Synthesis of (R)-tembamide and (R)-aegeline via asymmetric transfer hydrogenation in water

The synthesis of (R)-tembamide and (R)-aegeline via asymmetric transfer hydrogenation involving enantioenriched monosulfonamide–RhCp∗ complex in aqueous sodium formate as hydride donor is described.

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(R)-(−)-N-(2-Hydroxy-2-(4-methoxyphenyl)ethyl)benzamideC16H17NO3>99% ee (by HPLC)[α]D20=-58.4 (c 0.5 CHCl3)Source of chirality: Asymmetric transfer hydrogenation of the ketoneAbsolute configuration: (R)

(R)-(−)-N-(2-Hydroxy-2-(4-methoxyphenyl)ethyl)cinnamamideC18H19NO3>99% ee (by HPLC)[α]D20=-39.3 (c 0.4 CHCl3)Source of chirality: Asymmetric transfer hydrogenation of the ketoneAbsolute configuration: (R)

3-Hydroxy-N-3-diphenylpropanamideC15H15NO2>99% ee (by HPLC)[α]D20=+25 (c 0.4 MeOH)Source of chirality: Asymmetric transfer hydrogenation of the ketoneAbsolute configuration: ND

(R)-(+)-Ethyl-3-hydroxy-3-phenylpropanoateC11H14O3>99% ee (by HPLC)[α]D20=+76 (c 0.4 CH2Cl2)Source of chirality: Asymmetric transfer hydrogenation of the ketoneAbsolute configuration: (R)

(R)-(+)-3-(Pyrrolidin-1-yl)-1-p-tolylpropan-1-olC14H21NO>99% ee (by HPLC)[α]D20=+18 (c 0.3 CHCl3)Source of chirality: Asymmetric transfer hydrogenation of the ketoneAbsolute configuration: (R)

(R)-(+)-3-(Dimethylamino)-1-phenylpropan-1-olC11H17NO>99% ee (by HPLC)[α]D20=+24 (c 0.5 CHCl3)Source of chirality: Asymmetric transfer hydrogenation of the ketoneAbsolute configuration: (R)