Nucleophilic substitution reactions are commonplace in organic chemistry, and they can be broadly categorised as taking place at a saturated aliphatic carbon or at ( less often ) a saturated aromatic or other unsaturated carbon centre.

** Nucleophilic aromatic substitution

* Nucleophilic aromatic substitution

* Nucleophilic aromatic substitution, a reaction in organic chemistry

* Nucleophilic aromatic substitution often requires an electrofuge at C2, such as chlorine with

Nucleophilic aromatic substitution

Nucleophilic aromatic substitution is not limited to arenes, however ; the reaction takes place even more readily with heteroarenes.

Nucleophilic aromatic substitution at pyridine

# redirect Nucleophilic aromatic substitution

* Nucleophilic attack: the carbocation reacts with the nucleophile.

The final cyclophane is put together by reaction with 1, 3, 5-tris ( mercaptomethyl ) benzene with nucleophilic sulfhydryl groups and electrophilic alkyl bromides in a Nucleophilic aliphatic Substitution.

Nucleophilic substitution at sp < sup > 3 </ sup > centres can proceed by the stereospecific S < sub > N </ sub > 2 mechanism, causing only inversion, or by the non-specific S < sub > N </ sub > 1 mechanism, the outcome of which can show a modest selectivity for inversion, depending on the reactants and the reaction conditions to which the mechanism does not refer.

S < sub > N </ sub > i or Substitution Nucleophilic internal stands for a specific but not often encountered nucleophilic aliphatic substitution reaction mechanism.

Nucleophilic substitution can take place by two different mechanisms, S < sub > N </ sub > 1 and S < sub > N </ sub > 2.

Nucleophilic addition of a carbanion or another nucleophile to the double bond of an alpha, beta unsaturated carbonyl compound can proceed via the Michael reaction, which belongs to the larger class of conjugate additions.

Nucleophilic describes the affinity of a nucleophile to the nuclei.

* Electrophilic Bimolecular Substitution as an Alternative to Nucleophilic Monomolecular Substitution in Inorganic and Organic Chemistry / N. S. Imyanitov.

Nucleophilic alkylating agents can also displace halide substituents on a carbon atom.

Nucleophilic N-heterocyclic carbenes ( NHCs ) behave like typical σ-donor ligands that can substitute 2-electron ligands ( i. e., amines, phosphanes ) in metal coordination

# Nucleophilic attack by one water molecule R < sup >+</ sup > + OH < sup >-</ sup > → ROH.

An aromatic hydrocarbon or arene ( or sometimes aryl hydrocarbon ) is a hydrocarbon with alternating double and single bonds between carbon atoms forming rings.

In organic chemistry, compounds composed of carbon and hydrogen are divided into two classes: aromatic compounds, which contain benzene or similar rings of atoms, and aliphatic compounds (; G. aleiphar, fat, oil ), which do not contain those rings.

Archibald Scott Couper in 1858 and Joseph Loschmidt in 1861 suggested possible structures that contained multiple double bonds or multiple rings, but the study of aromatic compounds was in its earliest years, and too little evidence was then available to help chemists decide on any particular structure.

Discotics are flat disc-like molecules consisting of a core of adjacent aromatic rings.

In contrast to the more strict definition proposed by IUPAC, which requires a d-block metal and a sandwich structure, the term metallocene and thus the denotation-ocene, is applied in the chemical literature also to non-transition metal compounds, such as Cp < sub > 2 </ sub > Ba, or structures where the aromatic rings are not co-planar, such as found in manganocene or titanocene dichloride ( Cp < sub > 2 </ sub > TiCl < sub > 2 </ sub >).

Saturated cyclic compounds contain single bonds only, whereas aromatic rings have an alternating ( or conjugated ) double bond.

* Simple aromatic rings

This commonly seen model of aromatic rings, namely the idea that benzene was formed from a six-membered carbon ring with alternating single and double bonds ( cyclohexatriene ), was developed by Kekulé ( see History section below ).

Polycyclic aromatic hydrocarbons are molecules containing two or more simple aromatic rings fused together by sharing two neighboring carbon atoms ( see also simple aromatic rings ).

Many chemical compounds are aromatic rings with other functional groups attached.

A manufactured fiber in which the fiber-forming substance is a long-chain synthetic polyamide in which at least 85 % of the amide linkages, (- CO-NH -) are attached directly to two aromatic rings.

In benzene and other aromatic rings, the delocalized pi-electrons are sometimes pictured as a solid circle.

Anthracene is a solid polycyclic aromatic hydrocarbon consisting of three fused benzene rings.

These allow Claisen-like reactions to occur, generating aromatic rings.

An aromatic amine is an amine with an aromatic substituent-that is-NH < sub > 2 </ sub >,-NH-or nitrogen group ( s ) attached to an aromatic hydrocarbon, whose structure usually contains one or more benzene rings.

* with 5 – 7 aromatic rings per 1000 Da,

They contain one or more all-carbon rings which may be either saturated or unsaturated, but do not have aromatic character.

The configuration of six carbon atoms in aromatic compounds is known as a benzene ring, after the simplest possible such hydrocarbon, benzene.

Other specialized cycloadditions include multicomponent reactions such as alkyne trimerisation to give aromatic compounds and the cycloaddition of an alkyne, alkene and carbon monoxide in the Pauson – Khand reaction.

Exports from the Funan Empire were largely forest products and precious metals — including accessories such as gold elephants, ivory, rhinoceros horn, kingfisher feathers, wild spices like cardamom, lacquer hides and aromatic wood.

Like caraway, its fernlike leaves are aromatic and are used to flavor many foods, such as gravlax ( cured salmon ), borscht and other soups, and pickles ( where the dill flower is sometimes used ).

The aromatic acids, such as malic acid, come mostly from the flowers, adding to the aroma and taste of the honey.

Solutions of iodine in strong donor solvents such as acetone, tetrahydrofuran, pyridine appears brown or yellow ( λ < sub > max </ sub > = 460-480 nm ), while in solvents of weaker donors such as dichloromethane it appears crimson red, in aromatic hydrocarbons such as benzene and toluene it appears pink or reddish-brown.

The plants are frequently aromatic in all parts and include many widely used culinary herbs, such as basil, mint, rosemary, sage, savory, marjoram, oregano, thyme, lavender, and perilla.

* Synthetic-tanned leather is tanned using aromatic polymers such as the Novolac or Neradol types ( syntans, contraction for synthetic tannins ).

Many compounds, such as PAHs, aromatic amines, aflatoxin and pyrrolizidine alkaloids, may form reactive oxygen species catalyzed by cytochrome P450.

Many fungi are able to break down complex organic biomolecules such as lignin, the more durable component of wood, and pollutants such as xenobiotics, petroleum, and polycyclic aromatic hydrocarbons.

Solvents can be either pure substances like ether or ethyl alcohol, or mixtures, such as the paraffinic solvents such as the various petroleum ethers and white spirits, or the range of pure or mixed aromatic solvents obtained from petroleum or tar fractions by physical separation or by chemical conversion.

Factors such as climate, seasons and soil composition may affect the aromatic oils present, and this effect may be greater than the differences between the various species of plants.

The hydrocarbons in crude oil are mostly alkanes, cycloalkanes and various aromatic hydrocarbons while the other organic compounds contain nitrogen, oxygen and sulfur, and trace amounts of metals such as iron, nickel, copper and vanadium.

Different enzymes have different specificity for their substrate ; trypsin for example cleaves the peptide bond after a positively charge residue ( arginine and lysine ), chymotrypsin cleaves the bond after an aromatic residue ( phenylalanine, tyrosine, and tryptophan ), elastase cleaves the bond after a small non-polar residue such as alanine or glycine.

Its distinctive aromatic, pleasantly sharp, very salty flavour means that in Italian cuisine, it is preferred for some pasta dishes with highly-flavoured sauces, especially those of Roman origin, such as bucatini all ' amatriciana or spaghetti alla carbonara.

The harmful effects of tobacco derive from the thousands of different compounds generated in the smoke, including polycyclic aromatic hydrocarbons ( such as benzpyrene ), formaldehyde, cadmium, nickel, arsenic, radioactive polonium-210, tobacco-specific nitrosamines ( TSNAs ), phenols, and many others.

* A small container with a perforated top, used to contain an aromatic substance such as vinegar or smelling salts, especially popular for women in Victorian era to combat the aroma from the waste products common in cities

The initial studies revealed the typical radii of atoms, and confirmed many theoretical models of chemical bonding, such as the tetrahedral bonding of carbon in the diamond structure, the octahedral bonding of metals observed in ammonium hexachloroplatinate ( IV ), and the resonance observed in the planar carbonate group and in aromatic molecules.

Another component of all such catalysts is an organic modifier, usually an ester of an aromatic diacid or a diether.