Direct asymmetric aldol reactions in water with a β-aminosulfonamide organocatalyst

Organocatalyst 4 promoted the direct asymmetric aldol reactions of aldehydes with ketones in brine or in the presence of water to afford the corresponding anti-aldol products in moderate to excellent yields with up to 97% ee.

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(S)-N-(2-Amino-3-phenylpropyl)trifluoromethanesulfonamideC10H13F3N2O2SEe = 100%[α]D25=+10.7 (c 2.01, MeOH)Source of chirality: l-phenylalanineAbsolute configuration: (S)

(S)-tert-Butyl 1-phenyl-3-(trifluoromethylsulfonamido)propan-2-ylcarbamateC15H21F3N2O4SEe = 100%[α]D25=-13.6 (c 1.35, CHCl3)Source of chirality: l-phenylalanineAbsolute configuration: (S)

(S)-N-(2-Amino-3-phenylpropyl)-2,3,4,5,6-pentafluorobenzenesulfonamideC15H13F5N2O2SEe = 100%[α]D22=+8.7 (c 1.00, MeOH)Source of chirality: l-phenylalanineAbsolute configuration: (S)

(S)-N-(2-Amino-3-methylbutyl)trifluoromethanesulfonamideC6H13F3N2O2SEe = 100%[α]D24=+15.1 (c 0.87, MeOH)Source of chirality: l-valineAbsolute configuration: (S)