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Hayashi Rearrangement
The Hayashi rearrangement is the chemical reaction of ''ortho''-benzoylbenzoic acids catalysis, catalyzed by sulfuric acid or phosphorus pentoxide. This reaction proceeds through electrophilic acylium ion attack with a Spiro compound, spiro intermediate.''Name Reactions: A Collection of Detailed Reaction Mechanisms'' By Jie Jack Li Published 2003 Springer : References {{Reflist Rearrangement reactions Name reactions ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chemical Reaction
A chemical reaction is a process that leads to the chemistry, chemical transformation of one set of chemical substances to another. When chemical reactions occur, the atoms are rearranged and the reaction is accompanied by an Gibbs free energy, energy change as new products are generated. Classically, chemical reactions encompass changes that only involve the positions of electrons in the forming and breaking of chemical bonds between atoms, with no change to the Atomic nucleus, nuclei (no change to the elements present), and can often be described by a chemical equation. Nuclear chemistry is a sub-discipline of chemistry that involves the chemical reactions of unstable and radioactive Chemical element, elements where both electronic and nuclear changes can occur. The substance (or substances) initially involved in a chemical reaction are called reagent, reactants or reagents. Chemical reactions are usually characterized by a chemical change, and they yield one or more Product (c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Catalysis
Catalysis () is the increase in rate of a chemical reaction due to an added substance known as a catalyst (). Catalysts are not consumed by the reaction and remain unchanged after it. If the reaction is rapid and the catalyst recycles quickly, very small amounts of catalyst often suffice; mixing, surface area, and temperature are important factors in reaction rate. Catalysts generally react with one or more reactants to form intermediates that subsequently give the final reaction product, in the process of regenerating the catalyst. The rate increase occurs because the catalyst allows the reaction to occur by an alternative mechanism which may be much faster than the noncatalyzed mechanism. However the noncatalyzed mechanism does remain possible, so that the total rate (catalyzed plus noncatalyzed) can only increase in the presence of the catalyst and never decrease. Catalysis may be classified as either homogeneous, whose components are dispersed in the same phase (usual ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sulfuric Acid
Sulfuric acid (American spelling and the preferred IUPAC name) or sulphuric acid (English in the Commonwealth of Nations, Commonwealth spelling), known in antiquity as oil of vitriol, is a mineral acid composed of the elements sulfur, oxygen, and hydrogen, with the molecular formula . It is a colorless, odorless, and Viscosity, viscous liquid that is Miscibility, miscible with water. Pure sulfuric acid does not occur naturally due to its Dehydration reaction, strong affinity to water vapor; it is Hygroscopy, hygroscopic and readily absorbs water vapor from the Atmosphere of Earth, air. Concentrated sulfuric acid is a strong oxidant with powerful dehydrating properties, making it highly corrosive towards other materials, from rocks to metals. Phosphorus pentoxide is a notable exception in that it is not dehydrated by sulfuric acid but, to the contrary, dehydrates sulfuric acid to sulfur trioxide. Upon addition of sulfuric acid to water, a considerable amount of heat is releas ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phosphorus Pentoxide
Phosphorus pentoxide is a chemical compound with molecular formula Phosphorus, P4Oxygen, O10 (with its common name derived from its empirical formula, P2O5). This white crystalline solid is the anhydride of phosphoric acid. It is a powerful desiccant and dehydration reaction, dehydrating agent. Structure Phosphorus pentoxide crystallizes in at least four forms or polymorphism (materials science), polymorphs. The most familiar one, a metastable form (shown in the figure), comprises molecules of P4O10. Weak van der Waals forces hold these molecules together in a hexagonal lattice (However, in spite of the high symmetry of the molecules, the crystal packing is not a close packing). The structure of the P4O10 cage is reminiscent of adamantane with ''T''d symmetry point group. It is closely related to the corresponding anhydride of phosphorous acid, phosphorus trioxide, P4O6. The latter lacks terminal oxo groups. Its density is 2.30 g/cm3. It boils at 423 °C under atmospheric pre ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Journal Of The Chemical Society
The ''Journal of the Chemical Society'' was a scientific journal established by the Chemical Society in 1849 as the ''Quarterly Journal of the Chemical Society''. The first editor was Edmund Ronalds. The journal underwent several renamings, splits, and mergers throughout its history. In 1980, the Chemical Society merged with several other organizations into the Royal Society of Chemistry. The journal's continuity is found in '' Chemical Communications'', '' Dalton Transactions'', '' Faraday Transactions'', and '' Perkin Transactions'', all of which are published by the Royal Society of Chemistry. History ;'' Proceedings of the Chemical Society'' * ''Memoirs of the Chemical Society of London'' (1841) * ''Proceedings of the Chemical Society of London'' (1842–1843) * ''Memoirs and Proceedings of the Chemical Society'' (1843–1848) * ''Proceedings of the Chemical Society, London'' (1885–1914) * Published as a supplement to ''Journal of the Chemical Society'' from 1914 to 1956 * ' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hayashi Rearrangement Scheme
Hayashi (林, literally " woods"), is the 19th most common Japanese surname. It shares the same character as the Chinese surname Lin and the Korean surname Im. Notable people with the surname *, Japanese synchronized swimmer *, Japanese footballer *, Japanese scholar and diplomat *, Japanese swimmer *, Japanese singer *Cheryl Hayashi, American biologist *, Japanese businesswoman *, Japanese naval surgeon and Reiki practitioner *, Japanese astrophysicist *, Japanese voice actress *, Japanese footballer *, Japanese sport shooter *, Japanese musician *, Japanese tennis player *, pen name of Kaitarō Hasegawa (1900–1935), Japanese writer *, Japanese writer and poet *, Japanese politician *, Japanese manga artist *, Japanese economist *, Japanese physician *, pen name of Toshio Gotō, Japanese writer *, Japanese neo-Confucian philosopher and writer *, Japanese neo-Confucian philosopher *, Japanese diplomat *, Japanese physician *, Japanese rower *, Japanese samurai *, Japanese cla ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acylium Ion
In organic chemistry, acylium ions are cations with the formula RCO+, where R = alkyl or aryl. They are a kind of carbocation. Structure, bonding, synthesis In acylium ions, the C-C-O linkage is linear. The oxygen and the central carbon can be described as sp hybridized. A triple bond exists between C and O. Acylium ions can be viewed as C-alkylated derivatives of carbon monoxide (which also has a C-O triple bond). They are typically prepared by removal of chloride from acyl chlorides using strong Lewis acids such as antimony pentachloride. Several acylium salts have been characterized by X-ray crystallography, including the propionyl and mesityl derivatives. Because acylium cation is highly electrophilic, its salts can only be isolated with weakly coordinating anions. : Acetyl hexafluoroantimonate and hexachloroantimonate are other early examples. The strength of the bond is indicated by the frequency of its vibration (νCO). These values are 2300 and 2200 cm−1, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spiro Compound
In organic chemistry, spiro compounds are Organic compound, compounds that have at least two Cyclic compound, molecular rings sharing one common atom. Simple spiro compounds are bicyclic (having just two rings). The presence of only one common atom connecting the two rings distinguishes spiro compounds from other bicyclics.For all four categories, see The specific chapters can be found aan respectively, same access date. For the description featuring adjacent atoms for all but the isolated category, see Clayden, op. cit. Spiro compounds may be fully carbocyclic (all carbon) or heterocyclic (having one or more non-carbon atom). One common type of spiro compound encountered in educational settings is a heterocyclic one— the acetal formed by reaction of a diol with a cyclic ketone. The common atom that connects the two (or sometimes three) rings is called the ''spiro atom''. In carbocyclic spiro compounds like spiro[5.5]undecane, the spiro-atom is a quaternary carbon, and as the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hayashi RearrangementMechanism
Hayashi (林, literally " woods"), is the 19th most common Japanese surname. It shares the same character as the Chinese surname Lin and the Korean surname Im. Notable people with the surname *, Japanese synchronized swimmer *, Japanese footballer *, Japanese scholar and diplomat *, Japanese swimmer *, Japanese singer *Cheryl Hayashi, American biologist *, Japanese businesswoman *, Japanese naval surgeon and Reiki practitioner *, Japanese astrophysicist *, Japanese voice actress *, Japanese footballer *, Japanese sport shooter *, Japanese musician *, Japanese tennis player *, pen name of Kaitarō Hasegawa (1900–1935), Japanese writer *, Japanese writer and poet *, Japanese politician *, Japanese manga artist *, Japanese economist *, Japanese physician *, pen name of Toshio Gotō, Japanese writer *, Japanese neo-Confucian philosopher and writer *, Japanese neo-Confucian philosopher *, Japanese diplomat *, Japanese physician *, Japanese rower *, Japanese samurai *, Japanese cla ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rearrangement Reactions
In organic chemistry, a rearrangement reaction is a broad class of organic reactions where the carbon skeleton of a molecule is rearranged to give a structural isomer of the original molecule. Often a substituent moves from one atom to another atom in the same molecule, hence these reactions are usually intramolecular. In the example below, the substituent R moves from carbon atom 1 to carbon atom 2: :\underset\ce\ce\underset\ce\ce Intermolecular rearrangements also take place. A rearrangement is not well represented by simple and discrete electron transfers (represented by curved arrows in organic chemistry texts). The actual mechanism of alkyl groups moving, as in Wagner–Meerwein rearrangement, probably involves transfer of the moving alkyl group fluidly along a bond, not ionic bond-breaking and forming. In pericyclic reactions, explanation by orbital interactions give a better picture than simple discrete electron transfers. It is, nevertheless, possible to draw the curved ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
