The historical development of asymmetric hydrogenation of N-acyl dehyd
roamino acids and their derivatives is reported. Both homogeneous and
heterogeneous catalysis are illustrated by selected examples. Catalysi
s by water soluble complexes and transfer hydrogenation are also treat
ed in this review. The mechanism of catalytic hydrogenation, its eleme
ntary steps and the origin of enantioselection are discussed.