Synthesis of 1,2-diferrocenyl-3-(diacylmethylidene)cyclopropenes and 1,1-diacyl-2,3-diferrocenyl-4-methylsulfanylbuta-1,3-dienes, their structures and electrochemical properties

2,3-Diferrocenyl-1-morpholinocyclopropenylium tetrafluoroborate reacts with 1,3-diketones in the presence of triethylamine to give 3-diacylmethylidene-1,2-diferrocenylcyclopropenes (8a–d). Under similar conditions, 2,3-diferrocenyl-1-methylsulfanylcyclopropenylium iodide affords 8a–c (∼25–30%) and 1,1-diacyl-2,3-diferrocenyl-4-methylsulfanylbuta-1,3-dienes (10a–c) (∼50–60%). The structures of the products obtained were established based on the data from 1H (1D NOE) and 13C NMR spectra and X-ray diffraction analysis. Electrochemical properties of several (diacylmethylidene)diferrocenylcyclopropenes (8a–c) and 1,1-diacyl-2,3-diferrocenyl-4-methylsulfanylbuta-1,3-dienes (10a–c) are studied.