2015/09/13 by Emily G. Mackay, Christopher G. Newton, Henry Toombs‐Ruane +5 · 2 citations
Chemistry · #Synthesis and Properties of Aromatic Compounds #Synthesis and characterization of novel inorganic/organometallic compounds #Cyclization and Aryne Chemistry
paper · doi:10.1021/jacs.5b07445
openalex publication_date 2015/09/13 · openalex created_date 2022/05/12 · openalex updated_date 2026/07/11
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.