Diphosphine, Noyori catalytic asymmetric

The first catalysts used were Co(I)-DIOP (DIOP, see Figure 11b) based systems. Up to 32% ee was achieved with 39% yield in the isomerization of (A, AO-diethylgeranylamine to (i )-citronellal. Subsequently, some rhodium (I)-DIOP or BINAP (BINAP = 2,2 -bis(diphenylphosphino)-1,1 -binaphthyl) systems proved to be very active. In particular, cationic rhodium(I)-BINAP complexes show very high selectivities and catalytic activities for this isomerization. BINAP is an atropoisomeric diphosphine (Figure 20) which was first synthesized by Noyori and Takaya and since then its metal complexes have been extensively used as catalysts in a variety of asymmetric syntheses. 

---