scholarly journals Microwave-Assisted Organic Reactions: Eco-friendly Synthesis of Dibenzylidenecyclohexanone Derivatives via Crossed Aldol Condensation

2017 ◽  
Vol 17 (2) ◽  
pp. 336 ◽  
Author(s):  
Sri Handayani ◽  
Cornelia Budimarwanti ◽  
Winarto Haryadi
Keyword(s):  
Optimum Condition ◽  
Microwave Irradiation ◽  
Organic Synthesis ◽  
Aldol Condensation ◽  
Condensation Reaction ◽  
Environmentally Friendly ◽  
Optimum Concentration ◽  
Reaction Yield ◽  
Microwave Assisted ◽  
Benzaldehyde Derivatives

The synthesis of dibenzylidenecyclohexanone derivatives via environmentally friendly Microwave Assisted Organic Synthesis (MAOS) crossed aldol condensation had been carried out. The condensation reaction to synthesize the dibenzylidenecyclohexanone 8b was performed by reacting benzaldehyde 4 and cyclohexanone 2 (mole ratio of 2:1) with NaOH as catalyst for 2 min under microwave irradiation. The benzaldehyde derivatives used in this study were 4-methoxybenzaldehyde and 3,4-dimethoxybenzaldehyde and gave of (2E,6E)-bis(4-methoxy benzylidene)cyclohexanone 8a and (2E,6E)-bis(3,4-dimethoxybenzylidene)cyclohexanone 8c, respectively. The study was commenced by searching the optimum concentration of NaOH. The reaction yield was determined by TLC scanner and the structure was elucidated by FTIR and NMR spectrometers. For the comparison, the reaction was also carried out by using stirring method. The results showed that optimum concentration of NaOH was 5 mmole. By using the optimum condition via MAOS method, the compounds 8a, 8b and 8c were obtained in 100, 98 and 93%, respectively. The research also proved that the method of dibenzylidenecyclohexanones (8) synthesis using MAOS was more efficient than stirring method.

scholarly journals Cycloaddition of Thiourea- and Guanidine-Substituted Furans to Dienophiles: A Comparison of the Environmentally-Friendly Methods

2020 ◽  
Vol 3 (1) ◽  
pp. 57
Author(s):  
Luka Barešić ◽  
Davor Margetić ◽  
Zoran Glasovac
Keyword(s):  
High Pressure ◽  
Functional Groups ◽  
Organic Synthesis ◽  
High Speed ◽  
Environmentally Friendly ◽  
Microwave Assisted ◽  
Pressure Synthesis ◽  
Ultrasound Assisted ◽  
Substituted Furans ◽  
Guanidine Moiety

The cycloaddition strategy was employed in order to obtain a 7-oxanorbornene framework substituted with a guanidine moiety or its precursor functional groups: protected amine or thiourea. In order to optimize the conditions for the cycloaddition, several environmentally-friendly methods—microwave assisted organic synthesis, high pressure synthesis, high speed vibrational milling, and ultrasound assisted synthesis—were employed. The outcomes of the cycloaddition reactions were interpreted in terms of endo/exo selectivity, the conversion of the reactants to the product, and the isolated yields. In general, our results indicated the HP and HSVM approaches as the methods of choice to give good yields and conversions.

Quinoline and phenanthroline preparation starting from glycerol via improved microwave-assisted modified Skraup reaction

RSC Advances ◽  
2014 ◽  
Vol 4 (41) ◽  
pp. 21456-21464 ◽  
Author(s):  
Hanen Saggadi ◽  
Denis Luart ◽  
Nicolas Thiebault ◽  
Isabelle Polaert ◽  
Lionel Estel ◽  
...  
Keyword(s):  
Microwave Irradiation ◽  
Environmentally Friendly ◽  
Microwave Assisted ◽  
Neat Water ◽  
Skraup Reaction

An efficient “green” modified Skraup reaction in neat water was developed using inexpensive, abundant and environmentally-friendly glycerol under microwave irradiation conditions.

Microwave-assisted Carbon-carbon and Carbon-heteroatom Cross-coupling Reactions in Organic Synthesis

2020 ◽  
Vol 7 (2) ◽  
pp. 86-98
Author(s):  
Rammyani Pal ◽  
Chhanda Mukhopadhyay
Keyword(s):  
Microwave Irradiation ◽  
Organic Synthesis ◽  
Cross Coupling ◽  
Side Reactions ◽  
Coupling Reactions ◽  
Considerable Effort ◽  
Microwave Assisted ◽  
External Heat Source ◽  
Cross Coupling Reactions ◽  
Metal Catalyzed

Conventionally, the organic reactions are accomplished by conductive heating with an external heat source like an oil bath. On the contrary, since its inception, the application of microwave irradiation is growing as a suitable alternate heating method in organic synthesis. Microwave heating considerably reduces the reaction time without promoting any side reactions. The fundamental synthetic organic chemistry majorly deals with transition-metal-catalyzed C–C and C–heteroatom bond formation reactions. It is one of the most important methods in contemporary chemistry resulting in a tremendous increment in the applications of these reactions during the last few years. This field has been acknowledged with a number of Nobel Prizes during the last decade (2001, 2005 and 2010). A considerable effort has been done on the continuous development of new ligands and catalysts as well as an increased understanding of the mechanisms for the improvement of the reaction condition. This review focuses on some of the latest developments in the area of cross-coupling reactions aided by microwave irradiation.

scholarly journals Gold film-catalysed benzannulation by Microwave-Assisted, Continuous Flow Organic Synthesis (MACOS)

2009 ◽  
Vol 5 ◽  
Author(s):  
Gjergji Shore ◽  
Michael Tsimerman ◽  
Michael G Organ
Keyword(s):  
Microwave Irradiation ◽  
Functional Groups ◽  
Organic Synthesis ◽  
Continuous Flow ◽  
Metal Film ◽  
Silver Film ◽  
Gold Film ◽  
Microwave Assisted ◽  
Glass Capillaries ◽  
Inner Surface

Methodology has been developed for laying down a thin gold-on-silver film on the inner surface of glass capillaries for the purpose of catalysing benzannulation reactions. The cycloaddition precursors are flowed through these capillaries while the metal film is being heated to high temperatures using microwave irradiation. The transformation can be optimized rapidly, tolerates a wide number of functional groups, is highly regioselective, and proceeds in good to excellent conversion.

scholarly journals Microwave-Assisted Synthesis of Arylidene Acetophenones

2013 ◽  
Vol 2013 ◽  
pp. 1-5
Author(s):  
Sheauly Khatun ◽  
M. Z. H. Khan ◽  
Khodeza Khatun ◽  
M. A. Sattar
Keyword(s):  
Microwave Irradiation ◽  
Microwave Heating ◽  
Spectral Data ◽  
Condensation Reaction ◽  
Aromatic Aldehydes ◽  
Conventional Heating ◽  
Microwave Assisted Synthesis ◽  
Efficient Synthesis ◽  
H Nmr ◽  
Microwave Assisted

An efficient synthesis of arylidene acetophenones have been achieved by using the microwave heating in comparison to the conventional heating. In this work compound 1-phenyle-3-(4-droxyphenyle)-2-propen-1-one, 1-(4-chlorophenyle)-3-phenyle-2-propen-1-one, and 1-(4-chlorophenyle)-3-(4-hydroxyphenyle)-2-propen-1-one have been synthesized by the condensation reaction between aromatic aldehydes and substituted acetophenones under microwave irradiation. The compounds of aldehydes and acetophenones were used as benzaldehyde, parahydroxybenzaldehyde, acetophenone, and parachloroacetophenone. The result shows that the time taken for the reaction was reduced from the conventional 1-2 hours to 60–120 seconds. The yield of the compounds in the conventional heating was moderate while the highest yield of 90–98% was observed in MWI method. The structure of the compounds was characterized by their IR,1H-NMR spectral data.

scholarly journals L-Lactide polymerization by calix[4]arene-titanium (IV) complex using conventional heating and microwave irradiation

e-Polymers ◽  
2010 ◽  
Vol 10 (1) ◽  
Author(s):  
Marco Frediani ◽  
David Sémeril ◽  
Dominique Matt ◽  
Fabio Rizzolo ◽  
Anna Maria Papini ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Microwave Irradiation ◽  
Organic Synthesis ◽  
Ring Opening ◽  
Ring Opening Polymerization ◽  
Polymerization Rate ◽  
The Other ◽  
Conventional Heating ◽  
Microwave Assisted ◽  
Microwave Effect

AbstractSince the first contributions by Gedye and Giguere in 1986, growing attention has been registered on the use of microwave heating in organic synthesis. However still many aspects need to be clarified especially about the so called “microwave effect” and the possible degradation phenomena that may be recognized during polymer synthesis. In this work the complex cone-25,27- dipropyloxy-26,28-dioxo-calix[4]arene titanium (IV) dichloride (1) has been tested for the ring opening polymerization of L-lactide, comparing the effect of conventional heating with a possible microwave assisted strategy. The polymers obtained were fully characterized (NMR, IR, HPLC-SEC, DSC, MALDI-TOF and WAXD analysis). As expected the use of microwave irradiation induced an increase of the polymerization rate. On the other side the use of microwaves resulted in a slight loss of the control over molecular weight and molecular weight distribution if compared with a conventional thermal treatment.

Microwave-assisted one-pot syntheses of 4-aminoquinazolines

2016 ◽  
Vol 5 (3) ◽  
Author(s):  
Wenting Song ◽  
Shunli He ◽  
Zeli Yuan ◽  
Guangqing Yu ◽  
Di Wu ◽  
...  
Keyword(s):  
Microwave Irradiation ◽  
Environmentally Friendly ◽  
One Pot ◽  
Microwave Assisted

AbstractA simple, environmentally friendly, one-pot method for the synthesis of 4-aminoquinazolines using microwave irradiation has been developed. Structures of derivatives

Microwave-assisted expeditious O-alkylation of meso-hydroxyphenylporphyrins

2009 ◽  
Vol 13 (08n09) ◽  
pp. 888-892 ◽  
Author(s):  
Vincent Chaleix ◽  
Pierre Couleaud ◽  
Vincent Sol ◽  
Rachida Zerrouki ◽  
Sandra Alves ◽  
...  
Keyword(s):  
Reaction Time ◽  
Microwave Irradiation ◽  
Reaction Yield ◽  
Thermal Heating ◽  
Dramatic Decrease ◽  
Microwave Assisted

A mild method for O-alkylation of meso-hydroxyphenylporphyrin has been developed using microwave irradiation. This method is clean and efficient for many substrates and results in significant improvement in reaction yield and in a dramatic decrease in reaction time in comparison to thermal heating.

scholarly journals Optimized Methodologies in Asymmetric Organic Synthesis Applying Microwaves

2019 ◽  
Vol 53 (3) ◽  
Author(s):  
Yamir Bandala ◽  
Roberto Melgar-Fernández ◽  
Ramón Guzmán-Mejía ◽  
José Luis Olivares-Romero ◽  
Blanca Rosa Díaz-Sánchez ◽  
...  
Keyword(s):  
Amino Acids ◽  
Microwave Heating ◽  
Organic Synthesis ◽  
Reaction Times ◽  
Environmentally Friendly ◽  
Product Yield ◽  
Chiral Molecules ◽  
Reaction Conditions ◽  
Microwave Assisted ◽  
Reaction Processes

The use of microwave heating is a valuable tool for synthetic chemists. Being able to reduce reaction times and to increase product yield, this methodology offers to organic chemists the potential to optimize reaction processes. Additionally, microwave-assisted reactions provide more environmentally friendly reaction conditions. In this report, we describe results in the optimization of several organic reactions employed in the synthesis of various chiral molecules such as heterocycles, β-amino acids, and β-peptides, among others.

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