Microwave-Assisted Synthesis of 2-Substituted 2-Thiazolines and 5,6-Dihydro-4H-1,3-thiazines

Synthesis ◽  
2020 ◽  
Vol 52 (11) ◽  
pp. 1666-1679
Author(s):  
Liliana R. Orelli ◽  
María C. Mollo ◽  
Juan A. Bisceglia ◽  
Natalia B. Kilimciler ◽  
Michele Mancinelli
Keyword(s):  
Reaction Times ◽  
Ring Closure ◽  
Cyclization Reaction ◽  
Microwave Assisted Synthesis ◽  
Metal Free ◽  
Microwave Assisted ◽  
Whole Process ◽  
High Yields ◽  
General Method

An efficient and general method for the synthesis of 2-substituted thiazolines and 5,6-dihydro-4H-1,3-thiazines is developed via microwave-assisted ring closure of ω-thioamidoalcohols promoted by ethyl polyphosphate (PPE). The cyclization reaction involves an SN2-type mechanism and features the advantages of very short reaction times, high yields and a predictable stereochemical outcome. The acyclic precursors are prepared in high overall yields by an improved diacylation–thionation–saponification sequence from commercially available ω-amino­alcohols. The whole process is metal-free and operationally simple.

scholarly journals Microwave-assisted cyclizations promoted by polyphosphoric acid esters: a general method for 1-aryl-2-iminoazacycloalkanes

2016 ◽  
Vol 12 ◽  
pp. 2026-2031 ◽  
Author(s):  
Jimena E Díaz ◽  
María C Mollo ◽  
Liliana R Orelli
Keyword(s):  
Polyphosphoric Acid ◽  
General Procedure ◽  
Reaction Times ◽  
Ring Closure ◽  
Heterocyclic Synthesis ◽  
Microwave Assisted ◽  
Solvent Free Conditions ◽  
High Yields ◽  
Acid Esters ◽  
General Method

The first general procedure for the synthesis of 5 to 7-membered 1-aryl-2-iminoazacycloalkanes is presented, by microwave-assisted ring closure of ω-arylaminonitriles promoted by polyphosphoric acid (PPA) esters. 1-Aryl-2-iminopyrrolidines were easily prepared from the acyclic precursors employing a chloroformic solution of ethyl polyphosphate (PPE). The use of trimethylsilyl polyphosphate (PPSE) in solvent-free conditions allowed for the synthesis of 1-aryl-2-iminopiperidines and hitherto unreported 1-aryl-2-iminoazepanes. The cyclization reaction involves good to high yields and short reaction times, and represents a novel application of PPA esters in heterocyclic synthesis.

Microwave-assisted synthesis of hydroxyl-containing isoquinolines by metal-free radical cyclization of vinyl isocyanides with alcohols

2017 ◽  
Vol 15 (47) ◽  
pp. 10044-10052 ◽  
Author(s):  
Dengqi Xue ◽  
Hao Chen ◽  
Yulong Xu ◽  
Haihua Yu ◽  
Linqian Yu ◽  
...  
Keyword(s):  
Free Radical ◽  
Radical Cyclization ◽  
Cyclization Reaction ◽  
Microwave Assisted Synthesis ◽  
Metal Free ◽  
Microwave Assisted

A convenient microwave-assisted protocol for the synthesis of hydroxyl-containing isoquinolines from a metal-free radical cyclization reaction of vinyl isonitriles with alcohols was developed with moderate-to-excellent yields.

scholarly journals Microwave-assisted synthesis of 2-substituted 4,5,6,7-tetrahydro-1,3-thiazepines from 4-aminobutanol

2020 ◽  
Vol 16 ◽  
pp. 32-38
Author(s):  
María C Mollo ◽  
Natalia B Kilimciler ◽  
Juan A Bisceglia ◽  
Liliana R Orelli
Keyword(s):  
General Procedure ◽  
Reaction Times ◽  
Solvent Free ◽  
Ring Closure ◽  
Microwave Assisted Synthesis ◽  
Microwave Assisted ◽  
Solvent Free Conditions

A general procedure for the synthesis of 2-substituted tetrahydro-1,3-thiazepines by MW-assisted cyclization of 4-thioamidobutanols is presented. The acyclic precursors were prepared in high overall yields by an expeditious three-step diacylation/thionation/deprotection sequence from 4-aminobutanol. Microwave-assisted ring closure of 4-thioamido alcohols promoted by trimethylsilyl polyphosphate (PPSE) in solvent-free conditions allowed for the synthesis of several hitherto unreported seven-membered iminothioethers bearing 2-aryl, alkenyl, aralkyl and alkyl substituents. The cyclodehydration reaction is likely to involve an SN2-type displacement and affords good to excellent yields of the desired heterocycles in very short reaction times.

Sonication and Microwave-Assisted Primary Amination of Potassium­ Aryltrifluoroborates and Phenylboronic Acids under Metal-Free Conditions

Synthesis ◽  
2017 ◽  
Vol 49 (11) ◽  
pp. 2555-2561 ◽  
Author(s):  
Dale Kuik ◽  
J. McCubbin ◽  
Geoffrey Tranmer
Keyword(s):  
Transition Metal ◽  
Reaction Times ◽  
Aqueous Sodium Hydroxide ◽  
Metal Free ◽  
Microwave Assisted ◽  
Free Generation ◽  
Phenylboronic Acids ◽  
Microwave Assisted Method ◽  
General Method ◽  
Electron Withdrawing Substituents

The transition-metal-free generation of a series of primary arylamines from potassium aryltrifluoroborates and phenylboronic acids­ is reported. The method uses a mild, inexpensive source of nitrogen (hydroxylamine-O-sulfonic acid) in cooperation with aqueous sodium hydroxide in acetonitrile. Both a sonication and a microwave-assisted method were developed, which are capable of converting ArBF3K functionalities into primary arylamines (ArNH2) in isolated yields of up to 78% (10 examples for each method). This report represents the first general method for the conversion of aryltrifluoroborates into primary arylamines under mild, transition-metal-free conditions in moderate to very good yields. The method is applicable to a wide array of substrates containing electron-donating, electron-neutral, or electron-withdrawing substituents. Both the sonication and microwave methods were also applied to the generation of anilines from phenylboronic acids in isolated yields of up to 96% (12 examples for each method) that were superior to existing room temperature methods in terms of yield, while also offering much shorter reaction times (15 min vs 16 h). In particular, the microwave method is the first to allow for the conversion of arylboronic acids containing strongly electron-withdrawing substituents into the corresponding anilines in good yields, along with electron-donating­ substituents in very good to excellent yields.

Microwave-assisted synthesis of porphyrins and metalloporphyrins: a rapid and efficient synthetic method

2007 ◽  
Vol 11 (02) ◽  
pp. 77-84 ◽  
Author(s):  
Bruno F. O. Nascimento ◽  
Marta Pineiro ◽  
António M. d'A. Rocha Gonsalves ◽  
Manuela Ramos Silva ◽  
Ana Matos Beja ◽  
...  
Keyword(s):  
Transition Metals ◽  
Reaction Times ◽  
Microwave Assisted Synthesis ◽  
Synthetic Method ◽  
One Pot ◽  
Microwave Assisted ◽  
Experimental Protocols ◽  
Porphyrin Core ◽  
High Yields

The effective 'one-pot' microwave-assisted synthesis of several substituted 5,10,15,20-tetraarylporphyrins is reported. The microwave-assisted insertion of five different transition metals into the 5,10,15,20-tetraphenylporphyrin, 5,10,15,20-tetrakis(4-chlorophenyl)porphyrin and 5,10,15,20-tetrakis(3-hydroxyphenyl)porphyrin core was also achieved with high yields. In addition to their simplicity, both these straightforward, experimental protocols were also characterized by extremely short reaction times and quite small quantities of solvents employed.

scholarly journals Microwave-assisted Synthesis of 2-Substituted 4,5,6,7-Tetrahydro-1,3-thiazepines from 4-Aminobutanol

2019 ◽  
Author(s):  
María C Mollo ◽  
Natalia B Kilimciler ◽  
Juan A Bisceglia ◽  
Liliana R Orelli
Keyword(s):  
General Procedure ◽  
Reaction Times ◽  
Solvent Free ◽  
Ring Closure ◽  
Microwave Assisted Synthesis ◽  
Microwave Assisted ◽  
Solvent Free Conditions

A general procedure for the synthesis of 2-substituted tetrahydro-1,3-thiazepines is presented, by MW-assisted cyclization of 4-thioamidobutanols. The acyclic precursors were prepared in high overall yields by an expeditious three step diacylation/thionation/deprotection sequence from 4-aminobutanol. Microwave assisted ring closure of 4-thioamidoalcohols promoted by trimethylsilyl polyphosphate (PPSE) in solvent-free conditions allowed for the synthesis of several hitherto unreported seven-membered iminothioethers bearing 2-aryl, alkenyl, aralkyl and alkyl substituents. The cyclodehydration reaction is likely to involve a SN2-type displacement and affords good to excellent yields of the desired heterocycles in very short reaction times.

scholarly journals Microwave Assisted Synthesis of 1,5-Benzothiazepines Using Greener Reaction Medium

2019 ◽  
Vol 31 (5) ◽  
pp. 993-996 ◽  
Author(s):  
Sanjay S. Kotalwar ◽  
Amol D. Kale ◽  
Ram B. Kohire ◽  
Vasant B. Jagrut
Keyword(s):  
Reaction Time ◽  
Microwave Irradiation ◽  
Reaction Medium ◽  
Microwave Assisted Synthesis ◽  
Reaction Conditions ◽  
Renewable Sources ◽  
Microwave Assisted ◽  
High Yields

An efficient and eco-friendly synthesis of 1,5-benzothiazepines has been developed by the reaction of various 2-propen-1-ones with 2-aminothiophenol using microwave irradiation in greener reaction medium, glycerol. The clean reaction conditions, shorter reaction time, high yields and non-toxic, biodegradable reaction medium manufactured from renewable sources are unique features of this method.

scholarly journals Microwave assisted synthesis of five membered nitrogen heterocycles

RSC Advances ◽  
2020 ◽  
Vol 10 (59) ◽  
pp. 36031-36041
Author(s):  
Gopinadh Meera ◽  
K. R. Rohit ◽  
Salim Saranya ◽  
Gopinathan Anilkumar
Keyword(s):  
Reaction Time ◽  
Nitrogen Heterocycles ◽  
Product Formation ◽  
Microwave Assisted Synthesis ◽  
Short Reaction Time ◽  
Microwave Assisted ◽  
High Yields

Microwave assisted synthesis of N-heterocycles with short reaction time, high yields and high product purities along with a decrease in the rate of by-product formation.

Microwave-assisted synthesis of zinc 5-(4-carboxyphenyl)-10,15,20-triphenylporphyrin and zinc 5-(4-carboxyphenyl)-10,15,20-triphenylchlorin

2015 ◽  
Vol 19 (04) ◽  
pp. 595-600 ◽  
Author(s):  
Rima Chouikrat ◽  
Aymeric Champion ◽  
Régis Vanderesse ◽  
Céline Frochot ◽  
Albert Moussaron
Keyword(s):  
Reaction Times ◽  
Microwave Assisted Synthesis ◽  
Spectroscopic Techniques ◽  
H Nmr ◽  
Microwave Assisted ◽  
Experimental Protocols ◽  
Time Of Reaction

The microwave-assisted synthesis of zinc 5-(4-carboxyphenyl)-10,15,20-triphenylporphyrin and zinc 5-(4-carboxyphenyl)-10,15,20-triphenylchlrorin are described and compared to classic conditions of synthesis in terms of time of reaction and yields obtained. The new experimental protocols are easy to implement required small amounts of reagents and solvents and lead to short reaction times. All compounds have been characterized by 1 H NMR, MS and spectroscopic techniques.

A biocompatible, metal-free catalyst and its application in microwave-assisted synthesis of functional polyesters

2012 ◽  
Vol 3 (2) ◽  
pp. 384-389 ◽  
Author(s):  
Zhengwei You ◽  
Xiaoping Bi ◽  
Eric M. Jeffries ◽  
Yadong Wang
Keyword(s):  
Microwave Assisted Synthesis ◽  
Metal Free ◽  
Microwave Assisted
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