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Dithiol
In organic chemistry, a dithiol is a type of organosulfur compound with two thiol () functional groups. Their properties are generally similar to those of monothiols in terms of solubility, odor, and volatility. They can be classified according to the relative location of the two thiol groups on the organic backbone. File:C6H4(SH)2.svg, Benzene-1,2-dithiol, the parent aromatic dithiol File:1,3-Propandithiol Structural Formula V1.svg, Propane-1,3-dithiol File:Meso-2,3-dimercaptosuccinic-acid-2D-skeletal-A-configurations-labelled.png, The drug meso-2,3-dimercaptosuccinic acid File:Dimercaprol.svg, Dimercaprol ("British anti-Lewisite"), an early antidote for arsenic poisoning File:Dihydrolipoic-acid-2D-skeletal.png, Dihydrolipoic acid, a vitamin File:Dithiothreitol.png, Dithiothreitol, a reagent in protein biochemistry Geminal dithiols Geminal dithiols have the formula RR'C(SH)2. They are derived from aldehydes and ketones by the action of hydrogen sulfide. Their stability con ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Geminal Dithiol
In organic chemistry, a dithiol is a type of organosulfur compound with two thiol () functional groups. Their properties are generally similar to those of monothiols in terms of solubility, odor, and volatility. They can be classified according to the relative location of the two thiol groups on the organic backbone. File:C6H4(SH)2.svg, Benzene-1,2-dithiol, the parent aromatic dithiol File:1,3-Propandithiol Structural Formula V1.svg, Propane-1,3-dithiol File:Meso-2,3-dimercaptosuccinic-acid-2D-skeletal-A-configurations-labelled.png, The drug meso-2,3-dimercaptosuccinic acid File:Dimercaprol.svg, Dimercaprol ("British anti-Lewisite"), an early antidote for arsenic poisoning File:Dihydrolipoic-acid-2D-skeletal.png, Dihydrolipoic acid, a vitamin File:Dithiothreitol.png, Dithiothreitol, a reagent in protein biochemistry Geminal dithiols Geminal dithiols have the formula RR'C(SH)2. They are derived from aldehydes and ketones by the action of hydrogen sulfide. Their stability c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ethane-1,2-dithiol
Ethane-1,2-dithiol, also known as EDT, is a colorless liquid with the formula C H( SH). It has a very characteristic odor which is compared by many people to rotten cabbage. It is a common building block in organic synthesis and an excellent ligand for metal ions. Preparation Ethane-1,2-dithiol is made commercially by the reaction of 1,2-dichloroethane with aqueous sodium bisulfide. In the laboratory, it can also be prepared by the action of 1,2-dibromoethane on thiourea followed by hydrolysis. Applications As a 1,2-dithiol, this compound is widely used in organic chemistry because it reacts with aldehydes and ketones to give 1,3-dithiolanes, which are useful intermediates. R. E. Conrow "Ethanedithiol" in Encyclopedia of Reagents for Organic Synthesis (Ed: L. Paquette) 2004, J. Wiley & Sons, New York. ::CH(SH) + RR'CO → CHSCRR' + HO Other 1,2- and 1,3-dithiols undergo this reaction to give related 1,3-dithiolanes and 1,3-dithianes (six-membered rings). Diols such as ethy ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ethane-1,1-dithiol
Ethane-1,1-dithiol is an organosulfur compound with formula CH3CH(SH)2. It is a colourless smelly liquid that is added to or found in some foods. The compound is an example of a geminal dithiol. Use Flavouring uses of ethane-1,1-dithiol may include drinks, oil, gravy, soup, meat, fruit, seasonings, and snacks. Maximum concentrations in use that are generally recognised as safe (GRAS) is five parts per million (ppm) but typical uses are around 0.2 ppm. It is supplied as a 1% solution in ethanol, due to its strong offensive smell. In the diluted form with 4% ethyl acetate and ethanol the CAS number is 69382-62-3. Toxicity may be due to metabolism products hydrogen sulfide and acetaldehyde, however as used it has a margin of safety of over 10,000,000. Other ways that it is modified in the body apart from hydrolysis is methylation to 1-methylsulfanyl-ethanethiol, oxidation of the sulfur to an ethyl sulfonate, glucuronidation of the sulfur, or combination with cysteine by way of a d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Propane-1,3-dithiol
1,3-Propanedithiol is the chemical compound with the formula HSCH2CH2CH2SH. This dithiol is a useful reagent in organic synthesis. This liquid, which is readily available commercially, has an intense stench. Use in organic synthesis 1,3-Propanedithiol is mainly used for the protection of aldehydes and ketones via their reversible formation of dithianes. A prototypical reaction is its formation of 1,3-dithiane from formaldehyde. The reactivity of this dithiane illustrates the concept of umpolung. Alkylation gives thioethers, e.g. 1,5-dithiacyclooctane. The unpleasant odour of 1,3-propanedithiol has encouraged the development of alternative reagents that generate similar derivatives. 1,3-Propanedithiol is used in the synthesis of tiapamil. Use in inorganic synthesis 1,3-Propanedithiol reacts with metal ions to form chelate rings. Illustrative is the synthesis of the derivative diiron propanedithiolate hexacarbonyl upon reaction with triiron dodecacarbonyl: :Fe3(CO)12 + C ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sodium 1,3-dithiole-2-thione-4,5-dithiolate
Sodium 1,3-dithiole-2-thione-4,5-dithiolate is the organosulfur compound with the formula Na2C3S5, abbreviated Na2dmit. It is the sodium salt of the conjugate base of the 1,3-dithiole-2-thione-4,5-dithiol. The salt is a precursor to dithiolene complexes and tetrathiafulvalenes. Reduction of carbon disulfide with sodium affords sodium 1,3-dithiole-2-thione-4,5-dithiolate together with sodium trithiocarbonate: : 4 Na + 4 CS2 → Na2C3S5 + Na2CS3 Before the characterization of dmit2-, reduction of CS2 was thought to give tetrathiooxalate (Na2C2S4). The dianion C3S52- is purified as the tetraethylammonium salt of the zincate complex n(C3S5)2sup>2-. This salt converts to the bis(thioester) upon treatment with benzoyl chloride: : (C2H5)4sub>2 n(C3S5)2 + 4 C6H5COCl → 2 C3S3(SC(O)C6H5)2 + (C2H5)4sub>2 nCl4Cleavage of the thioester with sodium methoxide Sodium methoxide is the simplest sodium alkoxide. With the formula , it is a white solid, which is formed ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1,2-Benzenedithiol
Benzene-1,2-dithiol is the organosulfur compound with the formula CH(SH). This colourless viscous liquid consists of a benzene ring with a pair of adjacent thiol groups. The conjugate base of this diprotic compound serves as chelating agent in coordination chemistry and a building block for the synthesis of other organosulfur compounds.Karlin, K. D.; Stiefel, E. I., Eds. “Progress in Inorganic Chemistry, Dithiolene Chemistry: Synthesis, Properties, and Applications” Wiley-Interscience: New York, 2003. Synthesis The compound is prepared by ortho-lithiation of benzenethiol using butyl lithium (BuLi) followed by sulfidation: :CHSH + 2 BuLi → CHSLi-2-Li + 2 BuH :CHSLi-2-Li + S → CH(SLi) :CH(SLi) + 2 HCl → CH(SH) + 2 LiCl The compound was first prepared from 2-aminobenzenethiol via diazotization. Alternatively, it forms from 1,2-dibromobenzene. Reactions Oxidation mainly affords the polymeric disulfide. Reaction with metal dihalides and metal oxides gives the dithiolate ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Benzene-1,2-dithiol
Benzene-1,2-dithiol is the organosulfur compound with the formula CH(SH). This colourless viscous liquid consists of a benzene ring with a pair of adjacent thiol groups. The conjugate base of this diprotic compound serves as chelating agent in coordination chemistry and a building block for the synthesis of other organosulfur compounds.Karlin, K. D.; Stiefel, E. I., Eds. “Progress in Inorganic Chemistry, Dithiolene Chemistry: Synthesis, Properties, and Applications” Wiley-Interscience: New York, 2003. Synthesis The compound is prepared by ortho-lithiation of benzenethiol using butyl lithium (BuLi) followed by sulfidation: :CHSH + 2 BuLi → CHSLi-2-Li + 2 BuH :CHSLi-2-Li + S → CH(SLi) :CH(SLi) + 2 HCl → CH(SH) + 2 LiCl The compound was first prepared from 2-aminobenzenethiol via diazotization. Alternatively, it forms from 1,2-dibromobenzene. Reactions Oxidation mainly affords the polymeric disulfide. Reaction with metal dihalides and metal oxides gives the dithiolate ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Methanedithiol
Methanedithiol is an organosulfur compound with the formula H2C(SH)2. It forms when formaldehyde Formaldehyde ( , ) (systematic name methanal) is a naturally occurring organic compound with the formula and structure . The pure compound is a pungent, colourless gas that polymerises spontaneously into paraformaldehyde (refer to section Fo ... is treated with hydrogen sulfide under pressure. The reaction competes with formation of trithiane. The compound forms a solid dibenzoate upon treatment with benzoic anhydride.{{cite journal, title=gem-Dithiols, authors=Cairns, T. L.; Evans, G. L.; Larchar, A. W.; McKusick, B. C., journal=Journal of the American Chemical Society, year=1952, volume=74, issue=16, pages=3982–9, doi=10.1021/ja01136a004 References Thiols Functional groups Organosulfur compounds Foul-smelling chemicals ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dithiane
A dithiane is a heterocyclic compound composed of a cyclohexane core structure wherein two methylene bridges (-- units) are replaced by sulfur centres. The three isomeric parent heterocycles are 1,2-dithiane, 1,3-dithiane and 1,4-dithiane. 1,3-Dithianes 1,3-Dithianes are protecting group of some carbonyl-containing compounds due to their inertness to many conditions. They form by treatment of the carbonyl compound with 1,3-propanedithiol under conditions that remove water from the system. The protecting group can be removed with mercuric reagents, a process that exploits the high affinity of Hg(II) for thiolates. 1,3-Dithianes are also employed in umpolung reactions, such as the Corey–Seebach reaction:T. W. Green, P. G. M. Wuts, "Protective Groups in Organic Synthesis" Wiley-Interscience, New York, 1999. . : Typically, in organic synthesis, ketones and aldehydes are protected as their dioxolane Dioxolane is a heterocyclic acetal with the chemical formula (CH2)2O ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chelation Therapy
Chelation therapy is a medical procedure that involves the administration of chelating agents to remove heavy metals from the body. Chelation therapy has a long history of use in clinical toxicology and remains in use for some very specific medical treatments, although it is administered under very careful medical supervision due to various inherent risks, including the mobilization of mercury and other metals through the brain and other parts of the body by the use of weak chelating agents that unbind with metals before elimination, exacerbating existing damage. To avoid mobilization, some practitioners of chelation use strong chelators, such as selenium, taken at low doses over a long period of time. Chelation therapy must be administered with care as it has a number of possible side effects, including death. In response to increasing use of chelation therapy as alternative medicine and in circumstances in which the therapy should not be used in conventional medicine, vario ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Umpolung
In organic chemistry, umpolung () or polarity inversion is the chemical modification of a functional group with the aim of the reversal of polarity of that group. This modification allows secondary reactions of this functional group that would otherwise not be possible. The concept was introduced by D. Seebach (hence the German word for reversed polarity) and E.J. Corey. Polarity analysis during retrosynthetic analysis tells a chemist when umpolung tactics are required to synthesize a target molecule. Introduction The vast majority of important organic molecules contain heteroatoms, which polarize carbon skeletons by virtue of their electronegativity. Therefore, in standard organic reactions, the majority of new bonds are formed between atoms of opposite polarity. This can be considered to be the "normal" mode of reactivity. One consequence of this natural polarization of molecules is that 1,3- and 1,5- heteroatom substituted carbon skeletons are extremely easy to synthesize ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dihydrolipoic Acid
Dihydrolipoic acid is an organic compound that is the reduced form of lipoic acid. This carboxylic acid features a pair of thiol groups, and therefore is a dithiol. It is optically active, but only the R-enantiomer is biochemically significant. The lipoic acid/dihydrolipoic acid pair participate in a variety of biochemical transformations. See also * Dihydrolipoamide * Lipoamide Lipoamide is a trivial name for 6,8-dithiooctanoic amide. It is the functional form of lipoic acid, i.e the carboxyl group is attached to protein via an amine with an amide linkage. Illustrative of the biochemical role of lipoamide is in the conv ... References {{Reflist Carboxylic acids Thiols ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
