Method for producing optically active 1,2-bis(dialkylphosphino)benzene derivative

A method for preparing an optically active 1,2-bis(dialkylphosphino)benzene derivative represented by the following general formula (A), characterized in that a phosphine-borane compound represented by the following general formula (1) is subjected to deboronation reaction, followed by lithiation, then the reaction product is subjected to reaction with an alkyldihalogenophosphine represented by RaPX′2 (where, Ra is either R1 or R2 defined in formula (A), and X′ represents a halogen atom) and thereafter the reaction product is subjected to reaction with a Grignard reagent represented by the general formula RbMgX″ (where, Rb is ether R1 or R2 as defined in formula (A), provided that Ra and Rb are not the same, and X″ represents a halogen atom) to produce an optically active 1,2-bis(dialkylphosphino)benzene derivative.

• (Where:
• R1 and R2 respectively represent an alkyl group having 1 to 8 carbon atoms, and the number of carbon atoms is different between R1 and R2)
• (Where:
• R1 and R2 have the same meaning as defined in formula (A), and X represents a halogen atom.)