Collect. Czech. Chem. Commun. 1982, 47, 1988-1996

The study of the acid catalysed Michael addition to ferrocene derivatives of α,β-unsaturated ketones. Kinetics of cyclization of 1-acetyl-1'-(p-chlorocinnamoyl)ferrocene

Štefan Tomaa and Anton Gáplovskýb

a Department of Organic Chemistry
b Institute of Chemistry, Comenius University, 842 15 Bratislava


Cyclization of 1-acetyl-1'-(p-chlorocinnamoyl)ferrocene catalysed by H2SO4, HCl, CF3COOH and BF3.(C2H5)2O has been studied. Kinetic study of the title reaction catalysed by HCl showed that the rate of cyclization increases with the catalyst concentration. Activation parameters of the cyclization are as follows: ΔH##f = 81.76 kJ mol-1, -ΔS##f = 55.73 J mol-1 K-1. Attempts at acid catalysed addition of several C-nucleophiles to cinnamoylferrocene and acryloylferrocene have been unsuccessful. The effect of the acidity of reaction medium on the electronic spectra of studied ferrocene derivatives is discussed.