Cl-MeO-BIPHEP

Fig. 3 Proposed stereochemical model accounting for the observed sense of absolute stereoinduction (chiral ligand = (5)-Cl,MeO-BIPHEP)...

To a solution of enyne 301d in dichloroethane (0.1 M) at ambient temperature was added Rh(cod)20Tf (5 mol%) and (/ )-Cl,MeO-BIPHEP (5 mol%). The system was purged with hydrogen gas and the reaction mixture was allowed to stir under an atmosphere of hydrogen until complete consumption of 301d was observed, at which point the reaction mixture was evaporated onto silica gel and the product purified by column chromatography... 

Cl]2> (Sy or (/ )-Cl,MeO-BIPHEP, 4-chloro-3-nitro-benzoic acid, and allyl acetate as a highly efficient and selective system for diol C-allylation [76], Under these conditions, diol Ih is converted to the homoallylic alcohol 2h in 79% isolated yield as a single diastereomer, as determined by NMR analysis of the crude reaction mixture (Scheme 7). 

In 2004, Krische and colleagues demonstrated that exposure of Morita-Baylis-Hillman acetates to tertiary phosphine catalysts in the presence of 4,5-dichlorophthalimide enabled regiospecific allylic substitution through a tandem Sn2 -Sn2 mechanism. Through the use of the chiral phosphine catalyst, (i )-Cl-MeO-BIPHEP, the racemic Morita-Baylis-Hillman acetate depicted in Scheme 2.108 was converted into the corresponding enantiomerically enriched allylic amination product, thus establishing the feasibility of DKR. 

Scheme 2.108 DKR of Morita Baylis Hillman acetate catalysed by (R)-Cl-MeO-BIPHEP.

Major Pharmaceutical/Integrated Chemical Companies. Bayer Development of proprietary binap analogs (bibfiip, Cl-MeO-biphep). Now property... 

Chan and coworkers developed a new diphosphine 9, related to MeO-BiPhep 5 (Fig. 10) [21]. [lr(p-Cl)(COD)]2/9/l2 catalytic system provided similar enantios-electivities than [lr(p-Cl)(COD)]2/5/l2 in the Ir-catalyzed hydrogenation of quinolines but higher enantioselectivitites in the reduction of 2-methyl-quinoxaline and 2,3,3-trimethylindolenine (Fig. 10). 

Bayer entered the asymmetric hydrogenation field with the development of a biphenyl ligand similar to MeO-Biphemp called Cl-MeO-biphemp (96b). This ligand has been prepared at kilogram scale by two procedures. One approach is an analogue of that used for MeO-Biphep (96a) (Scheme 12.30).121-124 The second method proceeds through a tricyclic intermediate (Scheme 12.32).122125... 

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