Comparison of Conventional and Microwave Heating for Evaluation of Microwave Effects

2016 ◽  
Vol 69 (8) ◽  
pp. 865 ◽  
Author(s):  
Péter Bana ◽  
István Greiner
Keyword(s):  
Temperature Measurement ◽  
Microwave Heating ◽  
Organic Synthesis ◽  
Convenient Method ◽  
Thermal Effects ◽  
Fibre Optic ◽  
Organic Transformations ◽  
Microwave Assisted ◽  
Microwave Reactor ◽  
Microwave Effects

In microwave-assisted organic synthesis, the question of microwave effects is still debated. Proper examination of these hypothesized phenomena is encumbered by some specific features of microwave heating. We devise a convenient method to eliminate most of the irreproducibility observed in microwave-heated organic transformations by thermal conditioning of the microwave reactor cavity. To show the utility of this approach, we investigated a reaction of 2-chloropyridine, in which microwave conditions were shown to be beneficial by previous studies. Using our method to ensure proper reproducibility together with fibre optic temperature measurement, the observed differences were traced back to large hidden thermal differences, while non-thermal effects could not be detected in the comparison experiments.

CH4 Decomposition over Pyrolysis Residue of Sewage Sludge under Microwave Heating

2014 ◽  
Vol 953-954 ◽  
pp. 935-938
Author(s):  
Wen Yi Deng ◽  
Shu Gang Liu ◽  
Ya Xin Su
Keyword(s):  
Sewage Sludge ◽  
Microwave Heating ◽  
Low Cost ◽  
Methane Decomposition ◽  
Initial Activity ◽  
Microwave Assisted ◽  
Microwave Reactor ◽  
Pyrolysis Residue

The microwave-assisted CH4decomposition over a pyrolysis residue of sewage sludge (PRSS), which acted as a microwave receptor and a low-cost catalyst without further activation, was investigated in a multimode microwave reactor. The results indicated that the microwave heating of PRSS is heavily influenced by atmosphere. The PRSS temperature in CH4, N2and H2atmosphere follow the sequence ofTCH4<TH2<TN2. PRSS shows excellent initial activity for methane decomposition, but it deactivated very quickly. It was inferred that the fast deactivation of PRSS was mainly caused by temperature falling in CH4atmosphere.

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.

A Green Approach for Organic Transformations Using Microwave Reactor

2019 ◽  
Vol 16 (5) ◽  
pp. 730-764 ◽  
Author(s):  
Subrata Das ◽  
Rupak Banik ◽  
Brajesh Kumar ◽  
Subhadip Roy ◽  
Noorussabah ◽  
...  
Keyword(s):  
Microwave Irradiation ◽  
Microwave Heating ◽  
Organic Synthesis ◽  
Reaction Times ◽  
Green Technology ◽  
Conventional Heating ◽  
Organic Transformations ◽  
Green Approach ◽  
Site Selectivity ◽  
Recent Developments

Microwave-assisted organic transformation (MAOR) is presently gaining wide popularity in the field of organic synthesis. The conventional heating technique is gradually being removed from the laboratory and a novel microwave heating technique established to be used in both academia and industry. As compared to the classical organic methodology, the green technology tools have several advantages like dramatically reduced reaction times, improved yields, site selectivity, and the increased product purities with simplification of work-up procedures. In the current study, we have briefly described the overview of recent developments and applications of microwave irradiation in organic transformation with schematic compiling of the organic reactions, bioactive heterocyclic compounds, and so on. This review also presents a critical analysis of the various advantages of microwave irradiation in organic synthesis/transformation compared to the classical or conventional heating. So, we believe that our current study of the green microwave heating technique will be highly beneficial for the researchers from both academia and industry in their near future.

Developments in Microwave-Assisted Organic Chemistry

1995 ◽  
Vol 48 (10) ◽  
pp. 1665 ◽  
Author(s):  
CR Strauss ◽  
RW Trainor
Keyword(s):  
Organic Chemistry ◽  
Organic Synthesis ◽  
Batch Reactor ◽  
Environmentally Benign ◽  
Safety Issues ◽  
Microwave Assisted ◽  
Heating And Cooling ◽  
Microwave Reactor ◽  
Microwave Reactors ◽  
Indole Synthesis

Microwave-assisted organic chemistry is reviewed in the context of the methods employed. A range of technical difficulties indicated that specifically designed reactors were required. Hence, the CSIRO continuous microwave reactor (CMR) and microwave batch reactor (MBR) were developed for organic synthesis. On the laboratory scale, they operated at temperatures (pressures) up to 200°C (1400 kPa) and 260°C (10 MPa), respectively. Advantages and applications of the units are discussed, along with safety issues. Features include the capability for rapid, controlled heating and cooling of reaction mixtures, and elimination of wall effects. Concurrent heating and cooling, and differential heating were unique methodologies introduced to organic synthesis through the MBR. Applications of the microwave reactors for optimizing high-temperature preparations, e.g, the Willgerodt reaction and the Fischer indole synthesis, were demonstrated. Water was a useful pseudo-organic solvent, applicable to environmentally benign synthetic chemistry.

Microwave-Assisted Organic Synthesis

1992 ◽  
Vol 269 ◽  
Author(s):  
Raymond J. Giguere
Keyword(s):  
Microwave Heating ◽  
Organic Synthesis ◽  
Relevant Literature ◽  
Conventional Heating ◽  
Microwave Assisted ◽  
Concise Overview ◽  
Materials Research ◽  
Heating Mode

ABSTRACTA concise overview of the use of microwave heating in organic synthesis is presented. The role of solvents and representative examples from the relevant literature are discussed to illustrate the significant impact this non-conventional heating mode continues to have in this area of materials research.

The Synthesis and Application of Functionalized Mesoporous Silica SBA-15 as Heterogeneous Catalyst in Organic Synthesis

2020 ◽  
Vol 24 ◽  
Author(s):  
Ghodsi Mohammadi Ziarani ◽  
Shima Roshankar ◽  
Fatemeh Mohajer ◽  
Alireza Badiei
Keyword(s):  
Mesoporous Silica ◽  
Heterogeneous Catalyst ◽  
Organic Synthesis ◽  
Lewis Acid ◽  
Heterogeneous Catalysts ◽  
Organic Transformations ◽  
Functionalized Mesoporous Silica ◽  
Silica Nanomaterials ◽  
Wide Range ◽  
Target Molecules

Abstract:: Mesoporous silica nanomaterials provide an extraordinary advantage for making new and superior heterogeneous catalysts because of their surface silanol groups. The functionalized mesoporous SBA-15, such as acidic, basic, BrÖnsted, lewis acid, and chiral catalysts, are used for a wide range of organic synthesis. The importance of the chiral ligands, which were immobilized on the SBA-15, was mentioned in this review to achieve chiral products as valuable target molecules. Herein, their synthesis and application in different organic transformations are reviewed from 2016 till date 2020.

Microwave Assisted Organic Synthesis: Cross Coupling and Multicomponent Reactions

2013 ◽  
Vol 17 (5) ◽  
pp. 474-490 ◽  
Author(s):  
Amit Kumar Gupta ◽  
Neetu Singh ◽  
Krishna Nand Singh
Keyword(s):  
Organic Synthesis ◽  
Multicomponent Reactions ◽  
Cross Coupling ◽  
Microwave Assisted
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