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Cyclopropene
Cyclopropene is an organic compound with the formula . It is the simplest cycloalkene. Because the ring is highly strained, cyclopropene is difficult to prepare and highly reactive. This colorless gas has been the subject for many fundamental studies of bonding and reactivity. It does not occur naturally, but derivatives are known in some fatty acids. Derivatives of cyclopropene are used commercially to control ripening of some fruit. Structure and bonding The molecule has a triangular structure. The reduced length of the double bond compared to a single bond causes the angle opposite the double bond to narrow to about 51° from the 60° angle found in cyclopropane. As with cyclopropane, the carbon–carbon bonding in the ring has increased p character: the alkene carbon atoms use sp2.68 hybridization for the ring. Synthesis of cyclopropene and derivatives Early syntheses The first confirmed synthesis of cyclopropene, carried out by Dem'yanov and Doyarenko, involved the the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cycloalkene
A cycloalkene or cycloolefin is a type of alkene hydrocarbon which contains a closed ring of carbon Atom, atoms and either one or more double bonds, but has no Aromaticity, aromatic character. Some cycloalkenes, such as cyclobutene and cyclopentene, can be used as Monomer, monomers to produce polymer chains. Due to geometrical considerations, smaller cycloalkenes are almost always the Cis–trans isomerism, ''cis'' isomers, and the term ''cis'' tends to be omitted from the names. Cycloalkenes require considerable p-orbital overlap in the form of a bridge between the carbon-carbon double bond, however, this is not feasible in smaller molecules due to the increase of strain that could break the molecule apart. In greater carbon number cycloalkenes, the addition of CH2 substituents decreases strain. trans-Cycloalkenes with 7 or fewer carbons in the ring will not occur under normal conditions because of the large amount of ring strain needed. In larger rings (8 or more atoms), Cis–tran ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sodium Amide
Sodium amide, commonly called sodamide (systematic name sodium azanide), is the inorganic compound with the formula . It is a salt composed of the sodium cation and the azanide anion. This solid, which is dangerously reactive toward water, is white, but commercial samples are typically gray due to the presence of small quantities of metallic iron from the manufacturing process. Such impurities do not usually affect the utility of the reagent. conducts electricity in the fused state, its conductance being similar to that of NaOH in a similar state. has been widely employed as a strong base in organic synthesis. Preparation and structure Sodium amide can be prepared by the reaction of sodium with ammonia gas, but it is usually prepared by the reaction in liquid ammonia using iron(III) nitrate as a catalyst. The reaction is fastest at the boiling point of the ammonia, c. −33 °C. An electride, , is formed as a reaction intermediate. : is a salt-like material and as such, c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ring Strain
In organic chemistry, ring strain is a type of instability that exists when bonds in a molecule form angles that are abnormal. Strain is most commonly discussed for small rings such as cyclopropanes and cyclobutanes, whose internal angles are substantially smaller than the idealized value of approximately 109°. Because of their high strain, the heat of combustion for these small rings is elevated. Ring strain results from a combination of angle strain, conformational strain or Pitzer strain (torsional eclipsing interactions), and transannular strain, also known as van der Waals strain or Prelog strain. The simplest examples of angle strain are small cycloalkanes such as cyclopropane and cyclobutane. Ring strain energy can be attributed to the energy required for the distortion of bond and bond angles in order to close a ring. Ring strain energy is believed to be the cause of accelerated rates in altering ring reactions. Its interactions with traditional bond energies chan ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sodium Bis(trimethylsilyl)amide
Sodium bis(trimethylsilyl)amide is the organosilicon compound with the formula . This species, usually called NaHMDS (sodium hexamethyldisilazide), is a strong base used for deprotonation reactions or base-catalyzed reactions. Its advantages are that it is commercially available as a solid and it is soluble not only in ethers, such as THF or diethyl ether, but also in aromatic solvents, like benzene and toluene by virtue of the lipophilic TMS groups. NaHMDS is quickly destroyed by water to form sodium hydroxide and bis(trimethylsilyl)amine. Structure Although the Na–N bond is polar covalent as a solid, when dissolved in nonpolar solvents this compound is trimeric, consisting of a central ring. Applications in synthesis NaHMDS is used as a strong base in organic synthesis. Typical reactions: *To deprotonate ketones and esters to generate enolate derivatives. *Generate carbenes by dehydrohalogenation of halocarbons. These carbene reagents add to alkenes to give substituted cy ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cyclopropane
Cyclopropane is the cycloalkane with the molecular formula (CH2)3, consisting of three methylene groups (CH2) linked to each other to form a ring. The small size of the ring creates substantial ring strain in the structure. Cyclopropane itself is mainly of theoretical interest but many of its derivatives are of commercial or biological significance. History Cyclopropane was discovered in 1881 by August Freund, who also proposed the correct structure for the substance in his first paper. Freund treated 1,3-dibromopropane with sodium, causing an intramolecular Wurtz reaction leading directly to cyclopropane. The yield of the reaction was improved by Gustavson in 1887 with the use of zinc instead of sodium. Cyclopropane had no commercial application until Henderson and Lucas discovered its anaesthetic properties in 1929; industrial production had begun by 1936. In modern anaesthetic practice, it has been superseded by other agents. Anaesthesia Cyclopropane was introduced into cli ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sodium Methoxide
Sodium methoxide is the simplest sodium alkoxide. With the formula , it is a white solid, which is formed by the deprotonation of methanol. Itis a widely used reagent in industry and the laboratory. It is also a dangerously caustic base. Preparation and structure Sodium methoxide is prepared by treating methanol with sodium: : The reaction is so exothermic that ignition is possible. The resulting solution, which is colorless, is often used as a source of sodium methoxide, but the pure material can be isolated by evaporation followed by heating to remove residual methanol. As a solid, sodium methoxide is polymeric, with sheet-like arrays of centers, each bonded to four oxygen centers. The structure, and hence the basicity, of sodium methoxide in solution depends on the solvent. It is a significantly stronger base in DMSO where it is more fully ionized and free of hydrogen bonding. Applications Organic synthesis Sodium methoxide is a routinely used base in organic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Allylamine
Allylamine is an organic compound with the formula C3H5NH2. This colorless liquid is the simplest stable unsaturated amine. Production and reactions All three allylamines, mono-, di-, and triallylamine, are produced by the treating allyl chloride with ammonia followed by distillation. Or by the reaction of allyl chloride with Hexamine. Pure samples can be prepared by hydrolysis of allyl isothiocyanate. It behaves as a typical amine.Henk de Koning, W. Nico Speckamp "Allylamine" in ''Encyclopedia of Reagents for Organic Synthesis'', 2001, John Wiley & Sons, Weinheim. Article Online Posting Date: April 15, 2001 Polymerization can be used to prepare the homopolymer ( polyallylamine) or copolymers. The polymers are promising membranes for use in reverse osmosis. Other allylamines Diallylamine is a precursor to industrial products. Functionalized allylamines have pharmaceutical applications. Pharmaceutically important allylamines include flunarizine and naftifine. Flunarizine a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Toluene
Toluene (), also known as toluol (), is a substituted aromatic hydrocarbon. It is a colorless, water-insoluble liquid with the smell associated with paint thinners. It is a mono-substituted benzene derivative, consisting of a methyl group (CH3) attached to a phenyl group. As such, its systematic IUPAC name is methylbenzene. Toluene is predominantly used as an industrial feedstock and a solvent. As the solvent in some types of paint thinner, permanent markers, contact cement and certain types of glue, toluene is sometimes used as a recreational inhalant and has the potential of causing severe neurological harm. History The compound was first isolated in 1837 through a distillation of pine oil by the Polish chemist Filip Walter, who named it ''rétinnaphte''. In 1841, French chemist Henri Étienne Sainte-Claire Deville isolated a hydrocarbon from balsam of Tolu (an aromatic extract from the tropical Colombian tree ''Myroxylon balsamum''), which Deville recognized as similar to Wa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phenyllithium
Phenyllithium or lithobenzene is an organometallic agent with the empirical formula C6H5Li. It is most commonly used as a metalating agent in organic syntheses and a substitute for Grignard reagents for introducing phenyl groups in organic syntheses. Crystalline phenyllithium is colorless; however, solutions of phenyllithium are various shades of brown or red depending on the solvent used and the impurities present in the solute. Preparation Phenyllithium was first produced by the reaction of lithium metal with diphenylmercury: :(C6Η5)2Ηg + 2Li → 2C6Η5Li + Ηg Reaction of a phenyl halide with lithium metal produces phenyllithium: :X-Ph + 2Li → Ph-Li + LiX Phenyllithium can also be synthesized with a metal-halogen exchange reaction: :n-BuLi + X-Ph → n-BuX + Ph-Li The predominant method of producing phenyllithium today are the latter two syntheses. Reactions The primary use of PhLi is to facilitate formation of carbon-carbon bonds by nucleophilic addition and substitut ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Organic Compound
In chemistry, organic compounds are generally any chemical compounds that contain carbon-hydrogen or carbon-carbon bonds. Due to carbon's ability to catenate (form chains with other carbon atoms), millions of organic compounds are known. The study of the properties, reactions, and syntheses of organic compounds comprise the discipline known as organic chemistry. For historical reasons, a few classes of carbon-containing compounds (e.g., carbonate salts and cyanide salts), along with a few other exceptions (e.g., carbon dioxide, hydrogen cyanide), are not classified as organic compounds and are considered inorganic. Other than those just named, little consensus exists among chemists on precisely which carbon-containing compounds are excluded, making any rigorous definition of an organic compound elusive. Although organic compounds make up only a small percentage of Earth's crust, they are of central importance because all known life is based on organic compounds. Living t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ethyl Diazoacetate
Ethyl diazoacetate (N=N=CHC(O)OC2H5) is a diazo compound and a reagent in organic chemistry. It was discovered by Theodor Curtius in 1883. The compound can be prepared by reaction of the ethyl ester of glycine with sodium nitrite and sodium acetate in water. : As a carbene precursor, it is used in the cyclopropanation of alkenes. Although the compound is hazardous, it is used in chemical industry as a precursor to trovafloxacin. Procedures for safe industrial handling have been published. Another location where EDA was used is in the production of BI-4752, a recently invented 5-HT2C agonist that is even superior to lorcaserin Lorcaserin, marketed under the brand name Belviq was a weight-loss drug developed by Arena Pharmaceuticals. It reduces appetite by activating a type of serotonin receptor known as the 5-HT2C receptor in a region of the brain called the hypothal .... References {{DEFAULTSORT:Ethyl Diazoacetate Diazo compounds Reagents for organic chemistry Ethy ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
2-butyne
2-Butyne (dimethylacetylene, crotonylene or but-2-yne) is an alkyne with chemical formula CH3C≡CCH3. Produced artificially, it is a colorless, volatile, pungent liquid at standard temperature and pressure. 2-Butyne is of interest to physical chemists because of its very low torsional barrier and the problem of determining that barrier using high-resolution infrared spectroscopy. Analysis of its spectrum leads to a determination that the torsional barrier is only 6 cm−1 (1.2 J or 72 J mol−1). However, it has not been determined whether the equilibrium structure is eclipsed (D3h) or staggered (D3d). Symmetry analysis using the Molecular Symmetry Group G36 shows that one would need to analyse its high resolution rotation-vibration Raman spectrum to determine its equilibrium structure. 2-Butyne (''dimethylethyne'') forms with 5-decyne (''dibutylethyne''), 4-octyne (''dipropylethyne'') and 3-hexyne (''diethylethyne'') a group of symmetric alkynes. Synthesis 2-Butyne can b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
