Cargando…

A Diels–Alder super diene breaking benzene into C(2)H(2) and C(4)H(4) units

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...

Descripción completa

Detalles Bibliográficos
Autores principales: Inagaki, Yusuke, Nakamoto, Masaaki, Sekiguchi, Akira
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Nature Pub. Group 2014
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3941017/
https://www.ncbi.nlm.nih.gov/pubmed/24398593
http://dx.doi.org/10.1038/ncomms4018
Descripción
Sumario: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 C(2)H(2) and C(4)H(4) 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.