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Skattebøl Rearrangement
The Skattebøl rearrangement is an organic reaction for converting a geminal dihalo cyclopropane to an allene using an organolithium base. This rearrangement reaction is named after its discoverer, Lars Skattebøl, Professor emeritus at the University of Oslo. It proceeds through a carbene reaction intermediate: When the cyclopropane ring is fitted with a 2-vinyl group, a cyclopentadiene is formed through a so-called foiled carbene intermediate.Leo A. Paquette and Mark L. McLaughlin Organic Syntheses, CV 8, 22Link This process is more generally known as a vinylcyclopropane rearrangement The vinylcyclopropane rearrangement or vinylcyclopropane-cyclopentene rearrangement is a ring expansion reaction, converting a vinyl-substituted cyclopropane ring into a cyclopentene ring. Intense experimental as well as computational investigati .... The reaction is closely related to the earlier Doering-LaFlamme procedure ( Doering-LaFlamme allene synthesis), in which a ''gem-''dibromocyclo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Organic Reaction
Organic reactions are chemical reactions involving organic compounds. The basic organic chemistry reaction types are addition reactions, elimination reactions, substitution reactions, pericyclic reactions, rearrangement reactions, Mechanistic Organic Photochemistry, photochemical reactions and organic redox reaction, redox reactions. In organic synthesis, organic reactions are used in the construction of new organic molecules. The production of many man-made chemicals such as drugs, plastics, food additives, fabrics depend on organic reactions. The oldest organic reactions are combustion of organic fuels and saponification of fats to make soap. Modern organic chemistry starts with the Wöhler synthesis in 1828. In the history of the Nobel Prize in Chemistry awards have been given for the invention of specific organic reactions such as the Grignard reaction in 1912, the Diels-Alder reaction in 1950, the Wittig reaction in 1979 and olefin metathesis in 2005. Classifications Organic c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Skattebøl Rearrangement General
Skattebøl may refer to: People * Lars Skattebøl (born 1927), Norwegian scientist *Ole Larsen Skattebøl Ole Larsen Skattebøl (2 March 1844 – 8 June 1929) was a Norwegian judge and politician for the Conservative Party. He was born in Ål. He was elected to the Parliament of Norway in 1877, representing the constituency of Buskeruds Amt, and wa ... (1844–1929), Norwegian judge and politician Other uses * Skattebøl rearrangement, organic reaction {{Disambiguation, surname ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Doering–LaFlamme Allene Synthesis
In organic chemistry, the Doering–LaFlamme allene synthesis is a reaction of alkenes that converts them to allenes by insertion of a carbon atom. This name reaction is named for William von Eggers Doering and a co-worker, who first reported it. The reaction is a two-stage process, in which first the alkene is reacted with dichlorocarbene or dibromocarbene to form a dihalocyclopropane. This intermediate is then reacted with a reducing metal, such as sodium or magnesium, or with an organolithium reagent. Either approach results in metal-halogen exchange to convert the ''gem''-dihalogenated carbon to a 1-metallo-1-halocyclopropane. This species undergoes α-elimination of metal halide and ring-opening via an electrocyclic reaction (at least formally) to give the allene. Several different reaction mechanism, mechanisms for the electrocyclic rearrangement have been studied. In a study in which an enantioenriched substituted cyclopropyl Grignard reagent was prepared, the reaction wa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Skattebøl Rearrangement
The Skattebøl rearrangement is an organic reaction for converting a geminal dihalo cyclopropane to an allene using an organolithium base. This rearrangement reaction is named after its discoverer, Lars Skattebøl, Professor emeritus at the University of Oslo. It proceeds through a carbene reaction intermediate: When the cyclopropane ring is fitted with a 2-vinyl group, a cyclopentadiene is formed through a so-called foiled carbene intermediate.Leo A. Paquette and Mark L. McLaughlin Organic Syntheses, CV 8, 22Link This process is more generally known as a vinylcyclopropane rearrangement The vinylcyclopropane rearrangement or vinylcyclopropane-cyclopentene rearrangement is a ring expansion reaction, converting a vinyl-substituted cyclopropane ring into a cyclopentene ring. Intense experimental as well as computational investigati .... The reaction is closely related to the earlier Doering-LaFlamme procedure ( Doering-LaFlamme allene synthesis), in which a ''gem-''dibromocyclo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vinylcyclopropane Rearrangement
The vinylcyclopropane rearrangement or vinylcyclopropane-cyclopentene rearrangement is a ring expansion reaction, converting a vinyl-substituted cyclopropane ring into a cyclopentene ring. Intense experimental as well as computational investigations have revealed that mechanistically, the vinylcyclopropane rearrangement can be thought of as either a diradical-mediated two-step and/or orbital-symmetry-controlled pericyclic process. The amount by which each of the two mechanisms is operative is highly dependent on the substrate. Due to its ability to form cyclopentene rings the vinylcyclopropane rearrangement has served several times as a key reaction in complex natural product synthesis. Origins and history In 1959, a young research chemist with Humble Oil and Refining (Esso, now Exxon) named Norman P. Neureiter was instructed to find new uses for the excess butadiene produced from one of the refinery processes. Discussions about carbene chemistry with one of the company's most ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Organic Syntheses
''Organic Syntheses'' is a peer-reviewed scientific journal that was established in 1921. It publishes detailed and checked procedures for the synthesis of organic compounds. A unique feature of the review process is that all of the data and experiments reported in an article must be successfully repeated in the laboratory of a member of the editorial board as a check for reproducibility prior to publication. The journal is published by Organic Syntheses, Inc., a non-profit corporation. An annual print version is published by John Wiley & Sons on behalf of Organic Syntheses, Inc. History Prior to World War I, work on synthetic organic chemistry in the United States had been quite limited, and most of the reagents used in laboratories had to be imported from Europe. When export stoppages and trade embargoes cut off this source, Clarence Derick, a professor of chemistry at University of Illinois at Urbana-Champaign, began an effort to synthesize these needed chemicals in industr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tetrahedron (journal)
''Tetrahedron'' is a weekly peer-reviewed scientific journal covering the field of organic chemistry. According to the ''Journal Citation Reports'', ''Tetrahedron'' has a 2020 impact factor of 2.457. ''Tetrahedron'' and Elsevier, its publisher, support an annual symposium. In 2010, complaints were raised over its high subscription cost. Notable papers , the Web of Science lists ten papers from ''Tetrahedron'' that have more than 1000 citations. The four articles that have been cited more than 2000 times are: * – cited 2228 times * – cited 2162 times * – cited 2124 times * – cited 2107 times See also * ''Tetrahedron Letters'' * ''Tetrahedron Computer Methodology'' * ''Polyhedron In geometry, a polyhedron (plural polyhedra or polyhedrons; ) is a three-dimensional shape with flat polygonal faces, straight edges and sharp corners or vertices. A convex polyhedron is the convex hull of finitely many points, not all on th ...'' (journal) Refere ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Foiled Carbene
A foiled carbene in organic chemistry is a special type of stabilized carbene due to the proximity of a double bond. This type of reactive intermediate is implicated in certain organic reactions. The positive interaction between carbene and double bond is only present in the singlet type and based on through-space electron transfer between the empty carbene p-orbital (LUMO) and filled alkene double bond p-orbitals (HOMO). The result is a three-center two-electron bond akin to certain non-classical ions. The increased stabilization blocks certain otherwise ordinary reaction modes for the carbene, hence the term ''foiled''. An example is ''norbornen-7-ylidene'', which is norbornene with a carbenic carbon atom at the bridge position. In silico experiments reveal that the bridge in this molecule is actually bending towards the double bond with an optimum angle of around 90° vs 130° for norbornene.''Foiled Carbenes Revisited: When -Stabilization Surpasses -Stabilization'' Jean-Luc M ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cyclopentadiene
Cyclopentadiene is an organic compound with the chemical formula, formula C5H6.LeRoy H. Scharpen and Victor W. Laurie (1965): "Structure of cyclopentadiene". ''The Journal of Chemical Physics'', volume 43, issue 8, pages 2765-2766. It is often abbreviated CpH because the cyclopentadienyl anion is abbreviated Cp−. This colorless liquid has a strong and unpleasant odor. At room temperature, this cyclic diene dimer (chemistry), dimerizes over the course of hours to give dicyclopentadiene via a Diels–Alder reaction. This dimer can be retro-Diels–Alder reaction, restored by heating to give the monomer. The compound is mainly used for the production of cyclopentene and its derivatives. It is popularly used as a precursor to the cyclopentadienyl anion (Cp−), an important ligand in cyclopentadienyl complexes in organometallic chemistry. Production and reactions Cyclopentadiene production is usually not distinguished from dicyclopentadiene since they interconvert. They ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vinyl Group
In organic chemistry, a vinyl group (abbr. Vi; IUPAC name: ethenyl group) is a functional group with the formula . It is the ethylene (IUPAC name: ethene) molecule () with one fewer hydrogen atom. The name is also used for any compound containing that group, namely where R is any other group of atoms. An industrially important example is vinyl chloride, precursor to PVC, a plastic commonly known as ''vinyl''. Vinyl is one of the alkenyl functional groups. On a carbon skeleton, sp2-hybridized carbons or positions are often called vinylic. Allyls, acrylates and styrenics contain vinyl groups. (A styrenic crosslinker with two vinyl groups is called '' divinyl benzene''.) Vinyl polymers Vinyl groups can polymerize with the aid of a radical initiator or a catalyst, forming vinyl polymers. Vinyl polymers contain no vinyl groups. Instead they are saturated. The following table gives some examples of vinyl polymers. Reactivity Vinyl derivatives are alkenes. If activated ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Reaction Intermediate
In chemistry, a reaction intermediate or an intermediate is a molecular entity that is formed from the reactants (or preceding intermediates) but is consumed in further reactions in stepwise chemical reactions that contain multiple elementary steps. Intermediates are the reaction product of one elementary step, but do not appear in the chemical equation for an overall chemical equation. For example, consider this hypothetical stepwise reaction: :A + B -> C + D The reaction includes two elementary steps: :A + B -> X :X -> C + D In this example, X is a reaction intermediate. IUPAC definition The IUPAC Gold Book defines an ''intermediate'' as a compound that has a lifetime greater than a molecular vibration that is formed (directly or indirectly) from the reactants and reacts further to give (either directly or indirectly) the products of a chemical reaction. The lifetime condition distinguishes true, chemically distinct intermediates from vibrational states or such transition st ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Geminal
In chemistry, the descriptor geminal () refers to the relationship between two atoms or functional groups that are attached to the same atom. A geminal diol, for example, is a diol (a molecule that has two alcohol functional groups) attached to the same carbon atom, as in methanediol. Also the shortened prefix ''gem'' may be applied to a chemical name to denote this relationship, as in a ''gem''-dibromide for "geminal dibromide". The concept is important in many branches of chemistry, including synthesis and spectroscopy, because functional groups attached to the same atom often behave differently from when they are separated. Geminal diols, for example, are easily converted to ketones or aldehydes with loss of water.Peter Taylor (2002)''Mechanism and synthesis'' Book 10 of ''Molecular world''. Open University, Royal Society of Chemistry; . 368 pages The related term vicinal refers to the relationship between two functional groups that are attached to adjacent atoms. The rel ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
