This stoichiometric reaction can be converted into a catalytic process if a redox system is also present which regenerates the pd2 I from Pu. Cu(1l)-salts are generally used for this purpose. In analogy to the oxidation of ethylene to acetaldehyde (cf Section 7.3.1 .l) Cu can readily oxidize the zerovalent palla dium to Pd2 The copper cation, which is reduced to the monovalent state, is regenerated with air to Cu"". The multi- step reaction can be summarized in the net equation