Stereoselective conjugate addition of carbonyl compounds to maleimides using a diaminomethyleneindenedione organocatalyst

A diaminomethyleneindenedione motif can serve as an excellent double hydrogen bonding donor. Bifunctional chiral primary amine 3 bearing a diaminomethyleneindenedione motif is an excellent organocatalyst to promote the asymmetric conjugate additions of various carbonyl compounds to maleimides in high yields with up to 99% ee.

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2-({[(1R,2R)-2-Aminocyclohexyl]amino}{[3,5-bis(trifluoromethyl)benzyl]amino}methylidene)-2,3-dihydro-1H-indene-1,3-dioneC25H23F6N3O2E.e. = 100%[α]D29 = −10.9 (c 1.00, CH2Cl2)Source of chirality: (1R,2R)-1,2-cyclohexanediamineAbsolute configuration: (1R,2R)

(S)-3-(2-Oxopropyl)-1-phenylpyrrolidine-2,5-dioneC13H13NO3E.e. = 92%[α]D27 = +10.0 (c 1.00, CH2Cl2)Absolute configuration: (S)

(S)-1-Benzyl-3-(2-oxopropyl)pyrrolidine-2,5-dioneC14H15NO3E.e. = 95%[α]D27 = −2.0 (c 1.00, CH2Cl2)Absolute configuration: (S)

(S)-3-(2-Oxopropyl)-1-[3-(trifluoromethyl)phenyl]pyrrolidine-2,5-dioneC14H12F3NO3E.e. = 92%[α]D25 = +7.3 (c 1.00, CH2Cl2)Absolute configuration: (S)

(R)-2-(2,5-Dioxo-1-phenylpyrrolidin-3-yl)-2-methylpropanalC14H15NO3E.e. = 94%[α]D27 = +1.8 (c 1.00, CH2Cl2)Absolute configuration: (R)

(R)-1-(2,5-Dioxo-1-phenylpyrrolidin-3-yl)cyclohexane-1-carbaldehydeC17H19NO3E.e. = 94%[α]D20 = +1.8 (c 1.00, CHCl3)Absolute configuration: (R)