OPTICALLY ACTIVE 1-2-BIS(DIALKYLPHOSPHINO)BENZENE DERIVATIVE AND ITS PRODUCTION, AND RHODIUM METAL COMPLEX WITH THE SAME AS LIGAND

摘要

PROBLEM TO BE SOLVED: To obtain a new compound useful as a ligand of a transition metal catalyst for asymmetric hydrogeneration reaction. SOLUTION: This compound is a compound of formula I (R1 is a 2-6C alkyl; *denotes an asymmetric phosphorus), e.g. (S,S)-1,2-bis(isopropylmethylphosphino) benzene. The compound of formula I is. obtained by optically resolving a compound of formula II [e.g. 1,2-bis(isopropylmethylphosphinoyl)benzene] with an optically active dibenzoyl tartaric acid [e.g. (+)-dibenzoyl tartaric acid] followed by reduction with a reducing agent (preferably phenylsilane), normally at 105-110 deg.C, preferably for 4-10 h. The temperature to precipitate a poorly soluble diastereomer salt in the optical resolution as described above is normally 0-100 deg.C.