 These spaces can be obtained by taking a projectivization of
a minimal nilpotent orbit of the respective complex Lie group.The holomorphic contact structure is apparent, because
the nilpotent orbits of semisimple Lie groups 
are equipped with the Kirillov-Kostant holomorphic symplectic form.This argument also explains how one
can associate a unique Wolf space to each of the simple
complex Lie groups.