In most cases the oxidative Addition is the rate determining step of the catalytic cycle.[12] During this step, the palladium catalyst is oxidized from palladium(0) to palladium(II). The palladium catalyst 1 is coupled with the alkyl halide 2 to yield an organopalladium complex 3. As you can see in the diagram the oxidative addition step breaks the carbon-halogen bond where the palladium is now bound to both the halogen and the R group.Oxidative addition proceeds with retention of stereochemistry with vinyl halides, while giving inversion of stereochemistry with allylic and benzylic halides.[13] The oxidative addition initially forms the cis–palladium complex, which rapidly isomerizes to the trans-complex