| Autor: |
Mackay EG; Research School of Chemistry, Australian National University , Canberra, Australian Capital Territory 2601, Australia., Newton CG; Research School of Chemistry, Australian National University , Canberra, Australian Capital Territory 2601, Australia., Toombs-Ruane H; Research School of Chemistry, Australian National University , Canberra, Australian Capital Territory 2601, Australia., Lindeboom EJ; Research School of Chemistry, Australian National University , Canberra, Australian Capital Territory 2601, Australia., Fallon T; Research School of Chemistry, Australian National University , Canberra, Australian Capital Territory 2601, Australia., Willis AC; Research School of Chemistry, Australian National University , Canberra, Australian Capital Territory 2601, Australia., Paddon-Row MN; School of Chemistry, The University of New South Wales , Sydney, New South Wales 2052, Australia., Sherburn MS; Research School of Chemistry, Australian National University , Canberra, Australian Capital Territory 2601, Australia. |
| Abstrakt: |
The [n]radialenes are a unique family of fundamental [n]-membered carbocyclic structures with radiating alkenes, which have attracted significant synthetic and theoretical attention. Whereas [3]-, [4]-, and [6]radialenes have been prepared and studied, all efforts to synthesize the five-membered ring compound have thus far met with failure. Here we describe the first synthesis of the fundamental hydrocarbon [5]radialene, C10H10. Our approach was a departure from previous radialene syntheses in that it utilized a low-temperature decomplexation of a stable organometallic compound, rather than high-temperature elimination or rearrangement. Our strategy was guided by analysis of previous radialene syntheses, which indicated rapid decomposition in oxygen, and ab initio calculations, which revealed an extraordinary susceptibility of [5]radialene to undergo Diels-Alder dimerization/polymerization. The origin of this susceptibility was traced to a small distortion energy associated with the formation of the transition structure geometry from the relaxed reactant monomers and to a narrow HOMO-LUMO gap. |
