Phosphine compounds represented by the following formula (1): ##STR1##

wherein R¹, R², R³, R⁴, R⁵, R⁶ and R⁷ represent substituents, and asymmetric synthesis catalysts containing transition metal phosphine complexes with the compounds contained as ligands therein. The novel phosphine compounds according to the present invention are useful especially as ligands in transition metal complexes. The transition metal phosphine complexes are useful as catalysts for asymmetric synthetic reactions. The novel phosphine compounds useful as ligands can be prepared by a relatively economical preparation process. Further, use of these catalysts can afford hydrogenated products with high optically purity and is also extremely useful from the industrial standpoint.