Polymer-supported chiral phosphinooxazolidine ligands for palladium-catalyzed asymmetric allylic alkylations and Diels–Alder reactions

Polymer-supported chiral phosphinooxazolidine (POZ) ligands 9a–c and cationic palladium-POZ catalysts 16a–c have been prepared. The former ligands were used in the Pd-catalyzed asymmetric allylic alkylation, while the latter catalysts were used in the Diels–Alder reaction to afford good to excellent enantioselectivities (Pd-catalyzed allylation: up to 99% ee, Diels–Alder reaction: up to 92% ee).

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(2R,5S)-1-Aza-4,4-diphenyl-2-(2′-diphenylphosphino-5′-hydroxy)phenyl-3-oxobicyclo[3.3.0]octaneC36H32NO2PEe = 100%[α]D20=+15.0 (c 0.16, CHCl3)Source of chirality: (S)-(−)-α,α-diphenyl-2-pyrrolidinemethanolAbsolute configuration: 2R,5S

Dichloro[(2R,5S)-1-aza-4,4-diphenyl-2-(2′-diphenylphosphino-5′-hydroxy)phenyl-3-oxobicyclo[3.3.0]octane]palladiumC36H32NO2PCl2PdEe = 100%[α]D20=-95.0 (c 0.20, DMSO)Source of chirality: (S)-(−)-α,α-diphenyl-2-pyrrolidinemethanolAbsolute configuration: 2R,5S

(2R,5S)-1-Aza-4,4-diphenyl-2-(2′-diphenylphosphino-5′-triethylsilyloxy)phenyl-3-oxobicyclo[3.3.0]octaneC42H46NO2PSiEe = 100%[α]D20=-65.0 (c 0.20, CHCl3)Source of chirality: (S)-(−)-α,α-diphenyl-2-pyrrolidinemethanolAbsolute configuration: 2R,5S

Dichloro[(2R,5S)-1-aza-4,4-diphenyl-2-(2′-diphenylphosphino-5′-triethylsilyloxy)phenyl-3-oxobicyclo[3.3.0]octane]palladiumC42H46NO2PSiCl2PdEe = 100%[α]D20=-235.6 (c 0.90, DMSO)Source of chirality: (S)-(−)-α,α-diphenyl-2-pyrrolidinemethanolAbsolute configuration: 2R,5S

(2R,5S)-2-(5′-Acetoxy-2′-diphenylphosphino)phenyl-1-aza-4,4-diphenyl-3-oxobicyclo[3.3.0]octaneC38H34NO3PEe = 100%[α]D20=-52.0 (c 1.00, CHCl3)Source of chirality: (S)-(−)-α,α-diphenyl-2-pyrrolidinemethanolAbsolute configuration: 2R,5S

Dichloro[(2R,5S)-2-(5′-acetoxy-2′-diphenylphosphino)phenyl-1-aza-4,4-diphenyl-3-oxobicyclo[3.3.0]octane]palladiumC36H32NO2PCl2PdEe = 100%[α]D20=-260.9 (c 0.46, DMSO)Source of chirality: (S)-(−)-α,α-diphenyl-2-pyrrolidinemethanolAbsolute configuration: 2R,5S