Cubane

Cubane (C₈H₈) is a synthetic strained and hence unstable. Surprisingly, once formed, cubane is actually quite kinetically stable due to a lack of readily available decomposition paths.

Cubane and its derivative compounds have many important properties. The 90-degree bonding angle of the carbon atoms in cubane means that the bonds are highly strained. Therefore, cubane compounds are highly reactive, which in principle may make them useful as high-density, high-energy fuels and explosives. Cubane also has the highest density of any hydrocarbon, further contributing to its ability to store large amounts of energy. Researchers are looking into using cubane and similarly synthesized cubic molecules in medicine and nanotechnology.

Synthesis

The original 1964 cubane organic synthesis is a classic and starts from 2-cyclopentenone (compound 1.1 in scheme 1)^[1][2]:

Reaction with diethyl ether to bromocyclopentadienone 1.4

In the second part (scheme 2), the spontaneous hydrochloric acid to 2.3

In the next step endo isomer 2.3 with both pyridine) to 2.7. then the acetal is once more removed in 2.8, another Favorskii rearrangement gives 2.9 and finally another decarboxylation 2.10 and 2.11.

Inorganic cubes and related derivatives

The cube motif occurs outside of the area of organic chemistry. A prevalent non-organic cube are the [Fe₄-S₄] clusters found pervasively Ph₃PAg)₄I₄,

See also

• Octanitrocubane (explosive)
• Heptanitrocubane (explosive)
• dodecahedrane

References

1. ^ ^{a b} Cubane Philip E. Eaton and Thomas W. Cole J. Am. Chem. Soc.; 1964; 86(15) pp 3157 - 3158; doi:10.1021/ja01069a041.
2. ^ The Cubane System Philip E. Eaton and Thomas W. Cole J. Am. Chem. Soc.; 1964; 86(5) pp 962 - 964; doi:10.1021/ja01059a072