Compounds containing 2,2'-bis-(diphenylphosphino)-1,1'-binaphthyl and catalytic metal complexes thereof.

摘要

A phosphine compound 2,2 min -bis[di-(3,5-dialkylphenyl) phosphino]-1,1 min -binaphthyl is represented by the formula <CHEM> wherein R represents a C1-4 alkyl group. Synthesis is by reacting 2,2 min -dibromo-1,1 min -binaphthyl (see JP-A-55-61937) with Mg and reacting the resultant Grignard reagent with a bis(3,5-dialkyphenyl phosphonyl chloride;the resulting racemic phosphoryl binaphthyl is dissolved and crystals thereof recrystallised to purify them; (+)- and (-)- forms of the free phosphine oxide are obtained and reduced with trichlorosilane to provide the (+)- or (-)- isomers of the novel compound; or the racemate can be produced. The compound can be reacted with a compound of a transition element such as rhodium, palladium or ruthenium as a ligand to make a complex thereof which is useful as a catalyst in an asymmetric synthesis reaction, e.g. asymmetric hydrogenation of a beta -keto ester, to give a product of high optical purity in high yield.