Synthesis and electrochemical properties of carbocyclic and heterocyclic diazulenylethenes

Article abstract of DOI:10.1002/ejoc.201300354

An efficient two-step method was developed for the synthesis of 1,2-di(azulen-1-yl)ethenes 15-17, having the double bond included in a five-membered carbocyclic or heterocyclic ring. The method involves preparation of the appropriate diketone precursors through Vilsmeier-Haack or Friedel-Crafts reactions, followed by their McMurry cyclization. Alkenes 16 and 17 were quantitatively converted into the corresponding dehydro derivatives 24 and 25, respectively, by oxidation with 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ). The electrochemical properties of compounds 15-17, 24 and 25 were examined by cyclic voltammetry (CV) and differential pulse voltammetry (DPV), and the relationship between their structure and electrochemical behavior was established. Novel 1,2-di(azulen-1-yl)ethenes, having the double bond included in a five-membered carbocyclic or heterocyclic ring, were conveniently synthesized by McMurry coupling reactions. Their electrochemical properties were examined by cyclic voltammetry (CV) and differential pulse voltammetry (DPV), and the electrochemical behavior-structure relationship was established. Copyright