| abstract |
A ruthenium-phosphine complex having a 2,2 min bis(diphenylphosphino)-1,1 min -binapthyl ligand is of the general formula: [RU(R-BINAP)MClk]lXm wherein R-BlNAP represents a tertiary phosphine represented by the formula: <CHEM> wherein R represents hydrogen or methyl; M represents Zn, Al, Ti or Sn; X represents N(C2 H5)3 or CH3CO2 ; when X represents N(C2 H 5)3, l is 2 and m is 1, and when M represents Zn, k is 4, when M represents Al, k is 5, and when M represents Ti or Sn, k is 6; and when X represents CH3CO2 , l is 1 and m is 2, and when M represents Zn, k is 2, when M represents Al, k is 3, and when M represents Ti or Sn, k is 4. 16 specific complexes are exemplified. Synthesis is from Ru2 Cl4 (R-BINAP)NC2 H5 or Ru(CH3CO2)2 (R-BlNAP), by reaction with the Lewis acid ZnCl 2, AlCl3 , TiCl6 or SnCl to give the desired MCl3 group at 10-25 DEG C for 2-20 hours in a solvent, e.g. methylene chloride. Optically active R-BINAP can be used. The complex is an excellent catalyst for asymmetric hydrogenation of enamides with high activity. |