MeO-BIPHEP

Figure 4 Chiral Pd complexes (a) PdBr(p-CNC6H4)( S -MeO-Biphep) (b) PdBr(C6F5)( S -MeO-Biphep). Potential aromatic 7r-7r stacking interactions are indicated by arrows.

R)-liINAP-RuBr2 can be successfully applied to the enantioselective hydrogenation of /i-kelo esters in the synthesis of (+)-(2R,3 W)-corynomycolic acid 115. ( S )-MeO-BIPHEP-RuBr2 was used in a similar manner in the synthesis of (R)-fluoxetine (116, Prozac ) and (S)-duloxetine (117).648... 

Modification of the electronic and steric properties of BINAP, BIPHEMP, and MeO-BIPHEP can lead to the development of new efficient atropisomeric ligands (Figure 1). In fact, Takaya has found that a modified BINAP... 

Using RuCl3/CK)-MeO-BIPHEP catalytic system, the /Uhydroxy ester, a key intermediate to vWF receptor antagonists Sulfobacin A, was produced through asymmetric hydrogenation in 96% yield and 99% ee (Scheme 8).266 The... 

BINAP system with excellent ee s. For example, 0// 0-bromoacetophenone can be converted into the corresponding chiral alcohol with 96% ee (Equation (72)). However, this type of substrate can be hydrogenated more effectively with the Ru/chiral phosphine/diamine system.279 Asymmetric hydrogenation of phenylthioketones has been realized with Ru catalysts. BINAP, MeO-BIPHEP,280 BDPP281 and Me-CnrPHOS,62c are efficient for this transformation (Table 17). 

A series of /3-keto phosphonates have been hydrogenated with the Ru-BINAP system to give various chiral /3-hydroxyl phosphonates (Equation (75)).286 An Ru-MeO-BIPHEP catalyst is also effective for this transformation.287 /3-Keto thiophosphonates can also be smoothly transformed into /3-hydroxyl thiophosphonates with high ee.287... 

Using Ir/MeO-Biphep/l2 catalyst system, a variety of substituted quinoline derivatives were hydrogenated in 95% yield and up to 96% ee. This method provided an efficient accesss to three naturally occurring alkaloids (Scheme 17).328 Ferrocene N, P ligand 108 is also effective for the asymmetric hydrogenation of quinolines with up to 92% ee.188a... 

The sense of diastereoselectivity in the dynamic kinetic resolution of 2-substi-tuted / -keto esters depends on the structure of the keto ester. The ruthenium catalyst with atropisomeric diphosphine ligands (binap, MeO-biphep, synphos, etc.) induced syn-products in high diastereomeric and enantiomeric selectivity in the dynamic kinetic resolution of / -keto esters with an a-amido or carbamate moiety (Table 21.21) [119-121, 123, 125-127]. In contrast to the above examples of a-amido-/ -keto esters, the TsOH or HC1 salt of /l-keto esters with an a-amino unit were hydrogenated with excellent cwti-selectivity using ruthenium-atropiso-... 

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