A Diels-Alder super diene breaking benzene into C2H2 and C4H4 units

作者：Inagaki Yusuke; Nakamoto Masaaki; Sekiguchi Akira^*

来源：Nature Communications, 2014, 5(1): 3018.

DOI：10.1038/ncomms4018

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 degrees 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.

• 出版日期2014-1