DABCO

Last updated
DABCO
DABCO (bridgehead) V1.svg
DABCO-3D-balls.png
Names
Preferred IUPAC name
1,4-Diazabicyclo[2.2.2]octane
Other names
Triethylenediamine, TEDA
Identifiers
3D model (JSmol)
ChEBI
ChEMBL
ChemSpider
ECHA InfoCard 100.005.455 OOjs UI icon edit-ltr-progressive.svg
EC Number
  • 205-999-9
PubChem CID
UNII
  • InChI=1S/C6H12N2/c1-2-8-5-3-7(1)4-6-8/h1-6H2 Yes check.svgY
    Key: IMNIMPAHZVJRPE-UHFFFAOYSA-N Yes check.svgY
  • InChI=1S/C6H12N2/c1-2-8-5-3-7(1)4-6-8/h1-6H2
    Key: IMNIMPAHZVJRPE-UHFFFAOYSA-N
  • InChI=1/C6H12N2/c1-2-8-5-3-7(1)4-6-8/h1-6H2
    Key: IMNIMPAHZVJRPE-UHFFFAOYAP
  • C1CN2CCN1CC2
  • N12CCN(CC1)CC2
Properties
C6H12N2
Molar mass 112.176 g·mol−1
AppearanceWhite crystalline powder
Melting point 156 to 160 °C (313 to 320 °F; 429 to 433 K)
Boiling point 174 °C (345 °F; 447 K)
Soluble, hygroscopic
Acidity (pKa)3.0, 8.8 (in water, for conjugated acid) [1]
Hazards
Occupational safety and health (OHS/OSH):
Main hazards
Harmful
GHS labelling:
GHS-pictogram-flamme.svg GHS-pictogram-acid.svg GHS-pictogram-exclam.svg
Danger
H228, H302, H315, H319, H335, H412
P210, P261, P273, P305+P351+P338
NFPA 704 (fire diamond)
[2]
NFPA 704.svgHealth 2: Intense or continued but not chronic exposure could cause temporary incapacitation or possible residual injury. E.g. chloroformFlammability 2: Must be moderately heated or exposed to relatively high ambient temperature before ignition can occur. Flash point between 38 and 93 °C (100 and 200 °F). E.g. diesel fuelInstability 1: Normally stable, but can become unstable at elevated temperatures and pressures. E.g. calciumSpecial hazards (white): no code
2
2
1
Flash point 62 °C (144 °F; 335 K)
Related compounds
Related compounds
Quinuclidine
Tropane
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Yes check.svgY  verify  (what is  Yes check.svgYX mark.svgN ?)

DABCO (1,4-diazabicyclo[2.2.2]octane), also known as triethylenediamine or TEDA, is a bicyclic organic compound with the formula N2(C2H4)3. This colorless solid is a highly nucleophilic tertiary amine base, which is used as a catalyst and reagent in polymerization and organic synthesis. [3]

Contents

It is similar in structure to quinuclidine, but the latter has one of the nitrogen atoms replaced by a carbon atom. Regarding their structures, both DABCO and quinuclidine are unusual in that the methylene hydrogen atoms are eclipsed within each of the three ethylene linkages. Furthermore, the diazacyclohexane rings, of which there are three, adopt the boat conformations, not the usual chair conformations.

Reactions

The pKa of [HDABCO]+ (the protonated derivative) is 8.8, which is almost the same as ordinary alkylamines. The nucleophilicity of the amine is high because the amine centers are unhindered. It is sufficiently basic to promote a variety of coupling reactions.

Catalyst

DABCO is used as a nucleophilic catalyst for:

Baylis Hilman Reaction Scheme.png

Lewis base

Selectfluor F-TEDA-BF4.svg
Selectfluor

The reagent Selectfluor is derived by alkylation of DABCO with dichloromethane following by treatment with fluorine. A colourless salt that tolerates air, Selectfluor has been commercialized for use for electrophilic fluorination. [6]

As an unhindered amine, it is a strong ligand and Lewis base. It forms a crystalline 2:1 adduct with hydrogen peroxide [7] and sulfur dioxide. [8]

Quencher of singlet oxygen

DABCO and related amines are quenchers of singlet oxygen and effective antioxidants, [9] and can be used to improve the lifetime of dyes. This makes DABCO useful in dye lasers and in mounting samples for fluorescence microscopy (when used with glycerol and PBS). [10] DABCO can also be used to demethylate quaternary ammonium salts by heating in dimethylformamide (DMF). [11]

Production

It is produced by thermal reactions of compounds of the type H2NCH2CH2X (X = OH, NH2, or NHR) in the presence of zeolitic catalysts. An idealized conversion is shown for the conversion from ethanolamine: [12]

3 H2NCH2CH2OH → N(CH2CH2)3N + NH3 + 3 H2O

Uses

In chemical and biological defense, activated carbon is impregnated with DABCO for use in filters for masks, collective protection systems, and the like. [13]

Related Research Articles

<span class="mw-page-title-main">Alkylation</span> Transfer of an alkyl group from one molecule to another

Alkylation is a chemical reaction that entails transfer of an alkyl group. The alkyl group may be transferred as an alkyl carbocation, a free radical, a carbanion, or a carbene. Alkylating agents are reagents for effecting alkylation. Alkyl groups can also be removed in a process known as dealkylation. Alkylating agents are often classified according to their nucleophilic or electrophilic character. In oil refining contexts, alkylation refers to a particular alkylation of isobutane with olefins. For upgrading of petroleum, alkylation produces a premium blending stock for gasoline. In medicine, alkylation of DNA is used in chemotherapy to damage the DNA of cancer cells. Alkylation is accomplished with the class of drugs called alkylating antineoplastic agents.

<span class="mw-page-title-main">Imine</span> Organic compound or functional group containing a C=N bond

In organic chemistry, an imine 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 bonds. Imines are common in synthetic and naturally occurring compounds and they participate in many reactions.

In organic chemistry, an acyl chloride is an organic compound with the functional group −C(=O)Cl. Their formula is usually written R−COCl, where R is a side chain. They are reactive derivatives of carboxylic acids. A specific example of an acyl chloride is acetyl chloride, CH3COCl. Acyl chlorides are the most important subset of acyl halides.

<span class="mw-page-title-main">Acyl halide</span> Oxoacid compound with an –OH group replaced by a halogen

In organic chemistry, an acyl halide is a chemical compound derived from an oxoacid by replacing a hydroxyl group with a halide group.

<span class="mw-page-title-main">Trimethylaluminium</span> Chemical compound

Trimethylaluminium is one of the simplest examples of an organoaluminium compound. Despite its name it has the formula Al2(CH3)6 (abbreviated as Al2Me6 or TMA), as it exists as a dimer. This colorless liquid is pyrophoric. It is an industrially important compound, closely related to triethylaluminium.

<span class="mw-page-title-main">Raney nickel</span> Chemical compound

Raney nickel, also called spongy nickel, is a fine-grained solid composed mostly of nickel derived from a nickel–aluminium alloy. Several grades are known, of which most are gray solids. Some are pyrophoric, but most are used as air-stable slurries. Raney nickel is used as a reagent and as a catalyst in organic chemistry. It was developed in 1926 by American engineer Murray Raney for the hydrogenation of vegetable oils. Raney is a registered trademark of W. R. Grace and Company. Other major producers are Evonik and Johnson Matthey.

<span class="mw-page-title-main">1,8-Diazabicyclo(5.4.0)undec-7-ene</span> Chemical compound

1,8-Diazabicyclo[5.4.0]undec-7-ene, or more commonly DBU, is a chemical compound and belongs to the class of amidine compounds. It is used in organic synthesis as a catalyst, a complexing ligand, and a non-nucleophilic base.

<i>N</i>,<i>N</i>-Diisopropylethylamine Chemical compound

N,N-Diisopropylethylamine, or Hünig's base, is an organic compound that is a tertiary amine. It is named after the German chemist Siegfried Hünig. It is used in organic chemistry as a non-nucleophilic base. It is commonly abbreviated as DIPEA,DIEA, or i-Pr2NEt.

In organic chemistry, the Menshutkin reaction converts a tertiary amine into a quaternary ammonium salt by reaction with an alkyl halide. Similar reactions occur when tertiary phosphines are treated with alkyl halides.

<span class="mw-page-title-main">Finkelstein reaction</span> Chemistry

The Finkelstein reaction, named after the German chemist Hans Finkelstein, is a type of SN2 reaction that involves the exchange of one halogen atom for another. It is an equilibrium reaction, but the reaction can be driven to completion by exploiting the differential solubility of various halide salts, or by using a large excess of the desired halide.

Diisopropylamine is a secondary amine with the chemical formula (Me2CH)2NH (Me = methyl). Diisopropylamine is a colorless liquid with an ammonia-like odor. Its lithium derivative, lithium diisopropylamide, known as LDA is a widely used reagent.

The reduction of nitro compounds are chemical reactions of wide interest in organic chemistry. The conversion can be effected by many reagents. The nitro group was one of the first functional groups to be reduced. Alkyl and aryl nitro compounds behave differently. Most useful is the reduction of aryl nitro compounds.

<span class="mw-page-title-main">Quinuclidine</span> Chemical compound

Quinuclidine is an organic compound with the formula HC(C2H4)3N. It is a bicyclic amine that can be viewed as a tied back version of triethylamine. It is a colorless solid. It is used as a reagent (base) and catalyst. It can be prepared by reduction of quinuclidone.

Selectfluor, a trademark of Air Products and Chemicals, is a reagent in chemistry that is used as a fluorine donor. This compound is a derivative of the nucleophillic base DABCO. It is a colourless salt that tolerates air and even water. It has been commercialized for use for electrophilic fluorination.

In nitrile reduction a nitrile is reduced to either an amine or an aldehyde with a suitable chemical reagent.

Amide reduction is a reaction in organic synthesis where an amide is reduced to either an amine or an aldehyde functional group.

<span class="mw-page-title-main">Carbonyl reduction</span> Organic reduction of any carbonyl group by a reducing agent

In organic chemistry, carbonyl reduction is the conversion of any carbonyl group, usually to an alcohol. It is a common transformation that is practiced in many ways. Ketones, aldehydes, carboxylic acids, esters, amides, and acid halides - some of the most pervasive functional groups, -comprise carbonyl compounds. Carboxylic acids, esters, and acid halides can be reduced to either aldehydes or a step further to primary alcohols, depending on the strength of the reducing agent. Aldehydes and ketones can be reduced respectively to primary and secondary alcohols. In deoxygenation, the alcohol group can be further reduced and removed altogether by replacement with H.

In organic chemistry, the Baylis–Hillman, Morita–Baylis–Hillman, or MBH reaction is a carbon-carbon bond-forming reaction between an activated alkene and a carbon electrophile in the presence of a nucleophilic catalyst, such as a tertiary amine or phosphine. The product is densely functionalized, joining the alkene at the α-position to a reduced form of the electrophile.

Hydroxylamine-<i>O</i>-sulfonic acid Chemical compound

Hydroxylamine-O-sulfonic acid (HOSA) or aminosulfuric acid is the inorganic compound with molecular formula H3NO4S that is formed by the sulfonation of hydroxylamine with oleum. It is a white, water-soluble and hygroscopic, solid, commonly represented by the condensed structural formula H2NOSO3H, though it actually exists as a zwitterion and thus is more accurately represented as +H3NOSO3. It is used as a reagent for the introduction of amine groups (–NH2), for the conversion of aldehydes into nitriles and alicyclic ketones into lactams (cyclic amides), and for the synthesis of variety of nitrogen-containing heterocycles.

<span class="mw-page-title-main">3-Quinuclidone</span> Chemical compound

3-Quinuclidinone is a bicyclic organic compounds with chemical formula HC(C2H4)2(C CH2)N. Its basicity is indicated by the pKa of the conjugate acid, which is 7.2. In contrast quinuclidine is about 100x more basic.

References

  1. D. H. Ripin; D. A. Evans (2002). "pKa's of Nitrogen Acids" (PDF).
  2. "Safety data for 1,4-diazabicyclo[2.2.2]octane (see MSDS)". Sigma-Aldrich.
  3. Uppuluri V. Mallavadhani, Nicolas Fleury-Bregeot. "1,4-Diazabicyclo [2.2.2]octane". In Encyclopedia of Reagents for Organic Synthesis, 2010, John Wiley & Sons, Ltd. doi : 10.1002/047084289X.rd010m.pub2
  4. "Polyurethane additives guide" (PDF). Air Products & Chemicals. Archived from the original (PDF) on 2016-03-06.
  5. Baylis, A. B.; Hillman, M. E. D. German Patent 2155113, 1972.
  6. Banks, R. Eric; Murtagh, Vincent; An, Ilhwan; Maleczka, Robert E. (2007). "1-(Chloromethyl)-4-fluoro-1,4-diazoniabicyclo[2.2.2]octane Bis(tetrafluoroborate)". Encyclopedia of Reagents for Organic Synthesis. doi:10.1002/047084289X.rc116.pub2. ISBN   978-0471936237.
  7. P. Dembech, A. Ricci, G. Seconi, and M. Taddei "Bis(trimethylsilyl) Peroxide" Org. Synth. 1997, volume 74, pp. 84. doi : 10.15227/orgsyn.074.0084
  8. Ludovic Martial and Laurent Bischoff "Preparation of DABSO from Karl-Fischer Reagent" Org. Synth. 2013, volume 90, pp. 301. doi : 10.15227/orgsyn.090.0301
  9. Ouannes, C.; Wilson, T. (1968). "Quenching of singlet oxygen by tertiary aliphatic amines. Effect of DABCO (1,4-diazabicyclo[2.2.2]octane)". Journal of the American Chemical Society . 90 (23): 6527–6528. doi:10.1021/ja01025a059.
  10. Valnes, K.; Brandtzaeg, P. (1985). "Retardation of immunofluorescence fading during microscopy". Journal of Histochemistry and Cytochemistry. 33 (8): 755–761. doi: 10.1177/33.8.3926864 . PMID   3926864.
  11. Ho, T. L. (1972). "Dealkylation of Quaternary Ammonium Salts with 1,4-Diazabicyclo[2.2.2]octane". Synthesis . 1972 (12): 702. doi:10.1055/s-1972-21977.
  12. Karsten Eller, Erhard Henkes, Roland Rossbacher, Hartmut Höke "Amines, Aliphatic" in Ullmann's Encyclopedia of Industrial Chemistry, Wiley-VCH, Weinheim, 2005. doi : 10.1002/14356007.a02_001
  13. Mahle, J.; et al. (2010). "Role of TEDA as an Activated Carbon Impregnant for the Removal of Cyanogen Chloride from Air Streams: Synergistic Effect with Cu(II)". Journal of Physical Chemistry C. 114 (47): 20083–20090. doi:10.1021/jp106730j . Retrieved 2022-03-17.

Further reading