Monophosphine compound, transition metal complex thereof and production method of optically active compound using the complex as asymmetric catalyst

A compound represented by the formula (I):

• wherein ring A is void or a benzene ring optionally having substituent(s), R1 and R2 are each independently a phenyl group optionally having substituent(s), a cyclohexyl group, a 2-furyl group or a 3-furyl group, R3 and R4 are each independently a hydrogen atom, a halogen atom, a lower alkyl group, a lower alkoxy group, a cycloalkyl group optionally having substituent(s), an aralkyl group optionally having substituent(s) or an aryl group optionally having substituent(s), and X is a residue represented by —OR5 or —NHR6
• wherein R5 and R6 are each a lower alkyl group optionally having substituent(s), an aralkyl group optionally having substituent(s), an aryl group optionally having substituent(s) or a heteroaryl group optionally having substituent(s),
• wherein each substituent of the benzene ring is independently a halogen atom, a lower alkyl group, a lower alkoxy group, a cycloalkyl group optionally having substituent(s), an aralkyl group optionally having substituent(s), or an aryl group optionally having substituent(s);
• each substituent of the cycloalkyl group is independently a halogen atom, a lower alkyl group, a lower alkoxy group, a hydroxyl group, an amino group, a nitro group, a cyano group, a carboxyl group, an alkoxycarbonyl group, an aryl group, an aralkyl group, or oxo;
• each substituent of the phenyl, aryl, aralkyl, and heteroaryl group is independently a halogen atom, a lower alkyl group, a lower alkoxy group, a hydroxyl group, an amino group, a nitro group, a cyano group, a carboxyl group, an alkoxycarbonyl group, an aryl group, or an aralkyl group;
• and
• each substituent of the lower alkyl group is independently is a halogen atom, a lower alkoxy group, a hydroxyl group, oxo, an amino group, a nitro group, a cyano group, a carboxyl group, or an alkoxycarbonyl group.