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The longest series of linked carbon atoms in a molecule is known as its carbon skeleton or carbon backbone. The number of carbon atoms may be considered as the size of the alkane. One group of the higher alkanes are waxes, solids at standard ambient temperature and pressure (SATP), for which the number of carbon atoms ...
Linear alkane
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With their repeated –CH2 units, the alkanes constitute a homologous series of organic compounds in which the members differ in molecular mass by multiples of 14.03 u (the total mass of each such methylene-bridge unit, which comprises a single carbon atom of mass 12.01 u and two hydrogen atoms of mass ~1.01 u each). Met...
Linear alkane
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Nevertheless, most alkanes do not have much biological activity. They can be viewed as molecular trees upon which can be hung the more active/reactive functional groups of biological molecules. The alkanes have two main commercial sources: petroleum (crude oil) and natural gas. An alkyl group is an alkane-based molecul...
Linear alkane
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In organic chemistry, an alkene is a hydrocarbon containing a carbon–carbon double bond. The double bond may be internal or in the terminal position. Terminal alkenes are also known as α-olefins. The International Union of Pure and Applied Chemistry (IUPAC) recommends using the name "alkene" only for acyclic hydrocarbo...
Alkene oxidation
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When n is four or more, isomers are possible, distinguished by the position and conformation of the double bond. Alkenes are generally colorless non-polar compounds, somewhat similar to alkanes but more reactive. The first few members of the series are gases or liquids at room temperature. The simplest alkene, ethylene...
Alkene oxidation
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In organic chemistry, an alkyl group is an alkane missing one hydrogen. The term alkyl is intentionally unspecific to include many possible substitutions. An acyclic alkyl has the general formula of −CnH2n+1.
Tertiary alkyl
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A cycloalkyl group is derived from a cycloalkane by removal of a hydrogen atom from a ring and has the general formula −CnH2n−1. Typically an alkyl is a part of a larger molecule. In structural formulae, the symbol R is used to designate a generic (unspecified) alkyl group. The smallest alkyl group is methyl, with the ...
Tertiary alkyl
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In organic chemistry, an alkyne is an unsaturated hydrocarbon containing at least one carbon—carbon triple bond. The simplest acyclic alkynes with only one triple bond and no other functional groups form a homologous series with the general chemical formula CnH2n−2. Alkynes are traditionally known as acetylenes, althou...
C2R2
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In organic chemistry, an allene oxide is an epoxide of an allene. The parent allene oxide is CH2=C(O)CH2 (CAS RN 40079-14-9), a rare and reactive species of only theoretical interest. Typical allene oxides require steric protection for their isolation.
Allene oxide
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Certain derivatives can be prepared by epoxidation of the allenes with peracetic acid. Allene oxides tend to rearrange to cyclopropanones.Despite the esoteric character of synthetic allene oxides, allene oxides occur naturally. They are intermediates in the chemical defense of some plants against attack by herbivores.
Allene oxide
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Specifically, a hydroperoxide of linolenic acid is the substrate for the enzyme allene oxide synthase. The resulting allene oxide in turn is converted by allene oxide cyclase to jasmonic acid. == References ==
Allene oxide
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In organic chemistry, an allyl group is a substituent with the structural formula −CH2−HC=CH2. It consists of a methylene bridge (−CH2−) attached to a vinyl group (−CH=CH2). The name is derived from the scientific name for garlic, Allium sativum.
Allyl cation
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In 1844, Theodor Wertheim isolated an allyl derivative from garlic oil and named it "Schwefelallyl". The term allyl applies to many compounds related to H2C=CH−CH2, some of which are of practical or of everyday importance, for example, allyl chloride. Allylation is any chemical reaction that adds an allyl group to a su...
Allyl cation
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In organic chemistry, an amide, also known as an organic amide or a carboxamide, is a compound with the general formula R−C(=O)−NR′R″, where R, R', and R″ represent any group, typically organyl groups or hydrogen atoms. The amide group is called a peptide bond when it is part of the main chain of a protein, and an isop...
Amide bond
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Some uncommon examples of amides are N-chloroacetamide (H3C−C(=O)−NH−Cl) and chloroformamide (Cl−C(=O)−NH2). Amides are qualified as primary, secondary, and tertiary according to whether the amine subgroup has the form −NH2, −NHR, or −NRR', where R and R' are groups other than hydrogen.The core −C(=O)−(N) of amides is ...
Amide bond
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Proteins and important plastics like Nylons, Aramid, Twaron, and Kevlar are polymers whose units are connected by amide groups (polyamides); these linkages are easily formed, confer structural rigidity, and resist hydrolysis. Amides include many other important biological compounds, as well as many drugs like paracetam...
Amide bond
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In organic chemistry, an aminal or aminoacetal is a functional group or type of organic compound that has two amine groups attached to the same carbon atom: −C(NR2)(NR2)−. (As is customary in organic chemistry, R can represent hydrogen or an alkyl group). A common aminal is bis(dimethylamino)methane, a colorless liquid...
Aminal
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Several examples exist in nature. Naturally occurring aminals Hexahydro-1,3,5-triazine ((CH2NH)3), an intermediate in the condensation of formaldehyde and ammonia, tends to degrade to hexamethylene tetraamine. Cyclic aminals can be obtained by the condensation of a diamine and an aldehyde. Imidazolidines are one class ...
Aminal
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In organic chemistry, an amino sugar (or more technically a 2-amino-2-deoxysugar) is a sugar molecule in which a hydroxyl group has been replaced with an amine group. More than 60 amino sugars are known, with one of the most abundant being N-Acetyl-d-glucosamine, which is the main component of chitin. Derivatives of am...
Amino sugars metabolism
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In organic chemistry, an aminomethyl group is a monovalent functional group with formula −CH2−NH2. It can be described as a methyl group substituted by an amino group −NH2.
Aminomethyl group
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In organic chemistry, an aromatic amine is an organic compound consisting of an aromatic ring attached to an amine. It is a broad class of compounds that encompasses anilines, but also many more complex aromatic rings and many amine substituents beyond NH2. Such compounds occur widely. Aromatic amines are widely used a...
Aromatic amines
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In organic chemistry, an aryl halide (also known as haloarene) is an aromatic compound in which one or more hydrogen atoms, directly bonded to an aromatic ring are replaced by a halide. The haloarene are different from haloalkanes because they exhibit many differences in methods of preparation and properties. The most ...
Aryl halide
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In organic chemistry, an aryl is any functional group or substituent derived from an aromatic ring, usually an aromatic hydrocarbon, such as phenyl and naphthyl. "Aryl" is used for the sake of abbreviation or generalization, and "Ar" is used as a placeholder for the aryl group in chemical structure diagrams, analogous ...
Aryl hydrocarbons
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A simple aryl group is phenyl (C6H5), a group derived from benzene. Examples of other aryl groups consist of: The tolyl group (CH3C6H4) which is derived from toluene (methylbenzene) The xylyl group (2C6H3), which is derived from xylene (dimethylbenzene) The naphthyl group (C10H7), which is derived from naphthaleneAryla...
Aryl hydrocarbons
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In organic chemistry, an auxochrome (from Ancient Greek αὐξάνω (auxanō) 'increase', and χρῶμα (chrōma) 'colour') is a group of atoms attached to a chromophore which modifies the ability of that chromophore to absorb light. They themselves fail to produce the colour, but instead intensify the colour of the chromogen whe...
Auxochrome
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In organic chemistry, an aza-crown ether is an aza analogue of a crown ether (cyclic polyether). That is, it has a nitrogen atom (amine linkage, −NH− or >N−) in place of each oxygen atom (ether linkage, −O−) around the ring. While the parent crown ethers have the formulae (CH2CH2O)n, the parent aza-crown ethers have th...
Aza-crown ether
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In organic chemistry, an azo coupling is an organic reaction between a diazonium compound (R−N≡N+) and another aromatic compound that produces an azo compound (R−N=N−R’). In this electrophilic aromatic substitution reaction, the aryldiazonium cation is the electrophile and the activated carbon (usually from an arene wh...
Azo coupling
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In organic chemistry, an electrocyclic reaction is a type of pericyclic rearrangement where the net result is one pi bond being converted into one sigma bond or vice versa. These reactions are usually categorized by the following criteria: Reactions can be either photochemical or thermal. Reactions can be either ring-o...
Electrocyclic reaction
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In organic chemistry, an electrophilic addition reaction is an addition reaction where a chemical compound containing a double or triple bond has a π bond broken, with the formation of two new σ bonds.The driving force for this reaction is the formation of an electrophile X+ that forms a covalent bond with an electron-...
Electrophilic addition
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The exact nature of the electrophile and the nature of the positively charged intermediate are not always clear and depend on reactants and reaction conditions. In all asymmetric addition reactions to carbon, regioselectivity is important and often determined by Markovnikov's rule. Organoborane compounds give anti-Mark...
Electrophilic addition
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In organic chemistry, an electrophilic aromatic halogenation is a type of electrophilic aromatic substitution. This organic reaction is typical of aromatic compounds and a very useful method for adding substituents to an aromatic system. A few types of aromatic compounds, such as phenol, will react without a catalyst, ...
Electrophilic halogenation
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In organic chemistry, an epoxide is a cyclic ether, where the ether forms a three-atom ring: two atoms of carbon and one atom of oxygen. This triangular structure has substantial ring strain, making epoxides highly reactive, more so than other ethers. They are produced on a large scale for many applications. In general...
Epoxy group
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In organic chemistry, an ester is formed as the condensation product of a carboxylic acid and an alcohol, with water formed as the condensate by-product. An ester can also be produced with an acyl halide and an alcohol, in which case the condensate by-product is a hydrogen halide. Polyesters are a category of polymers ...
Polyester resins
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Polyesters are produced commercially both as saturated and unsaturated resins. The most common and highest volume produced polyester is Polyethylene terephthalate (PET), which is an example of a saturated polyester and finds utilization in such applications as fibers for clothing and carpet, food and liquid containers ...
Polyester resins
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The ester forms of these two molecules are maleate and fumarate, respectively. When curing a UPR, the fumarate form is known to react more rapidly with the styrene radical, so isomerization catalysts, such as N,N-dimethylacetoacetamide (DMAA), are often employed in the synthesis process which converts the maleates into...
Polyester resins
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Within the UPR industry, the classification of the resins is generally based on the primary saturated acid. For example, a resin containing primarily terephthalic acid is known as a Tere resin, a resin containing primarily phthalic anhydride is known as an Ortho resin, and a resin containing primarily isophthalic acid ...
Polyester resins
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In one process, the DCPD is cracked in situ to form cyclopentadiene which can then be reacted with maleate/fumarate groups along the polymer chain via a Diels-alder reaction. This type of resin is known as a Nadic resin and is referred to as a poor man's Ortho, due to sharing many similar properties of an Ortho resin a...
Polyester resins
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This product is then used to end-cap the UPR resin which yields a product with unsaturation on the end-groups. This type of resin is referred to as a DCPD resin. Ortho resins comprise the most common type of UPR, and many are known as general purpose resins.
Polyester resins
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FRP composites utilizing ortho resins are found in such application as boat hulls, bath ware, and bowling ball cores. Iso resins are generally on the higher end of UPR products, both because of the relatively higher cost of the isophthalic acid as well as the superior properties they possess. Iso resins are the primary...
Polyester resins
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Gel coat resins must have lower color (almost clear) so as to not impart additional color to the part or so that they can be dyed properly. Gel coats must also have strong resistance to UV-weathering and water blistering. Tere resins are often used when high modulus and strength are desired, but the low color propertie...
Polyester resins
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Terephthalic acid is generally lower cost than isophthalic acid, but both give similar strength characteristics to a UPR product. There exists a special sub-set of Tere resins, known as PET UPR resins, which are produced by catalytically cracking PET resin in the reactor to yield a mixture of terephthalic acid and ethy...
Polyester resins
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The end product is functionally the same as a Tere resin, but can often be lower cost to manufacture as scrap PET can be sourced cheaply. If a glycol-modified PET (PET-G) is used, exceptional properties can be imparted to the resin due to some of the exotic materials used in PET-G production. Tere and PET-UPR resins ar...
Polyester resins
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In organic chemistry, an ethyl group (abbr. Et) is an alkyl substituent with the formula −CH2CH3, derived from ethane (C2H6). Ethyl is used in the International Union of Pure and Applied Chemistry's nomenclature of organic chemistry for a saturated two-carbon moiety in a molecule, while the prefix "eth-" is used to ind...
Ethyl group
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In organic chemistry, an imide is a functional group consisting of two acyl groups bound to nitrogen. The compounds are structurally related to acid anhydrides, although imides are more resistant to hydrolysis. In terms of commercial applications, imides are best known as components of high-strength polymers, called po...
Imide
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In organic chemistry, an imine ( or ) is a functional group or organic compound containing a carbon–nitrogen double bond (C=N). The nitrogen atom can be attached to a hydrogen or an organic group (R). The carbon atom has two additional single bonds. Imines are common in synthetic and naturally occurring compounds and t...
Imine
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In organic chemistry, an iminium cation is a polyatomic ion with the general structure +. They are common in synthetic chemistry and biology.
Iminium
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In organic chemistry, an imino acid is any molecule that contains both imine (>C=NH) and carboxyl (-C(=O)-OH) functional groups. Imino acids are structurally related to amino acids, which have amino group instead of imine—a difference of single vs double-bond between nitrogen and carbon. The simplest example is dehydro...
Imino acid
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In organic chemistry, an intramolecular Diels-Alder cycloaddition is a Diels–Alder reaction in which the diene and a dienophile are both part of the same molecule. The reaction leads to the formation of the same cyclohexene-like structure as usual for a Diels–Alder reaction, but as part of a more complex fused or bridg...
Intramolecular Diels–Alder cycloaddition
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In organic chemistry, an isodiazene, also known by the incorrectly constructed (but commonly used) name 1,1-diazene or systematic name diazanylidene, is an organic derivative of the parent isodiazene (H2N+=N–, also called 1,1-diimide) with general formula R1R2N+=N–. The functional group has two major resonance forms, a...
Isodiazene
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Isodiazenes participate in cycloaddition reactions with alkenes to generate N-aminoaziridines. In the absence of other reactants, they undergo reactions in which N2 is eliminated to give an organic residue or residues through both concerted and nonconcerted pathways. Cyclic isodizenes in particular readily undergo cycl...
Isodiazene
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Some of these reactions are believed to be concerted pericyclic processes, as evidenced by stereospecificity that is consistent with the conservation of orbital symmetry. The absence of cyclobutane from the decomposition of the isodiazene derived from the saturated 5-membered azacycle is evidence against radical interm...
Isodiazene
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In organic chemistry, an organic sulfide (British English sulphide) or thioether is an organosulfur functional group with the connectivity R−S−R' as shown on right. Like many other sulfur-containing compounds, volatile sulfides have foul odors. A sulfide is similar to an ether except that it contains a sulfur atom in p...
Sulfide (organic)
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In organic chemistry, an ortho ester is a functional group containing three alkoxy groups attached to one carbon atom, i.e. with the general formula RC(OR′)3. Orthoesters may be considered as products of exhaustive alkylation of unstable orthocarboxylic acids and it is from these that the name 'ortho ester' is derived....
Ortho ester
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In organic chemistry, an oxime is a organic compound belonging to the imines, with the general formula RR’C=N−OH, 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 ox...
Amidoxime
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In organic chemistry, an ynone is an organic compound containing a ketone (>C=O) functional group and a C≡C triple bond. Many ynones are α,β-ynones, where the carbonyl and alkyne groups are conjugated. Capillin is a naturally occurring example. Some ynones are not conjugated.
Ynone
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In organic chemistry, an α-halo ketone is a functional group consisting of a ketone group or more generally a carbonyl group with an α-halogen substituent. α-Halo ketones are alkylating agents. Prominent α-halo ketones include phenacyl bromide and chloroacetone.
Α-Halo ketone
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In organic chemistry, anti-periplanar, or antiperiplanar, describes the A−B−C−D bond angle in a molecule. In this conformer, the dihedral angle of the A−B bond and the C−D bond is greater than +150° or less than −150° (Figures 1 and 2). Anti-periplanar is often used in textbooks to mean strictly anti-coplanar, with an ...
Antiperiplanar geometry
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In a Newman projection, the molecule will be in a staggered arrangement with the anti-periplanar functional groups pointing up and down, 180° away from each other (see Figure 4). Figure 5 shows 2-chloro-2,3-dimethylbutane in a sawhorse projection with chlorine and a hydrogen anti-periplanar to each other. Syn-periplana...
Antiperiplanar geometry
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In organic chemistry, aromatic compounds contain atomic rings, such as benzene rings (the Kekulé structure) consisting of five or six, usually carbon, atoms. So does the surface of "buckyballs" (buckminsterfullerene). This ring behaves like a circular waveguide, with the valence electrons orbiting in both directions. T...
Circular potential well
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In organic chemistry, benzenoids are a class of organic compounds with at least one benzene ring. These compounds have increased stability due to resonance in the benzene rings. Most aromatic hydrocarbons are benzenoid. Notable counterexamples are cyclooctadecanonaene, azulene and trans-bicalicene.
Benzenoid
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In organic chemistry, benzoyl (, BENZ-oh-il) is the functional group with the formula −COC6H5 and structure −C(=O)−C6H5. It can be viewed as benzaldehyde missing one hydrogen. The benzoyl group has a mass of 105 amu. The term "benzoyl" should not be confused with benzyl, which has the formula −CH2−C6H5. The benzoyl gro...
Benzoyl group
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In organic chemistry, benzyl is the substituent or molecular fragment possessing the structure R−CH2−C6H5. Benzyl features a benzene ring (C6H6) attached to a methylene group (−CH2−) group.
Benzyl group
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In organic chemistry, borate esters are organoboron compounds which are conveniently prepared by the stoichiometric condensation reaction of boric acid with alcohols. There are two main classes of borate esters: orthoborates, B(OR)3 and metaborates, B3O3(OR)3. Metaborates contain 6-membered boroxine rings. B ( OH ) 3 +...
Borate ester
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Borate esters are volatile and can be purified by distillation. This procedure is used for analysis of trace amounts of borate and for analysis of boron in steel. Like all boron compounds, alkyl borates burn with a characteristic green flame.
Borate ester
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This property is used to determine the presence of boron in qualitative analysis. Borate esters form spontaneously when treated with diols such as sugars and the reaction with mannitol forms the basis of a titrimetric analytical method for boric acid. Metaborate esters show considerable Lewis acidity and can initiate e...
Borate ester
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The Lewis acidity of orthoborate esters, as determined by the Gutmann-Beckett method, is relatively low. Trimethyl borate, B(OCH3)3, is used as a precursor to boronic esters for Suzuki couplings: Unsymmetrical borate esters are prepared from alkylation of trimethyl borate: ArMgBr + B ( OCH 3 ) 3 ⟶ MgBrOCH 3 + ArB ( OCH...
Borate ester
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In organic chemistry, brosyl (or para-bromophenylsulfonyl) group is a functional group with the chemical formula BrC6H4SO2. This group is usually introduced using the compound brosyl chloride, BrC6H4SO2Cl, which forms sulfonyl esters and amides of p-bromophenylsulfonic acid. The term brosylate refers to the anion of p-...
Brosyl group
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In organic chemistry, butyl is a four-carbon alkyl radical or substituent group with general chemical formula −C4H9, derived from either of the two isomers (n-butane and isobutane) of butane. The isomer n-butane can connect in two ways, giving rise to two "-butyl" groups: If it connects at one of the two terminal carbo...
Tert-butyl group
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In organic chemistry, carbenes are molecules which have carbon atoms with only six electrons in their valence shells and therefore disobey the octet rule. Carbenes generally split into singlet carbenes and triplet carbenes, named for their spin multiplicities. Both have two non-bonding electrons; in singlet carbenes th...
Multiplicity (chemistry)
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In organic chemistry, carboboration describes an addition of both a carbon and a boron moiety to certain carbon-containing double and triple bonds, such as alkenes, alkynes, and allenes. In the synthesis of organic compounds, this chemical reaction is used to install a new carbon-carbon bond and carbon-boron bond. The ...
Carboboration
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The carbon-boron bond can be transformed into a variety of functional groups and moieties, making it highly useful in pharmaceutical chemistry and organic synthesis. Carboboration was developed soon after the advent and widespread use of hydroboration. Carboboration is often facilitated via catalysis, often employing t...
Carboboration
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In organic chemistry, carbon nitrides are compounds consisting only of carbon and nitrogen atoms.
Carbon nitride
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In organic chemistry, carbon tetrachloride serves as a source of chlorine in the Appel reaction. Carbon tetrachloride made from heavy chlorine-37 has been used in the detection of neutrinos.
Carbon Tetrachloride
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In organic chemistry, carbonyl allylation describes methods for adding an allyl anion to an aldehyde or ketone to produce a homoallylic alcohol. The carbonyl allylation was first reported in 1876 by Alexander Zaitsev and employed an allylzinc reagent.
Carbonyl allylation
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In organic chemistry, carbonyl reduction is the organic reduction of any carbonyl group by a reducing agent. Typical carbonyl compounds are ketones, aldehydes, carboxylic acids, esters, and acid halides. Carboxylic acids, esters, and acid halides can be reduced to either aldehydes or a step further to primary alcohols,...
Conjugate reduction
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In organic chemistry, carbon–hydrogen bond functionalization (C−H functionalization) is a type of organic reaction in which a carbon–hydrogen bond is cleaved and replaced with a C−X bond (where X is usually carbon, oxygen, or nitrogen). The term usually implies that a transition metal is involved in the C−H cleavage pr...
C-H functionalization
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Important to this definition is the requirement that during the C−H cleavage event, the hydrocarbyl species remains associated in the inner-sphere and under the influence of "M".As an alternative definition, other authors use the term C−H functionalization to mean any organic transformation in which the net result is t...
C-H functionalization
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However, this definition would also include iron-catalyzed alkane functionalization reaction that proceed through the oxygen rebound mechanism (e.g. cytochrome P450 enzymes and their synthetic analogues), in which a metal–carbon bond is not believed to be involved. Likewise, the ligand-based reactivity of many metal ca...
C-H functionalization
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In organic chemistry, cheletropic reactions, also known as chelotropic reactions, are a type of pericyclic reaction (a chemical reaction that involves a transition state with a cyclic array of atoms and an associated cyclic array of interacting orbitals). Specifically, cheletropic reactions are a subclass of cycloaddit...
Cheletropic reaction
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In organic chemistry, chlorins are tetrapyrrole pigments that are partially hydrogenated porphyrins. The parent chlorin is an unstable compound which undergoes air oxidation to porphine. The name chlorin derives from chlorophyll.
Chlorin
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Chlorophylls are magnesium-containing chlorins and occur as photosynthetic pigments in chloroplasts. The term "chlorin" strictly speaking refers to only compounds with the same ring oxidation state as chlorophyll. Chlorins are excellent photosensitizing agents. Various synthetic chlorins analogues such as m-tetrahydrox...
Chlorin
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In organic chemistry, cis- and trans- prefixes are used to describe the position of functional groups attached to carbon atoms in a double bond. In Latin, cis and trans mean "on this side of" and "on the other side of" respectively. Therefore, if the functional groups are on the same side of the carbon chain, the bond ...
Unsaturated hydrocarbon
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E- and Z- configuration can be used instead in a more general case where all four functional groups attached to carbon atoms in a double bond are different. E- and Z- are the abbreviations of German words zusammen (together) and entgegen (opposite).
Unsaturated hydrocarbon
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In E- and Z- isomerism, each functional group is assigned a priority based on the Cahn–Ingold–Prelog priority rules. If the two groups with higher priority are on the same side of the double bond, the bond is assigned Z- configuration, otherwise (i.e. the two groups with higher priority are on the opposite side of the ...
Unsaturated hydrocarbon
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In organic chemistry, crown ethers are cyclic chemical compounds that consist of a ring containing several ether groups (R−O−R’). The most common crown ethers are cyclic oligomers of ethylene oxide, the repeating unit being ethyleneoxy, i.e., −CH2CH2O−. Important members of this series are the tetramer (n = 4), the pen...
Crown ether
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The first number in a crown ether's name refers to the number of atoms in the cycle, and the second number refers to the number of those atoms that are oxygen. Crown ethers are much broader than the oligomers of ethylene oxide; an important group are derived from catechol.
Crown ether
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Crown ethers strongly bind certain cations, forming complexes. The oxygen atoms are well situated to coordinate with a cation located at the interior of the ring, whereas the exterior of the ring is hydrophobic. The resulting cations often form salts that are soluble in nonpolar solvents, and for this reason crown ethe...
Crown ether
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The denticity of the polyether influences the affinity of the crown ether for various cations. For example, 18-crown-6 has high affinity for potassium cation, 15-crown-5 for sodium cation, and 12-crown-4 for lithium cation. The high affinity of 18-crown-6 for potassium ions contributes to its toxicity.
Crown ether
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The smallest crown ether still capable of binding cations is 8-crown-4, with the largest experimentally confirmed crown ether being 81-crown-27. Crown ethers are not the only macrocyclic ligands that have affinity for the potassium cation. Ionophores such as valinomycin also display a marked preference for the potassiu...
Crown ether
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In organic chemistry, cyanocarbons are a group of chemical compounds that contain several cyanide functional groups. Such substances generally are classified as organic compounds, since they are formally derived from hydrocarbons by replacing one or more hydrogen atoms with a cyanide group. One of the simplest member i...
Cyanocarbon
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Organic chemists often refer to cyanides as nitriles. In general, cyanide is an electronegative substituent. Thus, for example, cyanide-substituted carboxylic acids tend to be stronger than the parents. The cyanide group can also stabilize anions by delocalizing negative charge as revealed by resonance structures.
Cyanocarbon
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In organic chemistry, cyanopolyynes are a family of organic compounds with the chemical formula HCnN (n = 3,5,7,…) and the structural formula H−nC≡N (n = 1,2,3,…). Structurally, they are polyynes with a cyano group (−C≡N) covalently bonded to one of the terminal acetylene units (H−C≡C). A rarely seen group of molecules...
Cyanopolyyne
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Interference with hydrogen is one of the reason for the molecule's instability due to the energetically favorable dissociation back into hydrogen cyanide and acetylene.Cyanopolyynes were first discovered in interstellar molecular clouds in 1971 using millimeter wave and microwave telescopes. Since then many higher weig...
Cyanopolyyne
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The simplest example is cyanoacetylene, H−C≡C−C≡N. Cyanoacetylene is more common on Earth and it is believed to be the initial reagent for most of the photocatalyzed formation of the interstellar cyanopolyynes. Cyanoacetylene is one of the molecules that was produced in the Miller–Urey experiment and is expected to be ...
Cyanopolyyne
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This is commonly done with measurement of the rotational constant, the energy of the rotational transitions, or a measurement of the dissociation energy. These spectra can either be generated ab initio from a computational chemistry program or, such as with the more stable cyanoacetylene, by direct measurement of the s...
Cyanopolyyne
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In organic chemistry, cyclopentanonide is a functional group which is composed of a cyclic ketal of a diol with cyclopentanone. It is seen in amcinonide (triamcinolone acetate cyclopentanonide).
Cyclopentanonide
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In organic chemistry, cyclopropanation refers to any chemical process which generates cyclopropane ((CH2)3) rings. It is an important process in modern chemistry as many useful compounds bear this motif; for example pyrethroid insecticides and a number of quinolone antibiotics (ciprofloxacin, sparfloxacin, etc.). Howev...
Kishner cyclopropane synthesis
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In organic chemistry, dehalogenation is a set of chemical reactions that involve the cleavage of carbon-halogen bonds; as such, it is the inverse reaction of halogenation. Dehalogenations come in many varieties, including defluorination (removal of fluorine), dechlorination (removal of chlorine), debromination (removal...
Dehalogenation
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In organic chemistry, diazirines are a class of organic molecules consisting of a carbon bound to two nitrogen atoms, which are double-bonded to each other, forming a cyclopropene-like ring, 3H-diazirene (>CN2). They are isomeric with diazocarbon groups (>C=N=N), and like them can serve as precursors for carbenes by lo...
Diazirine
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In organic chemistry, dilute solutions of chromic acid can be used to oxidize primary or secondary alcohols to the corresponding aldehydes and ketones. Similarly, it can also be used to oxidize an aldehyde to its corresponding carboxylic acid. Tertiary alcohols and ketones are unaffected. Because the oxidation is signa...
H2Cr2O7