A process for making a cycloalkyl phosphine comprising hydrogenating an aryl phosphine in the presence of an effective amount of an aryloxide of a metal selected from the group consisting of niobium and tantalum is disclosed. Cycloalkyl phosphine products of this process, useful as ligands in a complex of a transition metal which acts as a catalyst in the formation of stereoisomers, are also set forth. Furthermore, niobium or tantalum organometallic compounds, generated in this process, useful in the catalytic hydrogenation of aryl phosphines and arene-containing polymers, is also described.