Hydride transfer mechanism in the catalytic allylation of norbornadiene with allyl formate

Allylation of norbornadiene with allyl formate in the presence of the palladium catalytic systems is characterized by several peculiarities associated with the new reaction route: hydroallylation (reductive allylation) occurs along with the traditional allylation (oxidative allylation). Both processes are considered from the single point of view, and the mechanism assuming different routes of the hydride transfer in the key intermediates was proposed. It was proved by using deuterated reactants that the hydride transfer can involve the allyl, norbornenyl, or formyl moieties. In all cases, the hydrogen atom bound to the carbon atom in the β-position relative to palladium is eliminated in this step.