Catalytic asymmetric transformations with fine-tunable biphenol-based monodentate ligands

A library of new fine-tunable monodentate phosphite and phosphoramidite ligands based on chiral biphenol have been designed and developed. These monodentate phosphorus ligands have exhibited excellent enantioselectivity in the Pd-catalyzed asymmetric allylic alkylation and Rh-catalyzed asymmetric hydrogenation.

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N,N-[(S)-1-(Naphthalen-2-yl)ethyl][(S)-1-(2-methoxyphenyl)ethyl]amineC21H23NOEe: 99% (by 1H NMR of the corresponding diastereoisomer)[α]D22=-187 (c 1.66, CHCl3)Source of chirality: (S)-(−)-1-(2-naphthyl)ethylamine (99.0%)Absolute configuration: (S,S)

O,O′-(S)-(5,5′,6,6′-Tetramethyl-2,2′-diyl)-N,N-bis[(S)-1-(naphthalen-1-yl)ethyl]phosphoramiditeC40H38NO2PEe: 99% (by 1H NMR of the corresponding diastereoisomer)[α]D22=+168.2 (c 1.32, CHCl3)Source of chirality: resolutionAbsolute configuration: (S,S,S)

O,O′-(S)-(5,5′,6,6′-Tetramethyl-2,2′-diyl)-N,N-bis[(S)-1-(naphthalen-2-yl)ethyl]phosphoramiditeC40H38NO2PEe: 99% (by 1H NMR of the corresponding diastereoisomer)[α]D22=-415.3 (c 0.98, CHCl3)Source of chirality: resolutionAbsolute configuration: (S,S,S)

O,O′-(S)-(5,5′,6,6′-Tetramethyl-2,2′-diyl)-N,N-[(S)-1-phenylethyl][(S)-1-(2-methoxyphenyl)ethyl]phosphoramiditeC33H37NO3PEe: 99% (by 1H NMR of the corresponding diastereoisomer)[α]D22=-102.4 (c 1.25, CHCl3)Source of chirality: resolutionAbsolute configuration: (S,S,S)

O,O′-(S)-(5,5′,6,6′-Tetramethyl-2,2′-diyl)-N,N-[(S)-1-phenylethyl][(S)-1-(2-methylphenyl)ethyl]phosphoramiditeC33H36NO2PEe: 99% (by 1H NMR of the corresponding diastereoisomer)[α]D22=-126 (c 1.10, CHCl3)Source of chirality: resolutionAbsolute configuration: (S,S,S)

O,O′-(S)-(5,5′,6,6′-Tetramethyl-2,2′-diyl)-N,N-bis[(S)-1-(2-methylphenyl)ethyl]phosphoramiditeC34H39NO2PEe: 99% (by 1H NMR of the corresponding diastereoisomer)[α]D22=+72 (c 1.05, CHCl3)Source of chirality: resolutionAbsolute configuration: (S,S,S)

O,O′-(S)-(5,5′,6,6′-Tetramethyl-2,2′-diyl)-N,N-bis[(S)-1-(2-methoxyphenyl)ethyl]phosphoramiditeC34H39NO3PEe: 99% (by 1H NMR of the corresponding diastereoisomer)[α]D22=+34.4 (c 0.64, CHCl3)Source of chirality: resolutionAbsolute configuration: (S,S,S)

O,O′-(S)-(5,5′,6,6′-Tetramethyl-2,2′-diyl)-N,N-[(S)-1-(naphthalen-1-yl)ethyl][(S)-1-(2-methoxyphenyl)ethyl]phosphoramiditeC37H39NO3PEe: 99% (by 1H NMR of the corresponding diastereoisomer)[α]D22=+96.7 (c 1.23, CHCl3)Source of chirality: resolutionAbsolute configuration: (S,S,S)

O,O′-(S)-(5,5′,6,6′-Tetramethyl-2,2′-diyl)-N,N-[(S)-1-(naphthalen-2-yl)ethyl][(S)-1-(2-methoxyphenyl)ethyl]phosphoramiditeC37H39NO3PEe: 99% (by 1H NMR of the corresponding diastereoisomer)[α]D22=+246 (c 0.80, CHCl3)Source of chirality: resolutionAbsolute configuration: (S,S,S)

(3aR,7aS)-1-[6-Bromo-3,4-(methylenedioxy)benzyl]-3a,4,5,7a-tetrahydroindolin-2-oneC17H22NOEe: 99.4% (by HPLC Chiralpak ADRH CH3CN/H2O 60:40)[α]D22=-40.0 (c 0.5, CHCl3)Source of chirality: asymmetric synthesisAbsolute configuration: (R,S)

(3aR,11bS,11cS)-4-Methoxycarbonyl-3,3a,4,7,11b,11c-hexahydro-9,10-(methylenedioxy)pyrrolo[3,2,1de]phenanthridin-5- oneC18H18NO5Ee: 99.4% (by 1H NMR of the corresponding diastereoisomer)[α]D22=-19.6 (c 0.51, CHCl3)Source of chirality: asymmetric synthesisAbsolute configuration: (R,S,S)

(3aR,12bS,12cS)-5-Oxo-γ-lycoraneC16H16NO3PEe: 99.4% (by 1H NMR of the corresponding diastereoisomer)[α]D22=+83.8 (c 0.74, CHCl3)Source of chirality: asymmetric synthesisAbsolute configuration: (R,S,S)

(+)-γ-LycoraneC16H20NO2Ee: 99.4% (by 1H NMR of the corresponding diastereoisomer)[α]D22=+18.1 (c 1.10, EtOH)Source of chirality: asymmetric synthesisAbsolute configuration: (S,S,S)