organic chemistry Organic chemistry is a subdiscipline within chemistry involving the scientific study of the structure, properties, and reactions of organic compounds and organic materials, i.e., matter in its various forms that contain carbon atoms.Clayden, J.; ...

, a nucleophilic addition reaction is an

addition reaction In organic chemistry, an addition reaction is, in simplest terms, an organic reaction where two or more molecules combine to form a larger one (the adduct).. Addition reactions are limited to chemical compounds that have multiple bonds, such as ...

where a

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 ...

with an

electrophilic In chemistry, an electrophile is a chemical species that forms bonds with nucleophiles by accepting an electron pair. Because electrophiles accept electrons, they are Lewis acids. Most electrophiles are positively charged, have an atom that carri ...

double A double is a look-alike or doppelgänger; one person or being that resembles another. Double, The Double or Dubble may also refer to: Film and television * Double (filmmaking), someone who substitutes for the credited actor of a character * Th ...

triple bond A triple bond in chemistry is a chemical bond between two atoms involving six bonding electrons instead of the usual two in a covalent single bond. Triple bonds are stronger than the equivalent single bonds or double bonds, with a bond order o ...

reacts with a

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 ...

, such that the double or triple bond is broken. Nucleophilic additions differ from electrophilic additions in that the former reactions involve the group to which atoms are added accepting electron pairs, whereas the latter reactions involve the group donating electron pairs.

Addition to carbon–heteroatom double bonds

Nucleophilic addition reactions of nucleophiles with electrophilic double or triple bond (π bonds) create a new carbon center with two additional single, or σ, bonds.March Jerry; (1985). Advanced Organic Chemistry reactions, mechanisms and structure (3rd ed.). New York: John Wiley & Sons, inc. Addition of a nucleophile to carbon–heteroatom double or triple bonds such as >C=O or -C≡N show great variety. These types of bonds are

polar Polar may refer to: Geography Polar may refer to: * Geographical pole, either of two fixed points on the surface of a rotating body or planet, at 90 degrees from the equator, based on the axis around which a body rotates * Polar climate, the c ...

(have a large difference in

electronegativity Electronegativity, symbolized as , is the tendency for an atom of a given chemical element to attract shared electrons (or electron density) when forming a chemical bond. An atom's electronegativity is affected by both its atomic number and the d ...

between the two atoms); consequently, their carbon atoms carries a partial positive charge. This makes the molecule an electrophile, and the carbon atom the electrophilic center; this atom is the primary target for the nucleophile. Chemists have developed a geometric system to describe the approach of the nucleophile to the electrophilic center, using two angles, the Bürgi–Dunitz and the Flippin–Lodge angles after scientists that first studied and described them. : This type of reaction is also called a 1,2-nucleophilic addition. The

stereochemistry Stereochemistry, a subdiscipline of chemistry, involves the study of the relative spatial arrangement of atoms that form the structure of molecules and their manipulation. The study of stereochemistry focuses on the relationships between stereois ...

of this type of nucleophilic attack is not an issue, when both alkyl substituents are dissimilar and there are not any other controlling issues such as

chelation Chelation is a type of bonding of ions and molecules to metal ions. It involves the formation or presence of two or more separate coordinate bonds between a Denticity, polydentate (multiple bonded) ligand and a single central metal atom. These l ...

with a

Lewis acid A Lewis acid (named for the American physical chemist Gilbert N. Lewis) is a chemical species that contains an empty orbital which is capable of accepting an electron pair from a Lewis base to form a Lewis adduct. A Lewis base, then, is any sp ...

, the reaction product is a

racemate In chemistry, a racemic mixture, or racemate (), is one that has equal amounts of left- and right-handed enantiomers of a chiral molecule or salt. Racemic mixtures are rare in nature, but many compounds are produced industrially as racemates. ...

. Addition reactions of this type are numerous. When the addition reaction is accompanied by an elimination the reaction type is

nucleophilic acyl substitution Nucleophilic acyl substitution describe a class of substitution reactions involving nucleophiles and acyl compounds. In this type of reaction, a nucleophile – such as an alcohol, amine, or enolate – displaces the leaving group of an acyl deriv ...

or an addition-elimination reaction.

Addition to carbonyl groups

With a carbonyl compound as an electrophile, the nucleophile can be: *

water Water (chemical formula ) is an inorganic, transparent, tasteless, odorless, and nearly colorless chemical substance, which is the main constituent of Earth's hydrosphere and the fluids of all known living organisms (in which it acts as a ...

hydration Hydration may refer to: * Hydrate, a substance that contains water * Hydration enthalpy, energy released through hydrating a substance * Hydration reaction, a chemical addition reaction where a hydroxyl group and proton are added to a compound * ...

to a

geminal In chemistry, the descriptor geminal () refers to the relationship between two atoms or functional groups that are attached to the same atom. A geminal diol, for example, is a diol (a molecule that has two alcohol functional groups) attached t ...

diol (hydrate) * an alcohol in

acetalisation In organic chemistry, an acetal is a functional group with the connectivity . Here, the R groups can be organic fragments (a carbon atom, with arbitrary other atoms attached to that) or hydrogen, while the R' groups must be organic fragments no ...

to an

acetal In organic chemistry, an acetal is a functional group with the connectivity . Here, the R groups can be organic fragments (a carbon atom, with arbitrary other atoms attached to that) or hydrogen, while the R' groups must be organic fragments n ...

* a

hydride In chemistry, a hydride is formally the anion of hydrogen( H−). The term is applied loosely. At one extreme, all compounds containing covalently bound H atoms are called hydrides: water (H2O) is a hydride of oxygen, ammonia is a hydride ...

in reduction to an alcohol * an

amine In chemistry, amines (, ) are compounds and functional groups that contain a basic nitrogen atom with a lone pair. Amines are formally derivatives of ammonia (), wherein one or more hydrogen atoms have been replaced by a substituen ...

with formaldehyde and a carbonyl compound in the

Mannich reaction In organic chemistry, the Mannich reaction is a three-component organic reaction that involves the amino alkylation of an acidic proton next to a carbonyl () functional group by formaldehyde () and a primary or secondary amine () or ammonia (). ...

* an

enolate ion In organic chemistry, alkenols (shortened to enols) are a type of reactive structure or intermediate in organic chemistry that is represented as an alkene ( olefin) with a hydroxyl group attached to one end of the alkene double bond (). The t ...

in an

aldol reaction The aldol reaction is a means of forming carbon–carbon bonds in organic chemistry. Discovered independently by the Russian chemist Alexander Borodin in 1869 and by the French chemist Charles-Adolphe Wurtz in 1872, the reaction combines two c ...

Baylis–Hillman reaction The Baylis–Hillman reaction is a carbon-carbon bond forming reaction between the α-position of an activated alkene and a carbon electrophile such as an aldehyde. Employing a nucleophilic catalyst, such as a tertiary amine and phosphine, this rea ...

* an

organometallic Organometallic chemistry is the study of organometallic compounds, chemical compounds containing at least one chemical bond between a carbon atom of an organic molecule and a metal, including alkali, alkaline earth, and transition metals, and so ...

in the

Grignard reaction The Grignard reaction () is an organometallic chemical reaction in which alkyl, allyl, vinyl, or aryl-magnesium halides ( Grignard reagent) is added to a carbonyl group in an aldehyde or ketone. This reaction is important for the formation of ...

or the related

Barbier reaction The Barbier reaction is an organometallic reaction between an alkyl halide (chloride, bromide, iodide), a carbonyl group and a metal. The reaction can be performed using magnesium, aluminium, zinc, indium, tin, samarium, barium or their salts. ...

or a

Reformatskii reaction The Reformatsky reaction (sometimes misspelled Reformatskii reaction) is an organic reaction which condenses aldehydes or ketones with α-halo esters using metallic zinc to form β-hydroxy-esters: The organozinc reagent, also called a 'Reform ...

ylide An ylide or ylid () is a neutral dipolar molecule containing a formally negatively charged atom (usually a carbanion) directly attached to a heteroatom with a formal positive charge (usually nitrogen, phosphorus or sulfur), and in which both atoms ...

s such as a

Wittig reagent In organic chemistry, Wittig reagents are organophosphorus compounds of the formula R3P=CHR', where R is usually phenyl. They are used to convert ketones and aldehydes to alkenes: : Preparation Because they typically hydrolyze and oxidize readily ...

or the Corey–Chaykovsky reagent or α-silyl carbanions in the

Peterson olefination The Peterson olefination (also called the Peterson reaction) is the chemical reaction of α-silyl carbanions (1 in diagram below) with ketones (or aldehydes) to form a β-hydroxysilane (2) which eliminates to form alkenes (3). Several reviews h ...

* a phosphonate carbanion in the

Horner–Wadsworth–Emmons reaction The Horner–Wadsworth–Emmons (HWE) reaction is a chemical reaction used in organic chemistry of stabilized phosphonate carbanions with aldehydes (or ketones) to produce predominantly E-alkenes. In 1958, Leopold Horner published a modifi ...

* a pyridine zwitterion in the Hammick reaction * an

acetylide In organometallic chemistry, acetylide refers to chemical compounds with the chemical formulas and , where M is a metal. The term is used loosely and can refer to substituted acetylides having the general structure (where R is an organic side c ...

alkynylation In organic chemistry, alkynylation is an addition reaction in which a terminal alkyne () is added to a carbonyl group () to form an Alpha and beta carbon, α-alkynyl alcohol (chemistry), alcohol (). When the acetylide is formed from acetylene () ...

reactions. * a cyanide ion in

cyanohydrin reaction A cyanohydrin reaction is an organic chemical reaction in which an aldehyde or ketone reacts with a cyanide anion or a nitrile to form a cyanohydrin. This nucleophilic addition is a reversible reaction but with aliphatic carbonyl compounds eq ...

s In many nucleophilic reactions, addition to the carbonyl group is very important. In some cases, the C=O

double bond In chemistry, a double bond is a covalent bond between two atoms involving four bonding electrons as opposed to two in a single bond. Double bonds occur most commonly between two carbon atoms, for example in alkenes. Many double bonds exist betw ...

is reduced to a C-O single bond when the nucleophile bonds with carbon. For example, in the cyanohydrin reaction a cyanide ion forms a

C-C bond CC, cc, or C-C may refer to: Arts, entertainment, and media Fictional characters * C.C. (''Code Geass''), a character in the ''Code Geass'' anime series, pronounced "C-two" * C.C. Babcock, a character in the American sitcom ''The Nanny'' * Com ...

by breaking the carbonyl's double bond to form a

cyanohydrin In organic chemistry, a cyanohydrin or hydroxynitrile is a functional group found in organic compounds in which a cyano and a hydroxy group are attached to the same carbon atom. The general formula is , where R is H, alkyl, or aryl. Cyanohydrin ...

Addition to nitriles

With

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 met ...

electrophiles, nucleophilic addition take place by: * hydrolysis of a

to form an

amide In organic chemistry, an amide, also known as an organic amide or a carboxamide, is a compound with the general formula , where R, R', and R″ represent organic groups or hydrogen atoms. The amide group is called a peptide bond when it is ...

or a

carboxylic acid In organic chemistry, a carboxylic acid is an organic acid that contains a carboxyl group () attached to an R-group. The general formula of a carboxylic acid is or , with R referring to the alkyl, alkenyl, aryl, or other group. Carboxylic ...

* organozinc nucleophiles in the

Blaise reaction The Blaise reaction is an organic reaction that forms a β-ketoester from the reaction of zinc metal with a α-bromoester and a nitrile. The reaction was first reported by Edmond Blaise (1872–1939) in 1901. The final intermediate is a metaloim ...

* alcohols in the

Pinner reaction The Pinner reaction refers to the acid catalysed reaction of a nitrile with an alcohol to form an imino ester salt (alkyl imidate salt); this is sometimes referred to as a Pinner salt. The reaction is named after Adolf Pinner, who first describ ...

. * the (same) nitrile α-carbon in the

Thorpe reaction The Thorpe reaction is a chemical reaction described as a self-condensation of aliphatic nitriles catalyzed by base to form enamines. The reaction was discovered by Jocelyn Field Thorpe. Thorpe–Ziegler reaction The Thorpe–Ziegler reaction ...

. The intramolecular version is called the

Thorpe–Ziegler reaction The Thorpe reaction is a chemical reaction described as a self-condensation of aliphatic nitriles catalyzed by base to form enamines. The reaction was discovered by Jocelyn Field Thorpe. Thorpe–Ziegler reaction The Thorpe–Ziegler reaction ...

. *

Grignard reagent A Grignard reagent or Grignard compound is a chemical compound with the general formula , where X is a halogen and R is an organic group, normally an alkyl or aryl. Two typical examples are methylmagnesium chloride and phenylmagnesium bromide ...

s to form

imine In organic chemistry, an imine ( or ) is a functional group or organic compound containing a carbon–nitrogen double bond (). The nitrogen atom can be attached to a hydrogen or an organic group (R). The carbon atom has two additional single bo ...

s. The route affords

ketone In organic chemistry, a ketone is a functional group with the structure R–C(=O)–R', where R and R' can be a variety of carbon-containing substituents. Ketones contain a carbonyl group –C(=O)– (which contains a carbon-oxygen double bo ...

s following

hydrolysis Hydrolysis (; ) is any chemical reaction in which a molecule of water breaks one or more chemical bonds. The term is used broadly for substitution reaction, substitution, elimination reaction, elimination, and solvation reactions in which water ...

or primary

s following imine reduction.

Addition to carbon–carbon double bonds

The driving force for the addition to

alkenes In organic chemistry, an alkene is a hydrocarbon containing a carbon–carbon double bond. Alkene is often used as synonym of olefin, that is, any hydrocarbon containing one or more double bonds.H. Stephen Stoker (2015): General, Organic, an ...

is the formation of a

X⁻ that forms a

covalent bond A covalent bond is a chemical bond that involves the sharing of electrons to form electron pairs between atoms. These electron pairs are known as shared pairs or bonding pairs. The stable balance of attractive and repulsive forces between atoms ...

with an electron-poor unsaturated system -C=C- (step 1). The negative charge on X is transferred to the carbon – carbon bond. : In step 2 the negatively charged

carbanion In organic chemistry, a carbanion is an anion in which carbon is trivalent (forms three bonds) and bears a formal negative charge (in at least one significant resonance form). Formally, a carbanion is the conjugate base of a carbon acid: :R3C ...

combines with (Y) that is electron-poor to form the second covalent bond. Ordinary alkenes are not susceptible to a nucleophilic attack (apolar bond).

Styrene Styrene () is an organic compound with the chemical formula C6H5CH=CH2. This derivative of benzene is a colorless oily liquid, although aged samples can appear yellowish. The compound evaporates easily and has a sweet smell, although high concen ...

reacts in

toluene Toluene (), also known as toluol (), is a substituted aromatic hydrocarbon. It is a colorless, water-insoluble liquid with the smell associated with paint thinners. It is a mono-substituted benzene derivative, consisting of a methyl group (CH3) at ...

with

sodium Sodium is a chemical element with the symbol Na (from Latin ''natrium'') and atomic number 11. It is a soft, silvery-white, highly reactive metal. Sodium is an alkali metal, being in group 1 of the periodic table. Its only stable iso ...

to 1,3-diphenylpropane ''Sodium-catalyzed Side Chain Aralkylation of Alkylbenzenes with Styrene'' Herman Pines, Dieter Wunderlich J. Am. Chem. Soc.; 1958; 80(22)6001–6004. through the intermediate carbanion: : Another exception to the rule is found in the

Varrentrapp reaction The Varrentrapp reaction, also named Varrentrapp degradation, is a name reaction in the organic chemistry. It is named after Franz Varrentrapp, who described this reaction in 1840.F. Varrentrapp, Ann., 36, 196 (1840) The reaction entails the degrad ...

Fullerene A fullerene is an allotrope of carbon whose molecule consists of carbon atoms connected by single and double bonds so as to form a closed or partially closed mesh, with fused rings of five to seven atoms. The molecule may be a hollow sphere, ...

s have unusual

reactivity and additions such as the

Bingel reaction The Bingel reaction in fullerene chemistry is a fullerene cyclopropanation reaction to a methanofullerene first discovered by C. Bingel in 1993 with the bromo derivative of diethyl malonate in the presence of a base such as sodium hydride or DBU ...

are more frequent. When X is a

carbonyl group In organic chemistry, a carbonyl group is a functional group composed of a carbon atom double-bonded to an oxygen atom: C=O. It is common to several classes of organic compounds, as part of many larger functional groups. A compound containing a ...

like C=O or COOR or a

cyanide Cyanide is a naturally occurring, rapidly acting, toxic chemical that can exist in many different forms. In chemistry, a cyanide () is a chemical compound that contains a functional group. This group, known as the cyano group, consists of ...

group (CN), the reaction type is a

conjugate addition reaction Nucleophilic conjugate addition is a type of organic reaction. Ordinary nucleophilic additions or 1,2-nucleophilic additions deal mostly with additions to carbonyl compounds. Simple alkene compounds do not show 1,2 reactivity due to lack of pola ...

. The substituent X helps to stabilize the negative charge on the carbon atom by its

inductive effect In chemistry, the inductive effect in a molecule is a local change in the electron density due to electron-withdrawing or electron-donating groups elsewhere in the molecule, resulting in a permanent dipole in a bond. It is present in a σ (sigma ...

. In addition when Y-Z is an active hydrogen compound the reaction is known as a

Michael reaction In organic chemistry, the Michael reaction or Michael addition is a reaction between a Michael donor (an enolate or other nucleophile) and a Michael acceptor (usually an α,β-unsaturated carbonyl) to produce a Michael adduct by creating a carbon ...

. Perfluorinated alkenes (alkenes that have all hydrogens replaced by

fluorine Fluorine is a chemical element with the symbol F and atomic number 9. It is the lightest halogen and exists at standard conditions as a highly toxic, pale yellow diatomic gas. As the most electronegative reactive element, it is extremely reacti ...

) are highly prone to nucleophilic addition, for example by fluoride ion from caesium fluoride or

silver(I) fluoride Silver(I) fluoride is the inorganic compound with the formula AgF. It is one of the three main fluorides of silver, the others being silver subfluoride and silver(II) fluoride. AgF has relatively few niche applications; it has been employed as ...

to give a perfluoroalkyl anion.

References

{{Authority control * Reaction mechanisms