CHIRAL LIGANDS

摘要

Chiral compounds of the formula (1 ), which are optically pure or highly optically enriched in which R0 is C1-C12-alkyl which is unsubstituted or substituted by 1 to 2 C1-C4-alkoxy; cyclo- pentyl or cyclohexyl, which is unsubstituted or substituted by 1 to 3 C1-C4-alkyl or C1-C4-alkoxy; or benzyl, phenyl or naphtyl which is unsubstituted or substituted by 1 to 3 C1-C4-alkyl, C1-C4-alkoxy, C1-C4-fluoroalkyl or C1-C4-fluoroalkoxy, F or Cl, or R0 is -C R5 R6 OH or -C R5 R6 OSi(C1-C8-alkyl)3 wherein R5 and R6 are indedendently selected from the group consisting of H, unsubstituted C1 - C12 alkyl, substituted C1 - C12 alkyl, unsubstituted C4 - C8 cyclo alkyl, substituted C4 - C8 cyclo alkyl, unsubstituted aryl, substituted aryl or wherein R5 and R6 can form an unsubstituted 5-6 membered aliphatic carbocycle or a substituted 5-6 membered aliphatic carbocycle, each of R1 and R'1 independently is hydrogen or has the meaning of R0 whereby R1, R'1 and R0 can be same or different, R2 and R3 are independently a C-bonded hydrocarbon radical or a heterohydrocarbon radical, and each of both R4 is C1-C6-alkyl, cyclopentyl, cyclohexyl, phenyl, methylphenyl, methylbenzyl or benzyl, or both R4 together form an aliphatic C4-C6 carbocycle. Metal complexes of these ligands are homogeneous catalysts for asymmetric addition reaction, particularly hydrogenations.