Heterogeneous Catalysis with Basic Compounds to Achieve the Synthesis and C–N Cleavage of Azetidin-2-ones under Microwave Irradiation

Synthesis ◽  
2019 ◽  
Vol 51 (19) ◽  
pp. 3625-3637 ◽  
Author(s):  
Adriana Galván ◽  
Fabiola N. de la Cruz ◽  
Francisco Cruz ◽  
Merced Martínez ◽  
Clarisa Villegas Gomez ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Heterogeneous Catalysis ◽  
Microwave Irradiation ◽  
Bond Cleavage ◽  
Reaction Times ◽  
Organic Additives ◽  
Acyl Chlorides ◽  
Solid Catalysts ◽  
Basic Compounds ◽  
High Yields

The synthesis of azetidin-2-ones with a completely heterogeneous catalysis is reported. The use of basic compounds as solid catalysts allowed for the synthesis of azetidin-2-ones under microwave irradiation without organic additives such as triethylamine. An excellent catalyst for this transformation was Mg-Al hydroxide (MAH). The present methodology offers the advantages of non-hazardous reaction conditions, short reaction times, high yields, and catalyst reusability. Different substitution groups were tested on the imines and acyl chlorides to explore the scope of the reaction. Unconventional N–C4 bond cleavage was detected in azetidin-2-ones. MAH was characterized by N2 adsorption–desorption, X-ray diffraction (XRD), scanning electron microscopy (SEM), and high-resolution transmission electron microscopy (HR-TEM).

A One-Pot, Three-Component, Solvent-Free Synthesis of Novel 6H-Chromeno[3’,4’:5,6]Pyrido[2,3-d]Pyrimidine-Triones under Microwave Irradiation

2018 ◽  
Vol 42 (12) ◽  
pp. 604-607
Author(s):  
Loghman Firoozpour ◽  
Hoda Yahyavi ◽  
Ramona Ejtemaei ◽  
Setareh Moghimi ◽  
Alireza Foroumadi
Keyword(s):  
Microwave Irradiation ◽  
Efficient Method ◽  
Barbituric Acid ◽  
Reaction Times ◽  
Solvent Free ◽  
One Pot ◽  
Solvent Free Conditions ◽  
Substituted Benzaldehydes ◽  
High Yields ◽  
Solvent Free Synthesis

A green and efficient method for preparing novel heterocyclic systems is established through the reaction of differently substituted benzaldehydes, barbituric acid and 4-amino-2H-chromene-2-one under solvent-free conditions. This method affords 6H-chromeno[3’,4’:5,6] pyrido[2,3-d]pyrimidine-trione derivatives in high yields and short reaction times.

scholarly journals Regioselective Copper-Catalysed Amination of Halobenzoic Acids using Aromatic Amines

2007 ◽  
Vol 2007 (10) ◽  
pp. 587-589 ◽  
Author(s):  
Mohan Babu Maradolla ◽  
Amaravathi Mandha ◽  
Chandra Mouli Garimella
Keyword(s):  
Microwave Irradiation ◽  
Aromatic Amines ◽  
Reaction Times ◽  
Efficient Catalyst ◽  
High Yields

Copper dipyridine dichloride (CuPy2Cl2) has been found to be an efficient catalyst for the synthesis of N-arylanthranilic acids from ortho halobenzoic acids and aromatic amines under microwave irradiation. Some of the advantages of this method are high chemoselectivity, ease of operation, less reaction times and high yields. (61–98%).

1,3-Dibromo-5,5-dimethylhydantoin as a useful reagent for efficient synthesis of 3,4-dihydropyrimidin-2-(1H)-ones under solvent-free conditions

2009 ◽  
Vol 63 (1) ◽  
Author(s):  
Mohammad Abdollahi-Alibeik ◽  
Zahra Zaghaghi
Keyword(s):  
Microwave Irradiation ◽  
Ethyl Acetoacetate ◽  
Biginelli Reaction ◽  
Reaction Times ◽  
Solvent Free ◽  
Efficient Synthesis ◽  
One Pot ◽  
Aliphatic Aldehydes ◽  
Solvent Free Conditions ◽  
High Yields

AbstractEfficient syntheses of 3,4-dihydropyrimidin-2-(1H)-ones and the corresponding thioxo derivatives using 1,3-dibromo-5,5-dimethylhydantoin (DBH) catalysis of a one-pot three-component Biginelli reaction of aldehydes, ethyl acetoacetate, and urea or thiourea under microwave irradiation are described. The advantages of this method are its short reaction times, high yields of the products, inexpensive and commercially available catalyst, and solvent-free conditions. Typical isolated yields exceed 70 % for arylaldehydes (9 examples) and aliphatic aldehydes (2 examples).

scholarly journals Friedel-Crafts benzoylation reaction of aromatic compounds using zinc oxide nanoparticles in deep eutectic solvent (choline chloride/urea) under microwave irradiation

2019 ◽  
Vol 2 (2) ◽  
pp. 62-70
Author(s):  
Hai Truong Nguyen ◽  
Dung Thi Kim Ngo ◽  
Thinh Nguyen Huu Pham ◽  
Phuong Hoang Tran
Keyword(s):  
Zinc Oxide ◽  
Microwave Irradiation ◽  
Aromatic Compounds ◽  
Zinc Oxide Nanoparticles ◽  
Choline Chloride ◽  
Deep Eutectic Solvent ◽  
Reaction Times ◽  
Oxide Nanoparticles ◽  
X Ray ◽  
High Yields

Synthesis of zinc oxide nanoparticles (ZnO) which was found to be effective catalyst for Friedel-Crafts benzoylation reaction in the presence of deep eutectic solvent (DES). The method is one of the most important intermediates for preparing fine chemicals in the field of pharmaceuticals, which is a tool for organic syntheses of aromatic ketones. ZnO precursor was prepared from Zn(CH3COO)2.2H2O and H2C2O4.2H2O, ZnO nanoparticles were characterized by using X-ray Powder Diffraction (XRD), Scanning Electron Microscope (SEM). The benzoylation of aromatic compounds and benzoyl chloride using nanoparticles ZnO/ [CholineCl][Urea]2, under microwave irradiation afforded the desired products in high yields and short reaction times. The catalyst/solvent could be recycled several times without loss of efficient catalytic activity.

scholarly journals Organozinc-mediated direct cross-coupling under microwave irradiation

2021 ◽  
pp. 174751982110264
Author(s):  
Chun-Jing Li
Keyword(s):  
Microwave Irradiation ◽  
Functional Group ◽  
Bond Cleavage ◽  
Reaction Times ◽  
Coupling Reaction ◽  
Cross Coupling ◽  
Cross Coupling Reaction ◽  
Direct Cross ◽  
Methyl Pyrrolidone ◽  
Work Up

We report a direct cross-coupling reaction between (het)aryl pivalates/tosylates and di(het)arylzinc species in 2-methyltetrahydrofuran/ N-methyl pyrrolidone (1:1), which occurs via C–O bond cleavage under microwave irradiation. The reaction takes place smoothly in short reaction times without the addition of any catalyst or ligand. The reaction is suitable for a broad scope of substrates and exhibits good functional group compatibility, utilizes a simple work-up procedure, and gives the desired products in high purity.

scholarly journals [DBN][HSO4]-Promoted facile and green synthesis of 2-Amino-4H-pyrans derivatives under microwave irradiation

2021 ◽  
Vol 11 (2-S) ◽  
pp. 89-97
Author(s):  
Vishal Mane ◽  
Dhanjay Mane
Keyword(s):  
Ionic Liquid ◽  
Microwave Irradiation ◽  
Room Temperature ◽  
Knoevenagel Condensation ◽  
Reaction Times ◽  
Environmentally Benign ◽  
Successive Reaction ◽  
Solvent Free Conditions ◽  
High Yields ◽  
First Time

The [DBN][HSO4] -promoted Knoevenagel condensation followed by cyclization protocol has been developed for the first time by a successive reaction of aldehydes, dimedone and malononitrile to afford 2-Amino-4H-pyrans derivatives in high to excellent yields at room temperature. The synergic couple of microwave and ionic liquid provided the capability to allow a variability of functional groups, short reaction times, easy workup, high yields, recyclability of the catalyst, and solvent-free conditions, thus providing economic and environmental advantages. Keywords: [DBN][HSO4], Environmentally benign, 2-Amino-4H-pyrans, Knoevenagel condensation, Microwave irradiation

Zur gezielten Synthese funktionell substituierter Oligosilane aus Silyltriflaten und Aminosilyllithiumverbindungen / Tailor-Made Synthesis of Functional Substituted Oligosilanes from Silyl Triflates and (Aminosilyl)Lithium Compounds

2003 ◽  
Vol 58 (1) ◽  
pp. 183-190 ◽  
Author(s):  
Wolfram Uhlig
Keyword(s):  
Bond Cleavage ◽  
Reaction Times ◽  
Coupling Reaction ◽  
Building Blocks ◽  
Side Reactions ◽  
Coupling Reactions ◽  
Polymer Backbone ◽  
Exchange Processes ◽  
Halogen Exchange ◽  
High Yields

Abstract Diethylamino substituted silyllithium compounds have been prepared in situ from the corresponding phenylchlorosilanes and lithium. These reagents undergo coupling reactions with triflate derivatives of silanes and oligosilanes. Exchange processes analogous to metal halogen exchange and Si-Si bond cleavage, which are side reactions with chlorosilanes, were not observed. Based on the coupling reaction and the amino-to-triflate transformation, functionalized tri-, tetra-, penta- und hexasilanes have been synthesized. α,ω-Triflate substituted oligosilanes containing π-systems have also been obtained. These compounds are useful building blocks for new organosilicon polymers. The formation of the silicon polymers at low temperatures, in short reaction times, and with high yields is reported. The 29Si NMR spectra indicate a regular, alternating arrangement of the building blocks in the polymer backbone.

TiO2 NPs-Coated Carbone Nanotubes as a Green and Efficient Catalyst for the Synthesis of [1]Benzopyrano[b][1]benzopyranones and Xanthenols in Water

2018 ◽  
Vol 21 (8) ◽  
pp. 594-601 ◽  
Author(s):  
Shahrzad Abdolmohammadi
Keyword(s):  
Electron Microscopy ◽  
Biological Activities ◽  
Reaction Times ◽  
Ongoing Research ◽  
Tio2 Nps ◽  
X Ray ◽  
Three Component Reaction ◽  
Active Methylene Compounds ◽  
High Yields ◽  
Active Methylene

Aim and Objective: Results of pharmacological studies have revealed that chromenes (2H-1-benzopyran derivatives) and xanthenes (dibenzopyrans) constitute major classes of heterocyclic compounds, due to their useful biological activities. Moreover, during the last decade, the use of metal oxide nanoparticles (NPs) as heterogeneous catalysts has been extensively studied due to their high physical and chemical abilities. The aim of the ongoing research was to prove the catalytic efficiency of the synthesized TiO2 NPs supported by carbon nanotubes (TiO2-CNTs) for the preparation of these heterocyclic scaffolds. Materials and Methods: The present work is focused on a green and efficient synthesis of [1]benzopyrano[b][1]benzopyran-6-ones and xanthenols via a pseudo three-component reaction of salicylaldehydes with active methylene compounds including 4-hydroxycoumarin (4-hydroxy-2H-1- benzopyran-2-one) or 3,4-methylenedioxyphenol, in a molar ratio of 1:2. The reaction was carried out in the presence of the synthesized TiO2-CNTs as a catalyst in aqueous media at room temperature. The synthesized catalyst was fully characterized by the scanning electron microscopy (SEM), the transmission electron microscopy (TEM), the powder X-ray diffraction (XRD), and the energy dispersive X-ray detector (EDX) techniques. All the synthesized compounds were characterized by IR, 1H and 13C NMR spectroscopy, as well as elemental analyses. Results: Sixteen target compounds containing [1]benzopyrano[b][1]benzopyran-6-ones and xanthenols were successfully synthesized in high yields (92-98%) within short reaction times (1.5-3 h). Conclusion: In this research, TiO2-CNTs were used as an efficient recyclable catalyst for the synthesis of [1]benzopyrano[b][1]benzopyran-6-ones and xanthenols by the pseudo three-component reaction of salicylaldehydes with active methylene compounds including 4-hydroxycoumarin (4- hydroxy-2H-1-benzopyran-2-one) or 3,4-methylenedioxyphenol. The introduced method is mild, environmentally benign and effective to give the products in high yields and in short reaction times.

Efficient synthesis of novel β-sitosterol scaffolds containing 1,2,3-triazole via copper(I)-catalyzed click reaction under microwave irradiation

2017 ◽  
Vol 72 (10) ◽  
pp. 717-724 ◽  
Author(s):  
Jin-Wei Yuan ◽  
Ling-Bo Qu
Keyword(s):  
Microwave Irradiation ◽  
Click Reaction ◽  
Reaction Times ◽  
Cycloaddition Reactions ◽  
Efficient Synthesis ◽  
High Yields ◽  
Work Up ◽  
Derivatives Of

AbstractIn this work, new derivatives of the β-sitosterol scaffolds containing 1,2,3-triazole are prepared by the reaction of β-sitosterol with aromatic alkynes via copper(I)-catalyzed azide-alkyne cycloaddition reactions under microwave irradiation. The reaction has several advantages including high yields, short reaction times, and a simple work-up procedure.

Schwefel(VI)-oxid-chlorid-imide und Schwefel(VI)-oxid-fluorid-imide [1] / Sulfur(VI)-oxide-chloride-imides and Sulfur(VI)-oxide-fluoride-imides [1]

1981 ◽  
Vol 36 (9) ◽  
pp. 1093-1098 ◽  
Author(s):  
Rüdiger Mews ◽  
Peter Kricke ◽  
Ingo Stahl
Keyword(s):  
Room Temperature ◽  
Bond Cleavage ◽  
Reaction Times ◽  
Spectroscopic Methods ◽  
Sulfur Oxide ◽  
High Yields

Abstract At room temperature in the presence of CsF sulfur-oxide-chloride-fluoride-imides RfNSOFCl (8) (Rf = CF3, C2F5, i-C3F7, C6F5) are formed from N-perfluoroalkyl-sulfinyl-imides and Cl2. At prolonged reaction times or higher temperatures the chloride is ex-changed and the difluorides RfNSOF2 are isolated in high yields. In the same way (CF3)2CFNS(O)ClCF3 (12) and (CF3)2CClNS(O)ClCF3 (13) are obtained from (CF3)2C = N-S(O)CF3 (9) and Cl2/CsF. 12 can be fluorinated by CsF to give (CF3)2CFNS(O)FCF3 (14). 14 is also observed, when fluorine is added to 9 via XeF2 in the presence of BF3, but mainly C-S-bond cleavage occurs. SF5NS(O)FCF(CF3)2 (19) was identified by spectroscopic methods from the reaction of SF5NSOF2 and CF3CF = CF2 in the presence of CsF.

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