Quaternary carbon

quaternary carbon
Structural formula of neopentane (quaternary carbon is highlighted red)

A quaternary carbon is a carbon atom bound to four other carbon atoms.[1] For this reason, quaternary carbon atoms are found only in hydrocarbons having at least five carbon atoms. Quaternary carbon atoms can occur in branched alkanes, but not in linear alkanes.[2]

primary carbon secondary carbon tertiary carbon quaternary carbon
General structure
(R = Organyl group) 		frameless=1.0 frameless=1.0 frameless=1.0 frameless=1.0
Partial
Structural formula 		frameless=1.0 frameless=1.0 frameless=1.0 frameless=1.0

Synthesis

Bis-Phenol A synthesis from acetone and phenol

The formation of chiral quaternary carbon centers has been a synthetic challenge. Chemists have developed asymmetric Diels–Alder reactions,[3] Heck reaction, Enyne cyclization, cycloaddition reactions,[4] C–H activation, Allylic substitution,[5] Pauson–Khand reaction,[6] etc. to construct asymmetric quaternary carbon atoms.

One of the most industrially important compounds containing a quaternary carbon is bis-phenol A (BPA). The central atom is a quaternary carbon. Retrosynthetically, that carbon is the central atom of an acetone molecule before condensation with two equivalents of phenol - BPA Production Process

References

  1. ^ Smith, Janice Gorzynski (2011). "Chapter 4 Alkanes". Organic chemistry (3rd ed.). New York, NY: McGraw-Hill. p. 116. ISBN 978-0-07-337562-5. Archived from the original (Book) on 2018-06-28. Retrieved 2018-06-26.
  2. ^ Hans Peter Latscha, Uli Kazmaier, Helmut Alfons Klein (2016), Organische Chemie: Chemie-Basiswissen II (in German) (7. Auflage ed.), Berlin: Springer Spektrum, p. 40, ISBN 978-3-662-46180-8{{citation}}: CS1 maint: multiple names: authors list (link)
  3. ^ Nicolaou, K. C.; Vassilikogiannakis, G.; Mägerlein, W.; Kranich, R Angew. Chem. Int. Ed. Volume 2001, Issue 40, Pages 2482–2486 {{DOI: 10.1002/1521-3773(20010702)40:13<2482::AID-ANIE2482>3.0.CO;2-A}}
  4. ^ Quasdorf, K.W.; Overman, L. E. Nature Volume 2014, Volume 516, Pages 181 {{doi:10.1038/nature14007}}
  5. ^ Feng C, Kobayashi Y (2013). "Allylic Substitution for Construction of a Chiral Quaternary Carbon Possessing an Aryl Group". J. Org. Chem. 78 (8): 3755–3766. doi:10.1021/jo400248y. PMID 23496084.
  6. ^ Ishizaki, M.; Niimi, Y.; Hoshino, O.; Hara, H.; Takahashi, T. Tetrahedron Volume 2001, Issue 61, Pages 4053–4065