Bromoarylation of Methyl 2-Chloroacrylate under Meerwein Conditions for the Synthesis of Substituted 3-Hydroxythiophenes

Synthesis ◽  
2021 ◽  
Author(s):  
Yurii V. Ostapiuk ◽  
Andreas Schmidt ◽  
Maksym Shehedyn ◽  
Oksana V. Barabash ◽  
Bohdan Demydchuk ◽  
...  
Keyword(s):  
Structural Variety ◽  
Meerwein Reaction ◽  
Wide Range ◽  
Arenediazonium Salts

AbstractMethyl 3-aryl-2-bromo-2-chloropropanoates can be prepared by Meerwein reaction from methyl 2-chloroacrylate and various arenediazonium salts under copper(II) bromide catalysis. The resulting readily available compounds were used as starting materials in reactions with substituted methanethiols for the construction of substituted 3-hydroxythiophenes which have not yet been accessible by other routes. Structural variety of the obtained 2-substituted 5-aryl-3-hydroxythiophenes has been achieved due to a wide range of available starting materials, including both anilines and thiols.

scholarly journals EPSRC-JSPS Core-to-Core Program "International Network on Polyoxometalate Science for Advanced Functional Energy Materials"

Impact ◽  
2020 ◽  
Vol 2020 (4) ◽  
pp. 40-42
Author(s):  
Masahiro Sadakane ◽  
R. John Errington
Keyword(s):  
Metal Oxide ◽  
Energy Conversion ◽  
New Technologies ◽  
Energy Materials ◽  
International Network ◽  
Metal Oxide Clusters ◽  
Structural Variety ◽  
Wide Range ◽  
Core Program ◽  
The Uk

The International Network on Polyoxometalate Science for Advanced Functional Energy Materials project is an EPSRC-JSPS Core-to-Core funded collaboration between Hiroshima University in Japan and Newcastle University in the UK, and the project also involves universities, academic institutions and industries in France, Germany and China. The main focus of the network is polyoxometalate (POM) science, from fundamental aspects to applications in energy materials. POMs are moleculer metal oxide clusters that boast a wide range of attractive properties, including impressive electronic versatility and structural variety. Network collaborations are seeking to exploit these properties in alternative catalytic processes and new technologies for energy conversion or storage.

Palladium catalyzed stereocontrolled synthesis of C-aryl glycosides using glycals and arenediazonium salts at room temperature

2018 ◽  
Vol 16 (28) ◽  
pp. 5107-5112 ◽  
Author(s):  
Adesh Kumar Singh ◽  
Jeyakumar Kandasamy
Keyword(s):  
Room Temperature ◽  
Stereocontrolled Synthesis ◽  
Wide Range ◽  
Palladium Catalyzed ◽  
Aryl Glycosides ◽  
Arenediazonium Salts

A wide range of glycals underwent C-arylation with aryldiazonium tetrafluoroborates and provided synthetically useful 2,3-deoxy 3-keto α-aryl-C-glycosides in good to excellent yields.

scholarly journals Hydrates of Silver(I) Fluoride and Zinc Chloride

2014 ◽  
Vol 70 (a1) ◽  
pp. C1722-C1722 ◽  
Author(s):  
Laura Folkers ◽  
Nils Trapp ◽  
Jack Dunitz ◽  
Michael Wörle
Keyword(s):  
Heat Storage ◽  
Octahedral Coordination ◽  
Tetrahedral Coordination ◽  
X Ray Diffraction ◽  
Coordination Polyhedra ◽  
X Ray ◽  
Structural Variety ◽  
Trigonal Bipyramidal ◽  
Wide Range ◽  
Heat Storage Materials

Hydrates of transition metal halides are routinely used in a wide range of applications as for example catalysts, electrolytes or heat storage materials[1] . The structural variety ranges from relatively simple structures with isolated coordination polyhedra to complex polymeric frameworks. Surprisingly, many of their crystal structures are still unknown. This is partially due to difficulties of growing and handling single crystals since the hydrates are often highly hygroscopic and deliquescent at ambient temperature. In order to prepare and systematically investigate these compounds by X-ray diffraction, the crystals have to be grown, selected and measured at low temperatures. Using a self-made device[2] to select and transfer the crystals while maintaining the cooling, we were able to grow suitable crystals and determine the structures of AgF·2H2O (trigonal bipyramidal coordination of Ag+ by 4 H2O and one F-), AgF·4H2O (octahedral coordination of Ag+ by 6 H2O) and ZnCl2·3H2O (octahedral coordination of Zn2+by 6 H2O and tetrahedral coordination by 4 Cl-).

[3+2]-Cycloaddition of α-Diazocarbonyl Compounds with Arenediazonium Salts Catalyzed by Silver Nitrate Delivers 2,5-Disubstituted Tetrazoles

Synthesis ◽  
2019 ◽  
Vol 51 (21) ◽  
pp. 3998-4005 ◽  
Author(s):  
Sergey Chuprun ◽  
Dmitry Dar’in ◽  
Grigory Kantin ◽  
Mikhail Krasavin
Keyword(s):  
Silver Nitrate ◽  
Medicinal Chemistry ◽  
Diazo Compounds ◽  
Wide Range ◽  
Arenediazonium Salts

[3+2]-Cycloaddition of arenediazonium salts with diazo compounds (earlier exemplified only for trimethylsilyldiazomethane and 2,2,2-trifluorodiazoethane) has been developed to include a wide range of readily available α-diazocarbonyl compounds. The resulting 2-aryl-5-acyl-2H-tetrazoles are of high value in medicinal chemistry.

Recent Applications of High Resolution Electron Microscopy to Crystalline Arrays of Virus Particles

1978 ◽  
Vol 36 (3) ◽  
pp. 470-482 ◽  
Author(s):  
R.W. Horne
Keyword(s):  
Electron Microscopy ◽  
Image Processing ◽  
Analytical Techniques ◽  
Staining Technique ◽  
High Resolution Electron Microscopy ◽  
Optical Diffraction ◽  
Full Potential ◽  
Virus Particles ◽  
Resolution Electron ◽  
Wide Range

The technique of surrounding virus particles with a neutralised electron dense stain was described at the Fourth International Congress on Electron Microscopy, Berlin 1958 (see Home & Brenner, 1960, p. 625). For many years the negative staining technique in one form or another, has been applied to a wide range of biological materials. However, the full potential of the method has only recently been explored following the development and applications of optical diffraction and computer image analytical techniques to electron micrographs (cf. De Hosier & Klug, 1968; Markham 1968; Crowther et al., 1970; Home & Markham, 1973; Klug & Berger, 1974; Crowther & Klug, 1975). These image processing procedures have allowed a more precise and quantitative approach to be made concerning the interpretation, measurement and reconstruction of repeating features in certain biological systems.

Microfabrication research at the National Submicron Facility

1983 ◽  
Vol 41 ◽  
pp. 86-89
Author(s):  
E.D. Wolf
Keyword(s):  
Integrated Circuits ◽  
Particle Physics ◽  
High Speed ◽  
New Technology ◽  
High Energy ◽  
High Energy Particle ◽  
New Science ◽  
Wide Range ◽  
Intermediate Domain ◽  
Circuit Function

Most microelectronics devices and circuits operate faster, consume less power, execute more functions and cost less per circuit function when the feature-sizes internal to the devices and circuits are made smaller. This is part of the stimulus for the Very High-Speed Integrated Circuits (VHSIC) program. There is also a need for smaller, more sensitive sensors in a wide range of disciplines that includes electrochemistry, neurophysiology and ultra-high pressure solid state research. There is often fundamental new science (and sometimes new technology) to be revealed (and used) when a basic parameter such as size is extended to new dimensions, as is evident at the two extremes of smallness and largeness, high energy particle physics and cosmology, respectively. However, there is also a very important intermediate domain of size that spans from the diameter of a small cluster of atoms up to near one micrometer which may also have just as profound effects on society as “big” physics.

Application of TEM to Deformation, Wear, and Fracture of Ceramics

1974 ◽  
Vol 32 ◽  
pp. 472-473
Author(s):  
B. J. Hockey
Keyword(s):  
Wear Resistance ◽  
High Temperature ◽  
Mechanical Behavior ◽  
Brittle Materials ◽  
High Temperature Strength ◽  
Wide Range ◽  
Corrosive Environments ◽  
Further Development

Ceramics, such as Al2O3 and SiC have numerous current and potential uses in applications where high temperature strength, hardness, and wear resistance are required often in corrosive environments. These materials are, however, highly anisotropic and brittle, so that their mechanical behavior is often unpredictable. The further development of these materials will require a better understanding of the basic mechanisms controlling deformation, wear, and fracture.The purpose of this talk is to describe applications of TEM to the study of the deformation, wear, and fracture of Al2O3. Similar studies are currently being conducted on SiC and the techniques involved should be applicable to a wide range of hard, brittle materials.

Observation of Atom Rows in Thorium Pyromellitate Using a Field Emission STEM

1977 ◽  
Vol 35 ◽  
pp. 80-81
Author(s):  
H. Todokoro ◽  
S. Nomura ◽  
T. Komoda
Keyword(s):  
Field Emission ◽  
Amorphous Carbon ◽  
Carbon Film ◽  
Dark Field Image ◽  
Dark Field ◽  
Amorphous Carbon Film ◽  
Atomic Size ◽  
Wide Range ◽  
A Chain

It is interesting to observe polymers at atomic size resolution. Some works have been reported for thorium pyromellitate by using a STEM (1), or a CTEM (2,3). The results showed that this polymer forms a chain in which thorium atoms are arranged. However, the distance between adjacent thorium atoms varies over a wide range (0.4-1.3nm) according to the different authors.The present authors have also observed thorium pyromellitate specimens by means of a field emission STEM, described in reference 4. The specimen was prepared by placing a drop of thorium pyromellitate in 10-3 CH3OH solution onto an amorphous carbon film about 2nm thick. The dark field image is shown in Fig. 1A. Thorium atoms are clearly observed as regular atom rows having a spacing of 0.85nm. This lattice gradually deteriorated by successive observations. The image changed to granular structures, as shown in Fig. 1B, which was taken after four scanning frames.

Development of a conical anode Fe-gun for low voltage SEM

1988 ◽  
Vol 46 ◽  
pp. 978-979
Author(s):  
T. Miyokawa ◽  
S. Norioka ◽  
S. Goto
Keyword(s):  
High Resolution ◽  
Field Emission ◽  
Low Voltage ◽  
Irradiation Damage ◽  
Cold Cathode ◽  
Virtual Source ◽  
Source Position ◽  
Electrostatic Lens ◽  
Electrostatic Lenses ◽  
Wide Range

Field emission SEMs (FE-SEMs) are becoming popular due to their high resolution needs. In the field of semiconductor product, it is demanded to use the low accelerating voltage FE-SEM to avoid the electron irradiation damage and the electron charging up on samples. However the accelerating voltage of usual SEM with FE-gun is limited until 1 kV, which is not enough small for the present demands, because the virtual source goes far from the tip in lower accelerating voltages. This virtual source position depends on the shape of the electrostatic lens. So, we investigated several types of electrostatic lenses to be applicable to the lower accelerating voltage. In the result, it is found a field emission gun with a conical anode is effectively applied for a wide range of low accelerating voltages.A field emission gun usually consists of a field emission tip (cold cathode) and the Butler type electrostatic lens.

Comparison of Deterministic and Linear Cosine Spatial Filtering of Transmission Electron Micrographs

1972 ◽  
Vol 30 ◽  
pp. 596-597
Author(s):  
David A. Ansley
Keyword(s):  
Spherical Aberration ◽  
Focal Length ◽  
Chromatic Aberration ◽  
Spatial Filter ◽  
Operating Conditions ◽  
Objective Lens ◽  
List Type ◽  
Spatial Filters ◽  
Transmission Electron ◽  
Wide Range

The coherence of the electron flux of a transmission electron microscope (TEM) limits the direct application of deconvolution techniques which have been used successfully on unmanned spacecraft programs. The theory assumes noncoherent illumination. Deconvolution of a TEM micrograph will, therefore, in general produce spurious detail rather than improved resolution.A primary goal of our research is to study the performance of several types of linear spatial filters as a function of specimen contrast, phase, and coherence. We have, therefore, developed a one-dimensional analysis and plotting program to simulate a wide 'range of operating conditions of the TEM, including adjustment of the:(1) Specimen amplitude, phase, and separation(2) Illumination wavelength, half-angle, and tilt(3) Objective lens focal length and aperture width(4) Spherical aberration, defocus, and chromatic aberration focus shift(5) Detector gamma, additive, and multiplicative noise constants(6) Type of spatial filter: linear cosine, linear sine, or deterministic

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