Highly Effective Catalytic Asymmetric Hydrogenations of α-Keto Esters and an α-Keto Acetal with New Neutral Chiral Pyrrolidinebisphosphine-Rhodium Complexes

1987 ◽  
Vol 16 (5) ◽  
pp. 855-858 ◽  
Author(s):  
Hisashi Takahashi ◽  
Toshiaki Morimoto ◽  
Kazuo Achiwa
Keyword(s):  
Rhodium Complexes ◽  
Keto Esters ◽  
Highly Effective ◽  
Catalytic Asymmetric ◽  
Asymmetric Hydrogenations

scholarly journals New P-chirogenic diphosphines and their use in catalytic asymmetric reactions

2001 ◽  
Vol 73 (2) ◽  
pp. 373-376 ◽  
Author(s):  
Tsuneo Imamoto
Keyword(s):  
Crystal Structures ◽  
Phosphorus Trichloride ◽  
Asymmetric Reactions ◽  
Rhodium Complexes ◽  
Enantiomerically Pure ◽  
Catalytic Asymmetric ◽  
Asymmetric Hydrogenations ◽  
Dehydroamino Acid ◽  
The Ideal ◽  
Catalytic Asymmetric Reactions

Enantiomerically pure (S,S) -1,2-bis[(o-alkylphenyl) phenylphosphino]ethanes (o-alkylphenyl = o-methylphenyl, o-ethylphenyl, o-isopropylphenyl, 5',6',7',8'-tetrahydro-naphthyl) , (S,S) -1,2-bis (alkyl-methylphosphino) ethanes (alkyl = t-butyl, 1-adamantyl, 1-methylcyclo-hexyl, 1,1-diethylpropyl, cyclopentyl, cyclohexyl) (abbreviated as BisP*) , and (R,R) -1,1-bis (alkylmethylphosphino) methanes (alkyl = isopropyl, t-butyl, cyclohexyl, phenyl) (abbreviated as MiniPHOS) were prepared from phosphorus trichloride via short routes using phosphine-boranes as intermediates. The crystal structures of cationic rhodium complexes, [Rh ((S,S) -1,2-bis ((phenyl) (5',6',7',8'-tetrahydronaphthyl) phosphino) ethane) (cod)]BF4, [Rh ((S,S) -t-Bu-BisP* (nbd))]BF4, and [Rh ((R,R) -t-Bu-MiniPHOS) 2]PF6, clearly indicate the ideal asymmetric environments. These ligands exhibited an excellent to almost perfect level of enantioselectivity in asymmetric hydrogenations of a-dehydroamino acid derivatives and other catalytic asymmetric reactions.

Developing chiral phosphorus ligands for asymmetric hydrogenations

2010 ◽  
Vol 82 (7) ◽  
pp. 1429-1441 ◽  
Author(s):  
Wei Li ◽  
Guohua Hou ◽  
Xianfeng Sun ◽  
Gao Shang ◽  
Weicheng Zhang ◽  
...  
Keyword(s):  
Phosphine Ligands ◽  
Chiral Ligands ◽  
Phosphorus Ligands ◽  
Keto Esters ◽  
Asymmetric Hydrogenations ◽  
Dehydroamino Acid

Chiral rigid and electron-donating phosphocyclic phosphine ligands and modular atropisomeric biaryl phosphine ligands were designed and synthesized. The performance of these chiral ligands in the asymmetric hydrogenations of prochiral dehydroamino acid derivatives, enamides, imines, keto esters, and ketones has been demonstrated to be excellent.

Catalytic Asymmetric Addition of Dimethylzinc to α-Keto Esters

Synfacts ◽  
2006 ◽  
Vol 2006 (6) ◽  
pp. 0593-0593
Author(s):  
J. Pedro ◽  
G. Blay ◽  
I. Fernández ◽  
A. Marco-Aleixandre
Keyword(s):  
Asymmetric Addition ◽  
Keto Esters ◽  
Catalytic Asymmetric
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