Quinuclidine

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.

Quinuclidine[1]
Skeletal formula of quinuclidine
Skeletal formula of quinuclidine
Ball-and-stick model of quinuclidine
Ball-and-stick model of quinuclidine
Names
Preferred IUPAC name
1-Azabicyclo[2.2.2]octane[2]
Other names
Quinuclidine[2]
Identifiers
3D model (JSmol)
103111
ChEBI
ChEMBL
ChemSpider
ECHA InfoCard 100.002.625
EC Number
  • 202-887-1
26726
UNII
  • InChI=1S/C7H13N/c1-4-8-5-2-7(1)3-6-8/h7H,1-6H2 checkY
    Key: SBYHFKPVCBCYGV-UHFFFAOYSA-N checkY
  • InChI=1/C7H13N/c1-4-8-5-2-7(1)3-6-8/h7H,1-6H2
    Key: SBYHFKPVCBCYGV-UHFFFAOYAA
  • N12CCC(CC1)CC2
Properties
C7H13N
Molar mass 111.188 g·mol−1
Density 0.97 g/cm3
Melting point 157 to 160 °C (315 to 320 °F; 430 to 433 K)
Boiling point 149.5 °C (301.1 °F; 422.6 K) at 760 mmHg
Acidity (pKa) 11.0 (conjugate acid)
Hazards
GHS labelling:[3]
GHS05: CorrosiveGHS06: ToxicGHS07: Exclamation mark
Danger
H301, H310, H315, H318
P262, P264, P264+P265, P270, P280, P301+P316, P302+P352, P305+P354+P338, P316, P317, P321, P330, P332+P317, P361+P364, P362+P364, P405, P501
Flash point 36.5 °C (97.7 °F; 309.6 K)
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
☒N verify (what is checkY☒N ?)
Infobox references

Structure and chemical properties

Regarding its structure, quinuclidine is unusual in that the methylene hydrogen atoms are eclipsed within each of the three ethylene linkages. Furthermore, the cyclohexane rings, of which there are three, adopt the chair conformations, not the usual boat conformations.[4]

Quinuclidine is a relatively strong organic base with pKa of the conjugate acid of 11.3.[5] The basicity of other quinuclidines have been evaluated: 3-hydroxy- quinuclidine (9.9), 3-acetoxyquinuclidine (9.3), 3-chloroquinuclidine (8.9), DABCO (8.7), and 3-quinuclidone (7.2).[6]

It forms adducts with a variety of Lewis acids. Because of its compact structure, quinuclidine binds to trimethylborane more tightly than does triethylamine.[7]

Derivatives and analogues

Quinine is a quinuclidine derivative.

Quinuclidine is structurally related to DABCO, in which the other bridgehead is also nitrogen, and to tropane, which has a slightly different carbon frame. Cinchona alkaloids, e.g. quinine, feature quinuclidine substituents.[7] Aceclidine, a simple quinuclidine derivative, is a drug used for treatment of glaucoma.

References

  1. Quinuclidine Archived October 15, 2007, at the Wayback Machine at Sigma-Aldrich
  2. Nomenclature of Organic Chemistry : IUPAC Recommendations and Preferred Names 2013 (Blue Book). Cambridge: The Royal Society of Chemistry. 2014. p. 169. doi:10.1039/9781849733069-FP001. ISBN 978-0-85404-182-4. The name quinuclidine is retained for general nomenclature only (see Table 2.6).
  3. "Quinuclidine". pubchem.ncbi.nlm.nih.gov.
  4. Blackstock, S. C.; Lorand, J. P.; Kochi, J. K. (1987). "Charge-Rransfer Interactions of Amines with Tetrahalomethanes. X-Ray Crystal Structures of the Donor-Acceptor Complexes of Quinuclidine and Diazabicyclo [2.2.2]Octane with Carbon Tetrabromide". The Journal of Organic Chemistry. 52 (8): 1451–1460. doi:10.1021/jo00384a013.
  5. Hext, N. M.; Hansen, J.; Blake, A. J.; Hibbs, D. E.; Hursthouse, M. B.; Shishkin, O. V.; Mascal, M. (1998). "Azatriquinanes: Synthesis, Structure, and Reactivity". J. Org. Chem. 63 (17): 6016–6020. doi:10.1021/jo980788s. PMID 11672206.
  6. Aggarwal, Varinder K.; Emme, Ingo; Fulford, Sarah Y. (2003). "Correlation between pKa and Reactivity of Quinuclidine-Based Catalysts in the Baylis−Hillman Reaction: Discovery of Quinuclidine as Optimum Catalyst Leading to Substantial Enhancement of Scope". The Journal of Organic Chemistry. 68 (3): 692–700. doi:10.1021/jo026671s. PMID 12558387.
  7. Hamama, Wafaa S.; El-Magid, Osama. M. Abd; Zoorob, Hanafi H. (2006). "Chemistry of quinuclidines as nitrogen bicyclic bridged-ring structures". Journal of Heterocyclic Chemistry. 43 (6): 1397–1420. doi:10.1002/jhet.5570430601.
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