# REDIRECT Electrophilic aromatic substitution

** Electrophilic aromatic substitution

* Electrophilic aromatic substitution, class of organic reactions

Electrophilic aromatic substitution is characteristic of aromatic compounds and is an important way of introducing functional groups onto benzene rings.

Electrophilic attack to an aromatic system results in electrophilic aromatic substitution rather than an addition reaction.

* Electrophilic aromatic substitution at C5 requires activating groups such as a methyl group in this bromination:

* Electrophilic aromatic substitution

* Electrophilic aromatic substitution

Electrophilic substitution reactions are chemical reactions in which an electrophile displaces a group in a compound, typically but not always hydrogen.

Electrophilic substitution is the counterpart of the nucleophilic substitution in that the attacking atom or molecule, an electrophile, has low electron density and thus a positive charge.

Electrophilic addition is one of the three main forms of reaction concerning alkenes.

* Electrophilic halogens: elemental fluorine, chlorine, bromine and iodine, and electrophilic salts such as sodium hypochlorite or N-chloro compounds such as chloramine-T ; halide ions are not corrosive, except for fluoride

# They undergo electrophilic substitution reactions and nucleophilic aromatic substitutions.

These reactions are called electrophilic aromatic substitutions.

It exhibits aromatic properties: ( i ) the peripheral bonds have similar lengths and ( ii ) it undergoes Friedel-Crafts-like substitutions.

Certain aromatic substitutions takes place by radical-nucleophilic aromatic substitution.

The chemical reaction ranks under electrophilic aromatic substitutions followed by an elimination of water and then a second aromatic substitution.

In contrast to aromatic nitration and other electrophilic aromatic substitutions this reaction is reversible.

Structurally they can be classified according to the functional groups ' locations as alpha-( α -), beta-( β -), gamma-( γ -) or delta-( δ -) amino acids ; other categories relate to polarity, acid / base / neutral, and side chain group type ( including: aliphatic, acyclic, hydroxyl or sulphur-containing, aromatic ).

In organic chemistry, phenols, sometimes called phenolics, are a class of chemical compounds consisting of a hydroxyl group (— OH ) bonded directly to an aromatic hydrocarbon group.

The reaction mechanism for this reaction is based on a catalytic cycle with cyanuric chloride activating the hydroxyl group via a nucleophilic aromatic substitution.

The name derives from poly -, from the ancient Greek word πολύς ( polus, meaning " many, much ") and the word phenol which refers to a chemical structure formed by attaching to an aromatic benzenoid ( phenyl ) ring, an hydroxyl (- OH ) group akin to that found in alcohols ( hence the "- ol " suffix ).

Individual polyphenols engage in reactions related to their core structure — standard phenolic reactions ( e. g., ionization, oxidations to ortho-and para-quinones, and other underlying aromatic transformations related to the presence of the phenolic hydroxyl, etc.

Phenols are aromatic compounds with a hydroxyl functional group.

Anisoyl chloride ( also called methoxybenzoyl chloride ) is an acyl halide, specifically an aromatic acyl chloride, and may be formed from anisic acid by replacing a hydroxyl group with a chloride group.

The chemicals are similar in structure ; the only difference is the location of the aromatic hydroxyl group.

Due to the aromatic hydroxyl group, the pharmacological profile is different to ephedrine ; synephrine as a catecholamine analog is acting predominantly on peripheral adrenergic receptors and does not have a pronounced effect on the CNS.

In the Meisenheimer complex, the nonbonded electrons of the carbanion become bonded to the aromatic pi system which allows the ipso carbon to temporarily bond with the hydroxyl group (- OH ).

The Apiaceae ( or Umbelliferae ), commonly known as carrot or parsley family, is a group of mostly aromatic plants with hollow stems.

Many plants of this group are also adapted to conditions that encourage heavy concentrations of essential oils, and as a result some are flavourful aromatic herbs.

It is aromatic because of the purine functional group.

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.

The 5-membered aromatic heterocycle of tryptophan is cleaved and rearranged with the alpha amino group of tryptophan into the 6-membered aromatic heterocycle of niacin.

* A shorthand representation for an aromatic functional group in organic chemistry.

Monoamine neurotransmitters are neurotransmitters and neuromodulators that contain one amino group that is connected to an aromatic ring by a two-carbon chain (- CH < sub > 2 </ sub >- CH < sub > 2 </ sub >-).

A stronger reagent, oleum, is needed to introduce the second nitro group onto the aromatic ring.

An explanation for the exceptional stability of benzene is conventionally attributed to Sir Robert Robinson, who was apparently the first ( in 1925 ) to coin the term aromatic sextet as a group of six electrons that resists disruption.

They are a widely occurring natural and manufactured group of aromatic organic compounds which are categorized as phenols ( sometimes called phenolics ).

Aliphatic and aromatic hydrogen atoms were included implicitly by representing the carbon atom and attached hydrogen atoms as a single group centered on the carbon atom, a united atom force field.

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.

In the context of organic molecules, aryl refers to any functional group or substituent derived from an aromatic ring, be it phenyl, naphthyl, thienyl, indolyl, etc.

* Phenyl group, either-Ph or Φ, highly-stable and aromatic hydrocarbon unit found in many organic compounds

On the molecular level, all auxins are compounds with an aromatic ring and a carboxylic acid group.

When the dye contains an electron-donating and an electron-accepting group at opposite ends of the aromatic system, this dye will probably be sensitive to the environment's polarity ( solvatochromic ), hence called environment-sensitive.