Tetrabutylammonium hydroxide

Tetrabutylammonium hydroxide

Names
IUPAC name tetrabutylammonium hydroxide
Identifiers
CAS Number	2052-49-5
ChEMBL	ChEMBL1078154
ChemSpider	2005872
Jmol 3D model	Interactive image
PubChem	2723671
InChI InChI=1S/C16H36N.H2O/c1-5-9-13-17(14-10-6-2,15-11-7-3)16-12-8-4;/h5-16H2,1-4H3;1H2/q+1;/p-1 Key: VDZOOKBUILJEDG-UHFFFAOYSA-M InChI=1/C16H36N.H2O/c1-5-9-13-17(14-10-6-2,15-11-7-3)16-12-8-4;/h5-16H2,1-4H3;1H2/q+1;/p-1 Key: VDZOOKBUILJEDG-REWHXWOFAE
SMILES [OH-].CCCC[N+](CCCC)(CCCC)CCCC
Properties
Chemical formula	C16H37NO
Molar mass	259.48 g·mol^−1
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Infobox references

Tetrabutylammonium hydroxide is the chemical compound with the formula (C₄H₉)₄NOH, abbreviated Bu₄NOH with the acronym TBAOH or TBAH. This species is employed as a solution in water or alcohols. It is a common base in organic chemistry. Relative to more conventional inorganic bases, such as KOH and NaOH, Bu₄NOH is more soluble in organic solvents.^[1]

Reactions

Attempted isolation of Bu₄NOH induces Hofmann elimination, leading to Bu₃N and 1-butene. Solutions of Bu₄NOH are typically contaminated with Bu₃N for this reason.^[1]

Treatment of Bu₄NOH with a wide range of acids gives water and the other tetrabutylammonium salts:

Bu₄NOH + HX → Bu₄NX + H₂O

Applications

Bu₄NOH is a strong base that is used often under phase-transfer conditions to effect alkylations and deprotonations. Typical reactions include benzylation of amines and generation of dichlorocarbene from chloroform.

Bu₄NOH can be neutralized with a variety of mineral acids to give lipophilic salts of the conjugate base. For example, treatment of Bu₄NOH with disodium pyrophosphate, Na₂H₂P₂O₇, gives (Bu₄N)₃[HP₂O₇], which is soluble in organic solvents.^[2] Similarly, neutralization of Bu₄NOH with hydrofluoric acid affords an relatively water-free Bu₄NF. This salt dissolves in organic solvents and is useful to desilylation.^[3]

References

1. Bos, M. E. "Tetra-n-butylammonium Hydroxide" in Encyclopedia of Reagents for Organic Synthesis (Ed: L. Paquette) 2004, J. Wiley & Sons, New York. doi:10.1002/047084289.
2. Woodside, A. B.; Huang, Z.; Poulter, C. D. (1993). "Trisammonium Geranyl Diphosphate". Org. Synth.; Coll. Vol. 8, p. 616
3. Kuwajima, I.; Nakamura, E. Hashimoto, K. (1990). "Silylation of Ketones with Ethyl Trimethylsilacetate: (Z)-3-Trimethylsiloxy-2-Pentene". Org. Synth.; Coll. Vol. 7, p. 512