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Organocuprate
A Gilman reagent is a lithium and copper (organocopper compound, diorganocopper) reagent compound, R2CuLi, where R is an alkyl or aryl. These reagents are useful because, unlike related Grignard reagents and organolithium reagents, they react with Organic halide, organic halides to replace the halides, halide group with an R group (the Corey–House synthesis, Corey–House reaction). Such displacement reactions allow for the synthesis of complex products from simple building blocks. Reactions These reagents were discovered by Henry Gilman and coworkers. Lithium dimethylcopper (CH3)2CuLi can be prepared by adding copper(I) iodide to methyllithium in tetrahydrofuran at −78 °C. In the reaction depicted below, the Gilman reagent is a methylating reagent reacting with an alkyne in a conjugate addition, and the negative charge is trapped in a nucleophilic acyl substitution with the ester group forming a cyclic Alpha-beta Unsaturated carbonyl compounds, enone. Due to the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Organolithium Reagent
In organometallic chemistry, organolithium reagents are chemical compounds that contain carbon–lithium (C–Li) bonds. These reagents are important in organic synthesis, and are frequently used to transfer the organic group or the lithium atom to the substrates in synthetic steps, through nucleophilic addition or simple deprotonation. Organolithium reagents are used in industry as an initiator for anionic polymerization, which leads to the production of various elastomers. They have also been applied in asymmetric synthesis in the pharmaceutical industry. Due to the large difference in electronegativity between the carbon atom and the lithium atom, the C−Li bond is highly ionic. Owing to the polar nature of the C−Li bond, organolithium reagents are good nucleophiles and strong bases. For laboratory organic synthesis, many organolithium reagents are commercially available in solution form. These reagents are highly reactive, and are sometimes pyrophoric. History and dev ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Organocopper Compound
Organocopper compounds is the chemistry of organometallic compounds containing a carbon to copper chemical bond. Organocopper chemistry is the study of organocopper compounds describing their physical properties, synthesis and reactions. They are reagents in organic chemistry. The first organocopper compound, the explosive copper(I) acetylide Cu2C2 (Cu−C≡C−Cu), was synthesized by Rudolf Christian Böttger in 1859 by passing acetylene gas through a solution of copper(I) chloride: :C2H2 + 2 CuCl → Cu2C2 + 2 HCl Structure and bonding Organocopper compounds are diverse in structure and reactivity, but organocopper compounds are largely limited in oxidation states to copper(I), sometimes denoted Cu+. As a d10 metal center, it is related to Ni(0), but owing to its higher oxidation state, it engages in less pi-backbonding. Organic derivatives of Cu(II) and Cu(III) are invoked as intermediates but rarely isolated or even observed. In terms of geometry, copper(I) adopts symmetri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Corey–House Synthesis
The Corey–House synthesis (also called the Corey–Posner–Whitesides–House reaction and other permutations) is an organic reaction that involves the reaction of a lithium cuprate, diorganylcuprate (R_CuLi) with an organic compound, organic pseudohalide (R'-X) to form a new alkane, as well as an ill-defined Organocopper compound, organocopper species and lithium halide as byproducts. :Li^[R-Cu-R]^- + R'-X ->R-R'+''R-Cu''+LiX In principle, a carbanion equivalent such as an Organolithium reagent, organolithium or Grignard reagent can react directly (without copper) with an alkyl halide in a nucleophilic substitution reaction to form a new carbon–carbon bond. However, aside from the use of metal acetylides as nucleophiles, such a process rarely works well in practice due to Organolithium reagent#Lithium–halogen exchange, metal–halogen exchange and/or the formation of large amounts of reduction or elimination side-products. As a solution to this problem, the Corey–House rea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ester
In chemistry, an ester is a compound derived from an oxoacid (organic or inorganic) in which at least one hydroxyl group () is replaced by an alkoxy group (), as in the substitution reaction of a carboxylic acid and an alcohol. Glycerides are fatty acid esters of glycerol; they are important in biology, being one of the main classes of lipids and comprising the bulk of animal fats and vegetable oils. Esters typically have a pleasant smell; those of low molecular weight are commonly used as fragrances and are found in essential oils and pheromones. They perform as high-grade solvents for a broad array of plastics, plasticizers, resins, and lacquers, and are one of the largest classes of synthetic lubricants on the commercial market. Polyesters are important plastics, with monomers linked by ester moieties. Phosphoesters form the backbone of DNA molecules. Nitrate esters, such as nitroglycerin, are known for their explosive properties. '' Nomenclature Etymology Th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tetrahydrofuran
Tetrahydrofuran (THF), or oxolane, is an organic compound with the formula (CH2)4O. The compound is classified as heterocyclic compound, specifically a cyclic ether. It is a colorless, water-miscible organic liquid with low viscosity. It is mainly used as a precursor to polymers. Being polar and having a wide liquid range, THF is a versatile solvent. Production About 200,000 tonnes of tetrahydrofuran are produced annually. The most widely used industrial process involves the acid-catalyzed dehydration of 1,4-butanediol. Ashland/ISP is one of the biggest producers of this chemical route. The method is similar to the production of diethyl ether from ethanol. The butanediol is derived from condensation of acetylene with formaldehyde followed by hydrogenation. DuPont developed a process for producing THF by oxidizing ''n''-butane to crude maleic anhydride, followed by catalytic hydrogenation. A third major industrial route entails hydroformylation of allyl alcohol followed by ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alkyne
\ce \ce Acetylene \ce \ce \ce Propyne \ce \ce \ce \ce 1-Butyne In organic chemistry, an alkyne is an unsaturated hydrocarbon containing at least one carbon—carbon triple bond. The simplest acyclic alkynes with only one triple bond and no other functional groups form a homologous series with the general chemical formula . Alkynes are traditionally known as acetylenes, although the name ''acetylene'' also refers specifically to , known formally as ethyne using IUPAC nomenclature. Like other hydrocarbons, alkynes are generally hydrophobic. Structure and bonding In acetylene, the H–C≡C bond angles are 180°. By virtue of this bond angle, alkynes are rod-like. Correspondingly, cyclic alkynes are rare. Benzyne cannot be isolated. The C≡C bond distance of 121 picometers is much shorter than the C=C distance in alkenes (134 pm) or the C–C bond in alkanes (153 pm). : The triple bond is very strong with a bond strength of 839 kJ/mol. The sigma bond contribute ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Conjugate Addition
Nucleophilic conjugate addition is a type of organic reaction. Ordinary nucleophilic additions or 1,2-nucleophilic additions deal mostly with additions to carbonyl compounds. Simple alkene compounds do not show 1,2 reactivity due to lack of polarity, unless the alkene is activated with special substituents. With α,β-unsaturated carbonyl compounds such as cyclohexenone it can be deduced from resonance structures that the β position is an electrophilic site which can react with a nucleophile. The negative charge in these structures is stored as an alkoxide anion. Such a nucleophilic addition is called a nucleophilic conjugate addition or 1,4-nucleophilic addition. The most important active alkenes are the aforementioned conjugated carbonyls and acrylonitriles. Reaction mechanism Conjugate addition is the vinylogous counterpart of direct nucleophilic addition. A nucleophile reacts with a α,β-unsaturated carbonyl compound in the β position. The negative charge carried by the n ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nucleophilic Acyl Substitution
Nucleophilic acyl substitution describe a class of substitution reactions involving nucleophiles and acyl compounds. In this type of reaction, a nucleophile – such as an alcohol, amine, or enolate – displaces the leaving group of an acyl derivative – such as an acid halide, anhydride, or ester. The resulting product is a carbonyl-containing compound in which the nucleophile has taken the place of the leaving group present in the original acyl derivative. Because acyl derivatives react with a wide variety of nucleophiles, and because the product can depend on the particular type of acyl derivative and nucleophile involved, nucleophilic acyl substitution reactions can be used to synthesize a variety of different products. Reaction mechanism Carbonyl compounds react with nucleophiles via an addition mechanism: the nucleophile attacks the carbonyl carbon, forming a tetrahedral intermediate. This reaction can be accelerated by acidic conditions, which make the carbonyl more electr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gilman Reagent2
Gilman may refer to: Places United States *Gilman Ranch, California *Gilman, Colorado *Gilman, Illinois *Gilman, Iowa * Gilman, Minnesota *Gilman, Montana *Gilman, Vermont * Gilman, Washington, former name of Issaquah *Gilman, Pierce County, Wisconsin *Gilman, Taylor County, Wisconsin *Gilman Lake, a lake in South Dakota *Gilmanton, New Hampshire *Gilmanton, Buffalo County, Wisconsin *Gilmanton Township, Benton County, Minnesota Other *Gilman (Yap), an administrative division of the Federated States of Micronesia *Gilman Street, a street in Central, Hong Kong Other uses *Gilman (name) *Gilman reagent, any of a group of reagents discovered by Henry Gilman *Gilman Paper Company, former paper producer ** Gilman Paper Company collection, photo archive in the Metropolitan Museum of Art *Gilman School, a private boys school in Baltimore, Maryland *924 Gilman Street The Alternative Music Foundation located at 924 Gilman Street, often referred to by its fans simply as "Gilman", i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alpha-beta Unsaturated Carbonyl Compounds
Alphabeta is an Israeli musical group. Alphabeta or Alpha Beta may also refer to: *The Greek alphabet, from ''Alpha'' (Αα) and ''Beta'' (Ββ), the first two letters *Alpha Beta, a former chain of Californian supermarkets *Alpha and beta anomers (chemistry) *Alpha–beta pruning, a type of search algorithm *Alpha-beta transformation, a mathematical transformation in electrical engineering *Alpha-beta unsaturated carbonyl compounds, a class of organic compounds *Alpha beta filter, a predictive filter *Alpha (finance) and Beta (finance), two measures characterizing the return of an investment portfolio *The Alpha Betas, a fraternity in the ''Revenge of the Nerds ''Revenge of the Nerds'' is a 1984 American comedy film directed by Jeff Kanew and starring Robert Carradine, Anthony Edwards, Ted McGinley, and Bernie Casey. The film's plot chronicles a group of nerds at the fictional Adams College trying ...'' film series *''Alpha Betas,'' an animated webseries created by Chris B ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Copper(I) Iodide
Copper(I) iodide is the inorganic compound with the formula CuI. It is also known as cuprous iodide. It is useful in a variety of applications ranging from organic synthesis to cloud seeding. Copper(I) iodide is white, but samples often appear tan or even, when found in nature as rare mineral marshite, reddish brown, but such color is due to the presence of impurities. It is common for samples of iodide-containing compounds to become discolored due to the facile aerobic oxidation of the iodide anion to molecular iodine. Structure Copper(I) iodide, like most binary (containing only two elements) metal halides, is an inorganic polymer. It has a rich phase diagram, meaning that it exists in several crystalline forms. It adopts a zinc blende structure below 390 °C (γ-CuI), a wurtzite structure between 390 and 440 °C (β-CuI), and a rock salt structure above 440 °C (α-CuI). The ions are tetrahedrally coordinated when in the zinc blende or the wurtzite struct ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gilman Reaction Example
Gilman may refer to: Places United States *Gilman Ranch, California *Gilman, Colorado *Gilman, Illinois *Gilman, Iowa * Gilman, Minnesota *Gilman, Montana *Gilman, Vermont * Gilman, Washington, former name of Issaquah *Gilman, Pierce County, Wisconsin *Gilman, Taylor County, Wisconsin *Gilman Lake, a lake in South Dakota *Gilmanton, New Hampshire *Gilmanton, Buffalo County, Wisconsin *Gilmanton Township, Benton County, Minnesota Other *Gilman (Yap), an administrative division of the Federated States of Micronesia *Gilman Street, a street in Central, Hong Kong Other uses *Gilman (name) *Gilman reagent, any of a group of reagents discovered by Henry Gilman *Gilman Paper Company, former paper producer ** Gilman Paper Company collection, photo archive in the Metropolitan Museum of Art *Gilman School, a private boys school in Baltimore, Maryland *924 Gilman Street The Alternative Music Foundation located at 924 Gilman Street, often referred to by its fans simply as "Gilman", i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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