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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 In organic chemistry, the Nef reaction is an organic reaction describing the acid hydrolysis of a salt of a primary or secondary nitroalkane () to an aldehyde () or a ketone () and nitrous oxide (). The reaction has been the subject of several ..., which is an unrelated chemical transformation discovered by the same chemist. See also * Alkynation References Carbon-carbon bond forming reactions Organometallic chemistry Addition reactions {{organic-chem-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
John Ulric Nef (chemist)
John Ulric Nef (Johann Ulrich Nef; June 14, 1862 – August 13, 1915) was a Swiss-born American chemist and the discoverer of the Nef reaction and Nef synthesis. He was a member of the American Academy of Arts and Sciences and the National Academy of Sciences. Life His parents emigrated from Switzerland to the United States, where Nef studied chemistry at Harvard University until 1884. Upon graduation, he joined Adolf von Baeyer at the University of Munich, where he received his Ph.D. in 1887. He was a professor at Purdue University from 1887 till 1889 and at Clark University from 1889 till 1892. In 1892 Nef joined the newly formed University of Chicago as Professor of Chemistry, where he spent the rest of his academic career. His son John Ulric Nef (economic historian), John Ulric Nef (1899–1988) became a Professor of Economic History and published several books. Work The discovery of the Nef reaction and the papers about divalent carbon (carbenes) were his major achieve ... [...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 (inclu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acetylide
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 a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aldehyde
In organic chemistry, an aldehyde () is an organic compound containing a functional group with the structure . The functional group itself (without the "R" side chain) can be referred to as an aldehyde but can also be classified as a formyl group. Aldehydes are common and play important roles in the technology and biological spheres. Structure and bonding Aldehydes feature a carbon center that is connected by a double bond to oxygen and a single bond to hydrogen and single bond to a third substituent, which is carbon or, in the case of formaldehyde, hydrogen. The central carbon is often described as being sp2- hybridized. The aldehyde group is somewhat polar. The C=O bond length is about 120-122 picometers. Physical properties and characterization Aldehydes have properties that are diverse and that depend on the remainder of the molecule. Smaller aldehydes are more soluble in water, formaldehyde and acetaldehyde completely so. The volatile aldehydes have pungent odors. Al ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ketone
In organic chemistry, a ketone is a functional group with the structure R–C(=O)–R', where R and R' can be a variety of carbon-containing substituents. Ketones contain a carbonyl group –C(=O)– (which contains a carbon-oxygen double bond C=O). The simplest ketone is acetone (where R and R' is methyl), with the formula . Many ketones are of great importance in biology and in industry. Examples include many sugars (ketoses), many steroids (e.g., testosterone), and the solvent acetone. Nomenclature and etymology The word ''ketone'' is derived from ''Aketon'', an old German word for ''acetone''. According to the rules of IUPAC nomenclature, ketone names are derived by changing the suffix ''-ane'' of the parent alkane to ''-anone''. Typically, the position of the carbonyl group is denoted by a number, but traditional nonsystematic names are still generally used for the most important ketones, for example acetone and benzophenone. These nonsystematic names are considered re ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nef Reaction
In organic chemistry, the Nef reaction is an organic reaction describing the acid hydrolysis of a salt of a primary or secondary nitroalkane () to an aldehyde () or a ketone () and nitrous oxide (). The reaction has been the subject of several literature reviews. The reaction was reported in 1894 by the chemist John Ulric Nef, who treated the sodium salt of nitroethane with sulfuric acid resulting in an 85–89% yield of nitrous oxide and at least 70% yield of acetaldehyde. However, the reaction was pioneered a year earlier in 1893 by Konovalov, who converted the potassium salt of 1-phenylnitroethane with sulfuric acid to acetophenone. Reaction mechanism The reaction mechanism starting from the nitronate salt as the resonance structures 1a and 1b is depicted below: The salt is protonated forming the nitronic acid 2 (in some cases these nitronates have been isolated) and once more to the iminium ion 3. This intermediate is attacked by water in a nucleophilic addition ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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. 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 in 1899 while experimenting with reactions of elemental sodium, phenylacetylene, and acetophenone. For this reason, the reaction is sometimes referred to as Nef synthesis. Sometimes this r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Organometallic Chemistry
Organometallic chemistry is the study of organometallic compounds, chemical compounds containing at least one chemical bond between a carbon atom of an organic molecule and a metal, including alkali, alkaline earth, and transition metals, and sometimes broadened to include metalloids like boron, silicon, and selenium, as well. Aside from bonds to organyl fragments or molecules, bonds to 'inorganic' carbon, like carbon monoxide (metal carbonyls), cyanide, or carbide, are generally considered to be organometallic as well. Some related compounds such as transition metal hydrides and metal phosphine complexes are often included in discussions of organometallic compounds, though strictly speaking, they are not necessarily organometallic. The related but distinct term " metalorganic compound" refers to metal-containing compounds lacking direct metal-carbon bonds but which contain organic ligands. Metal β-diketonates, alkoxides, dialkylamides, and metal phosphine complexes are r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
