Greener approach towards the facile synthesis of 1,4-dihydropyrano[2,3-c]pyrazol-5-yl cyanide derivatives at room temperature

This report describes triethylammonium acetate (TEAA) ionic liquid catalyzed one pot synthesis of 6-amino-4-aryl-5-cyano-3-methyl-1-phenyl-1,4-dihydropyrano[2,3-c]pyrazoles by the reaction of aromatic aldehyde, malononitrile and 3-methyl-1-phenyl-2-pyrazolin-5-one at room temperature. TEAA plays dual role as reaction media and catalyst. It can also be easily recovered and reused in several runs. TEAA provides greener reaction protocol to present methodology which obviates the need of organic solvents, expensive and toxic catalyst.     

The synthesis of 4,4′-arylmethylene-bis(3-(trifluoromethyl)-1-phenyl-1H-pyrazol-5-ol) in aqueous media without catalyst

The synthesis of 4,4′-arylmethylene-bis(3-(trifluoromethyl)-1-phenyl-1H-pyrazol-5-ol) was performed effectively in aqueous media without catalyst by the reaction of aryl aldehydes and 1-phenyl-3-trifluoromethylpyrazol-5-one. All of the compounds obtained were characterized by elemental analysis, FTIR and ¹H NMR. The structure of compound 3g was further confirmed by the X-ray single crystal diffraction. The method has the advantages of mild condition, without any catalyst, high yields and environmentally benign procedure.     

Sodium dodecyl benzene sulfonate-catalyzed reaction for aromatic aldehydes with 1-phenyl-3-methyl-5-pyrazolone in aqueous media

Sodium dodecyl benzene sulfonate was successfully used for the tandem Knoevenagel-Michael reaction of aromatic aldehydes with 1-phenyl-3-methyl-5-pyrazolone in water to synthesis of 4, 4′-arkylmethylene-bis(1-phenyl-3-methyl-5-pyrazolones) under mild reaction conditions. Efficient catalytic activity and high selectivity of the catalyst contributed to colloidal particle formation in water. The shape and size of the colloidal aggregates were confirmed by optical microscopy and dynamic light scattering.     

Asymmetrische homogene Hydrierung am Beispiel der Hydrierung eines Thiophenderivates

(+)-2-(4-Methoxy-5-phenyl-3-thienyl)propionic acid ( 1 ) was obtained by asymmetric hydrogenation of 2-(4-methoxy-5-phenyl-3-thienyl)acrylic acid ( 11 ) in 97% yield and with an optical purity of 88% using Kagan's catalyst. The racemic acid 1 was also prepared by an independent route and resolved by classical techniques.     

Xanthan Sulfuric Acid: An Efficient,Biosupported, and Recyclable Solid Acid Catalyst for the Synthesis of 4,4′-(Arylmethylene)bis(1H-pyrazol-5-ols)

A simple and efficient method has been developed for the synthesis of 4,4′-(arylmethylene)bis(1H-pyrazol-5-ols) by the condensation reaction between substituted aldehydes, and 1-phenyl-3-methylpyrazol-5-one in the presence of xanthan sulfuric acid (XSA) as a solid acid catalyst. This method is simple and cost-effective with short reaction times. Yields are excellent with high purity, and the catalyst could be easily recycled.     

One-pot three-component process for the synthesis of substituted pyrano[2,3-<Emphasis Type="Italic">c</Emphasis>]pyrazoles catalyzed by nanostructured FSM-16-SO<Subscript>3</Subscript>H

A three-component process for the one-pot synthesis of 6-amino-4-aryl-5-cyano-3-methyl-1-phenyl-1,4-dihydropyrano[2,3-c]pyrazoles by the reaction of aldehydes, 3-methyl-1-phenyl-1H-pyrazol-5(4H)-one, and malononitrile in the presence of FSM-16-SO₃H as an efficient mesoporous catalyst. The FSM-16-SO₃H was prepared and characterized by SEM, XRD, BET, and FT-IR techniques. The advantages of the presented method are high yields, short reaction times, easy purification of products, easy work-up, and reusability of the catalyst.     

Synthesis of N-confused porphyrin derivatives with a substituted 3-C position

Active methylene compounds such as 5,5-dimethylcyclohexane-1,3-dione, cyclohexane-1,3-dione, 3-methyl-1-phenyl-1H-pyrazol-5(4H)-one, 1,3-dimethyl-1H-pyrazol-5(4H)-one, and 3-methylisoxazol-5(4H)-one react with the 3-C position of N-confused porphyrin in THF for 5 min to afford a novel type of N-confused porphyrin derivatives in good yield without the need of any catalyst.     

磷钨酸铜绿色催化合成缩醛(酮)及其催化活性测定

合成了绿色杂多酸盐催化剂磷钨酸铜;将环己酮、苯甲醛同乙二醇、1,2-丙二醇的缩合反应作为探针反应,测定了催化剂的催化活性,比较系统地考察了催化剂用量、物料配比、反应时间、带水剂用量等因素对反应产率的影响.结果表明:在底物醛(酮)用量0.2 mol、醛(酮)/乙二醇(1,2-丙二醇)摩尔比1.0/1.5、催化剂用量0.5 g、带水剂环己烷用量18 mL、一定温度下回流反应2.0 h,1,4-二氧螺[4,5]癸烷产率为83.3%,3-甲基-1,4-二氧螺[4,5]癸烷产率为89.7%,2-苯基-1,3-二氧环戊烷产率为66.7%,4-甲基-2-苯基-1,3-二氧环戊烷产率为78.5%.     

Sulfamic-acid-catalyzed simple and efficient synthesis of 4-aryl-3-methyl-1-phenyl-1H-benzo[g]pyrazolo[3,4-b]quinoline-5,10-diones under solvent-free conditions

Abstract  

An efficient synthesis of 4-aryl-3-methyl-1-phenyl-1H-benzo[g]pyrazolo[3,4-b]quinoline-5,10-diones from the three-component condensation reaction of 3-methyl-1-phenyl-1H-pyrazol-5-amine, aromatic aldehydes, and 2-hydroxy-1,4-naphthoquinone under solvent-free conditions in good to excellent yields and short reaction times using sulfamic acid as heterogeneous acid catalyst has been investigated.     

Catalyst free synthesis of fused pyrido[2,3-d]pyrimidines and pyrazolo[3,4-b]pyridines in water

A one-pot,three-component condensation reaction of an aldehyde,benzoyl acetonitrile(3-oxo-3-phenylpropane nitrile) and 6- amino-1,3-dimethylpyrimidine-2,4(1H,3H)-dione or 3-methyl-1-phenyl-1H-pyrazol-5-amine in water to give fused pyrido[2,3- d]pyrimidines and pyrazolo[3,4-b]pyridines in high yields without any catalyst,is described.     

微波辐射一步法合成吡喃和吡喃[2, 3-c]吡唑衍生物

芳醛、丙二腈与5,5-二甲基-1,3-环己二酮或3-甲基-1-苯基-2-吡唑啉-5-酮在乙醇溶剂中用哌啶作催化剂,经微波辐射一步合成了2-氨基-3-氰基-4-芳基-7,7-二甲基-5-氧代-5,6,7,8-四氢苯并吡喃和6-氨基-5-氰基-4-芳基-1,4-二氢吡喃[2,3-c]吡唑,反应在2～12min内完成,产率53%～91%。     

均三唑并噻二唑衍生物的微波合成

在无溶剂无催化剂微波辐射下,羧酸与1,3-二氨基硫脲快速反应高产率得到了3-取代基-4-氨基-5-巯基-1,2,4-三唑,该化合物与苯甲酰氯在无溶剂无催化剂微波促进下可以方便地制备化合物3-取代基-6-苯基-1,2,4-三唑[3,4-b][1,3,4]噻二唑。该方法具有反应时间短、环境友好、易于纯化及高产率的优点。产物结构经IR和1HNMR谱进行了表征。     

水介质中4-芳基-3-甲基-1-苯基-4,5,6,7,8,9-六氢化吡唑并[5,4-b]喹啉-5-酮衍生物的三组分一锅合成

在水介质中有十二烷基磺酸钠(SDS)存在下, 以芳醛、5-氨基-3-甲基-1-苯基吡唑、1,3-环己二酮三组分一锅反应合成了4-芳基-3-甲基-1-苯基-4,5,6,7,8,9-六氢化吡唑并[5,4-b]喹啉-5-酮衍生物, 产物的结构通过IR, ¹H NMR确证, 化合物4e的结构经单晶X射线衍射确证.     

五羰基铁光催化烯丙基苯类化合物的异构化反应的研究

本文研究了以五羰基铁为催化剂,使不同取代基的烯丙基苯类化合物进行光异构化反应。苯环上不同极性的取代基对烯丙基苯类化合物异构化速度的影响也不同。烯丙基苯类化合物的异构化反应是一级反应。由活化能E_a及不同极性取代基对反应的影响,对它们可能的机理模型作了进一步讨论。     

Novel hydrido-ruthenium(II) complexes with histidine derivatives and their application in the hydrogenation of ketones

The complexes RuHCl((R)-binap)(L-NH2) with L-NH2 = (S)-histidine-Me-ester (1), histamine (3), (S)-histidinol (4) or 1-Me-(S)-histidine-Me-ester (5), and RuHCl((S)-binap)(L-NH(2)) with L-NH2 = (S)-histidine-Me-ester (2) have been prepared in 60-81% overall yields in a one-pot, three-step procedure from the precursor RuCl2(PPh3)3. Their octahedral structures with hydride trans to chloride were deduced from their NMR spectra and confirmed by the results of a single crystal X-ray diffraction study for complex 3. Under H2 and in the presence of KOtBu, complexes 1-5 in 2-propanol form moderately active catalyst precursors for the asymmetric hydrogenation of acetophenone to 1-phenylethanol. Complex 5 is more active and enantioselective than complexes 1-4, allowing complete conversion to 1-phenylethanol in 46% e.e. (R) in 72 h at 20 degrees C under 1 MPa of H2 with substrate : catalyst : base = 2000 : 1 : 30. Complex 5, when activated, also catalyzes the hydrogenation of trans-4-phenyl-3-buten-2-one to exclusively the allyl alcohol 4-phenyl-3-buten-2-ol under 2.7 MPa of H2 at 50 degrees C in 2-propanol. This selectivity for C=O versus C=C hydrogenation is consistent with a mechanism involving the outer sphere transfer of hydride and proton to the polar bond. Further extensions to complexes with peptides with N-terminal histidine groups appear feasible on the basis of the current work.     

A novel catalyst for alkene epoxidation: a polymer-supported CoLCl2 {L = 2-(alkylthio)-3-phenyl-5-(pyridine-2-ylmethylene)-3,5-dihydro-4H-imidazole-4-one} complex

A polymer-supported complex based on 3-phenyl-5-(2-pyridylmethylidene)-2-thiohydantoin has been synthesized and employed as a catalyst for the epoxidation of alkenes using iodosylbenzene and hydrogen peroxide as oxidants.     

An Efficient Synthesis of Pyrazolo[3,4-b]pyridine Derivatives in Ionic Liquid

A series of 3-methyl-1,4,6-triaryl-1H-pyrazolo[3,4-b]pyridines was synthesized via the reaction of 3-methyl-1-phenyl-1H-pyrazol-5-amine and α,β-unsaturated ketones in ionic liquid without any catalyst. This protocol has the advantages of easier work-up, milder reaction conditions, high yields and environmentally benign procedure.     

Optimization of asymmetric hydrogenation of 3-phenyl-3-butenoic acid catalyzed by rhodium(I)-4,5-bis[(diphenylphosphino)methyl]-2,2-dimethyldioxolane (DIOP)

Enantioselective, homogeneous hydrogenation of 3-phenyl-3-butenoic acid (1) has extensively been examined in the presence of the rhodium(I)/4,5-bis[(diphenylphosphino)methyl]-2,2-dimethyldioxolane (DIOP) catalyst systems. Optimization of the reaction conditions was undertaken mainly by controlling effects of added tertiary amines as well as solvent polarities on the enantio-selectivity of the product. The best asymmetric yield (85.1% e.e.) was attained when the hydrogenation was carried out in the presence of triethylamine (5 mol%) in 75% aqueous methanol using a neutral rhodium-DIOP catalyst.     

Polynuclear heterocyclic compounds

When 2, 3(CO)-benzoylene-4-phenyl-5-keto-7, 7-dimethyl-5, 6, 7, 8-tetrahydroquinoline is catalytically hydrogenated using Adams catalyst, the five-membered ring carbonyl group is reduced to an alcohol group. The acetate, urethane, monoxime, and hydrochloride of the reduction product are prepared. Their IR spectra are measured. When 2, 3 (CO)-benzoylene-4-phenyl-5-keto-7, 7-dimethyl-5, 6, 7, 8-tetrahydroquinoline is reduced by zinc dust and glacial acetic acid, both carbonyl groups are reduced to CH₂, and 2, 3 (CH₂)-benzylene-4-phenyl-5-keto-7, 7-dimethyl-5, 6, 7, 8-tetrahydroquinoline is formed.For Part XIX see [2].     

The stereochemical course of the catalytic hydrogenation of 3(2H)isoquinolinones

4-Benzylidene-1-phenyl-1,4-dihydro-3(2H)isoquinolinone ( 2 ), 4-benzyl-1-phenyl-3(2H)isoquino-linone ( 3 ) and 4-benzyl-3-ethoxy-1-phenylisoquinoline ( 6 ) have been hydrogenated on palladium-charcoal catalyst. The structure of the products and the ratio of the stereoisomers have been determined by nmr spectroscopy and by LIS measurements with Eu(dpm)₃.