Enantioselective hydrogenation of β-keto esters catalyzed by P-chiral bis(dialkylphosphino)ethanes-Ru(II)

Yamano, Toru; Taya, Naohiro; Kawada, Mayumi; Huang, Taiyi; Imamoto, Tsuneo

doi:10.1016/s0040-4039(99)00251-8

Cited by 51 publications

(22 citation statements)

References 24 publications

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“…BisP* and MiniPHOS were employed as the chiral ligands in other catalytic asymmetric reactions. The results summarized in equations [9][10][11][12] clearly indicate that these ligands are potentially useful for various transition metal-catalyzed asymmetric reactions.…”

Section: P-chirogenic 12-bis(alkylmethylphosphino)ethanes (Bisp*) Anmentioning

confidence: 94%

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

Imamoto

2001

Pure and Applied Chemistry

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Enantiomerically pure (S,S)-1,2-bis [(o-alkylphenyl)phenylphosphino]ethanes (o-alkylphenyl = o-methylphenyl, o-ethylphenyl, o-isopropylphenyl, 5',6',7',8'-tetrahydronaphthyl), (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)]BF 4 , [Rh((S,S)-t-Bu-BisP*(nbd))]BF 4 , and [Rh((R,R)-t-Bu-MiniPHOS) 2 ]PF 6 , clearly indicate the ideal asymmetric environments. These ligands exhibited an excellent to almost perfect level of enantioselectivity in asymmetric hydrogenations of α-dehydroamino acid derivatives and other catalytic asymmetric reactions.

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Section: P-chirogenic 12-bis(alkylmethylphosphino)ethanes (Bisp*) Anmentioning

confidence: 94%

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

Imamoto

2001

Pure and Applied Chemistry

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“…Indeed, only few examples describe the asymmetric reduction of sterically hindered derivatives possessing a quaternary carbon atom on the aposition. In these cases, reduction is usually performed by asymmetric catalytic hydrogenation using ruthenium and rhodium chiral complexes [5][6][7][8][9][10][11][12][13] or chiral reducing agents, such as diisopinocamphenylchloroborane. 14 In addition, the reduction of b-ketoesters, bearing a pre-existing a-quaternary chiral center is scarcely reported [15][16][17][18] and, to the best of our knowledge, only one example showed the reduction of chiral b-iminoesters by hydride transfer.…”

Section: Introductionmentioning

confidence: 99%

Asymmetric reduction of β‐ketoesters and chiral β‐iminoesters: Impact of a α‐quaternary stereocenter

et al. 2010

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Diastereomeric reduction of nonactivated, hindered β-keto and chiral β-iminoesters are described. The influence of a α-stereocontrolled center on the efficiency and stereoselectivity of the reduction was studied. Reaction conditions were optimized to synthesize β-hydroxy- and β-aminoesters in good yields. In the case of chiral β-iminoesters, influence of matched/mismatched diastereomeric pairs has been assessed.

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“…[4] Starting with the pioneering experiments with a Ru catalyst based on the atropisomeric ligand BINAP performed by Noyori et al, [5] a wide variety of other chiral phosphorus ligands have been developed, including other biaryl diphosphanes, [6] bisphospholanes, [7] P-chiral ligands, [8] monodentate phosphanes, [9] planar chiral diphosphanes derived from ferrocene, [10] and paracyclophane. [11] In contrast, the array of substrates investigated is rather limited, usually restricted to simple β-alkyl or aryl residues.…”

Section: Introductionmentioning

confidence: 99%

Highly Enantioselective Hydrogenation of Ethyl 5,5‐Dimethoxy‐3‐oxopentanoate and its Application for the Synthesis of a Statin Precursor

Korostylev

Andrushko

et al. 2008

Eur J Org Chem

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The highly enantioselective hydrogenation of ethyl 5,5-dimethoxy-3-oxopentanoate (3) to ethyl 3-hydroxy-5,5-dimethoxypentanoate (4) -a key intermediate in the synthesis of pharmacologically important statin drugs -has been investigated. The stereochemistry of the catalytic hydrogenation of the β-keto ester in the presence of a number of homogeneous chiral Rh I and Ru II complexes with phosphane ligands has been studied. The highest enantioselectivity for the homo-

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Enantioselective hydrogenation of β-keto esters catalyzed by P-chiral bis(dialkylphosphino)ethanes-Ru(II)

Cited by 51 publications

References 24 publications

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

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

Asymmetric reduction of β‐ketoesters and chiral β‐iminoesters: Impact of a α‐quaternary stereocenter

Highly Enantioselective Hydrogenation of Ethyl 5,5‐Dimethoxy‐3‐oxopentanoate and its Application for the Synthesis of a Statin Precursor

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