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Alkynylation
In organic chemistry, alkynylation is an addition reaction in which a terminal alkyne () is added to a carbonyl group () to form an Alpha and beta carbon, α-alkynyl alcohol (chemistry), alcohol (). When the acetylide is formed from acetylene (), the reaction gives an α-ethynyl alcohol. This process is often referred to as ethynylation. Such processes often involve metal acetylide intermediates. Scope The principal reaction of interest involves the addition of the acetylene () to a ketone () or aldehyde (): :RR'C=O + HC#CR'' -> RR'C(OH)C#CR'' The reaction proceeds with retention of the triple bond. For aldehydes and unsymmetrical ketones, the product is chiral, hence there is interest in asymmetric variants. These reactions invariably involve metal-acetylide intermediates. This reaction was discovered by chemist John Ulric Nef (chemist), John Ulric Nef in 1899 while experimenting with reactions of elemental sodium, phenylacetylene, and acetophenone. For this reason, the re ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Propargyl Alcohol
Propargyl alcohol, or 2-propyn-1-ol, is an organic compound with the chemical formula, formula C3H4O. It is the simplest stable Alcohol (chemistry), alcohol containing an alkyne functional group. Propargyl alcohol is a colorless viscous liquid that is miscible with water and most polar organic solvents. Reactions and applications Propargyl alcohol polymerizes with heating or treatment with base (chemistry), base. It is used as a corrosion inhibitor, a metal complex solution, a solvent stabilizer and an electroplating brightener additive. It is also used as an intermediate in organic synthesis. Secondary alcohol, Secondary and Tertiary alcohol, tertiary substituted propargylic alcohols undergo catalyzed rearrangement reactions to form carbonyl#α,β-Unsaturated carbonyl compounds, α,β-unsaturated carbonyl compounds via the Meyer–Schuster rearrangement and others. It can be oxidized to propynal or propargylic acid. As an indication of the electronegativity of an Orbital hybri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Organic Chemistry
Organic chemistry is a subdiscipline within chemistry involving the scientific study of the structure, properties, and reactions of organic compounds and organic materials, i.e., matter in its various forms that contain carbon atoms.Clayden, J.; Greeves, N. and Warren, S. (2012) ''Organic Chemistry''. Oxford University Press. pp. 1–15. . Study of structure determines their structural formula. Study of properties includes physical and chemical properties, and evaluation of chemical reactivity to understand their behavior. The study of organic reactions includes the chemical synthesis of natural products, drugs, and polymers, and study of individual organic molecules in the laboratory and via theoretical ( in silico) study. The range of chemicals studied in organic chemistry includes hydrocarbons (compounds containing only carbon and hydrogen) as well as compounds based on carbon, but also containing other elements, especially oxygen, nitrogen, sulfur, phosphorus (included in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nef Synthesis
In organic chemistry, Nef synthesis is the addition of sodium acetylides to aldehydes and ketones to yield acetylenic carbinols. It is named for John Ulric Nef, who discovered the reaction in 1899. This process is often erroneously referred to as the Nef reaction, which is an unrelated chemical transformation discovered by the same chemist. See also *Alkynation In organic chemistry, alkynylation is an addition reaction in which a terminal alkyne () is added to a carbonyl group () to form an α-alkynyl alcohol (). When the acetylide is formed from acetylene (), the reaction gives an α-ethynyl alcohol. ... References Carbon-carbon bond forming reactions Organometallic chemistry Addition reactions {{organic-chem-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lithium Amide
Lithium amide or lithium azanide is an inorganic compound with the chemical formula . It is a white solid with a tetragonal crystal structure. Lithium amide can be made by treating lithium metal with liquid ammonia: : Other lithium amides The conjugate bases of amines are known as amides. Thus, a ''lithium amide'' may also refer to any compound in the class of the lithium salt of an amine. These compounds have the general form , with the chemical lithium amide itself as the parent structure. Common lithium amides include lithium diisopropylamide (LDA), lithium tetramethylpiperidide (LiTMP), and lithium hexamethyldisilazide (LiHMDS). They are produced by the reaction of Li metal with the appropriate amine: : Lithium amides are very reactive compounds. Specifically, they are strong bases. Examples Lithium tetramethylpiperidide has been crystallised as a tetramer. On the other hand, the lithium derivative of bis(1-phenylethyl)amine crystallises as a trimer: It is also possibl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Grignard Reagent
A Grignard reagent or Grignard compound is a chemical compound with the general formula , where X is a halogen and R is an organic group, normally an alkyl or aryl. Two typical examples are methylmagnesium chloride and phenylmagnesium bromide . They are a subclass of the organomagnesium compounds. Grignard compounds are popular reagents in organic synthesis for creating new carbon-carbon bonds. For example, when reacted with another halogenated compound in the presence of a suitable catalyst, they typically yield and the magnesium halide as a byproduct; and the latter is insoluble in the solvents normally used. In this aspect, they are similar to organolithium reagents. Pure Grignard reagents are extremely reactive solids. They are normally handled as solutions in solvents such as diethyl ether or tetrahydrofuran; which are relatively stable as long as water is excluded. In such a medium, a Grignard reagent is invariably present as a complex with the magnesium atom conn ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arens–van Dorp Synthesis
The Arens–van Dorp synthesis is a name reaction in organic chemistry. It describes the addition of lithiated ethoxyacetylenes to ketones to give propargyl alcohols, which can undergo further reaction to form α,β-unsaturated aldehydes, or esters. There is also a variation of this reaction called the Isler modification, where the acetylide anion is generated in situ from β-chlorovinyl ether using lithium amide Lithium amide or lithium azanide is an inorganic compound with the chemical formula . It is a white solid with a tetragonal crystal structure. Lithium amide can be made by treating lithium metal with liquid ammonia: : Other lithium amides The co .... References {{DEFAULTSORT:Arens-van Dorp synthesis Name reactions Chemistry Organic chemistry ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acetylide Carbonyl Addition
In organometallic chemistry, acetylide refers to chemical compounds with the chemical formulas and , where M is a metal. The term is used loosely and can refer to substituted acetylides having the general structure (where R is an organic side chain). Acetylides are reagents in organic synthesis. The calcium acetylide commonly called calcium carbide is a major compound of commerce. Structure and bonding Alkali metal and alkaline earth metal acetylides of the general formula MC≡CM are salt-like Zintl phase compounds, containing ions. Evidence for this ionic character can be seen in the ready hydrolysis of these compounds to form acetylene and metal oxides, there is also some evidence for the solubility of ions in liquid ammonia. The ion has a closed shell ground state of 1Σ, making it isoelectronic to a neutral molecule N2, which may afford it some stability. Analogous acetylides prepared from other metals, particularly transition metals, show covalent character and are ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acetic Acid
Acetic acid , systematically named ethanoic acid , is an acidic, colourless liquid and organic compound with the chemical formula (also written as , , or ). Vinegar is at least 4% acetic acid by volume, making acetic acid the main component of vinegar apart from water and other trace elements. Acetic acid is the second simplest carboxylic acid (after formic acid). It is an important Reagent, chemical reagent and industrial chemical, used primarily in the production of cellulose acetate for photographic film, polyvinyl acetate for wood Adhesive, glue, and synthetic fibres and fabrics. In households, diluted acetic acid is often used in descaling agents. In the food industry, acetic acid is controlled by the E number, food additive code E260 as an acidity regulator and as a condiment. In biochemistry, the acetyl group, derived from acetic acid, is fundamental to all forms of life. When bound to coenzyme A, it is central to the metabolism of carbohydrates and fats. The global ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alkoxy Group
In chemistry, the alkoxy group is an alkyl group which is singularly bonded to oxygen; thus . The range of alkoxy groups is vast, the simplest being methoxy (). An ethoxy group () is found in the organic compound ethyl phenyl ether (, also known as ethoxybenzene). Related to alkoxy groups are aryloxy groups, which have an aryl group singularly bonded to oxygen such as the phenoxy group (). An alkoxy or aryloxy group bonded to an alkyl or aryl () is an ether. If bonded to H it is an alcohol. An alkoxide can refer to salts of alcohols, and they are ionic compounds containing an alkoxide ions ; it is a derivative of an alcohol where the hydrogen of the –OH group is replaced by a metal, for example sodium salt of ethanol () is sodium ethoxide Sodium ethoxide, also referred to as sodium ethylate, is the ionic, organic compound with the formula , or NaOEt (Et = ethane). It is a white solid, although impure samples appear yellow or brown. It dissolves in polar solvents such ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cyclopentanone
Cyclopentanone is the organic compound with the formula (CH2)4CO. This cyclic ketone is a colorless volatile liquid. Preparation Upon treatment with barium hydroxide at elevated temperatures, adipic acid undergoes ketonization to give cyclopentanone: :(CH2)4(CO2H)2 → (CH2)4CO + H2O + CO2 Uses Cyclopentanone is common precursor to fragrances, especially those related to jasmine and jasmone. Examples include 2-pentyl- and 2-heptylcyclopentanone.Johannes Panten and Horst Surburg "Flavors and Fragrances, 2. Aliphatic Compounds" in Ullmann's Encyclopedia of Industrial Chemistry, 2015, Wiley-VCH, Weinheim. It is a versatile synthetic intermediate, being a precursor to cyclopentobarbital. Cyclopentanone is also used to make cyclopentamine, the pesticide pencycuron, and pentethylcyclanone Pentethylcyclanone is an antitussive medication A medication (also called medicament, medicine, pharmaceutical drug, medicinal drug or simply drug) is a drug used to diagnose, c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
N-Butyllithium
''n''-Butyllithium C4H9Li (abbreviated ''n''-BuLi) is an organolithium reagent. It is widely used as a polymerization initiator in the production of elastomers such as polybutadiene or styrene-butadiene-styrene (SBS). Also, it is broadly employed as a strong base (superbase) in the synthesis of organic compounds as in the pharmaceutical industry. Butyllithium is commercially available as solutions (15%, 25%, 1.5 M, 2 M, 2.5 M, 10 M, etc.) in alkanes such as pentane, hexanes, and heptanes. Solutions in diethyl ether and THF can be prepared, but are not stable enough for storage. Annual worldwide production and consumption of butyllithium and other organolithium compounds is estimated at 2000 to 3000 tonnes. Although butyllithium is colorless, ''n''-butyllithium is usually encountered as a pale yellow solution in alkanes. Such solutions are stable indefinitely if properly stored,. but in practice, they degrade upon aging. Fine white precipitate (l ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
