The Mechanism of 1,4- and 1,6-Cuprate Additions: The First Determination of Activation Parameters

With a direct kinetic study , activation parameters for the 1,4-cuprate addition to enones (see the Arrhenius plot,▴) and the 1,6-addition to acceptor-substituted enynes (█) were determined for the first time. Both reactions might involve σ copper(III ) species which are formed by oxidative addition of the respective substrate to the cuprate.