5,5'- position linked 1,1'- biphenyl axial chiral ligand and method for preparing the same

A method for preparing 5,5′-position linked 1,1′-biphenyl axis chiral ligand, characterized in that,

• said method is a method for preparing 5,5′-position linked 1,1′-biphenyl axis chiral ligand of formula (I) comprising:
• reacting the compound of formula (IX) with an activator that can activate the hydroxyl group selected from the group consisting of alkyl halosulfonium compound, aryl halosulfonium compound, phosphorus oxychloride, phosphoryl chloride, phosphorus pentachloride, thionyl chloride and triphenyl phosphine, in the presence of alkali(s),
• wherein n, R1, R2, R3 and R4 are defined as above.

A method for preparing 5,5′-position linked 1,1′-biphenyl axial chiral ligand, characterized in that,

• the 2-bromo-4-methoxy benzophenone as starting material undergoes oxidation and esterification to give compound (V), the compound (V) is coupled through copper powder and undergoes demethylation reaction to give methyl 5,5′-dihydroxy-1,1′-biphenyl-2,2′-dicarboxylate (VII), then the compound (VII) reacts with a dihalo alkane to give a mixture of 5,5′-linked compounds (VIII) having configurations of (R) and (S), the compound (VIII) reacts with various chiral amino alcohol to give amide compounds (IX) having configurations of (R) and (S), then the compounds (IX) react with an activator that can activate the hydroxyl group selected from the group consisting of alkyl halosulfonium compound, aryl halosulfonium compound, phosphorus oxychloride, phosphoryl chloride, phosphorus pentachloride, thionyl chloride and triphenyl phosphine, in the presence of alkali(s) to give the target ligands (II) and (III) having configurations of (R) and (S):
• wherein n, R1, R2, R3 and R4 are defined as above.