C2-symmetrical ruthenocene diphosphine ligands only with surface chirality and their manufacture

A method for synthesizing a C2-symmetrical ruthenocene diphosphine ligand having only planar chirality, characterized by,

• synthesizing a C2-symmetrical ruthenocene diphosphine ligand having only planar chirality as shown in the following formula (1a),
• in the formula (1a), R represents a methyl or ethyl group, and R1 represents a linear or branched alkyl, cycloalkyl, alkoxy, aryl, aralkyl, alkyl amino group,
• the method for synthesizing includes:
• Step (1):
• reacting a bisoxazoline compound as shown in the following formula (2) with an acid in a solvent to open the oxazoline ring, and then reacting the thus obtained compound with acetic anhydride to give the corresponding ester amide compound,
• in the formula (2), R1 is defined as above, and R2 represents an alkyl group;
• Step (2A):
• reacting said ester amide compound with an alkoxide as shown in the following formula:
• R-OM
• wherein R is defined as above, and M represents an alkali metal atom.

A method for synthesizing a C2-symmetrical ruthenocene diphosphine ligand having only planar chirality, characterized by,

• synthesizing a C2-symmetrical ruthenocene diphosphine ligand having only planar chirality as shown in the following formula (1b),
• in the formula (1b), R represents a methyl or ethyl group, and R1 represents a linear or branched alkyl, cycloalkyl, alkoxy, aryl, aralkyl, alkyl amino group,
• the method for synthesizing includes:
• Step (1):
• reacting a bisoxazoline compound as shown in the following formula (2) with an acid in a solvent to open the oxazoline ring, and then reacting the thus obtained compound with acetic anhydride to give the corresponding ester amide compound,
• in the formula (2), R1 is defined as above, and R2 represents an alkyl group;
• Step (2B):
• reacting said ester amide compound with a strong base, and reacting the thus obtained compound with an alkylating agent as shown in the following formula under a basic condition:
• R2SO4
• wherein R is defined as above.