ReducQve eliminaQon from Int-8 via TS-4 was calculated to be a low energy process (DG ‡ 373K = 2.4 -3.6 kcal mol -1 ). The ammonium species was associated via a hydrogen bond throughout reducQve eliminaQon step, ulQmately forming the palladium hydride bromide complex Int-9. An analogue of Int-9 in which the amine ligand is replaced by PAd2 n Bu has been crystallographically characterised and proposed as an important off-cycle resQng state. DissociaQon of Me3NHBr from Int-9 completes catalyQc turnover with both the aldehyde and ammonium salt side-product liberated at this point.