Palladium catalyzed asymmetric sulfonylation mediated chiral β-hydroxy- and β-(o-diphenylphosphino)benzoyloxy (o-diphenyl phosphino)benzamides

The palladium catalyzed asymmetric allylic sulfonylation reaction has been investigated employing β-hydroxy- and β-(o-diphenylphosphino)benzoyloxy (o-diphenyl phosphino)benzamides as chiral, non-racemic ligands. The bisphosphine β-benzoyloxybenzamide ligands proved to be the best ligands for this process. Competitive transition states for the (1S,2R)-norephedrine derived ligand 14 are compared and a rationale is provided for the observed enantioselectivities.

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(S)-2-(2-(Diphenylphosphino)benzamido)-3-phenylpropyl 2-(diphenylphosphino)benzoateC47H39NO3P2[α]D23=+4.5 (c 1.00, CHCl3)Source of chirality: l-phenylalaninolAbsolute configuration: (S)

2-(Diphenylphosphino)-N-((1S,2R)-1-hydroxy-1-phenylpropan-2-yl)benzamideC28H26NO2P[α]D23=+34.9 (c 0.38, CHCl3)Source of chirality: (1S,2R)-norephedrineAbsolute configuration: (1S,2R)

(1S,2R)-2-(2-(Diphenylphosphino)benzamido)-1-phenylpropyl 2-(diphenylphosphino)benzoateC47H39NO3P2[α]D23=-10.80 (c 1.00, CHCl3)Source of chirality: (1S,2R)-norephedrineAbsolute configuration: (1S,2R)

(1S,2R)-2-(2-(Diphenylphosphino)benzamido)-1-phenylpropyl benzoateC35H30NO3P[α]D23=-31.0 (c 0.98, CHCl3)Source of chirality: (1S,2R)-norephedrineAbsolute configuration: (1S,2R)

(1S,2R)-2-(2-(Diphenylphosphino)benzamido)-1-phenylpropyl 1-napthoateC39H32NO3P[α]D23=-10.5 (c 0.35, CHCl3)Source of chirality: (1S,2R)-norephedrineAbsolute configuration: (1S,2R)