A cationic palladium complex catalyzes the title transformations, which are thought to proceed via a pi-allyl or pi-benzyl intermediate. The regioselectivity of the reaction (1,2- or 1,1-difunctionalization) depends on the type of terminal double bond (conjugated or nonconjugated) in the substrate (see scheme) and appears to be controlled by the relative rates of beta-hydride elimination and transmetalation. DMA=dimethylacetamide, Tf=triflyl.