Microwave-assisted organic syntheses: microwave effect on intramolecular reactions – the Claisen rearrangement of allylphenyl ether and 1-allyloxy-4-methoxybenzene

RSC Advances ◽  
2015 ◽  
Vol 5 (110) ◽  
pp. 90272-90280 ◽  
Author(s):  
Satoshi Horikoshi ◽  
Tomoki Watanabe ◽  
Momoko Kamata ◽  
Yumiko Suzuki ◽  
Nick Serpone
Keyword(s):  
Microwave Irradiation ◽  
Claisen Rearrangement ◽  
Solvent Free ◽  
Microwave Assisted ◽  
Organic Syntheses ◽  
Microwave Effect ◽  
Intramolecular Reactions ◽  
Rearrangement Process

We examined the possible effect microwaves may have on intramolecular reactions such as the Claisen-type rearrangement process carried out in DMSO solvent and in solvent-free microwave irradiation conditions.

Microwave-assisted synthesis of quinolones and 4H-1,4-benzo thiazine 1,1-dioxides

2005 ◽  
Vol 2005 (1) ◽  
pp. 27-28 ◽  
Author(s):  
Jaime Charris ◽  
Arthur Barazarte ◽  
José Domínguez ◽  
Neira Gamboa
Keyword(s):  
Microwave Irradiation ◽  
Rapid Method ◽  
Solvent Free ◽  
Microwave Assisted Synthesis ◽  
Microwave Assisted ◽  
Solvent Free Conditions

A rapid method for the preparation of N-aryl-2-methylthio-4-oxo-1,4-dihydro quinoline-3-carbonitriles (2a–e) and N-aryl-3-methylthio-4H-1,4-benzothiazine-2-carbonitrile 1,1-dioxides (2f–o) is reported. The cyclization is accelerated by microwave irradiation under solvent free conditions in the presence of K2CO3.

Microwave-assisted palladium mediated efficient synthesis of pyrazolo[3,4-b]pyridines, pyrazolo[3,4-b]quinolines, pyrazolo[1,5-a]pyrimidines and pyrazolo[1,5-a]quinazolines

RSC Advances ◽  
2014 ◽  
Vol 4 (46) ◽  
pp. 24001-24006 ◽  
Author(s):  
Kommuri Shekarrao ◽  
Partha Pratim Kaishap ◽  
Venkateshwarlu Saddanapu ◽  
Anthony Addlagatta ◽  
Sanjib Gogoi ◽  
...  
Keyword(s):  
Microwave Irradiation ◽  
Efficient Method ◽  
Solvent Free ◽  
Efficient Synthesis ◽  
Aryl Aldehydes ◽  
Microwave Assisted ◽  
Fused Heterocycles ◽  
Palladium Catalyzed ◽  
Solvent Free Reaction

An efficient method was developed for the synthesis of pyrazole fused heterocycles via the palladium-catalyzed solvent free reaction of β-halovinyl/aryl aldehydes and 3-aminopyrazoles/5-aminopyrazoles under microwave irradiation in good yields.

Microwave-assisted synthesis of 1,4-disubstituted thiosemicarbazides and semicarbazides under solvent-free conditions in the absence of catalyst

2005 ◽  
Vol 2005 (1) ◽  
pp. 71-72 ◽  
Author(s):  
Xi-Cun Wang ◽  
Zheng-Jun Quan ◽  
Zheng Li
Keyword(s):  
Microwave Irradiation ◽  
Solvent Free ◽  
Microwave Assisted Synthesis ◽  
Microwave Assisted ◽  
Solvent Free Conditions

Thirty-two 1-aroyl/aryloxyacetyl-4-(2-furoyl)thiosemicarbazides and corresponding semicarbazides were synthesised in excellent yields under microwave irradiation and solvent-free conditions without using any catalyst.

A sulfonated Schiff base dimethyltin(iv) coordination polymer: synthesis, characterization and application as a catalyst for ultrasound- or microwave-assisted Baeyer–Villiger oxidation under solvent-free conditions

RSC Advances ◽  
2016 ◽  
Vol 6 (81) ◽  
pp. 78225-78233 ◽  
Author(s):  
Luísa M. D. R. S. Martins ◽  
Susanta Hazra ◽  
M. Fátima C. Guedes da Silva ◽  
Armando J. L. Pombeiro
Keyword(s):  
Schiff Base ◽  
Coordination Polymer ◽  
Microwave Irradiation ◽  
Heterogeneous Catalyst ◽  
Polymer Synthesis ◽  
Solvent Free ◽  
Microwave Assisted ◽  
Solvent Free Conditions ◽  
Villiger Oxidation ◽  
Efficient Heterogeneous Catalyst

The sulfonated Schiff base dimethyltin(iv) coordination polymer is an efficient heterogeneous catalyst for the peroxidative Baeyer–Villiger oxidation of ketones, under ultrasound or microwave irradiation and solvent- and additive-free conditions.

Microwave assisted Acetylation of Amines using Imidazole Hydrochloride under solvent-free condition

2021 ◽  
Vol 25 (12) ◽  
pp. 116-121
Author(s):  
Anil Chikkulapalli ◽  
S. Sumathi
Keyword(s):  
Microwave Irradiation ◽  
Aromatic Amines ◽  
Solvent Free ◽  
Microwave Irradiation Method ◽  
Free Condition ◽  
Microwave Assisted ◽  
Solvent Free Condition

A simple and novel microwave irradiation method has been developed for N-acetylation of both aliphatic and aromatic amines with N,N-dimethylacetamide via Nacetyl imidazole by using Imidazole hydrochloride under solvent-free condition. The method proved more eco-friendly and economic.

Efficient, microwave-assisted intramolecular 1,3-dipolar cycloadditions of oximes and N-methylnitrones derived from o-alkenylmethoxy-acetophenones

2005 ◽  
Vol 83 (3) ◽  
pp. 260-265 ◽  
Author(s):  
Surinderjit Singh ◽  
M PS Ishar ◽  
Gajendra Singh ◽  
Rajinder Singh
Keyword(s):  
Microwave Irradiation ◽  
Microwave Heating ◽  
Reaction Times ◽  
Solvent Free ◽  
Dipolar Cycloadditions ◽  
Microwave Assisted ◽  
Solvent Free Conditions ◽  
A Minor ◽  
Acetophenone Oxime

Contrary to literature reports, the o-allyloxy- and crotyloxy-acetophenone-oximes (2a, 2b) are transformed to nitrones, which undergo regio- and stereoselective intramolecular 1,3-dipolar cycloadditions, both on microwave heating under solvent free conditions and refluxing in toluene, to afford novel cycloadducts (5a, 5b); the oxazepine-N-oxide (3a) reported to be formed in 98% yield was obtained only as a minor product (~10%). However, o-cinnamyloxy-acetophenone-oxime (2c) under similar conditions undergoes intramolecular N-alkylation to afford nitrone (3c). The reactions carried out under microwave irradiation are cleaner, require shorter reaction times, and have higher yields. Corresponding intramolecular 1,3-dipolar cycloadditions of N-methylnitrones (B), generated in situ from o-alkenylmethoxy-acetophenones (1a–1c) and N-methylhydroxylamine under solvent-free microwave irradiation conditions, are completely regio- and stereoselective, require much shorter reaction times, and afford adducts (4a–4c) in higher yields, as compared with their thermal counterparts.Key words: cycloadditions, nitrones, oximes, o-alkenylmethoxy-acetophenones, microwave, isoxazolidines.

scholarly journals N-methylimidazole mediated synthesis of aryl alkyl ethers under microwave irradiation and solvent free conditions

2015 ◽  
Vol 80 (4) ◽  
pp. 459-464
Author(s):  
Hoorieh Djahaniani ◽  
Laila Aghadadashi-Abhari ◽  
Bita Mohtat
Keyword(s):  
Microwave Irradiation ◽  
Solvent Free ◽  
High Yield ◽  
Phenol Derivatives ◽  
Microwave Assisted ◽  
Novel Approach ◽  
Solvent Free Conditions ◽  
Three Component Reaction ◽  
Alkyl Ethers

Microwave-assisted three-component reaction has been established for the synthesis of aryl alkyl ethers. The reaction was carried out under solvent free conditions in the presence of N-methylimidazole and dialkylacetylenedicarboxylate to furnish a novel approach to O-alkylation of phenol derivatives in high yield

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