|
Sodium Tert-butoxide
Sodium ''tert''-butoxide is the chemical compound with the formula (CH3)3CONa. It is a strong base and a non-nucleophilic base. It is flammable and moisture sensitive. It is sometimes written in chemical literature as sodium ''t''-butoxide. It is similar in reactivity to the more common potassium ''tert''-butoxide. The compound can be produced by treating ''tert''-butyl alcohol with sodium hydride. Reactions One application for sodium ''tert''-butoxide is as a non-nucleophilic base. It has been widely used in the Buchwald–Hartwig amination, as in this typical example: Sodium tert-butoxide is used to prepare tert-butoxide complexes. For example hexa(tert-butoxy)ditungsten(III) Hexa(''tert''-butoxy)ditungsten(III) is a coordination complex of tungsten(III). It is one of the homoleptic alkoxides of tungsten. A red, air-sensitive solid, the complex has attracted academic attention as the precursor to many organotungsten ... is thus converted by the salt metathesis react ... [...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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Zeitschrift Für Anorganische Und Allgemeine Chemie
The ''Zeitschrift für anorganische und allgemeine Chemie'' (''Journal of Inorganic and General Chemistry'') is a semimonthly peer-reviewed scientific journal covering inorganic chemistry, published by Wiley-VCH. The editors-in-chief are Thomas F. Fässler, Christian Limberg, Guodong Qian, and David Scheschkewitz. Originally the journal was published in German, but nowadays it is completely in English. Abstracting and indexing The journal is abstracted and indexed in the following databases: According to the ''Journal Citation Reports'', the journal has a 2021 impact factor The impact factor (IF) or journal impact factor (JIF) of an academic journal is a scientometric index calculated by Clarivate that reflects the yearly mean number of citations of articles published in the last two years in a given journal, as ... of 1.414, ranking it 40th out of 46 journals in the category "Chemistry, Inorganic & Nuclear". References External links * Chemistry journals Wiley-VC ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Non-nucleophilic Bases
As the name suggests, a non-nucleophilic base is a sterically hindered organic base that is a poor nucleophile. Normal bases are also nucleophiles, but often chemists seek the proton-removing ability of a base without any other functions. Typical non-nucleophilic bases are bulky, such that protons can attach to the basic center but alkylation and complexation is inhibited. Non-nucleophilic bases A variety of amines and nitrogen heterocycles are useful bases of moderate strength (pKa of conjugate acid * ''N'',''N''-Diisopropylethylamine (DIPEA, also called Hünig's Base), p * 1,8-Diazabicycloundec-7-ene (DBU) - useful for E2 elimination reactions, pKa = 13.5 * 1,5-Diazabicyclo(4.3.0)non-5-ene (DBN) - comparable to DBU * 2,6-Di-tert-butylpyridine, a weak non-nucleophilic base pKa = 3.58 * Phosphazene bases, such as t-Bu-P4''Activation in anionic polymerization: Why phosphazene bases are very exciting promoters'' S. Boileau, N. Illy Prog. Polym. Sci., 2011, 36, 1132-1151, {{doi, 10. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Reagents For Organic Chemistry
In chemistry, a reagent ( ) or analytical reagent is a substance or compound added to a system to cause a chemical reaction, or test if one occurs. The terms ''reactant'' and ''reagent'' are often used interchangeably, but reactant specifies a substance ''consumed'' in the course of a chemical reaction. ''Solvents'', though involved in the reaction mechanism, are usually not called reactants. Similarly, '' catalysts'' are not consumed by the reaction, so they are not reactants. In biochemistry, especially in connection with enzyme-catalyzed reactions, the reactants are commonly called substrates. Definitions Organic chemistry In organic chemistry, the term "reagent" denotes a chemical ingredient (a compound or mixture, typically of inorganic or small organic molecules) introduced to cause the desired transformation of an organic substance. Examples include the Collins reagent, Fenton's reagent, and Grignard reagents. Analytical chemistry In analytical chemistry, a reage ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alkoxides
In chemistry, an alkoxide is the conjugate base of an alcohol and therefore consists of an organic group bonded to a negatively charged oxygen atom. They are written as , where R is the organic substituent. Alkoxides are strong bases and, when R is not bulky, good nucleophiles and good ligands. Alkoxides, although generally not stable in protic solvents such as water, occur widely as intermediates in various reactions, including the Williamson ether synthesis. Transition metal alkoxides are widely used for coatings and as catalysts. Enolates are unsaturated alkoxides derived by deprotonation of a bond adjacent to a ketone or aldehyde. The nucleophilic center for simple alkoxides is located on the oxygen, whereas the nucleophilic site on enolates is delocalized onto both carbon and oxygen sites. Ynolates are also unsaturated alkoxides derived from acetylenic alcohols. Phenoxides are close relatives of the alkoxides, in which the alkyl group is replaced by a derivative o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lithium Tert-butoxide
Lithium ''tert''-butoxide is the metalloorganic compound with the formula LiOC(CH3)3. A white solid, it is used as a strong base in organic synthesis. The compound is often depicted as a salt, and it often behaves as such, but it is not ionized in solution. Both octameric and hexameric forms have been characterized by X-ray crystallography Preparation Lithium ''tert''-butoxide is commercially available as a solution and as a solid, but it is often generated ''in situ'' for laboratory use because samples are so sensitive and older samples are often of poor quality. It can be obtained by treating tert-butanol with butyl lithium. Reactions As a strong base, lithium ''tert''-butoxide is easily protonated. Lithium ''tert''-butoxide is used to prepare other ''tert''-butoxide compounds such as copper(I) t-butoxide and hexa(tert-butoxy)dimolybdenum(III): :2 MoCl3(thf)3 + 6 LiOBu-t → Mo2(OBu-t)6 + 6 LiCl + 6 thf Related compounds *Sodium tert-butoxide Sodium ''tert''-b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Potassium Tert-butoxide
Potassium ''tert''-butoxide is the chemical compound with the formula K+(CH3)3CO−. This colourless solid is a strong base (pKa of conjugate acid around 17), which is useful in organic synthesis. It exists as a tetrameric cubane-type cluster. It is often seen written in chemical literature as potassium ''t''-butoxide. The compound is often depicted as a salt, and it often behaves as such, but it is not ionized in solution. Preparation Potassium ''t''-butoxide is commercially available as a solution and as a solid, but it is often generated ''in situ'' for laboratory use because samples are so sensitive and older samples are often of poor quality. It is prepared by the reaction of dry ''tert''-butyl alcohol with potassium metal. The solid is obtained by evaporating these solutions followed by heating the solid. The solid can be purified by sublimation at 220 °C and 1 mmHg. Sublimation can also take place at 140 °C and 0.01 hPa. It is advisable to cover the r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dalton Transactions
''Dalton Transactions'' is a peer-reviewed scientific journal publishing original (primary) research and review articles on all aspects of the chemistry of inorganic, bioinorganic, and organometallic compounds. It is published weekly by the Royal Society of Chemistry. The journal was named after the English chemist, John Dalton, best known for his work on modern atomic theory. Authors can elect to have accepted articles published as open access. The editor is Andrew Shore. ''Dalton Transactions'' was named a "rising star" by ''In-cites'' from Thomson Scientific in 2006. Publication history The journal was established as the ''Journal of the Chemical Society A: Inorganic, Physical, Theoretical'' in 1966. In 1972, the journal was divided into three separate journals: ''Journal of the Chemical Society, Dalton Transactions'' (covering inorganic and organometallic chemistry), '' Journal of the Chemical Society, Faraday Transactions 1: Physical Chemistry in Condensed Phases'', and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chemical Formula
In chemistry, a chemical formula is a way of presenting information about the chemical proportions of atoms that constitute a particular chemical compound or molecule, using chemical element symbols, numbers, and sometimes also other symbols, such as parentheses, dashes, brackets, commas and ''plus'' (+) and ''minus'' (−) signs. These are limited to a single typographic line of symbols, which may include subscripts and superscripts. A chemical formula is not a chemical name, and it contains no words. Although a chemical formula may imply certain simple chemical structures, it is not the same as a full chemical structural formula. Chemical formulae can fully specify the structure of only the simplest of molecules and chemical substances, and are generally more limited in power than chemical names and structural formulae. The simplest types of chemical formulae are called ''empirical formulae'', which use letters and numbers indicating the numerical ''proportions'' of ato ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hexa(tert-butoxy)ditungsten(III)
Hexa(''tert''-butoxy)ditungsten(III) is a coordination complex of tungsten(III). It is one of the homoleptic alkoxides of tungsten. A red, air-sensitive solid, the complex has attracted academic attention as the precursor to many organotungsten derivatives. It an example of a charge-neutral complex featuring a W≡W bond, arising from the coupling of a pair of d3 metal centers. It has attracted particular attention for its reactions with alkynes, leading to alkyne metathesis. It can be prepared by the salt metathesis reaction from the thf complex of ditungsten heptachloride: :NaW2Cl7(THF)5 + 6 NaOBu-t → W2(OBu-t)6 + 7 NaCl + 5 THF It was originally prepared by alcoholysis of the amide W2(NMe2)6. The complex and its dimolybdenum analogue adopt a staggered, ethane-like conformation. The M-M distance is 233 pm. The complex is a weak Lewis acid, forming adducts with two pyridine ligands, for example.{{cite journal , doi=10.1016/S0277-5387(97)00290-8, title=Pyridine, is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
