Reactivities of mixed organozinc and mixed organocopper reagents. Part 7. Comparison of the transfer rate of the same group in allylation of mixed and homo diorganozinc reagents

A detailed direct kinetic study has been carried out to compare the reaction rate of transferable group, Ph in mixed phenylzinc reagents, RPhZn (R = n‐alkyl) and in homo diphenylzinc reagent, Ph₂Zn in their reactions with allyl bromide in THF at 25–(?15) °C. Empirical rata law and activation parameters are consistent with a second‐order substitution reaction. The allylation rate of transferable group Ph in RPhZn (R = n‐alkyl) has been found higher than the rate of Ph group in Ph₂Zn. A mechanism which accommodates the kinetic data and higher allylation rate of transferable group Ph in RPhZn than that in Ph₂Zn is given. Copyright © 2013 John Wiley & Sons, Ltd.