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Alexander Dilman
Alexander Davidovich Dilman () is a Russian organic chemist and is a professor of the Russian Academy of Sciences. Dilman currently is a Head of the Laboratory of Functional Organic Compounds at N. D. Zelinsky Institute of Organic Chemistry of the Russian Academy of Sciences (ZIOC RAS). Since 2022 he is a Corresponding Member of the Russian Academy of Sciences. Biography Dilman was born in Moscow in 1976. At the age of 15 he attended the Moscow Chemical Lyceum in order to deep dive in chemistry. In 1993 Dilman attended the Higher Chemical College of the Russian Academy of Sciences. During his undergraduate research he studied the chemistry of nitro- and organosilicon compounds at the ZIOC RAS under Vladimir Tartakovsky supervision. Dilman completed an internship in the group of at the Ludwig Maximilian University of Munich in 2000. The results he obtained in Germany became a part of his dissertation. In 2001 he defended his Ph.D. thesis on the topic "Chemistry of N,N-bi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Organic Chemistry
Organic chemistry is a subdiscipline within chemistry involving the science, scientific study of the structure, properties, and reactions of organic compounds and organic matter, 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 property, physical and Chemical property, chemical properties, and evaluation of Reactivity (chemistry), chemical reactivity to understand their behavior. The study of organic reactions includes the organic synthesis, 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 chemistry includes hydrocarbons (compounds containing only carbon and hydrogen) as well as compounds based on carbon, but a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Enamine
An enamine is an unsaturated compound derived by the condensation of an aldehyde or ketone with a secondary amine. Enamines are versatile intermediates. The word "enamine" is derived from the affix ''en''-, used as the suffix of alkene, and the root ''amine''. This can be compared with enol, which is a functional group containing both alkene (''en''-) and Alcohol (chemistry), alcohol (-''ol''). Enamines are considered to be nitrogen analogs of enols. If one or both of the nitrogen substituents is a hydrogen atom it is the tautomeric form of an imine. This usually will rearrange to the imine; however there are several exceptions (such as aniline). The enamine-imine tautomerism may be considered analogous to the keto-enol tautomerism. In both cases, a hydrogen atom switches its location between the heteroatom (oxygen or nitrogen) and the second carbon atom. Enamines are both good nucleophiles and good bases. Their behavior as carbon-based nucleophiles is explained with reference t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Living People
Purpose: Because living persons may suffer personal harm from inappropriate information, we should watch their articles carefully. By adding an article to this category, it marks them with a notice about sources whenever someone tries to edit them, to remind them of WP:BLP (biographies of living persons) policy that these articles must maintain a neutral point of view, maintain factual accuracy, and be properly sourced. Recent changes to these articles are listed on Special:RecentChangesLinked/Living people. Organization: This category should not be sub-categorized. Entries are generally sorted by family name In many societies, a surname, family name, or last name is the mostly hereditary portion of one's personal name that indicates one's family. It is typically combined with a given name to form the full name of a person, although several give .... Maintenance: Individuals of advanced age (over 90), for whom there has been no new documentation in the last ten ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1976 Births
Events January * January 2 – The International Covenant on Economic, Social and Cultural Rights enters into force. * January 5 – The Pol Pot regime proclaims a new constitution for Democratic Kampuchea. * January 18 – Full diplomatic relations are established between Bangladesh and Pakistan 5 years after the Bangladesh Liberation War. * January 27 ** The United States vetoes a United Nations resolution that calls for an independent Palestinian state. ** The First Battle of Amgala (1976), First Battle of Amgala breaks out between Morocco and Algeria in the Spanish Sahara. February * February 4 ** The 1976 Winter Olympics begin in Innsbruck, Austria. ** The 7.5 1976 Guatemala earthquake, Guatemala earthquake affects Guatemala and Honduras with a maximum Mercalli intensity of IX (''Violent''), leaving 23,000 dead and 76,000 injured. * February 9 – The Australian Defence Force is formed by unification of the Australian Army, the Royal Australian Navy and the Royal Au ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acridine
Acridine is an organic compound and a nitrogen heterocycle with the formula C13H9N. Acridines are substituted derivatives of the parent ring. It is a planar molecule that is structurally related to anthracene with one of the central CH groups replaced by nitrogen. Like the related molecules pyridine and quinoline, acridine is mildly basic. It is an almost colorless solid, which crystallizes in needles. There are few commercial applications of acridines; at one time acridine dyes were popular, but they are now relegated to niche applications, such as with acridine orange. The name is a reference to the acrid odour and acrid skin-irritating effect of the compound. Isolation and syntheses Carl Gräbe and Heinrich Caro first isolated acridine in 1870 from coal tar. Acridine is separated from coal tar by extracting with dilute sulfuric acid. Addition of potassium dichromate to this solution precipitates acridine bichromate. The bichromate is decomposed using ammonia. Acridi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Photoredox Catalysis
Photoredox catalysis is a branch of photochemistry that uses electron transfer, single-electron transfer. Photoredox catalysts are generally drawn from three classes of materials: transition-metal complexes, organic dyes, and semiconductors. While organic photoredox catalysts were dominant throughout the 1990s and early 2000s, soluble transition-metal complexes are more commonly used today. Photochemistry of transition metal sensitizers Sensitizers absorb light to give redox-active excited states. For many metal-based sensitizers, excitation is realized as a metal-to-ligand charge transfer, whereby an electron moves from the metal (e.g., a d orbital) to an orbital localized on the ligands (e.g. the Pi bond, π* orbital of an aromatic ligand). This initial excited electronic state relaxes to a singlet excited state through Internal conversion (chemistry), internal conversion, a process where energy is dissipated as vibrational energy (heat) rather than as electromagnetic radiati ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Medicinal Chemistry
Medicinal or pharmaceutical chemistry is a scientific discipline at the intersection of chemistry and pharmacy involved with drug design, designing and developing pharmaceutical medication, drugs. Medicinal chemistry involves the identification, synthesis and development of new chemical entity, new chemical entities suitable for therapeutic use. It also includes the study of existing drugs, their biological properties, and their quantitative structure-activity relationships (QSAR). Medicinal chemistry is a highly interdisciplinary science combining organic chemistry with biochemistry, computational chemistry, pharmacology, molecular biology, statistics, and physical chemistry. Compounds used as medicines are most often organic compounds, which are often divided into the broad classes of Small molecule, small organic molecules (e.g., atorvastatin, fluticasone, clopidogrel) and "biologic medical product, biologics" (infliximab, erythropoietin, insulin glargine), the latter of whic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Difluorocarbene
Difluorocarbene is the chemical compound with formula CF2. It has a short half-life, 0.5 and 20 ms, in solution and in the gas phase, respectively.Douglas A Jean Osteraas "Difluorocarbene Modification of Polymer and Fiber Surfaces," ''Journal of Applied Polymer''1969, volume 13, 1523-1535. Although highly reactive, difluorocarbene is an intermediate in the production of tetrafluoroethylene, which is produced on an industrial scale as the precursor to Teflon (PTFE). Bonding in difluorocarbene In general, carbenes exist in either singlet or triplet states, which are often quite close in energy. Singlet carbenes have spin-paired electrons and a higher energy empty 2p orbital. In a triplet carbene, one electron occupies the hybrid orbital and the other is promoted to the 2p orbital.Jones. Maitland.''Organic Chemistry'', 3rd ed, W. W. Norton, 2005, 460-465. . For most carbenes, the triplet state is more stable than the corresponding singlet. In the case of fluorinated carbenes, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trifluoromethyltrimethylsilane
Trifluoromethyltrimethylsilane (known as Ruppert-Prakash reagent, TMSCF3) is an organosilicon compound with the formula CF3Si(CH3)3. It is a colorless liquid. The compound is a reagent used in organic chemistry for the introduction of the trifluoromethyl group. The compound was first prepared in 1984 by Ingo Ruppert and further developed as a reagent by G. K. Surya Prakash. Preparation The reagent is prepared from trimethylsilyl chloride and bromotrifluoromethane in the presence of a phosphorus(III) reagent that serves as a halogen acceptor. Use in organic synthesis In the presence of a metal salt (M+ X−), the reagent reacts with aldehydes and ketones to give a trimethylsilyl ether, the net product of insertion of the carbonyl into the Si-CF3 bond. Hydrolysis gives trifluoromethyl methanols. The reagent also converts esters to trifluoromethyl ketones. A typical initiator is a soluble fluoride-containing species such as tetrabutylammonium fluoride; however, simple alkoxides ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trifluoromethyl Group
The trifluoromethyl group is a functional group that has the formula . The naming of is group is derived from the methyl group (which has the formula ), by replacing each hydrogen atom by a fluorine atom. Some common examples are trifluoromethane , 1,1,1-trifluoroethane , and hexafluoroacetone . Compounds with this group are a subclass of the organofluorines. Properties The trifluoromethyl group has a significant electronegativity that is often described as being intermediate between the electronegativities of fluorine and chlorine. For this reason, trifluoromethyl-substituted compounds are often strong acids, such as trifluoromethanesulfonic acid and trifluoroacetic acid. Conversely, the trifluoromethyl group lowers the basicity of compounds like trifluoroethanol. Uses The trifluoromethyl group occurs in certain pharmaceuticals, drugs, and abiotically synthesized natural fluorocarbon based compounds. The medicinal use of the trifloromethyl group dates from 1928, although res ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydrazone
Hydrazones are a class of organic compounds with the structure . They are related to ketones and aldehydes by the replacement of the oxygen =O with the = functional group. They are formed usually by the action of hydrazine on ketones or aldehydes. Synthesis Hydrazine, organohydrazines, and 1,1-diorganohydrazines react with aldehydes and ketones to give hydrazones. : Phenylhydrazine reacts with reducing sugars to form hydrazones known as osazones, which was developed by German chemist Emil Fischer as a test to differentiate monosaccharides. Uses image:Pigment Yellow 97.svg, left, Pigment Yellow 97, a popular yellow colorant, is a hydrazone., 160px Hydrazones are the basis for various analyses of ketones and aldehydes. For example, dinitrophenylhydrazine coated onto a silica sorbent is the basis of an adsorption cartridge. The hydrazones are then eluted and analyzed by high-performance liquid chromatography (HPLC) using a ultraviolet, UV detector. The compound carbonyl cyanide-p-t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Iminium
In organic chemistry, an iminium cation is a polyatomic ion with the general structure . They are common in synthetic chemistry and biology. Structure Iminium cations adopt alkene-like geometries: the central C=N unit is nearly coplanar with all four substituents. Unsymmetrical iminium cations can exist as cis and trans isomers. The C=N bonds, which are near 129 picometers in length, are shorter than C-N single bonds. Cis/trans isomers are observed. The C=N distance is slightly shorter in iminium cations than in the parent imine, and computational studies indicate that the C=N bonding is also stronger in iminium vs imine, although the C=N distance contracts only slightly. These results indicate that the barrier for rotation is higher than in the parent imines. Formation Iminium cations are obtained by protonation and alkylation of imines: : : They also are generated by the condensation of secondary amines with ketones or aldehydes: : This rapid, reversible reaction is one ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
