The present application is directed to i) a method for synthesizing aminophosphine (P,N) and phosphine-aminophosphine (P,N,P) ligands, ii) the use of such ligands in the preparation of metal complexes as hydrogenation catalysts, and iii) aminophosphine (P,N) and phosphine-aminophosphine (P,N,P) ligands of various structures. In particular, the methods in i) involve reacting a protected tertiary amine of formula (I) with a metal phosphide of the formula Y—PR8R9 to afford an aminophosphine of formula (II), which can then be optionally further reacted with a phosphine of the formula (III) to afford the phosphine-aminophosphine of formula (IV).