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Sulfonate
In organosulfur chemistry, a sulfonate is a salt or ester of a sulfonic acid. It contains the functional group , where R is an organic group. Sulfonates are the conjugate bases of sulfonic acids. Sulfonates are generally stable in water, non-oxidizing, and colorless. Many useful compounds and even some biochemicals feature sulfonates. Sulfonate salts Anions with the general formula are called sulfonates. They are the conjugate bases of sulfonic acids with formula . As sulfonic acids tend to be strong acids, the corresponding sulfonates are weak bases. Due to the stability of sulfonate anions, the cations of sulfonate salts such as scandium triflate have application as Lewis acids. A classic preparation of sulfonates is the Strecker sulfite alkylation, in which an alkali sulfite salt displaces a halide, typically in the presence of an iodine catalyst: :RX + M2SO3 -> RSO3M + MX An alternative is the condensation of a sulfonyl halide with an alcohol in pyridine: :ROH + ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sulfonate Anion Tet
In organosulfur chemistry, a sulfonate is a salt or ester of a sulfonic acid. It contains the functional group , where R is an organic group. Sulfonates are the conjugate bases of sulfonic acids. Sulfonates are generally stable in water, non-oxidizing, and colorless. Many useful compounds and even some biochemicals feature sulfonates. Sulfonate salts Anions with the general formula are called sulfonates. They are the conjugate bases of sulfonic acids with formula . As sulfonic acids tend to be strong acids, the corresponding sulfonates are weak bases. Due to the stability of sulfonate anions, the cations of sulfonate salts such as scandium triflate have application as Lewis acids. A classic preparation of sulfonates is the Strecker sulfite alkylation, in which an alkali sulfite salt displaces a halide, typically in the presence of an iodine catalyst: :RX + M2SO3 -> RSO3M + MX An alternative is the condensation of a sulfonyl halide with an alcohol in pyridine: :ROH + ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sulfonic Acid
In organic chemistry, sulfonic acid (or sulphonic acid) refers to a member of the class of organosulfur compounds with the general formula , where R is an organic alkyl or aryl group and the group a sulfonyl hydroxide. As a substituent, it is known as a sulfo group. A sulfonic acid can be thought of as sulfuric acid with one hydroxyl group replaced by an organic substituent. The parent compound (with the organic substituent replaced by hydrogen) is the parent sulfonic acid, , a tautomer of sulfurous acid, . Salts or esters of sulfonic acids are called sulfonates. Preparation Aryl sulfonic acids are produced by the process of sulfonation. Usually the sulfonating agent is sulfur trioxide. A large scale application of this method is the production of alkylbenzenesulfonic acids: :RC6H5 + SO3 -> RC6H4SO3H In this reaction, sulfur trioxide is an electrophile and the arene is the nucleophile. The reaction is an example of electrophilic aromatic substitution. Alkylsulfonic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Methyl Trifluoromethanesulfonate
Methyl trifluoromethanesulfonate, also commonly called methyl triflate and abbreviated MeOTf, is the organic compound with the formula CF3SO2OCH3. It is a colourless liquid which finds use in organic chemistry as a powerful methylating agent. The compound is closely related to methyl fluorosulfonate (FSO2OCH3). Although there has yet to be a reported human fatality, several cases were reported for methyl fluorosulfonate (LC50 (rat, 1 h) = 5 ppm), and methyl triflate is expected to have similar toxicity based on available evidence. Synthesis Methyl triflate is commercially available, however it may also be prepared in the laboratory by treating dimethyl sulfate with triflic acid. :CF3SO2OH + (CH3O)2SO2 → CF3SO2OCH3 + CH3OSO2OH Reactivity Hydrolysis Upon contact with water, methyl triflate loses its methyl group, forming triflic acid and methanol: :CF3SO2OCH3 + H2O → CF3SO2OH + CH3OH Methylation One ranking of methylating agents is (CH3)3O+ > CF3SO2OCH3 ≈ FSO2OCH ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Methyl Triflate
Methyl trifluoromethanesulfonate, also commonly called methyl triflate and abbreviated MeOTf, is the organic compound with the formula CF3SO2OCH3. It is a colourless liquid which finds use in organic chemistry as a powerful methylating agent. The compound is closely related to methyl fluorosulfonate (FSO2OCH3). Although there has yet to be a reported human fatality, several cases were reported for methyl fluorosulfonate (LC50 (rat, 1 h) = 5 ppm), and methyl triflate is expected to have similar toxicity based on available evidence. Synthesis Methyl triflate is commercially available, however it may also be prepared in the laboratory by treating dimethyl sulfate with triflic acid. :CF3SO2OH + (CH3O)2SO2 → CF3SO2OCH3 + CH3OSO2OH Reactivity Hydrolysis Upon contact with water, methyl triflate loses its methyl group, forming triflic acid and methanol: :CF3SO2OCH3 + H2O → CF3SO2OH + CH3OH Methylation One ranking of methylating agents is (CH3)3O+ > CF3SO2OCH3 ≈ FSO2OC ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1,4-Butane Sultone
1,4-butane sultone is a six-membered δ-sultone and the cyclic ester of 4-hydroxybutanesulfonic acid. As a sulfo-alkylating agent, 1,4-butanesultone is used to introduce the sulfobutyl group (–(CH2)4–SO3−) into hydrophobic compounds possessing nucleophilic functional groups, for example hydroxy groups (as in the case of β-cyclodextrin) or amino groups (as in the case of polymethine dyes). In such, the sulfobutyl group is present as neutral sodium salt and considerably increases the water solubility of the derivatives. Preparation A lab scale synthesis of 1,4-butanesultone starts from 4,4'-dichlorodibutyl ether (accessible from tetrahydrofuran treated with phosphorus oxychloride and concentrated sulfuric acid), which reacts with sodium sulfite forming the corresponding 4,4'-butanedisulfonic disodium salt. By passing it through an acidic ion exchanger, the disodium salt is converted into the disulphonic acid which forms two molecules of 1,4-butanesultone at elevated tem ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Scandium Triflate
Scandium trifluoromethanesulfonate, commonly called scandium triflate, is a chemical compound with formula Sc(SO3CF3)3, a salt consisting of scandium cations Sc3+ and triflate anions. Scandium triflate is used as a reagent in organic chemistry as a Lewis acid. Compared to other Lewis acids, this reagent is stable towards water and can often be used in organic reactions as a true catalyst rather than one used in stoichiometric amounts. The compound is prepared by reaction of scandium oxide with trifluoromethanesulfonic acid. An example of the scientific use of scandium triflate is the Mukaiyama aldol addition reaction between benzaldehyde and the silyl enol ether Silyl enol ethers in organic chemistry are a class of organic compounds that share a common functional group composed of an enolate bonded through its oxygen end to an organosilicon group. They are important intermediates in organic synthesis. Sy ... of cyclohexanone with an 81% yield. : See also * Lanth ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Functional Group
In organic chemistry, a functional group is a substituent or moiety in a molecule that causes the molecule's characteristic chemical reactions. The same functional group will undergo the same or similar chemical reactions regardless of the rest of the molecule's composition. This enables systematic prediction of chemical reactions and behavior of chemical compounds and the design of chemical synthesis. The reactivity of a functional group can be modified by other functional groups nearby. Functional group interconversion can be used in retrosynthetic analysis to plan organic synthesis. A functional group is a group of atoms in a molecule with distinctive chemical properties, regardless of the other atoms in the molecule. The atoms in a functional group are linked to each other and to the rest of the molecule by covalent bonds. For repeating units of polymers, functional groups attach to their nonpolar core of carbon atoms and thus add chemical character to carbon chains. F ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Leaving Group
In chemistry, a leaving group is defined by the IUPAC as an atom or group of atoms that detaches from the main or residual part of a substrate during a reaction or elementary step of a reaction. However, in common usage, the term is often limited to a fragment that departs with a pair of electrons in heterolytic bond cleavage. In this usage, a leaving group is a less formal but more commonly used synonym of the term '' nucleofuge''. In this context, leaving groups are generally anions or neutral species, departing from a neutral or cationic substrates, respectively, though in rare cases, cations leaving from a dicationic substrate are also known. A species' ability to serve as a leaving group depends on its ability to stabilize the additional electron density that results from bond heterolysis. Common anionic leaving groups are halides such as Cl−, Br−, and I−, and sulfonate esters such as tosylate (TsO−), while water (H2O), alcohols (HOR), and amines (R3N) are common neu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Organosulfur Chemistry
Organosulfur compounds are organic compounds that contain sulfur. They are often associated with foul odors, but many of the sweetest compounds known are organosulfur derivatives, e.g., saccharin. Nature abounds with organosulfur compounds—sulfur is vital for life. Of the 20 common amino acids, two (cysteine and methionine) are organosulfur compounds, and the antibiotics penicillin and sulfa drugs both contain sulfur. While sulfur-containing antibiotics save many lives, sulfur mustard is a deadly chemical warfare agent. Fossil fuels, coal, petroleum, and natural gas, which are derived from ancient organisms, necessarily contain organosulfur compounds, the removal of which is a major focus of oil refineries. Sulfur shares the chalcogen group with oxygen, selenium, and tellurium, and it is expected that organosulfur compounds have similarities with carbon–oxygen, carbon–selenium, and carbon–tellurium compounds. A classical chemical test for the detection of sulfur compounds ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ester
In chemistry, an ester is a compound derived from an oxoacid (organic or inorganic) in which at least one hydroxyl group () is replaced by an alkoxy group (), as in the substitution reaction of a carboxylic acid and an alcohol. Glycerides are fatty acid esters of glycerol; they are important in biology, being one of the main classes of lipids and comprising the bulk of animal fats and vegetable oils. Esters typically have a pleasant smell; those of low molecular weight are commonly used as fragrances and are found in essential oils and pheromones. They perform as high-grade solvents for a broad array of plastics, plasticizers, resins, and lacquers, and are one of the largest classes of synthetic lubricants on the commercial market. Polyesters are important plastics, with monomers linked by ester moieties. Phosphoesters form the backbone of DNA molecules. Nitrate esters, such as nitroglycerin, are known for their explosive properties. '' Nomenclature Etymology ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oxime
In organic chemistry, an oxime is a organic compound belonging to the imines, with the general formula , where R is an organic side-chain and R’ may be hydrogen, forming an aldoxime, or another organic group, forming a ketoxime. O-substituted oximes form a closely related family of compounds. Amidoximes are oximes of amides () with general structure . Oximes are usually generated by the reaction of hydroxylamine with aldehydes () or ketones (). The term ''oxime'' dates back to the 19th century, a combination of the words ''oxygen'' and ''imine''. Structure and properties If the two side-chains on the central carbon are different from each other—either an aldoxime, or a ketoxime with two different "R" groups—the oxime can often have two different geometric stereoisomeric forms according to the ''E''/''Z'' configuration. An older terminology of ''syn'' and ''anti'' was used to identify especially aldoximes according to whether the R group was closer or further from the hy ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Propane-1,3-sultone
1,3-Propane sultone is the organosulfur compound with the formula (CH2)3SO3. It is a cyclic sulfonate ester, a class of compounds called sultones. It is a readily melting colorless solid. Synthesis It may be prepared by the acid catalyzed reaction of allyl alcohol and sodium bisulfite. Reactions 1,3-propane sultone is an activated ester and is susceptible to nucleophilic attack. It hydrolyzes to the acid. : It has been used in the synthesis of specialist surfactants, such as CHAPS detergent. Safety Typical of activated esters, 1,3-propane sultone is an alkylating agent. 1,3-Propane sultone is toxic, carcinogenic, mutagenic, and teratogenic. See also * 1,4-Butane sultone * Dimethyl sulfate * Vinylsulfonic acid * Isethionic acid * Sulfolane Sulfolane (also ''tetramethylene sulfone'', systematic name: 1λ6-thiolane-1,1-dione) is an organosulfur compound, formally a cyclic sulfone, with the formula (CH2)4SO2. It is a colorless liquid commonly used in the chemical industry ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
