar 《Tetrahedron letters》2007,48(41):7343-7346
An environmentally benign aqueous Biginelli protocol for the synthesis of substituted 3,4-dihydropyrimidin-2(1H)-ones using polystyrenesulfonic acid (PSSA) as a catalyst has been achieved. These microwave-assisted reactions proceed efficiently in water in the absence of organic solvent, with simple filtration as the product isolation step. 相似文献
10.
An efficient method for synthesis of 2H-pyran-3,4-dicarboxylates using the three-component reaction of dithiocarbamates, dialkyl acetylenedicarboxylates, and isocyanides in solvent-free conditions is described. In these reactions, synthesis of dithiocarbamates is possibly based on the one-pot reaction of secondary amines, CS2, and alkyl halides in solvent-free conditions without using a catalyst. The mild reaction conditions and high yields of the reaction exhibit the good synthetic advantage of these methods. 相似文献
11.
Naseem Ahmed 《Tetrahedron letters》2007,48(31):5407-5409
An efficient TaBr5 (5-10 mol %)-catalyzed Biginelli reaction under solvent-free conditions for one-pot syntheses of 3,4-dihydropyrimidin-2-(1H)-ones (DHPMs) and their thione analogs is reported. The catalyst is stable at room temperature and employed under mild and environmentally friendly conditions. 相似文献
12.
Michael Umkehrer Cédric Kalinski Jürgen Kolb Christoph Burdack 《Tetrahedron letters》2006,47(14):2391-2393
A novel one-pot-synthesis of highly substituted indol-2-ones using a combination of Ugi and Heck reaction (U-4CR-Heck) is described. The synthesized indol-2-ones represent an interesting pharmacological scaffold with four potential points of diversity. Thus, this novel reaction-type is amenable to combinatorial high-throughput screening. 相似文献
13.
Grégori Binot 《Tetrahedron letters》2005,46(44):7503-7506
A novel route to 3,4-dihydroquinolin-2(1H)-ones involving two radical addition steps is reported, starting from readily accessible xanthates and N-aryl-3-butenamides. 相似文献
14.
Ravibabu Velpula Janardhan Banothu Rajitha Gali Rajitha Deshineni Rajitha Bavantula 《中国化学快报》2015,26(3):309-312
1-Sulfopyridinium chloride portrayed as an efficient and recyclable ionic liquid for the synthesis of fused3,4-dihydropyrimidin-2(1H)-ones and thiones via a modified Biginelli reaction involving one-pot three component condensation of 6-methoxy-1-tetralone,arylaldehydes and urea/thiourea under solventfree conditions.Analytically pure products are formed within 10–20 min in excellent yields. 相似文献
15.
<正>Silica-supported tin chloride and titanium tetrachloride were prepared by the reaction of tin chloride and titanium tetrachloride with activated silica gel in refluxing toluene.These solid acids have been employed as the catalysts for the synthesis of bisdihydropyrimidin -2(1H)-ones from aromatic dialdehydes,1,3-dicarbonyl compounds and urea at 90℃under solvent-free conditions. 相似文献
16.
Xi-Cun Wang Guo-Jun Yang Xiao-Dong Jia Zhang Zhang Yu-Xia Da Zheng-Jun Quan 《Tetrahedron》2011,67(18):3267-3272
The Biginelli 3,4-dihydropyrimidin-2(1H)-one was converted to various C2-multifunctionalized pyrimidines via the dehydrogenation and Mitsunobu reaction using amines, alcohols, phenols and carboxylic acids as nucleophiles. A possible mechanism was also proposed to rationalize the formation of products. 相似文献
17.
《Green Chemistry Letters and Reviews》2013,6(4):327-339
Abstract Heterogeneous Tin (IV) hydrogen phosphate nanodisks [Sn(HPO4)2.H2O] efficiently catalyzed the one-pot three component condensation of aromatic aldehydes, β-ketoesters and urea to produce 3,4–dihydropyrimidin-2-ones under solvent-free conditions at room temperature. Also, the catalyst is equally applicable for the preparation of 1,5–benzodiazepines under the same reaction conditions. The optimum load of the catalyst required is 10 mole% and reusable. Hence, the process is green.
Acknowledgements
The authors thank the Director, Dr. P.G. Rao, HOD, Dr. J.C.S. Kataky, Synthetic Organic Chemistry Division and the Analytical Division of NEIST, Jorhat, Assam, India, for their help. P.H. thanks CSIR, New Delhi, for the research fellowship. 相似文献18.
Quinazolin-4(3H)-one derivatives were synthesized successfully via a one-pot, three component reaction of isatoic anhydride and an orthoester with ammonium acetate or a primary amine catalyzed by silica sulfuric acid under solvent-free conditions. This is the first report on the synthesis of 2-substituted quinazolin-4(3H)-ones by this procedure. 相似文献
19.
Venkateswarlu Chimaladenne Ramesh Manda Ashok Reddy Gudipally Krishna Reddy Valluru Pradeep Kumar Brahman 《合成通讯》2020,50(19):2941-2949
Abstract A mild and efficient base promoted, microwave assisted, green synthesis of 2-amino-2-ene-1,4-diones has been described by the decomposition of phenacyl azides followed by treatment with pyridinium salts of phenacyl bromides in aqueous media. A diverse range of substrates bearing electron-releasing and electron-withdrawing substituents were well tolerated and delivered corresponding 2-amino-2-ene-1,4-diones in good yields. Synthesized 2-amino-2-ene-1,4-diones have been further explored in the synthesis of various substituted 4-hydroxypyrrolidin-2-ones. 相似文献
20.
Melamine trisulfonic acid(MTSA) can be used as an efficient and recyclable catalyst for the promotion of the synthesis of 3,4- dihydropyrimidin-2(1H)-ones/thiones(DHPMs) in the absence of solvent.All reactions were performed at 80℃in good to high yields. 相似文献