Co-catalysis between Mn+ and H+ in the direct addition of N–H bonds to CC double and triple bonds

A kinetic analysis of the addition of amines to CC double and triple bonds using different transition metal catalysts is presented. It is shown that the reaction is initiated by the Lewis acidic metal centres. In the presence of protons, the rate of reaction is drastically increased. The key role played by the protons in the catalytic system is discussed. Therefore, Brønsted and Lewis acids, and their respective properties, have to be taken into account in the rational design of hydroamination processes mediated by late transition metals.