Zinc-catalyzed multicomponent reactions: Facile synthesis of fully substituted pyridines

A first example of environmentally benign zinc complex catalyzed one-pot four-component reaction between malononitrile, ketone, ammonium acetate and aromatic aldehyde for the facile synthesis of fully substituted pyridines just within 2?min in environmentally friendly solvent ethanol has been optimized.     

Proton transfer process in synthesis of 3-acetyl-4-(substituted ethylenyl)coumarins and chromeno[3,4-c]pyridines

The triphenylphosphine mediated reactions of electron-deficient carbon-carbon triple bonds with 3-acetylcoumarins in dichloromethane afford functionalized 3-acetyl-4-(substituted ethylenyl)coumarins. Also, triphenylphosphine-catalyzed three-component cascade annulation reactions of 3-acetylcoumarins, activated acetylenic compounds, and hydrazines or amines provide a straightforward access to 3,5-dihydro-2H-chromeno[3,4-c]pyridine-1,2-dicarboxylates. In these strategies, the main step to the target products is proton transfer process. All products were obtained in good to high yields.     

Green chemical multicomponent approach for the synthesis of C3-pyranopyrazole-substituted coumarins

An efficient and rapid method was developed for the synthesis of C3-pyranopyrazole-substituted coumarins from one-pot five-component reaction of β-keto ester, hydrazine, O-hydroxy aromatic aldehydes, 6-methyl, 4-hydroxy pyranone and aromatic aldehyde in the presence of tri-ethylamine in solvent-free conditions. The microwave-assisted method reported herein offers advantageous shorter reaction times, higher yields and cleaner reaction compared with conventional heating methods.     

用碲Ylide合成杂环取代环丙烷衍生物

本文报道了由碲盐和杂环取代查尔酮反应合成杂环取代环丙烷衍生物的简便方法。     

Synthesis of two p-methoxyphenyl substituted phosphines

Bis(m-methoxyphenyl)(p-methoxyphenyl)phosphine (1) and di(n-butyl)(p-methoxy-phenyl)-phosphine (4) were synthesized and characterized by ¹H, ¹³C, and ³¹P NMR spectroscopy and 1 also by single crystal X-ray diffraction. The syntheses and analytical data are discussed.     

A Highly Stereoselective Synthesis of 2－Carbomethoxy－3－aryl－4－carboethoxy－5－methyl－cis－2，3－dihydrofurans

ＡＨｉｇｈｌｙＳｔｅｒｅｏｓｅｌｅｃｔｉｖｅＳｙｎｔｈｅｓｉｓｏｆ２－Ｃａｒｂｏｍｅｔｈｏｘｙ－３－ａｒｙｌ－４－ｃａｒｂｏｅｔｈｏｘｙ－５－ｍｅｔｈｙｌ－ｃｉｓ－２，３－ｄｉｈｙｄｒｏｆｕｒａｎｓＤＩＮＧＷｅｉ－ｙｕ；ＣＨＥＮＹａ－ｌｉ；ＺＨＡＮＧ...     

3-Phenoxy- and 3-phenylthio-1-propynyl substituted derivatives of silicon and germanium

Reactions of bromomagnesiopropargyl phenyl ethers and their isostmctural sulfides BrMgCCCH₂XPh (X = O, S) with MeVinSiCl₂, Me(CH₂Cl)SiCl₂, EtSiHCl₂, and Me₂SiHCl afforded the corresponding 3-phenoxy- and 3-phenylthio-1-propynyl substituted derivatives of silicon (PhXCH₂CC)₂SiRR¹ and PhXCH₂CCSiHMe₂ (X = O, S). Reactions of the above-mentioned Iotsitch reagents with GeCl₄ led to the corresponding germanium derivatives (PhXCH₂CC)₄Ge (X = O, S).Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 3, pp. 511–513, March, 1994.     

取代吲哚-3-甲醛类化合物的合成

取代邻硝基甲苯(1)、N,N-二甲基甲酰胺二甲基缩醛或二乙基缩醛和哌啶在溶剂N,N-二甲基甲酰胺中缩合制得取代的β-哌啶基-2-硝基甲苯(2), 2用铁粉和冰醋酸还原环合得到取代吲哚(3), 将3与三氯氧磷和N,N-二甲基甲酰胺通过Vilsmeier-Hacck反应制得了取代吲哚-3-甲醛类化合物4和5. 化合物4和5的结构经元素分析, IR和¹H NMR确认.     

3-取代苄氧基-6-取代氨基哒嗪衍生物的合成及其除草活性

通过3-取代苄氧基-6-氟哒嗪在75～80 ℃与二甲胺的绝对无水乙醇溶液封管反应, 或在回流条件下分别与吗啡啉或哌啶反应, 合成一系列新颖的3-取代苄氧基-6-取代氨基哒嗪类化合物, 它们的结构均经IR, ¹H NMR和元素分析确证. 初步的除草活性测定结果表明, 该类化合物具有一定的除草活性, 讨论了它们的结构与除草活性的关系.     

A convenient sonochemical synthesis of vicinally substituted 3-hydroxylaminopyridines

A method of synthesis of vicinally substituted N-(3-pyridyl)hydroxylamines by reducing the corresponding nitropyridines with Zn/NH₄Cl/EtOH under ultrasonication is proposed. Ultrasound irradiation increases the yields of these hydroxylamines and facilitates their isolation.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 2, pp. 365–367, February, 1993.     

Synthesis of pyrimidine derivatives via multicomponent reaction catalyzed by ferric chloride

An eco-friendly and practical approach was developed for the synthesis of pyrimidine derivatives via a one-pot, three-component coupling reaction of commercially available aldehydes, alkynes, and indazole3/triazole catalyzed by ferric chloride with good to excellent yields. The advantages of this method include environmentally friendly catalyst, easily available materials, and ease of product isolation.     

Synthesis of 3-(2-(4,5-Dihydro-3,5-diphenylpyrazol-1-yl)thiazol-4-yl)-2H-chromen-2-one Derivatives via Multicomponent Approach

An efficient synthesis of 3-(2-(4,5-dihydro-3,5-diphenylpyrazol-1-yl)thiazol-4-yl)-2H-chromen-2-one derivatives by a simple, atom-economical, and multicomponent reaction of chalcones, thiosemicarbazide, and 3-(2-bromoacetyl) coumarins in the presence of aqueous sodium hydroxide in refluxing ethanol is reported. The structures of newly prepared compounds have been confirmed by their analytical and spectral (IR, ¹HNMR, ¹³CNMR and mass) data.

[Supplementary materials are available for this article. Go to the publisher's online edition of Synthetic Communications® for the following free supplemental resource(s): Full experimental and spectral details.]     

Iridium-catalyzed asymmetric hydrogenation of 3-substituted unsaturated oxindoles to prepare C3-mono substituted oxindoles

An efficient and enantioselective hydrogenation of 3-substituted unsaturated oxindoles has been developed by an iridium complex of tropos phosphine-oxazoline ligands. It is the first example to prepare chiral C3-mono substituted oxindoles via asymmetric catalysis. And the reaction provides instant access to this kind of compounds with excellent conversion and enantioselectivities (up to 93% ee).     

Chemistry of 3-Hetarylcoumarins. 1. 3-(2-Benzazolyl)coumarins

The reaction of substituted salicylaldehydes with 2-benzimidazolyl- and 2-benzothiazolylacetonitriles gives the corresponding 3-hetarylcoumarins. The alkylation, acylation, and aminomethylation reactions of these 7-hydroxy-substituted hetero isoflavonoid analogs has been studied.     

Efficient and mild synthesis of highly substituted 2,5-dihydrofuran and furan derivatives via stepwise reaction

An efficient and mild synthesis of highly substituted 2,5-dihydrofuran and furan derivatives from a variety of alkylidene malonates and 1,4-butyne-diol via one-pot reaction was applied. With various conditions of base amount, temperature and time applied to the reaction, the 2,5-dihydrofuran and the furan derivatives could be selectively obtained. Moreover, the formation of furan derivatives with 2,5-dihydrofuran derivatives as intermediates was also investigated. Some of these 2,5-dihydrofuran derivatives showed potent in vitro anti-tumor activities against HeLa cells.     

An efficient non-ionic surfactant catalyzed multicomponent synthesis of novel benzylamino coumarin derivative via Mannich type reaction in aqueous media

An efficient non-ionic surfactant catalyzed multicomponent synthesis of novel benzylamino coumarin derivatives has been developed from secondary amines, aromatic aldehyde, and 4-hydroxy coumarin via Mannich type reaction in aqueous media. In this Mannich type reaction, surfactant forms stable colloidal medium to stabilize iminium ion which undergoes nucleophilic addition of 4-hydroxy coumarin to give benzylamino coumarin in very good yields.     

Synthesis of Dispirocyclopentyl‐3,3′‐bisoxindoles via Domino Cycloaddition Reactions of 4‐Dimethylaminopyridinium Bromides with 3‐Phenacylideneoxindoles

The base mediated cycloaddition reactions of 4‐dimethylamino‐1‐phenacylpyridinium bromides with two molecular 3‐phenacylideneoxindoles in methylene dichloride afforded functionalized dispirocyclopentyl‐3,3′‐bisoxindoles in good yields and with high diastereoselectivity. The similar cycloaddition reactions of 1‐(N,N‐dialkylcarbamoylmethyl) and 1‐cyanomethyl 4‐dimethylamino‐pyridinium bromide in refluxing ethanol in the presence of triethylamine also resulted in dispirocyclopentyl‐3,3′‐bisoxindoles with high diastereoselectivity. The stereochemistry of dispirocyclopentyl‐3,3′‐bisoxindoles was elucidated on the basis of ¹H NMR data and single crystal structures.     

肌肉醇取代苯甲酸盐的合成及生物活性

本文以硫脲和硫酸二甲酯为原料反应生成S-甲基异硫脲硫酸盐,再与2-甲基氨基乙醇反应生成肌肉醇硫酸盐,分离出肌肉醇碱,最后与具有生物活性的取代苯甲酸反应生成了7种肌肉醇取代苯甲酸盐。化合物结构经IR,1H NMR和元素分析进行表征,初步室内生测结果表明该类化合物具有一定的抑菌活性。     

3-(5-Substituted 2-Methoxyphenyl)-4-Nitro-2-Phenyl-5-Thiophene-2-yl-Isoxazolidines - Synthesis and Conformational Studies

Abstract

The synthesis of a new set of 2,3,4,5-substituted isoxazolidines having a sulfur containing heterocyclic moiety has been described. The structural features of the compounds have been analyzed by ¹H and ¹³C NMR spectroscopy as well as by single crystal X-ray studies.

[Supplemental materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfur, and Silicon and the Related Elements for the following free supplemental resource: .cif file.]     

Synthesis of 2-(4-Hydroxy-6-methyl-2-oxo-2H-pyran-3-carbonyl)-6,6-dimethyl-3-phenyl-3,5,6,7-tetrahydro-2H-benzofuran-4-one Derivatives via Multicomponent Reaction

A sequential one-pot, two-step reaction for an efficient preparation of 2-(4-hydroxy-6-methyl-2-oxo-2H-pyran-3-carbonyl)-6,6-dimethyl-3-phenyl-3,5,6,7-tetrahydro-2H-benzofuran-4-one derivatives has been described. One-pot reaction of in situ–formed benzopyran-substituted pyridinium ylides with aromatic aldehydes and dimedone gives corresponding 2,3-dihydrofurans in good yields. The structures of all the newly synthesized compounds were confirmed from their analytical and spectral data.