A Diels-Alder super diene breaking benzene into C2H2 and C4H4 units.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 24398593.
- Also identified by DOI 10.1038/ncomms4018 and PMC identifier 3941017.
- No licence information is recorded for this record.
- Because redistribution is not established, this page shows the abstract only. Follow the links below for the full text.
Abstract
Cyclic polyene with six carbon atoms (benzene) is very stable, whereas cyclic polyene with four carbon atoms (cyclobutadiene) is extremely unstable. The electron-withdrawing pentafluorophenyl group of a substituted cyclobutadiene lowers the energy of the lowest unoccupied molecular orbital, greatly increasing its reactivity as a diene in Diels-Alder reactions with acetylene, ethylene and even benzene. Here we show that the reaction with benzene occurs cleanly at the relatively low temperature of 120 °C and results in the formal fragmentation of benzene into C2H2 and C4H4 units, via a unique Diels-Alder/retro-Diels-Alder reaction. This is a new example of the rare case where breaking the C-C bond of benzene is possible with no activation by a transition metal.