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Organotrifluoroborate
Organotrifluoroborates are organoboron compounds that contain an anion with the general formula BF3sup>−. They can be thought of as protected boronic acids, or as adducts of carbanions and boron trifluoride. Organotrifluoroborates are tolerant of air and moisture and are easy to handle and purify. They are often used in organic synthesis as alternatives to boronic acids (RB(OH)2), boronate esters (RB(OR′)2), and organoboranes (R3B), particularly for Suzuki-Miyaura coupling. Structure Synthesis Boronic acids RB(OH)2 react with potassium bifluoride Potassium bifluoride is the inorganic compound with the formula . This colourless salt consists of the potassium cation () and the bifluoride anion (). The salt is used as an etchant for glass. Sodium bifluoride is related and is also of commercial ... K F2to form trifluoroborate salts K BF3 Reactivity Organotrifluoroborates are strong nucleophiles and react with electrophiles without transition-metal catalysts. Mecha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Suzuki-Miyaura Coupling
The Suzuki reaction is an organic reaction, classified as a cross-coupling reaction, where the coupling partners are a boronic acid and an organohalide and the catalyst is a palladium(0) complex. It was first published in 1979 by Akira Suzuki, and he shared the 2010 Nobel Prize in Chemistry with Richard F. Heck and Ei-ichi Negishi for their contribution to the discovery and development of palladium-catalyzed cross-couplings in organic synthesis. This reaction is also known as the Suzuki–Miyaura reaction or simply as the Suzuki coupling. It is widely used to synthesize poly olefins, styrenes, and substituted biphenyls. Several reviews have been published describing advancements and the development of the Suzuki reaction. The general scheme for the Suzuki reaction is shown below, where a carbon-carbon single bond is formed by coupling a halide (R1-X) with an organoboron species (R2-BY2) using a palladium catalyst and a base. Reaction mechanism The mechanism of the Suzuki re ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Organoboron Chemistry
Organoborane or organoboron compounds are chemical compounds of boron and carbon that are organic derivatives of BH3, for example trialkyl boranes. Organoboron chemistry or organoborane chemistry is the chemistry of these compounds. Organoboron compounds are important reagents in organic chemistry enabling many chemical transformations, the most important one called hydroboration. Reactions of organoborates and boranes involve the transfer of a nucleophilic group attached to boron to an electrophilic center either inter- or intramolecularly. α,β-Unsaturated borates, as well as borates with a leaving group at the α position, are highly susceptible to intramolecular 1,2-migration of a group from boron to the electrophilic α position. Oxidation or protonolysis of the resulting organoboranes may generate a variety of organic products, including alcohols, carbonyl compounds, alkenes, and halides. Properties of the B-C bond The C-B bond has low polarity (the difference in electron ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Organoboron Compounds
Organoborane or organoboron compounds are chemical compounds of boron and carbon that are organic derivatives of BH3, for example trialkyl boranes. Organoboron chemistry or organoborane chemistry is the chemistry of these compounds. Organoboron compounds are important reagents in organic chemistry enabling many chemical transformations, the most important one called hydroboration. Reactions of organoborates and boranes involve the transfer of a nucleophilic group attached to boron to an electrophilic center either inter- or intramolecularly. α,β-Unsaturated borates, as well as borates with a leaving group at the α position, are highly susceptible to intramolecular 1,2-migration of a group from boron to the electrophilic α position. Oxidation or protonolysis of the resulting organoboranes may generate a variety of organic products, including alcohols, carbonyl compounds, alkenes, and halides. Properties of the B-C bond The C-B bond has low polarity (the difference in electron ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chemical & Engineering News
''Chemical & Engineering News'' (''C&EN'') is a weekly news magazine published by the American Chemical Society, providing professional and technical news and analysis in the fields of chemistry and chemical engineering.C&EN Magazine Website Chemical and Engineering News, October 12, 2009, accessed October 12, 2009 It includes information on recent news and research in these fields, career and employment information, business and industry news, government and policy news, funding in these fields, and special reports. The magazine is available to all members of the American Chemical Society. History The magazine was established in 1923,C&EN- Happy Birthday to Us, accessed O ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Angewandte Chemie
''Angewandte Chemie'' (, meaning "Applied Chemistry") is a weekly peer-reviewed scientific journal that is published by Wiley-VCH on behalf of the German Chemical Society (Gesellschaft Deutscher Chemiker). Publishing formats include feature-length reviews, short highlights, research communications, minireviews, essays, book reviews, meeting reviews, correspondences, corrections, and obituaries. This journal contains review articles covering all aspects of chemistry. According to the ''Journal Citation Reports'', the journal had a 2021 impact factor of 16.823. Editions The journal appears in two editions with separate volume and page numbering: a German edition, ''Angewandte Chemie'' ( (print), (online)), and a fully English-language edition, ''Angewandte Chemie International Edition'' ( (print), (online)). The editions are identical in content with the exception of occasional reviews of German-language books or German translations of IUPAC recommendations. Business model ''A ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chemical Science (journal)
''Chemical Science'' is a weekly peer-reviewed scientific journal covering all aspects of chemistry. It is the flagship journal of the Royal Society of Chemistry. It was established in July 2010 and is published by the Royal Society of Chemistry; before 2018, it was published monthly. It won the Best New Journal 2011 award from the Association of Learned and Professional Society Publishers. The editor-in-chief is Andrew Ian Cooper (University of Liverpool). In January 2015, the journal moved to an open access publishing model. Abstracting and indexing The journal is abstracted and indexed in: *Science Citation Index Expanded *Current Contents/Physical, Chemical & Earth Sciences *Chemical Abstracts Service *Directory of Open Access Journals According to the ''Journal Citation Reports'', the journal has a 2021 impact factor of 9.969. See also * ''Chemical Communications'' * ''Chemical Society Reviews ''Chemical Society Reviews'' is a biweekly peer-reviewed scientific journal pub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Potassium Bifluoride
Potassium bifluoride is the inorganic compound with the formula . This colourless salt consists of the potassium cation () and the bifluoride anion (). The salt is used as an etchant for glass. Sodium bifluoride is related and is also of commercial use as an etchant as well as in cleaning products. Synthesis and reactions The salt was prepared by Edmond Frémy by treating potassium carbonate or potassium hydroxide with hydrofluoric acid: : With one more equivalent of HF, (CAS#12178-06-2, m.p. 71.7 C) is produced: : Thermal decomposition of gives hydrogen fluoride: : Applications The industrial production of fluorine entails the electrolysis of molten and . The electrolysis of was first used by Henri Moissan in 1886. See also * Ammonium bifluoride Ammonium hydrogen fluoride is the inorganic compound with the formula or . It is produced from ammonia and hydrogen fluoride. This colourless salt is a glass- etchant and an intermediate in a once-contemplated route to hydro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Space-filling Model
In chemistry, a space-filling model, also known as a ''calotte model'', is a type of three-dimensional (3D) molecular model where the atoms are represented by spheres whose radii are proportional to the radii of the atoms and whose center-to-center distances are proportional to the distances between the atomic nuclei, all in the same scale. Atoms of different chemical elements are usually represented by spheres of different colors. Space-filling calotte models are also referred to as CPK models after the chemists Robert Corey, Linus Pauling, and Walter Koltun, who over a span of time developed the modeling concept into a useful form. They are distinguished from other 3D representations, such as the ball-and-stick and skeletal models, by the use of the "full size" space-filling spheres for the atoms. The models are tactile and manually rotatable. They are useful for visualizing the effective shape and relative dimensions of a molecule, and (because of the rotatability) the s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acta Crystallographica
''Acta Crystallographica'' is a series of peer-reviewed scientific journals, with articles centred on crystallography, published by the International Union of Crystallography (IUCr). Originally established in 1948 as a single journal called ''Acta Crystallographica'', there are now six independent ''Acta Crystallographica'' titles: *'' Acta Crystallographica Section A: Foundations and Advances'' *'' Acta Crystallographica Section B: Structural Science, Crystal Engineering and Materials'' *'' Acta Crystallographica Section C: Structural Chemistry'' *'' Acta Crystallographica Section D: Structural Biology'' *'' Acta Crystallographica Section E: Crystallographic Communications'' *'' Acta Crystallographica Section F: Structural Biology Communications'' ''Acta Crystallographica'' has been noted for the high quality of the papers that it produces, as well as the large impact that its papers have had on the field of crystallography. The current six journals form part of the journal portf ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Crystal Structure
In crystallography, crystal structure is a description of the ordered arrangement of atoms, ions or molecules in a crystal, crystalline material. Ordered structures occur from the intrinsic nature of the constituent particles to form symmetric patterns that repeat along the principal directions of Three-dimensional space (mathematics), three-dimensional space in matter. The smallest group of particles in the material that constitutes this repeating pattern is the unit cell of the structure. The unit cell completely reflects the symmetry and structure of the entire crystal, which is built up by repetitive Translation (geometry), translation of the unit cell along its principal axes. The translation vectors define the nodes of the Bravais lattice. The lengths of the principal axes, or edges, of the unit cell and the angles between them are the lattice constants, also called ''lattice parameters'' or ''cell parameters''. The symmetry properties of the crystal are described by the con ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thermal Ellipsoid
Thermal ellipsoids, more formally termed atomic displacement parameters or anisotropic displacement parameters, are ellipsoids used in crystallography to indicate the magnitudes and directions of the thermal vibration of atoms in crystal structures. Since the vibrations are usually anisotropic (different magnitudes in different directions in space), an ellipsoid is a convenient way of visualising the vibration and therefore the symmetry and time averaged position of an atom in a crystal. Their theoretical framework was introduced by D. W. J. Cruickshank in 1956 and the concept was popularized through the program ORTEP (Oak Ridge Thermal-Ellipsoid Plot Program), first released in 1965. Thermal ellipsoids can be defined by a tensor In mathematics, a tensor is an algebraic object that describes a multilinear relationship between sets of algebraic objects related to a vector space. Tensors may map between different objects such as vectors, scalars, and even other tenso .. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
