ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Derivatives of ferrocene. XV. Investigation of the Michael addition to p-substituted cinnamoylferrocene derivatives

M. Furdík and Š. Toma

Komenský University, Bratislava

Abstract:  The Michael addn. reaction of the NCCH₂CO₂Et on the chalcones of the type Fc-COCH:CHC₆H₄X-p (Fc = ferrocenyl) was described. If an excess of NCCH₂CO₂Et is applied, then this reaction is 1st order in the relation to chalcone and the reaction rate is dependent on the substituent. In the correlation log κ vs. Hammett's consts. σ-(p), these values were detd.: ρ = 0.65 ± 0.035 at 60° and ρ = 0.54 ± 0.026 at 50°. The dependence of the reaction rate on temp. is small as indicated from the calcd. activation energy. An increase of 20° increased the reaction rate 2-fold. Comparing the reaction rates of the p-Me₂N deriv., p-MeO deriv., and β-ferrocenylacryloylferrocene showed that the Fc radical reaches as much as 60-70% of the electron-donor character of the p-Me₂NC₆H₄ group. The formation of an isomeric chalcone was observed for the β-ferrocenylacryloylferrocene and an isomerization through the addn. product occurred.

Full paper in Portable Document Format: 205a326.pdf (in Slovak)

Chemical Papers 20 (5) 326–335 (1966)