Quaternary carbon
| quaternary carbon |
|---|
| File:Neopentan (Quartäre Kohlenstoffatome) V1.svg |
| Structural formula of neopentane (quaternary carbon is highlighted red) |
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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) |
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| Partial Structural formula |
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Synthesis
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
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- ↑ Script error: No such module "citation/CS1".
- ↑ 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}}
- ↑ Quasdorf, K.W.; Overman, L. E. Nature Volume 2014, Volume 516, Pages 181 {{doi:10.1038/nature14007}}
- ↑ Script error: No such module "Citation/CS1".
- ↑ Ishizaki, M.; Niimi, Y.; Hoshino, O.; Hara, H.; Takahashi, T. Tetrahedron Volume 2001, Issue 61, Pages 4053–4065