Comparison of the reaction pathways and intermediate products of a microwave-assisted and high-pressure-promoted cycloaddition of vinyl-moiety-containing dienophiles on 2H-pyran-2-ones

Tetrahedron ◽  
2011 ◽  
Vol 67 (19) ◽  
pp. 3490-3500 ◽  
Author(s):  
Amadej Juranovič ◽  
Krištof Kranjc ◽  
Franc Perdih ◽  
Slovenko Polanc ◽  
Marijan Kočevar
Keyword(s):  
High Pressure ◽  
Reaction Pathways ◽  
Intermediate Products ◽  
Microwave Assisted

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.

Synthesize Ti3SiC2 and Ti3SiC2-Diamond Composites at High Pressure and High Temperature

2012 ◽  
Vol 512-515 ◽  
pp. 671-675 ◽  
Author(s):  
Ai Guo Zhou ◽  
Liang Li ◽  
Tai Chao Su ◽  
Shang Sheng Li
Keyword(s):  
High Pressure ◽  
High Temperature ◽  
Intermediate Products ◽  
Diamond Particles ◽  
Ternary Carbide ◽  
The Matrix

Ti3SiC2, a ternary carbide, was proposed at this paper to use as the binder of polycrystalline diamonds to overcome the weaknesses of traditional metal binders and ceramic binders. Ti3SiC2was first reported to be in-situ synthesized under high pressure (4GPa) and at high temperature (1400°C) (HPHT) from the mixtures of Ti, Si and graphite powders or the mixture of Ti, SiC and graphite powders. Ti3SiC2-damond composites were also made at HPHT from the previous mixtures and diamond particles. TiCx, Ti5Si3Cxand TiSi2were main impurities and/or intermediate products of Ti3SiC2samples synthesized at HPHT. Ti3SiC2content increased as synthesized time increased from 10 min to 60 min. For as-synthesized composites, diamond particles were evenly distributed in matrix. The diamond particles are bonded well with the matrix by three types of interface.

scholarly journals Microwave-assisted lignin liquefaction in hydrazine and ethylene glycol: Reaction pathways via response surface methodology

2021 ◽  
Vol 27 ◽  
pp. e00245
Author(s):  
Divine B. Nde ◽  
Mohamad Barekati-Goudarzi ◽  
Pranjali D. Muley ◽  
Lavrent Khachatryan ◽  
Dorin Boldor
Keyword(s):  
Response Surface Methodology ◽  
Ethylene Glycol ◽  
Response Surface ◽  
Reaction Pathways ◽  
Microwave Assisted

Qualities of High Pressure and Microwave-Assisted Thermally Pasteurized Ready-to-Eat Green Beans During Refrigerated Storage at 2 and 7 °C

2021 ◽  
Author(s):  
Sumeyye Inanoglu ◽  
Gustavo V. Barbosa-Cánovas ◽  
Zhongwei Tang ◽  
Frank Liu ◽  
Shyam S. Sablani ◽  
...  
Keyword(s):  
High Pressure ◽  
Refrigerated Storage ◽  
Green Beans ◽  
Microwave Assisted

Peraluminous sapphirine as a metastable reaction product in kyanite—gedrite—talc schist from Sar e Sang, Afghanistan

1975 ◽  
Vol 40 (310) ◽  
pp. 171-180 ◽  
Author(s):  
Werner Schreyer ◽  
Kurt Abraham
Keyword(s):  
High Pressure ◽  
Metastable Phases ◽  
Equilibrium Conditions ◽  
Host Mineral ◽  
Intermediate Products

SummaryMinute crystals of pure Mg-sapphirine approximating (Mg3.23Al4.74)vi(Al4.69Si1.31)ivO20, and thus having more aluminous compositions than the hitherto accepted 7:9:3 end member, were formed together with Mg-cordierite and corundum along narrow zones of the schist through reaction of the pre-existing high-pressure assemblages kyanite-gedrite and kyanite-talc. These sapphirines are considered to be metastable intermediate products growing under the influence of the structurally similar host mineral kyanite. Under equilibrium conditions they continued to react with kyanite to form the stable assemblage cordierite-corundum. Peraluminous sapphirines including those most recently synthesized may be metastable phases under all conditions of crystallization.

scholarly journals Microwave Assisted Reactions of Azaheterocycles Formedicinal Chemistry Applications

Molecules ◽  
2020 ◽  
Vol 25 (3) ◽  
pp. 716 ◽  
Author(s):  
Dorina Amariucai-Mantu ◽  
Violeta Mangalagiu ◽  
Ramona Danac ◽  
Ionel I. Mangalagiu
Keyword(s):  
Biological Activity ◽  
Medicinal Chemistry ◽  
Membered Ring ◽  
Reaction Pathways ◽  
Microwave Assisted ◽  
Main Series ◽  
Privileged Scaffolds

Microwave (MW) assisted reactions have became a powerful tool in azaheterocycles chemistry during the last decades. Five and six membered ring azaheterocycles are privileged scaffolds in modern medicinal chemistry possessing a large variety of biological activity. This review is focused on the recent relevant advances in the MW assisted reactions applied to azaheterocyclic derivatives and their medicinal chemistry applications from the last five years. The review is divided according to the main series of azaheterocycles, more precisely 5- and 6-membered ring azaheterocycles (with one, two, and more heteroatoms) and their fused analogues. In each case, the reaction pathways, the advantages of using MW, and considerations concerning biological activity of the obtained products were briefly presented.

Microwave-Assisted Hydrothermal Synthesis and Photocatalytic Properties of Cr and La-Codoped SrTiO3 Photocatalyst

2014 ◽  
Vol 608 ◽  
pp. 147-152
Author(s):  
Ryusuke Akita ◽  
Qiang Dong ◽  
Shu Yin ◽  
Tsugio Sato
Keyword(s):  
High Pressure ◽  
Hydrothermal Synthesis ◽  
Visible Light ◽  
Mercury Lamp ◽  
Photocatalytic Ability ◽  
Microwave Assisted ◽  
Bet Specific Surface Area ◽  
Photocatalytic Activities ◽  
Degussa P25 ◽  
Decomposition Of No

Cr and La-codoped SrTiO3nanoparticles were successfully prepared by a microwave-assisted hydrothermal synthesis. The products were characterized by XRD, TEM, BET specific surface area, and UV-Vis absorption spectra. The photocatalytic activity was determined by deNOxability under irradiation of a 450 W high-pressure mercury lamp. The products could absorb the visible light and showed high photocatalytic ability for the decomposition of NOxgas. All samples showed the photocatalytic activities superior to that of commercial titania (Degussa P25) in both UV and visible light regions.

scholarly journals Hochdrucksynthese quaternärer Chalkogenidhalogenide AB2X3Y (A = Cu, Ag; B = In; X = S, Se, Te; Y = Cl, Br, I)/High Pressure Synthesis of Quaternary Chalcogenide Halogenides AB2X3Y (A = Cu, Ag; B = In; X = S, Se, Te; Y = Cl, Br, I)

1983 ◽  
Vol 38 (2) ◽  
pp. 155-160 ◽  
Author(s):  
Klaus-Jürgen Range ◽  
Heinz-Joachim Hübner
Keyword(s):  
High Pressure ◽  
Crystal Structures ◽  
Spinel Structure ◽  
High Pressures ◽  
Reaction Pathways ◽  
High Pressure Synthesis ◽  
Quaternary Compounds ◽  
Pressure Synthesis ◽  
High Pressures And Temperatures

Abstract Quaternary compounds AB2X3Y (A = Cu, Ag; B = In; X = S, Se, Te; Y = Cl, Br, I) could be synthesized at high pressures and temperatures. The crystal structures found are defect-zincblende (AgIn2Se3I, AgIn2Te3l, CuIn2Se3Br, CuIn2Se3I, CuIn2Te3Cl, CuIn2Te3Br, CuInTe3I), spinel (AgIn2S3Cl, AgIn2S3Br, AgIn2Se3Cl, AgIn2Se3Br, AgIn2Se3l) and defect-rocksalt (AgIn2Te3Cl, AgIn2Te3Br). A second form of CuIn2Se3l is intermediate between the zincblende and spinel structure. A survey of the different reaction pathways of AB-B2X3 mixtures at high pressures and temperatures is given.

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