A multifunctional proline-based organic catalyst for enantioselective aldol reactions

The synthesis of multifunctional organic catalysts, easily obtained by the condensation of (S)-proline with 1,1′-binaphthyl-2,2′-diamine is reported. These C2 as well as C1 symmetric prolinamides were shown to be able to promote the direct aldol condensation between acetone, methoxyacetone or cyclohexanone and different aldehydes in very good yields and high enantioselectivities.

Multifunctional binaphthyl diamine-based organocatalysts were shown to be able to promote the direct aldol condensation between acetone, methoxyacetone or cyclohexanone and different aldehydes in very good yields and high enantioselectivities.Figure optionsDownload as PowerPoint slide

N′-Acetyl-N-(S)-prolyl-(R)-1,1′-binaphthyl-2,2′-diamineC27H25N3O2Ee = 100%[α]D23=+25.3 (c 0.31, DCM)

N′,N′-Dimethyl-N-(S)-prolyl-(R)-1,1′-binaphthyl-2,2′-diamineC27H25N3O2Ee = 100%[α]D23=-95.9 (c 0.21, DCM)

N′,N′-Dimethyl-N-(S)-prolyl-(S)-1,1′-binaphthyl-2,2′-diamineC27H25N3O2Ee = 100%[α]D23=-16.2 (c 0.35, DCM)