2-Benzylidene[3]ferrocenophane-1,3-diones and their spectral properties

Abstract

2-Benzylidene[3]ferrocenophane-1,3-diones were synthesized by condensation of substituted benzaldehydes and [3]ferrocenophane-1,3-dione with triethylamine as catalyst. Benzaldehydes bearing electron-accepting substituents gave bicyclic compounds as by-products; these were formed by extension of the three-membered bridged system to a seven-membered one. A correlation between ν(C=O) vibrations and σ+ constants of substituents was found. The UV and 1H-NMR spectra of the prepared compounds are commented.