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Blum–Ittah Aziridine Synthesis
The Blum–Ittah aziridine synthesis, also known as the Blum–Ittah-Shahak aziridine synthesis or simply the Blum aziridine synthesis is a name reaction of organic chemistry, for the generation of aziridines from oxiranes. Mechanism The oxirane is first converted into a 2-azidoalcohol with the use of an azide such as sodium azide. The azido alcohol is then reduced with the use of a trialkylphosphine such as triphenylphosphine in a manner similar to the Staudinger reaction The Staudinger reaction is a chemical reaction of an organic azide with a phosphine or phosphite produces an iminophosphorane. The reaction was discovered by and named after Hermann Staudinger. The reaction follows this stoichiometry: :R3P + ..., concomitant with loss of N2. The resulting phosphonimine (formerly called iminophosphorane) intermediate is then attacked by the alcohol, with oxygen forming a bond with the phosphorus atom. Forming a ring intermediate. After a proton transfer, a pair o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Name Reaction
A name reaction is a chemical reaction named after its discoverers or developers. Among the tens of thousands of organic reactions that are known, hundreds of such reactions are well-known enough to be named after people. Well-known examples include the Grignard reaction, the Sabatier reaction, the Wittig reaction, the Claisen condensation, the Friedel-Crafts acylation, and the Diels-Alder reaction. Books have been published devoted exclusively to name reactions;Alfred Hassner, C. Stumer. ''Organic syntheses based on name reactions''. Elsevier, 2002. Li, Jie Jack. ''Name Reactions: A Collection of Detailed Reaction Mechanisms''. Springer, 2003. the Merck Index, a chemical encyclopedia, also includes an appendix on name reactions. As organic chemistry developed during the 20th century, chemists started associating synthetically useful reactions with the names of the discoverers or developers; in many cases, the name is merely a mnemonic. Some cases of reactions that were not really ... [...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] |
Aziridines
220 px, chemotherapeutic agent by virtue of its antitumour activity. Aziridines are organic compounds containing the aziridine functional group, a three-membered heterocycle with one amine (-NR-) and two methylene bridges (--). The parent compound is aziridine (or ethylene imine), with molecular formula . Several drugs feature aziridine rings, including mitomycin C, porfiromycin, and azinomycin B (carzinophilin). Structure The bond angles in aziridine are approximately 60°, considerably less than the normal hydrocarbon bond angle of 109.5°, which results in angle strain as in the comparable cyclopropane and ethylene oxide molecules. A banana bond model explains bonding in such compounds. Aziridine is less basic than acyclic aliphatic amines, with a pKa of 7.9 for the conjugate acid, due to increased s character of the nitrogen free electron pair. Angle strain in aziridine also increases the barrier to nitrogen inversion. This barrier height permits the isolation of sepa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Epoxides
In organic chemistry, an epoxide is a cyclic ether () with a three-atom ring. This ring approximates an equilateral triangle, which makes it strained, and hence highly reactive, more so than other ethers. They are produced on a large scale for many applications. In general, low molecular weight epoxides are colourless and nonpolar, and often volatile. Nomenclature A compound containing the epoxide functional group can be called an epoxy, epoxide, oxirane, and ethoxyline. Simple epoxides are often referred to as oxides. Thus, the epoxide of ethylene (C2H4) is ethylene oxide (C2H4O). Many compounds have trivial names; for instance, ethylene oxide is called "oxirane". Some names emphasize the presence of the epoxide functional group, as in the compound ''1,2-epoxyheptane'', which can also be called ''1,2-heptene oxide''. A polymer formed from epoxide precursors is called an ''epoxy'', but such materials do not contain epoxide groups (or contain only a few residual epoxy grou ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Azide
In chemistry, azide is a linear, polyatomic anion with the formula and structure . It is the conjugate base of hydrazoic acid . Organic azides are organic compounds with the formula , containing the azide functional group. The dominant application of azides is as a propellant in air bags. Preparation Sodium azide is made industrially by the reaction of nitrous oxide, with sodium amide in liquid ammonia as solvent: : Many inorganic azides can be prepared directly or indirectly from sodium azide. For example, lead azide, used in detonators, may be prepared from the metathesis reaction between lead nitrate and sodium azide. An alternative route is direct reaction of the metal with silver azide dissolved in liquid ammonia. Some azides are produced by treating the carbonate salts with hydrazoic acid. Bonding Azide is isoelectronic with carbon dioxide , cyanate , nitrous oxide , nitronium ion and cyanogen fluoride NCF. Per valence bond theory, azide can be described ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Triphenylphosphine
Triphenylphosphine (IUPAC name: triphenylphosphane) is a common organophosphorus compound with the formula P(C6H5)3 and often abbreviated to P Ph3 or Ph3P. It is widely used in the synthesis of organic and organometallic compounds. PPh3 exists as relatively air stable, colorless crystals at room temperature. It dissolves in non-polar organic solvents such as benzene and diethyl ether. Preparation and structure Triphenylphosphine can be prepared in the laboratory by treatment of phosphorus trichloride with phenylmagnesium bromide or phenyllithium. The industrial synthesis involves the reaction between phosphorus trichloride, chlorobenzene, and sodium: :PCl3 + 3 PhCl + 6 Na → PPh3 + 6 NaCl Triphenylphosphine crystallizes in triclinic and monoclinic modification. In both cases, the molecule adopts a pyramidal structure with propeller-like arrangement of the three phenyl groups. Principal reactions with chalcogens, halogens, and acids Oxidation Triphenylphosphine undergoes slow ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Staudinger Reaction
The Staudinger reaction is a chemical reaction of an organic azide with a phosphine or phosphite produces an iminophosphorane. The reaction was discovered by and named after Hermann Staudinger. The reaction follows this stoichiometry: :R3P + R'N3 → R3P=NR' + N2 Staudinger reduction The Staudinger reduction is conducted in two steps. First phosphine imine-forming reaction is conducted involving treatment of the azide with the phosphine. The intermediate, e.g. triphenylphosphine phenylimide, is then subjected to hydrolysis to produce a phosphine oxide and an amine: :R3P=NR' + H2O → R3P=O + R'NH2 The overall conversion is a mild method of reducing an azide to an amine. Triphenylphosphine or tributylphosphine are most commonly used, yielding tributylphosphine oxide or triphenylphosphine oxide as a side product in addition to the desired amine. An example of a Staudinger reduction is the organic synthesis of the pinwheel compound 1,3,5-tris(aminomethyl)-2,4,6-triethylbenz ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Iminophosphorane
An ylide or ylid () is a electric charge, neutral Dipole, dipolar molecule containing a formally negatively charged atom (usually a carbanion) directly attached to a heteroatom with a formal positive charge (usually nitrogen, phosphorus or sulfur), and in which both atoms have full octets of electrons. The result can be viewed as a structure in which two adjacent atoms are connected by both a covalent bond, covalent and an ionic bond; normally written X+–Y−. Ylides are thus 1,2-dipolar compounds, and a subclass of zwitterions. They appear in organic chemistry as reagents or reactive intermediates. The class name "ylide" for the compound should not be confused with the suffix "-ylide". Resonance structures Many ylides may be depicted by a multiple bond form in a resonance structure, known as the ylene form, while the actual structure lies in between both forms: : The actual bonding picture of these types of ylides is strictly zwitterionic (the structure on the right) with the s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Name Reactions
A name reaction is a chemical reaction named after its discoverers or developers. Among the tens of thousands of organic reactions that are known, hundreds of such reactions are well-known enough to be named after people. Well-known examples include the Grignard reaction, the Sabatier reaction, the Wittig reaction, the Claisen condensation, the Friedel-Crafts acylation, and the Diels-Alder reaction. Books have been published devoted exclusively to name reactions;Alfred Hassner, C. Stumer. ''Organic syntheses based on name reactions''. Elsevier, 2002. Li, Jie Jack. ''Name Reactions: A Collection of Detailed Reaction Mechanisms''. Springer, 2003. the Merck Index, a chemical encyclopedia, also includes an appendix on name reactions. As organic chemistry developed during the 20th century, chemists started associating synthetically useful reactions with the names of the discoverers or developers; in many cases, the name is merely a mnemonic. Some cases of reactions that were not reall ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
