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Meta-selective C–H Functionalization
''Meta''-selective Carbon–hydrogen bond activation, C–H functionalization refers to the regioselectivity, regioselective reaction of a substituted aromatic ring on the C–H bond ''meta'' to the substituent. Substituted aromatic ring is an important type of substructure in pharmaceuticals and industrial compounds. Thus, synthetic methods towards substituted aromatic rings are always of great interest to chemists. Traditionally, regioselectivity on the aromatic ring is achieved by the electronic effect of substituents. Taking the well-known Friedel–Crafts reaction, Friedel–Craft electrophilic aromatic substitution as example, electron donating groups direct the electrophile to ''ortho-/para-''position while electron withdrawing groups direct the electrophile to ''meta''-position. However, with complicated systems, electronic difference between different C–H bonds can be subtle and electronic directing effect alone could become less synthetically useful. The fast developm ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carbon–hydrogen Bond Activation
In organic chemistry, carbon–hydrogen bond functionalization ( functionalization) is a type of organic reaction in which a carbon–hydrogen bond is Bond cleavage, cleaved and replaced with a bond (where X is usually carbon, oxygen, or nitrogen). The term usually implies that a transition metal is involved in the cleavage process. Reactions classified by the term typically involve the hydrocarbon first to react with a metal catalyst to create an organometallic complex in which the hydrocarbon is coordination chemistry, coordinated to the inner-sphere of a metal, either via an intermediate "alkane or arene compound, arene complex" or as a transition state leading to a "" Reaction intermediate, intermediate. The intermediate of this first step (known as activation and sometimes used interchangeably with functionalization) can then undergo subsequent reactions to produce the Late-stage functionalization, functionalized product. Important to this definition is the requirement th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anilide
Anilides (or phenylamides) are a class of chemical compounds, which are amide derivatives of aniline. Preparation Aniline reacts with acyl chlorides or carboxylic anhydrides to give anilides. For example, reaction of aniline with acetyl chloride provides acetanilide (CH3-CO-NH-C6H5). At high temperatures, aniline and carboxylic acids react to give anilides. Uses * Herbicides * Fungicides - Oxycarboxin, Carboxin {{Short pages monitor [Baidu] |
Nitrile
In organic chemistry, a nitrile is any organic compound that has a functional group. The prefix '' cyano-'' is used interchangeably with the term ''nitrile'' in industrial literature. Nitriles are found in many useful compounds, including methyl cyanoacrylate, used in super glue, and nitrile rubber, a nitrile-containing polymer used in latex-free laboratory and medical gloves. Nitrile rubber is also widely used as automotive and other seals since it is resistant to fuels and oils. Organic compounds containing multiple nitrile groups are known as cyanocarbons. Inorganic compounds containing the group are not called nitriles, but cyanides instead. Though both nitriles and cyanides can be derived from cyanide salts, most nitriles are not nearly as toxic. Structure and basic properties The N−C−C geometry is linear in nitriles, reflecting the sp hybridization of the triply bonded carbon. The C−N distance is short at 1.16 Å, consistent with a triple bond. Nitril ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alternative Mechanism Of Copper Catalyzed Meta-selective C-H Arylation
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Triflate
In organic chemistry, triflate ( systematic name: trifluoromethanesulfonate), is a functional group with the formula and structure . The triflate group is often represented by , as opposed to −Tf, which is the triflyl group, . For example, ''n''-butyl triflate can be written as . The corresponding triflate anion, , is an extremely stable polyatomic ion; this comes from the fact that triflic acid () is a superacid; i.e. it is more acidic than pure sulfuric acid, already one of the strongest acids known. Applications A triflate group is an excellent leaving group used in certain organic reactions such as nucleophilic substitution, Suzuki couplings and Heck reactions. Since alkyl triflates are extremely reactive in SN2 reactions, they must be stored in conditions free of nucleophiles (such as water). The anion owes its stability to resonance stabilization which causes the negative charge to be spread symmetrically over the three oxygen atoms. An additional stabili ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Density Functional Theory
Density-functional theory (DFT) is a computational quantum mechanical modelling method used in physics, chemistry and materials science to investigate the electronic structure (or nuclear structure) (principally the ground state) of many-body systems, in particular atoms, molecules, and the condensed phases. Using this theory, the properties of a many-electron system can be determined by using functionals, i.e. functions of another function. In the case of DFT, these are functionals of the spatially dependent electron density. DFT is among the most popular and versatile methods available in condensed-matter physics, computational physics, and computational chemistry. DFT has been very popular for calculations in solid-state physics since the 1970s. However, DFT was not considered accurate enough for calculations in quantum chemistry until the 1990s, when the approximations used in the theory were greatly refined to better model the exchange and correlation interactio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mechanism Of Copper Catalyzed Meta-selective C-H Arylation Involving "anti-oxy-cupration"
Mechanism may refer to: *Mechanism (engineering), rigid bodies connected by joints in order to accomplish a desired force and/or motion transmission * Mechanism (biology), explaining how a feature is created *Mechanism (philosophy), a theory that all natural phenomena can be explained by physical causes *Mechanism (sociology), a theory that all social phenomena can be explained by the existence of a deterministic mechanism * "The Mechanism", song by Disclosure * ''The Mechanism'' (TV series), a Netflix TV series See also *Machine * Machine (mechanical) * Linkage (mechanical) * Mechanism design, the art of designing rules of a game to achieve a specific outcome * Mechanism of action, the means by which a drug exerts its biological effects * Defence mechanism, unconscious mechanisms aimed at reducing anxiety *Reaction mechanism, the sequence of reactions by which overall chemical change occurs *Antikythera mechanism, an ancient Greek analog computer *Theory of operation A theory ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Reductive Elimination
Reductive elimination is an elementary step in organometallic chemistry in which the oxidation state of the metal center decreases while forming a new covalent bond between two ligands. It is the microscopic reverse of oxidative addition, and is often the product-forming step in many catalytic processes. Since oxidative addition and reductive elimination are reverse reactions, the same mechanisms apply for both processes, and the product equilibrium depends on the thermodynamics of both directions. General information Reductive elimination is often seen in higher oxidation states, and can involve a two-electron change at a single metal center (mononuclear) or a one-electron change at each of two metal centers (binuclear, dinuclear, or bimetallic). For mononuclear reductive elimination, the oxidation state of the metal decreases by two, while the d-electron count of the metal increases by two. This pathway is common for d8 metals Ni(II), Pd(II), and Au(III) and d6 metals P ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aromaticity
In chemistry, aromaticity is a chemical property of cyclic (ring-shaped), ''typically'' planar (flat) molecular structures with pi bonds in resonance (those containing delocalized electrons) that gives increased stability compared to saturated compounds having single bonds, and other geometric or connective non-cyclic arrangements with the same set of atoms. Aromatic rings are very stable and do not break apart easily. Organic compounds that are not aromatic are classified as aliphatic compounds—they might be cyclic, but only aromatic rings have enhanced stability. The term ''aromaticity'' with this meaning is historically related to the concept of having an aroma, but is a distinct property from that meaning. Since the most common aromatic compounds are derivatives of benzene (an aromatic hydrocarbon common in petroleum and its distillates), the word ''aromatic'' occasionally refers informally to benzene derivatives, and so it was first defined. Nevertheless, man ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oxidative Addition
Oxidative addition and reductive elimination are two important and related classes of reactions in organometallic chemistry. Oxidative addition is a process that increases both the oxidation state and coordination number of a metal centre. Oxidative addition is often a step in catalytic cycles, in conjunction with its reverse reaction, reductive elimination. Role in transition metal chemistry For transition metals, oxidative reaction results in the decrease in the d''n'' to a configuration with fewer electrons, often 2e fewer. Oxidative addition is favored for metals that are (i) basic and/or (ii) easily oxidized. Metals with a relatively low oxidation state often satisfy one of these requirements, but even high oxidation state metals undergo oxidative addition, as illustrated by the oxidation of Pt(II) with chlorine: : tCl4sup>2− + Cl2 → tCl6sup>2− In classical organometallic chemistry, the formal oxidation state of the metal and the electron count of the complex bot ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nucleophile
In chemistry, a nucleophile is a chemical species that forms bonds by donating an electron pair. All molecules and ions with a free pair of electrons or at least one pi bond can act as nucleophiles. Because nucleophiles donate electrons, they are Lewis bases. ''Nucleophilic'' describes the affinity of a nucleophile to bond with positively charged atomic nuclei. Nucleophilicity, sometimes referred to as nucleophile strength, refers to a substance's nucleophilic character and is often used to compare the affinity of atoms. Neutral nucleophilic reactions with solvents such as alcohols and water are named solvolysis. Nucleophiles may take part in nucleophilic substitution, whereby a nucleophile becomes attracted to a full or partial positive charge, and nucleophilic addition. Nucleophilicity is closely related to basicity. History The terms ''nucleophile'' and ''electrophile'' were introduced by Christopher Kelk Ingold in 1933, replacing the terms ''anionoid'' and ''cation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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