Thermal Activation of N-H Bonds by Transition-metal Oxide Cations: Does a Hierarchy Exist in the First Row? #chempaper 220

A computational and experimental study of N-H bond activation using first row transition metals except Cu. Because, they couldn't generate [CuO] cation. Three general reactions among the series as follows:

As expected, the three type of reactions are not observed among all the 1st row TMs. The oxophilic early metals for example tend to give the first type of reaction.

I think it is a good study and worth reading.