• Bulletin of the Korean Chemical Society
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• 제24권7호
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• pp.925-930
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• 2003

Kinetic studies of the reaction of Z-aryl cyclopropanecarboxylates with X-pyridines in acetonitrile at 55.0 ℃ have been carried out. The reaction proceeds by a stepwise mechanism in which the rate-determining step is the breakdown of the zwitterionic tetrahedral intermediate, $T^{\pm}$. These mechanistic conclusions are drawn base on (i) the large magnitude of ρx and ρz, (ii) the positive sign of ρxz and the larger magnitude of ρxz than normal $S_N2$ processes, (iii) a small positive enthalpy of activation, Δ$H^≠$, and a large negative, Δ$S^≠$, and lastly (iv) adherence to the reactivity-selectivity principle (RSP) in all cases.