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Hydrodimerization
Hydrodimerization is an organic reaction that couples two alkenes to give a symmetrical hydrocarbon. The reaction is often implemented electrochemically; in that case the reaction is called electrodimerization. The reaction can also be induced with samarium diiodide, a one-electron reductant. Hydrodimerization is the basis of the Monsanto adiponitrile synthesis: :2CH2=CHCN + 2e− + 2H+ → NCCH2CH2CH2CH2CN : The reaction applies to a number electrophilic alkenes (Michael acceptor In organic chemistry, the Michael reaction or Michael addition is a reaction between a Michael donor (an enolate or other nucleophile) and a Michael acceptor (usually an α,β-unsaturated carbonyl) to produce a Michael adduct by creating a carbo ...s). References Electrochemistry Industrial processes Organic chemistry Chemical synthesis Chemical processes Dimers_(chemistry) {{electrochem-stub ... [...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, photochemical reactions and 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 chemistry has a strong tradition of naming a spe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electrosynthesis
Electrosynthesis in chemistry is the synthesis of chemical compounds in an electrochemical cell. Compared to ordinary redox reaction, electrosynthesis sometimes offers improved selectivity and yields. Electrosynthesis is actively studied as a science and also has industrial applications. Electrooxidation has potential for wastewater treatment as well. Experimental setup The basic setup in electrosynthesis is a galvanic cell, a potentiostat and two electrodes. Typical solvent and electrolyte combinations minimizes electrical resistance. Protic conditions often use alcohol-water or dioxane-water solvent mixtures with an electrolyte such as a soluble salt, acid or base. Aprotic conditions often use an organic solvent such as acetonitrile or dichloromethane with electrolytes such as lithium perchlorate or tetrabutylammonium salts. The choice of electrodes with respect to their composition and surface area can be decisive. For example, in aqueous conditions the competing reactions in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Samarium Diiodide
Samarium(II) iodide is an inorganic compound with the formula SmI2. When employed as a solution for organic synthesis, it is known as Kagan's reagent. SmI2 is a green solid and solutions are green as well. It is a strong one-electron reducing agent that is used in organic synthesis. Structure In samarium(II) iodide, the metal centers are seven-coordinate with a face-capped octahedral geometry. In its ether adducts, samarium remains heptacoordinate with five ether and two terminal iodide ligands. Preparation Samarium iodide is easily prepared in nearly quantitative yields from samarium metal and either diiodomethane or 1,2-diiodoethane. When prepared in this way, its solutions is most often used without purification of the inorganic reagent. Solid, solvent-free SmI2 forms by high temperature decomposition of samarium(III) iodide (SmI3).G. Jantsch, N. Skalla: "Zur Kenntnis der Halogenide der seltenen Erden. IV. – Über Samarium(II)jodid und den thermischen Abbau des Samar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Reductions With Samarium(II) Iodide
Reductions with samarium(II) iodide involve the conversion of various classes of organic compounds into reduced products through the action of samarium(II) iodide, a mild one-electron reducing agent. History In 1979, Kagan observed the reduction of a variety of organic functional groups by samarium iodide under mild conditions. Since that time, samarium iodide has been employed in a variety of contexts in organic synthesis for both functional group manipulation and carbon-carbon bond formation. Samarium iodide is a one-electron reductant, and typically effects reduction through a series of electron transfer and proton transfer (from protic solvent) steps. Reducible functional groups include: *α-Functionalized carbonyl compounds *Ketones and aldehydes *Carboxylic acids (under strongly acidic or basic conditions) *Organic halides *Nitro compounds Some examples of functionality reduced by SmI2 are provided below. The reactivity of SmI2 is significantly affected by the choice of sol ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Adiponitrile
Adiponitrile is an organic compound with the chemical formula (CH2)4(CN)2. This viscous, colourless dinitrile is an important precursor to the polymer nylon 66. In 2005, about one million tonnes of adiponitrile were produced.M. T. Musser, "Adipic Acid" in Ullmann's Encyclopedia of Industrial Chemistry, Wiley-VCH, Weinheim, 2005. Production Early methods Because of the industrial value of adiponitrile, many methods have been developed for its synthesis. Early industrial methods started from furfural and later by the chlorination of butadiene to give 1,4-dichloro-2-butene, which with sodium cyanide, converts to 3-hexenedinitrile, which in turn can be hydrogenated to adiponitrile: :ClCH2CH=CHCH2Cl + 2 NaCN → NCCH2CH=CHCH2CN + 2 NaCl :NCCH2CH=CHCH2CN + H2 → NC(CH2)4CN Adiponitrile has also been produced from adipic acid, by dehydration of the diamide, but this is rarely employed. Modern methods After patent application in 2004, the majority of adiponitrile is prepar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Michael Acceptor
In organic chemistry, the Michael reaction or Michael addition is a reaction between a Michael donor (an enolate or other nucleophile) and a Michael acceptor (usually an α,β-unsaturated carbonyl) to produce a Michael adduct by creating a carbon-carbon bond at the acceptor's β-carbon. It belongs to the larger class of conjugate additions and is widely used for the mild formation of carbon-carbon bonds. The Michael addition is an important atom-economical method for diastereoselective and enantioselective C–C bond formation, and many asymmetric variants exist : In this general Michael addition scheme, either or both of R and R' on the nucleophile (the Michael donor) represent electron-withdrawing substituents such as acyl, cyano, nitro, or sulfone groups, which make the adjacent methylene hydrogen acidic enough to form a carbanion when reacted with the base, ''B:''. For the alkene (the Michael acceptor), the R" substituent is usually a carbonyl, which makes th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electrochemistry
Electrochemistry is the branch of physical chemistry concerned with the relationship between electrical potential difference, as a measurable and quantitative phenomenon, and identifiable chemical change, with the potential difference as an outcome of a particular chemical change, or vice versa. These reactions involve electrons moving via an electronically-conducting phase (typically an external electrical circuit, but not necessarily, as in electroless plating) between electrodes separated by an ionically conducting and electronically insulating electrolyte (or ionic species in a solution). When a chemical reaction is driven by an electrical potential difference, as in electrolysis, or if a potential difference results from a chemical reaction as in an electric battery or fuel cell, it is called an ''electrochemical'' reaction. Unlike in other chemical reactions, in electrochemical reactions electrons are not transferred directly between atoms, ions, or molecules, but via th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Industrial Processes
Industrial processes are procedures involving chemical, physical, electrical or mechanical steps to aid in the manufacturing of an item or items, usually carried out on a very large scale. Industrial processes are the key components of heavy industry. Chemical processes by main basic material Certain chemical process yield important basic materials for society, e.g., (cement, steel, aluminum, and fertilizer). However, these chemical reactions contribute to climate change by emitting carbon dioxide, a greenhouse gas, through chemical reactions, as well as through the combustion of fossil fuels to generate the high temperatures needed to reach the activation energies of the chemical reactions. Cement (the paste within concrete) * Calcination – Limestone, which is largely composed of fossilized calcium carbonate (CaCO3), breaks down at high temperatures into useable calcium oxide (CaO) and carbon dioxide gas (), which gets released as a by-product. This chemical reaction, call ... [...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 (i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chemical Synthesis
As a topic of chemistry, chemical synthesis (or combination) is the artificial execution of chemical reactions to obtain one or several products. This occurs by physical and chemical manipulations usually involving one or more reactions. In modern laboratory uses, the process is reproducible and reliable. A chemical synthesis involves one or more compounds (known as '' reagents'' or ''reactants'') that will experience a transformation when subjected to certain conditions. Various reaction types can be applied to formulate a desired product. This requires mixing the compounds in a reaction vessel, such as a chemical reactor or a simple round-bottom flask. Many reactions require some form of processing (" work-up") or purification procedure to isolate the final product. The amount produced by chemical synthesis is known as the ''reaction yield''. Typically, yields are expressed as a mass in grams (in a laboratory setting) or as a percentage of the total theoretical quantity ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chemical Processes
A chemical substance is a form of matter having constant chemical composition and characteristic properties. Some references add that chemical substance cannot be separated into its constituent elements by physical separation methods, i.e., without breaking chemical bonds. Chemical substances can be simple substances (substances consisting of a single chemical element), chemical compounds, or alloys. Chemical substances are often called 'pure' to set them apart from mixtures. A common example of a chemical substance is pure water; it has the same properties and the same ratio of hydrogen to oxygen whether it is isolated from a river or made in a laboratory. Other chemical substances commonly encountered in pure form are diamond (carbon), gold, table salt ( sodium chloride) and refined sugar ( sucrose). However, in practice, no substance is entirely pure, and chemical purity is specified according to the intended use of the chemical. Chemical substances exist as solids ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
