Etude cinétique et insertion de la réactivité de l’éthyl-2-cyano-3-phénylacrylate dans l’échelle de Mayr
Written by sctunisie no commentsKinetics of the addition of OH- to ethyl-2-cyano-3-phénylacrylate 1a have been determined by UV-vis spectroscopy in water at 20°C. The second-order rate constant (k) is employed to determine the electrophilicity parameter (E) of 1a as defined by the equation log k (20°C) = s (N +E) (Angew. Chem. Int. Ed. Engl., 1994, 33, 938-957). The increase in electrophilie brought about by the introduction of a second CO2Et group in 1a to give 1b is very large and equal to about 9 E units while that the transition from 1c to 1a is only of the order of 2,5 E units. This suggests that the two CO2Et group contributes very effectively to the resonance stabilization of the carbanion A.
N. Dhahri, T. Boubaker, R. Goumont
Electrophilicity Scale, Mayr Equation, Michael Acceptors
Pages: 169-174
