Evidence that Palladium(0)-Promoted Cyclizations of Unsaturated α-Iodocarbonyls Occur by an Atom Transfer Mechanism

Article abstract of DOI:10.1016/S0040-4039(00)94396-X

The isomerization of several unsaturated α-iodocarbonyls to cyclic γ-iodocarbonyls gave identical product mixtures by using catalytic quantities of either hexalkylditin or palladium(0).This indicates that palladium does not serve as a catalyst in an organometallic reaction, but as a promotor of a free radical chain involving atom transfer.In contrast, an allylic iodide showed no tendency to produce radical chain products when treated with Pd(0).