Tetrabutylammonium hydroxide is the

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 ele ...

with the formula (C₄H₉)₄NOH, abbreviated Bu₄NOH with the acronym TBAOH or TBAH. This species is employed as a solution in water or

alcohol Alcohol most commonly refers to: * Alcohol (chemistry), an organic compound in which a hydroxyl group is bound to a carbon atom * Alcohol (drug), an intoxicant found in alcoholic drinks Alcohol may also refer to: Chemicals * Ethanol, one of sev ...

s. It is a common base in

organic chemistry Organic chemistry is a subdiscipline within chemistry involving the science, 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.Clay ...

. Relative to more conventional inorganic bases, such as KOH and

NaOH Sodium hydroxide, also known as lye and caustic soda, is an inorganic compound with the formula NaOH. It is a white solid ionic compound consisting of sodium cations and hydroxide anions . Sodium hydroxide is a highly caustic base and alkali ...

, Bu₄NOH is more soluble in organic solvents..

Preparation and reactions

Solutions of Bu₄NOH are usually prepared ''in situ'' from butylammonium halides, Bu₄NX, for example by reacting them with

silver oxide Silver oxide is the chemical compound with the formula Ag2O. It is a fine black or dark brown powder that is used to prepare other silver compounds. Preparation Silver oxide can be prepared by combining aqueous solutions of silver nitrate and ...

or using an

ion exchange resin An ion-exchange resin or ion-exchange polymer is a resin or polymer that acts as a medium for ion exchange. It is an insoluble matrix (or support structure) normally in the form of small (0.25–1.43 mm radius) microbeads, usually white or ...

. Attempts to isolate Bu₄NOH induces

Hofmann elimination Hofmann elimination is an elimination reaction of an amine to form alkenes. The least stable alkene (the one with the least number of substituents on the carbons of the double bond), called the Hofmann product, is formed. This tendency, known as ...

, leading to Bu₃N and

1-butene 1-Butene (or 1-Butylene) is the organic compound with the formula CH3CH2CH=CH2. It is a colorless gas that is easily condensed to give a colorless liquid. It is classified as a linear alpha-olefin. It is one of the isomers of butene (butylene ...

. Solutions of Bu₄NOH are typically contaminated with Bu₃N for this reason. Treatment of Bu₄NOH with a wide range of acids gives water and the other

tetrabutylammonium Tetrabutylammonium is a quaternary ammonium cation with the formula (C4H9)4sup>+. It is used in the research laboratory to prepare lipophilic salts of inorganic anions. Relative to tetraethylammonium derivatives, tetrabutylammonium salts are more ...

salts: Bu4NOH + HX -> Bu4NX + H2O

Applications

Bu₄NOH is a strong base that is used often under phase-transfer conditions to effect

alkylation Alkylation is the transfer of an alkyl group from one molecule to another. The alkyl group may be transferred as an alkyl carbocation, a free radical, a carbanion, or a carbene (or their equivalents). Alkylating agents are reagents for effectin ...

s and

deprotonation Deprotonation (or dehydronation) is the removal (transfer) of a proton (or hydron, or hydrogen cation), (H+) from a Brønsted–Lowry acid in an acid–base reaction.Henry Jakubowski, Biochemistry Online Chapter 2A3, https://employees.csbsju. ...

s. Typical reactions include

benzyl In organic chemistry, benzyl is the substituent or molecular fragment possessing the structure . Benzyl features a benzene ring () attached to a methylene group () group. Nomenclature In IUPAC nomenclature, the prefix benzyl refers to a subst ...

ation of amines and generation of

dichlorocarbene Dichlorocarbene is the reactive intermediate with chemical formula CCl2. Although this chemical species has not been isolated, it is a common intermediate in organic chemistry, being generated from chloroform. This bent diamagnetic molecule rapidly ...

from

chloroform Chloroform, or trichloromethane, is an organic compound with formula C H Cl3 and a common organic solvent. It is a colorless, strong-smelling, dense liquid produced on a large scale as a precursor to PTFE. It is also a precursor to various re ...

. Bu₄NOH can be

neutralize Neutralization may refer to: * Neutralization (chemistry), a chemical reaction where a base and an acid react to form a salt * Neutralisation (immunology), pathogen neutralization caused by antibodies * Neutralisation (sociology) * Neutralizati ...

d with a variety of

mineral acid A mineral acid (or inorganic acid) is an acid derived from one or more inorganic compounds, as opposed to organic acids which are acidic, organic compounds. All mineral acids form hydrogen ions and the conjugate base when dissolved in water. Ch ...

s to give lipophilic salts of the

conjugate base A conjugate acid, within the Brønsted–Lowry acid–base theory, is a chemical compound formed when an acid donates a proton () to a base—in other words, it is a base with a hydrogen ion added to it, as in the reverse reaction it loses a ...

. For example, treatment of Bu₄NOH with disodium pyrophosphate, Na₂H₂P₂O₇, gives (Bu₄N)₃ P₂O₇ which is soluble in organic solvents. Similarly, neutralization of Bu₄NOH with

hydrofluoric acid Hydrofluoric acid is a solution of hydrogen fluoride (HF) in water. Solutions of HF are colourless, acidic and highly corrosive. It is used to make most fluorine-containing compounds; examples include the commonly used pharmaceutical antidepr ...

affords an relatively water-free Bu₄NF. This salt dissolves in organic solvents and is useful to desilylation.{{OrgSynth , authors = Kuwajima, I.; Nakamura, E.; Hashimoto, K. , title = Silylation of Ketones with Ethyl Trimethylsilacetate: (Z)-3-Trimethylsiloxy-2-Pentene , collvol = 7 , collvolpages = 512 , year = 1990 , prep = CV7P0512

References

Tetrabutylammonium salts Hydroxides