Synthesis and Redox Behavior of Cyanovinyl-Substituted 2H-Cyclohepta[b]furan-2-ones

Abstract

Cyanovinyl-substituted 2H-cyclohepta[b]furan-2-ones 3, 4, 5 and 7 were prepared by the Wittig, Knoevenagel and electrophilic substitution reaction, respectively. The intramolecular charge-transfer (ICT) interactions between the 2H-cyclohepta[b]furan-2-one ring and cyanovinyl acceptor moiety were investigated by UV/Vis spectroscopy and theoretical calculations. The redox behavior of these novel compounds was examined by cyclic voltammetry (CV) and differential pulse voltammetry (DPV). Significant color changes in these compounds were observed under electrochemical reduction conditions by visible spectroscopy. INTRODUCTION 2H-Cyclohepta[b]furan-2-one is known as a heteroazulene, a versatile precursor for azulene derivatives. Although unusual reactivity of the compound including its derivatives has already been revealed by many research groups, there are few derivatives for the application to the advanced materials with potentially useful electronic properties. † Dedicated to Prof. Ei-ichi Negishi on the occasion of his 77th birthday. HETEROCYCLES, Vol. 86, No. 1, 2012 305