Thermal and theemocatalytic reaction of ethyl diazoacetate with styrenes

Research paper by A. E. Vasil'vitskii, V. M. Shostakovskii, O. M. Nefedov

Indexed on: 01 Mar '79Published on: 01 Mar '79Published in: Russian Chemical Bulletin


A study was made of the thermal and thermocatalytic reaction of a series of p-substituted styrenes with ethyl diazoacetate and it was shown that the relative rate constants, determined by the method of competing reactions, correlate well with the Hammett σ constants.In the case of thermocatalytic reactions the constant ρ has negative values, while its value is independent of the valence state of the copper in the starting catalyst and is slightly dependent on the nature of the anion. The stereoselectivity of the reaction is slightly dependent on the steric effects caused by the size of the anion.When the reactions are run in the absence of catalyst the value of ρ indicates a noncarbene mechanism of the reaction, which proceeds either by the pyrazoline, or most probably the radical mechanism.