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Triflic Anhydride
Trifluoromethanesulfonic anhydride, also known as triflic anhydride, is the chemical compound with the formula (CF3SO2)2O. It is the acid anhydride derived from triflic acid. This compound is a strong electrophile, useful for introducing the triflyl group, CF3SO2. Abbreviated Tf2O, triflic anhydride is the acid anhydride of the strong acid triflic acid, CF3SO2OH. Preparation and uses Triflic anhydride is prepared by dehydration of triflic acid using P4O10. Triflic anhydride is useful for converting ketones into enol triflates. In a representative application, is used to convert an imine into a NTf group. It will convert phenols into a triflic ester, which enables cleavage of the C-O bond. Assay The typical impurity in triflic anhydride is triflic acid, which is also a colorless liquid. Samples of triflic anhydride can be assayed by 19F NMR spectroscopy: −72.6 ppm vs. −77.3 for TfOH (std CFCl3). Safety It is an aggressive electrophile and readily hydrolyzes to the strong ac ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chemical Compound
A chemical compound is a chemical substance composed of many identical molecules (or molecular entities) containing atoms from more than one chemical element held together by chemical bonds. A molecule consisting of atoms of only one element is therefore not a compound. A compound can be transformed into a different substance by a chemical reaction, which may involve interactions with other substances. In this process, bonds between atoms may be broken and/or new bonds formed. There are four major types of compounds, distinguished by how the constituent atoms are bonded together. Molecular compounds are held together by covalent bonds; ionic compounds are held together by ionic bonds; intermetallic compounds are held together by metallic bonds; coordination complexes are held together by coordinate covalent bonds. Non-stoichiometric compounds form a disputed marginal case. A chemical formula specifies the number of atoms of each element in a compound molecule, using the s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Triflic Acid
Triflic acid, the short name for trifluoromethanesulfonic acid, TFMS, TFSA, HOTf or TfOH, is a sulfonic acid with the chemical formula CF3SO3H. It is one of the strongest known acids. Triflic acid is mainly used in research as a catalyst for esterification. It is a hygroscopic, colorless, slightly viscous liquid and is soluble in polar solvents. Synthesis Trifluoromethanesulfonic acid is produced industrially by electrochemical fluorination (ECF) of methanesulfonic acid: : CH3SO3H + 4 HF ->CF3SO2F + H2O + 3 H2 The resulting CF3SO2F is hydrolyzed, and the resulting triflate salt is reprotonated. Alternatively, trifluoromethanesulfonic acid arises by oxidation of trifluoromethyl sulfenyl chloride: :CF3SCl + 2 Cl2 + 3 H2O -> CF3SO3H + 5 HCl Triflic acid is purified by distillation from triflic anhydride. Historical Trifluoromethanesulfonic acid was first synthesized in 1954 by Robert Haszeldine and Kidd by the following reaction: : Reactions As an acid In the laboratory, trifl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electrophile
In chemistry, an electrophile is a chemical species that forms bonds with nucleophiles by accepting an electron pair. Because electrophiles accept electrons, they are Lewis acids. Most electrophiles are positively charged, have an atom that carries a partial positive charge, or have an atom that does not have an octet of electrons. Electrophiles mainly interact with nucleophiles through addition and substitution reactions. Frequently seen electrophiles in organic syntheses include cations such as H+ and NO+, polarized neutral molecules such as HCl, alkyl halides, acyl halides, and carbonyl compounds, polarizable neutral molecules such as Cl2 and Br2, oxidizing agents such as organic peracids, chemical species that do not satisfy the octet rule such as carbenes and radicals, and some Lewis acids such as BH3 and DIBAL. Organic chemistry Addition of halogens These occur between alkenes and electrophiles, often halogens as in halogen addition reactions. Common reactions i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trifluoromethylsulfonyl
In organic chemistry, the triflyl group (systematic name: trifluoromethanesulfonyl group) is a functional group with the formula and structure . The triflyl group is often represented by –Tf. The related triflate group (trifluoromethanesulfonate) has the formula , and is represented by –OTf. See also * Triflyl azide, TfN3 * Trioctylmethylammonium bis(trifluoromethylsulfonyl)imide, * Comins' reagent * Bis(trifluoromethanesulfonyl)aniline * Triflic anhydride Trifluoromethanesulfonic anhydride, also known as triflic anhydride, is the chemical compound with the formula (CF3SO2)2O. It is the acid anhydride derived from triflic acid. This compound is a strong electrophile, useful for introducing the trif ... (CF3SO2)2O is a very strong triflating agent. References {{organic-chemistry-stub Triflyl compounds Functional groups ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acid Anhydride
An acid anhydride is a type of chemical compound derived by the removal of water molecules from an acid. In organic chemistry, organic acid anhydrides contain the functional group R(CO)O(CO)R'. Organic acid anhydrides often form when one equivalent of water is removed from two equivalents of an organic acid in a dehydration reaction. In inorganic chemistry, an acid anhydride refers to an acidic oxide, an oxide that reacts with water to form an oxyacid (an inorganic acid that contains oxygen or carbonic acid), or with a base to form a salt. Nomenclature The nomenclature of organic acid anhydrides is derived from the names of the constituent carboxylic acids which underwent dehydration to form the compound. In symmetrical acid anhydrides, where only one constituent carboxylic acid was used to form the compound (such as the dehydration of propanoic acid, 2CH3CH2COOH → CH3CH2C(O)OC(O)CH2CH3 + H2O), only the prefix of the original carboxylic acid is used and the suffix "anhydride" ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phenol
Phenol (also called carbolic acid) is an aromatic organic compound with the molecular formula . It is a white crystalline solid that is volatile. The molecule consists of a phenyl group () bonded to a hydroxy group (). Mildly acidic, it requires careful handling because it can cause chemical burns. Phenol was first extracted from coal tar, but today is produced on a large scale (about 7 billion kg/year) from petroleum-derived feedstocks. It is an important industrial commodity as a precursor to many materials and useful compounds. It is primarily used to synthesize plastics and related materials. Phenol and its chemical derivatives are essential for production of polycarbonates, epoxies, Bakelite, nylon, detergents, herbicides such as phenoxy herbicides, and numerous pharmaceutical drugs. Properties Phenol is an organic compound appreciably soluble in water, with about 84.2 g dissolving in 1000 mL (0.895 M). Homogeneous mixtures of phenol and water at phenol ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Methanesulfonic Anhydride
Methanesulfonic anhydride (Ms2O) is the acid anhydride of methanesulfonic acid. Like methanesulfonyl chloride (MsCl), it may be used to generate mesylates (methanesulfonyl esters). Preparation & purification Ms2O may be prepared by the dehydration of methanesulfonic acid with phosphorus pentoxide. :P2O5 + 6 CH3SO3H → 3 (CH3SO2)2O + 2 H3PO4 Ms2O can be purified by distillation under vacuum (distillation of a solid) or by recrystallized from Methyl tert-butyl ether/toluene. Reactions & Applications in synthesis Passage of hydrogen chloride through molten Ms2O yields MsCl. Similar to MsCl, Ms2O can perform mesylation of alcohols to form sulfonates. Use of Ms2O avoids the alkyl chloride, which often appears as a side-product when MsCl is used. Unlike MsCl, Ms2O may not be suitable for mesylation of the unsaturated alcohols. Examples of mesylation of alcohols with Ms2O: * Octadecyl methanesulfonate was prepared from octadecanol in pyridine. * Secondary alcohol at the anomeric c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Triflyl Compounds
In organic chemistry, the triflyl group (systematic name: trifluoromethanesulfonyl group) is a functional group with the formula and structure . The triflyl group is often represented by –Tf. The related triflate group (trifluoromethanesulfonate) has the formula , and is represented by –OTf. See also * Triflyl azide, TfN3 * Trioctylmethylammonium bis(trifluoromethylsulfonyl)imide, * Comins' reagent * Bis(trifluoromethanesulfonyl)aniline * Triflic anhydride Trifluoromethanesulfonic anhydride, also known as triflic anhydride, is the chemical compound with the formula (CF3SO2)2O. It is the acid anhydride derived from triflic acid. This compound is a strong electrophile, useful for introducing the trif ... (CF3SO2)2O is a very strong triflating agent. References {{organic-chemistry-stub Triflyl compounds Functional groups ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acid Anhydrides
An organic acid anhydride is an acid anhydride that is an organic compound. An acid anhydride is a compound that has two acyl groups bonded to the same oxygen atom. A common type of organic acid anhydride is a carboxylic anhydride, where the parent acid is a carboxylic acid, the formula of the anhydride being (RC(O))2O. Symmetrical acid anhydrides of this type are named by replacing the word ''acid'' in the name of the parent carboxylic acid by the word ''anhydride''. Thus, (CH3CO)2O is called ''acetic anhydride.'' Mixed (or unsymmetrical) acid anhydrides, such as acetic formic anhydride (see below), are known, whereby reaction occurs between two different carboxylic acids. Nomenclature of unsymmetrical acid anhydrides list the names of both of the reacted carboxylic acids before the word "anhydride" (for example, the dehydration reaction between benzoic acid and propanoic acid would yield "benzoic propanoic anhydride"). One or both acyl groups of an acid anhydride may also be ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
