Cumulenes have attracted considerable attention due to their unique structural and electronic properties. Despite their high potential for constructing condensed π-conjugated molecules, the synthetic utility of longer cumulenes remains to be established owing to their inherently high reactivity. Conjugated bisbutatrienes having two cumulene moieties linked by a spacer as a mimic of a longer cumulene were evaluated. Here, the synthesis and characterization of hexafluorocyclopentane-bridged bisbutatrienes are described. These bisbutatrienes underwent various cyclizations, to construct the unique π-extended frameworks inaccessible by other methodologies. The bisbutatrienes were converted into fulvenes, pentalene, germacycle, and benzocyclobutene under various conditions. Furthermore, a cyclooctatetraene derivative was synthesized by a one-step dimerization of the bisbutatriene.
Keywords: Butatriene; Cumulene; Cyclization; Cyclooctatetraene; Pentalene.
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